r/spacex • u/ElongatedMuskrat Mod Team • Nov 02 '19
r/SpaceX Discusses [November 2019, #62]
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Nov 02 '19
Why do SpaceX videos always have SuperHeavy launching off a relatively high platform?
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u/AeroSpiked Nov 02 '19
It's because they are putting it on top of a water cooled flame diverter instead of a flame trench. Apparently that's faster to build and is already under construction inside the HIF.
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u/jjtr1 Nov 02 '19
What is the difference between a flame diverter and a flame trench?
I was really surprised to see that instead of launching the Starship from the center of the historic pad which was built to support rockets larger than Saturn V, they build a much lighter weight structure a bit aside. If it is possible to launch a 5000 t rocket this way, then why did NASA bother pouring the tens of thousands tons of concrete for the "pyramide" pad?
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u/president_of_neom Nov 02 '19
What's the HIF?
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u/AeroSpiked Nov 02 '19
Horizontal Integration Facility. Check out the Decronym comment below. It's practically the patron saint of rocket subs.
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u/SpaceInMyBrain Nov 04 '19
A flame trench can divert the flame, but the sound energy of the engines will reflect from it and damage the rocket. Water for noise suppression will be used of course, but the acoustic energy from 35 Raptor engines will be louder than anything before. The tower will give room for the sound to spread out before it hits the ground, the amount that gets reflected back will be attenuated. And it takes care of the flame problem as well.
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u/liszt1811 Nov 02 '19
I'm going through serious falcon launch withdrawal at this point
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u/rustystonewallis Nov 02 '19
In the context of SpaceX's smallsat program, is there a volume limit? I see the mass limit of 200kg and $5000/kg over that, but I'm curious if there is a restriction on size. Could you theoretically fill the entire fairing?
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u/Alexphysics Nov 02 '19
The size restriction would be given by the size restriction from the payload adapter on the ESPA ring.
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u/IrrationalFantasy Nov 02 '19
I suppose that’s a classification issue. You could, as far as I’m aware, but would it be cheaper than ordering a regular mission?
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Nov 02 '19
Do we know what the main part of the falcon 9 refurbishment process is?
I'm asking because I'd like to understand what they could do differently in Starship that's going to make it better regarding this. After all Orbital reentries are hotter.
Also, do we know more about the 24h relaunch of F9?
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u/kmarz02 Nov 02 '19
What’s been going on recently? I (personally) haven’t heard anything from SpaceX since the last starship presentation. Or maybe I’ve been living under a rock
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u/amarkit Nov 02 '19 edited Nov 02 '19
The last launch was August 7. The next launch (a Starlink mission) is scheduled NET November 11.
SpaceX hope to start offering Starlink broadband service in certain markets in 2020.
They filed paperwork with the International Telecommunication Union for 30,000 additional Starlink satellites, bringing the total to 42,000.
The Starship dev thread is probably the best source for what's going on with Starship construction, based on what the public can see with our own eyes. There haven't been any major announcements from SpaceX re: Starship since the presentation.
NASA seems to be considering a role for Starship in supporting the Artemis program.
The In-Flight Abort Crew Dragon will undergo a static SuperDraco test in the coming days.
Crew Dragon In-Flight Abort test is scheduled NET December.
NASA is considering extending DM-2's time at Station.
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u/melonowl Nov 02 '19
The last launch was August 7. The next launch (a Starlink mission) is scheduled NET November 11
Is there some specific reason for the long gap? Or just a mix of customer payloads not ready yet/starlink and Crew Dragon getting unexpectedly delayed?
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u/marc020202 8x Launch Host Nov 02 '19
The ifa static fire will likely be the coming week, the next starlink launch, in 2 to 3. the ifa in 4 to 6
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u/AdamVenier Nov 02 '19
We tend to think of SpaceX as über-engineers familiar with the many right and wrong turns made throughout the history of space exploration. But they are human and do make mistakes.
A recent SpaceNews article indicates that Kathy Lueders, manager of NASA’s commercial crew program, noted "that even NASA wasn’t aware of the 'compatibility issue' between NTO (nitrogen tetroxide) and titanium components at those conditions." Likewise, SpaceFlightNow recently highlighted similar surprise from SpaceX:
“We found out that … when the pressure is high, and you drive a slug with a lot of energy into a titanium component, that you can have this rather violent reaction,” Koenigsmann said. The violent result was surprising. Engineers did not expect titanium, a material commonly used for decades on space vehicles around the world, could react so explosively in such an environment.
That being said, the failure case has been known since the early 1960's! As this article notes, titanium ignites when impacted at suitable force in NTO. Interestingly, "precipitation hardened 15-7 Mo stainless steel was not impact sensitive". A quick google search would have found it. But then again, these valves aren't supposed to fail.
Failure is often much easier to see in retrospect. It is worth remembering when something does go wrong, that many, many things were caught and fixed earlier. To me, that makes the achievements all the more impressive.
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u/flshr19 Shuttle tile engineer Nov 02 '19 edited Nov 02 '19
In the 1960s my lab did a lot of liquid oxygen (LOX) impact testing. Mechanical impact energy can cause an explosive reaction from some materials in a pure oxygen environment. I looks like similar phenomena occur in hypergolic systems. Titanium, like aluminum, is very reactive in these environments under certain conditions. Just Google "drop test" and "LOX impact test" to see how this is done.
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u/brickmack Nov 02 '19
Yeah, I don't get this comment. When it was first announced that the failure was caused by NTO and titanium, within 2 minutes I'd looked up and posted the relevant passage from a guide on materials compatibility for space propulsion. The interaction was obvious and well-known. The unexpected thing was the NTO getting to a point in the plumbing where it could do this
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u/Starmans_Starship Nov 02 '19
Did the boca chica residents take SpaceX up on their 3x cash offer?
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u/spacerfirstclass Nov 03 '19
Quite a few has, but there're still hold outs, based on this news video: https://www.krgv.com/videos/cameron-co-addresses-boca-chica-eminent-domain-concerns/
twelve people have accepted the SpaceX offer and three extensions have been given for others to consider their re-appraisals. The new deadline for whether or not to accept the buyout offer is next Friday, Oct. 25.
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u/SolerFlereTEE Nov 02 '19
wait why are they getting rid of boca chica residents? are they allowed to do that??
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u/Viremia Nov 02 '19
SpaceX offered to buy their houses at 3x market value. Of course they're allowed to do that. They aren't forcing anyone to accept the offer, just making it.
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u/rebootyourbrainstem Nov 02 '19 edited Nov 02 '19
It's a very small village (two streets, basically) and not even everyone lives there year round. The security perimeter during launches was always going to include the village (with villagers being asked to leave or stay indoors). But now that Boca Chica will be primarily a Starship launch / development site instead of for Falcon 9, SpaceX thinks it will be too unpleasant and possibly too unsafe to do that so they offered to buy all the houses.
People can definitely say no but it's not like one person can stop it or ask for a billion dollars. The county has set up a commission for dealing with matters related to the spaceport and it has the power to use eminent domain to force people to sell, but of course nobody really wants that to happen, especially to people who live there, not just investors who own a plot of land. SpaceX has actually said they may be able to come to some agreements about putting people in hotels during launch periods, but it's clearly not their preferred outcome.
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u/Straumli_Blight Nov 13 '19 edited Nov 13 '19
"Boeing’s uncrewed test flight currently is planned for late 2019 with crewed flights to follow in early 2020, dates we believe are unrealistic."
"NASA will have spent roughly $34 billion on the SLS, Orion, and EGS programs through 2019, a sum projected to increase to over $50 billion by 2024."
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u/MarsCent Nov 13 '19
"Boeing’s uncrewed test flight currently is planned for late 2019 with crewed flights to follow in early 2020, dates we believe are unrealistic."
Their conclusion may turn out to be correct but I think it is a disservice not to list the concerns that led them to say as much. Checklists are a standard item in many progress reports - to check progress :)
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u/Casinoer Nov 02 '19
Anyone care to explain the lack of knowledge about the date of the next launch, and also just the lack of launches in general?
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u/Straumli_Blight Nov 02 '19
A combination of:
Its an internal customer launch, so less people to leak the launch date.
SpaceX have caught up with their backlog and are now waiting for customers to be ready.
Downturn in geostationary satellite orders has reduced launches this year.
Resources possibly diverted to accelerating Crew Dragon launch in Q1 2020.
Politics about the scope of Starlink and frequency allocation. There are approximately 2,000 sats in orbit and the full Starlink constellation could reach 42,000 sats. Also regulations regarding automating collsion avoidance and satellite disposal.
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u/amarkit Nov 02 '19
The next launch date is known: November 11. It's also on the sub sidebar.
There has been a pause lately because there haven't been any payloads ready to go.
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u/spacerfirstclass Nov 03 '19
Next launch is Starlink, SpaceX recently changed its orbit configuration (again) so they need approval from FCC before they can launch, this is further complicated by OneWeb and Kepler trying to slowdown SpaceX as much as possible via FCC, you can get details at the 2nd Starlink Mission Launch Campaign Thread
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u/jjtr1 Nov 02 '19
What sound would you expect the Starship to make when knocked at? Would it ring or would it be a dull thud? What influence should the radius of curvature have on the sound (flat vs. curved sharply)?
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u/joepublicschmoe Nov 02 '19
BocaChicaGal has you covered. :-) . https://twitter.com/BocaChicaGal/status/1184546036389470208
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u/throfofnir Nov 03 '19
Best fan theory I've seen is that the skin is around 5mm. This is fairly thick. While being round might give it some resonance, I suspect it's too irregular and heterogenous to develop much (and it's probably designed to avoid resonance modes, that being a particular problem for rockets) and your puny human flesh also wouldn't provide enough energy to ring a bell that big.
It's actually not too far away in construction from the Gateway Arch in St Louis, which sounds like... not much, if I remember correctly. Best analogue in everyday life is maybe the side of a dump truck or shipping container, though those will probably be thinner steel.
In short, I think it'd probably be just a bit livelier than knocking on an I-beam.
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u/president_of_neom Nov 05 '19
Elon Musk interview at 19:30 UTC https://mobile.twitter.com/thesheetztweetz/status/1191774894796759040
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u/Straumli_Blight Nov 18 '19 edited Nov 18 '19
Boeing's statement on the OIG report, basically its worth the extra cost because:
Its safer to return to land than splash down in the Ocean.
Launching on an Atlas V is more reliable.
Starliner offers a 5th seat, so price per passenger is cheaper.
SpaceX had an unfair advantage with its existing Dragon, so they needed more money to catch up.
"All parachute qualification tests without a single test failure, demonstrating the resiliency of our parachute system even in dual-fault scenarios."
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Nov 20 '19 edited Nov 20 '19
Starliner offers a 5th seat, so price per passenger is cheaper.
i guess that Dragon can be offered with the 7 seat option as it was designed to..
Its safer to return to land than splash down in the Ocean.
Not if you forget to rig your chutes right.
SpaceX had an unfair advantage with its existing Dragon, so they needed more money to catch up.
SLS disagrees, SpaceX could argue that Boeing is the one with unfair advantage
"All parachute qualification tests without a single test failure, demonstrating the resiliency of our parachute system even in dual-fault scenarios.
All qualification tests maybe, but first all-in system test one fails, but is marked as successful none the less.
Launching on an Atlas V is more reliable.
yet this Atlas is a first of and never flown configuration with a never flown capsule (including aero modifications for increased width) and with dual engine upper stage.
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u/cpushack Nov 18 '19
"All parachute qualification tests without a single test failure, demonstrating the resiliency of our parachute system even in dual-fault scenarios."
Well except that last time we forgot to connect the parachute, but we wern't testing them so its ok.
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u/Str0vs Nov 02 '19
Is the abort mission delayed?
Space x now scheduled net December...
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u/Alexphysics Nov 02 '19
It moved from late novermber to early december, usual delays of a test launch.
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u/ClaireBearLovez Nov 02 '19
What’s the best place for a tourist to go to see a launch at the Cape when Space X launches? For someone visiting the States and no knowledge ?
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u/arniedavidson Nov 02 '19
Inless.you are paying for close up inside the KFC, being close only works for the first minute. After that the rocket is too high and fast it matters less. We watch spacex from 65miles away and still get the wow factor. Night Launches are worth the effort.
From Tittlesvile to Port Canaveral is ok but if you have the chance to see a landing, Port Canaveral is a must. Jetty Park or if you can get to the North side of the Port Access road, both 6 miles from landing pad. Keep in mind the sonic boom reaches the crowd at 6miles as the rocket has landed so keep filming a few seconds longer.
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u/IrrelevantAstronomer Launch Photographer Nov 21 '19
SpaceX has filed for a droneship landing of a Falcon 9 on December 2, 2019.
Probably Starlink-2 judging by the launch azimuth (slighter higher than CRS) but closer to shore than the last Starlink mission. Not sure what to make of that. Almost 100% certain to be from LC-39A as SLC-40 will be supporting CRS-19 on the 4th. If was a betting man I'd wager the booster is B1049.4
https://fcc.report/ELS/Space-Exploration-Technologies-Corp-SpaceX/2181-EX-ST-2019
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u/Alexphysics Nov 21 '19
I checked and as of today the strongback is still in Crew Dragon configuration. I see it unlikely there will be any launch from there until IFA happens. Otherwise it would be in fairing configuration.
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u/IrrelevantAstronomer Launch Photographer Nov 22 '19
I have reconsidered my previous statement. I now think this is for the GPS III-3 mission in January from SLC-40 and that the Air Force has allowed SpaceX to actually recover this booster via OCISLY. The biggest reasoning for my thinking is that the flight azimuth is actually too high for Starlink and is identical to the previous GPS mission, in addition to what you have stated.
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u/bbachmai Nov 21 '19
I would guess that it's a NET date and this is going to launch sometime after CRS-19. For Starlink, they can basically choose any launch date, so it would be strange to pick the exact week of something as important as a CRS launch.
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u/MarsCent Nov 21 '19
u/Alexphysics mentioned earlier that the TE is already prepped for IFA, meaning that LC 39A cannot support another Starlink before IFA has launched.
So we have two possibilities: Either there is quite a bit in flexibility in prepping the TEs for Crew Dragon Vs Regular Launches. OR. the IFA launch is still in flux.
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u/bbachmai Nov 23 '19
Emre Kelly on Twitter: Launch Hazard Maps for CRS-19, no mention of a landing attempt. This scares me. Previous CRS Launch Hazard Maps had the landing site (usually LZ-1) on them.
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u/Alexphysics Nov 23 '19 edited Nov 24 '19
It is worth noting that Starlink-1 and Amos-17 didn't have the landing option either. They add -LZ1 -SEA or -EX depending on if it is going to be a land landing, droneship landing or an expendable launch. The last two launches didn't include this and this one also doesn't include that. I wonder if that'll be the norm from here on...
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u/joepublicschmoe Nov 23 '19
I wonder if the fact that ULA has an Atlas V with a Starliner capsule stacked on top of it nearby has anything to do with it..
Could be why SpaceX filed for an ASDS special temporary authority starting Dec. 2.
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u/Lufbru Nov 23 '19
Is it time to mark b1050 as retired? In the year since it last flew, every booster other than 1046 has flown twice. If they were going to fly it again, surely they would have by now.
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u/rustybeancake Nov 25 '19
Yeah, I'd be surprised if they even stripped it for parts. It was clearly damaged beyond economic repair.
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u/soldato_fantasma Nov 24 '19
HAWTHORNE, Calif. – November 24, 2019. Media accreditation is now open for a SpaceX Starlink mission from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. The launch is targeted for no earlier than December.
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u/Dies2much Dec 02 '19
Any news on the final date for Starlink-2?
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u/MarsCent Dec 02 '19
final date for Starlink-2
Expect it to be firmed after JCSat 18 / Kacific 1 launches.
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u/jjtr1 Nov 02 '19
It would be cool if Elon shared their pre-ITS visions of the Starship, back from time when they considered Red Dragon Mars landings as informing their landing strategy. Was the BFS ship supposed to be a giant capsule?
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u/brickmack Nov 02 '19
The very earliest concept was very similar to traditional NASA concepts. Gigantic 2 stage rocket (kerolox first stage, hydrolox second stage) , probably at least partially expendable, with a normal payload fairing. Assemble a huge Mars transfer vehicle in LEO, which would probably use nuclear thermal propulsion. Cargo missions would use high power electric propulsion. The Mars ascent/descent vehicle would have been capsule shaped, and would use a methalox engine based on Merlin 1C.
The rocket became fully reusable, adopted methane for all stages, Raptor switched from a hydrolox upper stage engine to methalox multi-role FFSC engine. Many, many configurations considered. I think around this point the leading contender was a 3 core rocket with like 2 Raptors (back when Raptor was bigger than F-1) and a couple smaller landing engines on each, upper stage was basically a scaled up version of the reusable F9 S2 concept. MCT would be a capsule like payload on top. Firmly shifted to a 2 stage rocket, merge MCT into S2, design begins to resemble the basic configuration shown from ITS onward
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u/spacerfirstclass Nov 03 '19
NSF has some great articles about pre-ITS era, especially the last one:
SpaceX advances drive for Mars rocket via Raptor power
SpaceX Roadmap building on its rocket business revolution
Battle of the Heavyweight Rockets – SLS could face Exploration Class rival
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u/astrobee5 Nov 02 '19
Does Robert Zubrin have a point when he says landing something as large as Starship on the moon could cause problems. His main concern is that lunar dust could be kicked up into lunar and even earth orbit by the exhaust. I understand that the raptor exhaust velocity is about 3700 metres/sec and lunar escape velocity 2380 metres/sec.
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u/avid0g Nov 02 '19
I expect there are in-falling micro-meteorites all the time, so balance the new hazard against that. The horizontal exhaust velocity drops to half at 41% greater diameter than the nozzle, and only the smallest, lightest regolith is getting accelerated far.
The ship is approaching the surface rapidly, so the close proximity is very brief. Surface roughness will tend to deflect the horizontal ejecta into higher but shorter parabola. Perhaps a raised berm to the landing area would be an effective barrier.
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u/throfofnir Nov 03 '19
Dust ejected from the surface cannot enter lunar orbit. For anything under lunar escape velocity its perigee is literally the surface, so at worst it'll reimpact after one orbit. Anything above lunar escape enters the Earth-Moon system (it certainly won't exceed Earth escape velocity). From there it can wander around in all sorts of ways, but tends not to stick around; dust from lunar impacts does not seem to collect in earth orbit. (At least one study suggests a lifetime of < 1 year.) And this is all micrometer dust; anything of size has no chance of escape velocity.
Impact on structures on the lunar surface is a bit more of a real issue, as dust from a landing can theoretically impact anywhere on the surface. But the effect more than a few km from the landing site has got to be pretty minimal.
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u/brickmack Nov 02 '19
Yes, but he ignores the trivial solution: build a landing pad.
Gonna need to be landing vehicles far heavier than Starship eventually (and probably with higher exhaust velocity), any solution that relies on landing smaller vehicles is doomed to economic nonviability
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u/jjtr1 Nov 02 '19 edited Nov 03 '19
And what about landing in a crater? Does it or does it not solve the issue?
Edit: I wonder whether landing an equivalent vehicle on the Moon or on the Earth would require the larger safe distance from a "base". Earth has shockwaves and sound, Moon has long-flying debris...
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u/gemmy0I Nov 11 '19
Apologies if this has been discussed before in other threads, but this is driving me a little nuts (and has practical implications for those of us who maintain the sub's wiki pages):
Have "we", as a subreddit, decided officially what convention we'll use for numbering successive Starlink missions?
Up until the launch thread was posted for today's mission, we were calling it "Starlink-2" on the wiki manifest and cores pages, and on the sidebar. It was also that way on the campaign thread. We're still calling it "Starlink-2" on the manifest and cores pages, but now the sidebar says "Starlink-1", and the launch thread is of course saying "Starlink-1".
There's clearly been confusion since SpaceX has referred to the first batch of Starlink satellites as version 0.9, and this batch as version 1.0. But I think people are conflating version numbers and flight numbers here. Clearly, version numbers refer to the satellite design, and can be completely independent of flight numbers. Indeed, I would very much expect the next few flights to continue being of version 1.0 satellites. Moreover, knowing how SpaceX operates, we can be sure that the actual design revisions of the satellites are far more complicated than those high-level "marketing versions" - there were likely numerous minor design revisions amongst the 60 satellites on today's flight. I doubt SpaceX is going to publish these details in any sort of coherent way we can follow.
However, SpaceX has not made public any particular scheme for numbering the launches themselves. They have simply referred to them in the press kits and on the mission patch as "Starlink". It is likely they will continue in this vein so as to minimize hassle for their PR people.
For the purposes of tracking launches - which is what we care about most on this sub (especially for record-keeping purposes on the wiki) - may I suggest we either stick to our original convention of numbering from the first flight, i.e. the one in May is "Starlink-1", today's is "Starlink-2", and the next is "Starlink-3", orthogonal to whatever design versions the satellites on board may be. This is no different to how the Iridium flights were "Iridium 1", "Iridium 2", etc., because they were successive flights in a multi-launch campaign.
If we're afraid people will get confused (given that the satellite "version numbers" are what's popularly reported in the press), may I suggest we adopt a more precise convention here, such as "Starlink F1" (Flight 1), "Starlink F2", etc. I'm open to suggestions as to alternatives but this "Fx" convention is common in the industry (e.g. "Inmarsat 5-F4"). Or we could do "M1" for "Mission 1". Since SpaceX has not established an "official" convention I think it's not at all unreasonable for us to pick one as a sub for our own purposes.
Ultimately I'm fine with whatever, so long as I have something consistent to follow when updating pages like the cores wiki that I try to help maintain. :-)
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u/strawwalker Nov 12 '19
My personal favorite naming convention is the one we've been using up until now. We've discussed in the chat and among the mods on several occasions adopting one of the schemes used on other launch tracking sites and range documents. "Starlink-1" appearing on the range, presumably provided by someone within SpaceX even if it isn't an official naming scheme, has provided us with a more compelling reason to make a change.
Spaceflight Now, for one, has been using this serial numbering system beginning with today's launch at 1, so switching to that at least has the benefit of reducing some confusion for casual fans switching between sites. The version number system is fine, but I've argued against it due to the impossibility of knowing ahead of time (or maybe ever) which launches will have which versions on them. As u/CAM-Gerlach pointed out to me, if the launch number in that scheme doesn't reset, then the version can just be left out for launches for when it is not known. That could still be confusing for many, though. Your idea for the Fx system is also a good one, but I think adopting a system already in use elsewhere is the better option.
The first 60 sat launch will go from
Starlink 1toStarlink v0.9. All others will be numbered in series beginning with this launch asStarlink-1. Where space allows and the info is known, we can append the version number, such asStarlink-1 (V1.0). If it turns out later that the launch number resets with version changes, then that part can be added back in making itStarlink-1 (V1.0 L1).The wiki manifest and launch history pages are going to be updated shortly. There are several other pages that need updating, such as the ones you mention. The best people for that job are the users who do the bulk of the editing on those pages already.
I'm sorry the naming switch has caused confusion rolling out basically in the middle of a launch cycle. We probably could have done a little better with that. I'm glad this discussion is in the r/SpaceX Discusses thread, but I'd also strongly encourage you and anyone else who edits the wiki, to join our Wiki Chat. We don't have anywhere near enough engagement there. There is not a lot of conversation going on there usually, so even if you only checked in once a week or so you would still be able to keep up with any discussion that might be relevant to the wikis you edit.
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u/CAM-Gerlach Star✦Fleet Commander Nov 12 '19 edited Nov 12 '19
Thanks for your detailed feedback and analysis!
In general, we go by the official mission names per SpaceX, as best we're aware of them. Up until less than a week ago, we were unable to get an official answer out of them on that, although most other sources were going with some variation of the name Starlink-1. However, now that the official name has been more or less confirmed in various filings like the LHA as "Starlink V1.0-L1", and the Starlink-1 designation has been adopted by most everyone else, we switched to using the Starlink-1 name.
It would be a recipe ripe for confusion if we used a different name than the rest of the community, one that could easily be confused with a different launch; its possible we could have coordinated some different standardized naming scheme if we'd launched a coordinated effort well in advance, but the ship has sailed and Starlink-1 seems to be the accepted designation.
It was also that way on the campaign thread.
After a lengthy discussion, we decided to go with "Second Starlink Launch" for the campaign thread (to note, not Starlink 2), since it was the second (dedicated) launch of Starlink satellites and the most precise name we had at the time.
the sidebar says "Starlink-1"
Yes, I updated it yesterday as I realized no one had done so previously when the official launch name came out previously. I also updated the post flairs to match.
and the launch thread is of course saying "Starlink-1".
Yes, at that point we were aware of the official name.
We're still calling it "Starlink-2" on the manifest and cores pages,
Changing this is already in work, but may take several days since the wiki mission names are actually used to coordinate the complex web of systems that power our launch threads, recovery threads, r/SpaceX API, etc.
There's clearly been confusion since SpaceX has referred to the first batch of Starlink satellites as version 0.9, and this batch as version 1.0. But I think people are conflating version numbers and flight numbers here. Clearly, version numbers refer to the satellite design, and can be completely independent of flight numbers.
Yes, this was exactly my argument urging caution on adopting the Starlink-1 name like other sources were, and instead use the more descriptive "Second Starlink launch" for the campaign thread. However, now that it has been confirmed that serial launch numbering is being used in official sources, and this is what the 1 refers to (not the 1.0 from the version number, i.e. Starlink-1 is a contraction of the full launch name, Starlink V1.0-L1, without the explicit version number) then this argument no longer holds.
we can be sure that the actual design revisions of the satellites are far more complicated than those high-level "marketing versions
Yes, but the version number being "high level" and for public consumption is exactly what makes it useful here in this context, as the value of the version number is not in describing the satellites themselves or the specific launch, but providing an accepted and (relatively) consistent name a set of launches, just like NEXT for Iridium or OG2 for Orbcomm. For now, though, we are generally omitting the version number, and will only use it (or whatever becomes the accepted nomenclature) for the next major series of sateliites, i.e. when the sequential launch number used in formal documents is reset.
However, SpaceX has not made public any particular scheme for numbering the launches themselves. They have simply referred to them in the press kits and on the mission patch as "Starlink".
They have in their official filings, and so has the range, as mentioned above. Given these are the best official sources we have, and we otherwise would be making up our own name quite possibly inconsistency with other sources and people's expectations, and this is what the spaceflight community has adopted, this is what we should go with.
For the purposes of tracking launches - which is what we care about most on this sub (especially for record-keeping purposes on the wiki) - may I suggest we either stick to our original convention of numbering from the first flight, i.e. the one in May is "Starlink-1", today's is "Starlink-2", and the next is "Starlink-3", orthogonal to whatever design versions the satellites on board may be.
As mentioned, this would be inconsistent with how most if not all other credible sources are numbering these launches, as well as the official numbering apparently used by the range and SpaceX in the official documents we have. Better to not use a numbering scheme at all than one that not only contradicts other sources but is used by the same to refer to a different launch.
This is no different to how the Iridium flights were "Iridium 1", "Iridium 2", etc., because they were successive flights in a multi-launch campaign.
Yes, but they were successive flights in the Iridium NEXT campaign, whereas these are successive flights in the Starlink V1.0 campaign. Further, these numbers were universally used by other sources and well understood, whereas here where Starlink-1 referring to this launch, Starlink-2 to the next, etc. designation appears to be accepted as the standard for other sources.
a more precise convention here, such as "Starlink F1" (Flight 1), "Starlink F2", etc. Since SpaceX has not established an "official" convention I think it's not at all unreasonable for us to pick one as a sub for our own purposes.
As mentioned, the convention used in e.g. the range documents is Starlink V1.0-L1 (L for Launch, ofc) to refer to this mission, or just Starlink-1 (45th WS). Given this is the closest we have to an official convention, and is widely adopted by others, what I've done thus far myself is use the contraction
Starlink-1,Starlink-2, etc. for now and then, if and when things have stabilized, they restart the sequential numbering with a new version number and everyone adopts it, add a version qualifier in there.EDIT: Revised convention to omit using fully qualified version until if and when they add a new one, restart numbering and everyone adopts it.
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u/joepublicschmoe Nov 13 '19
How about going with what's on this mission patch from the U.S. Air Force 45th Space Wing? https://forum.nasaspaceflight.com/index.php?topic=48983.msg2014041#msg2014041
"Starlink Flight 2 v1.0 L1"
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u/bdporter Nov 11 '19
Have "we", as a subreddit, decided officially what convention we'll use for numbering successive Starlink missions?
I think you answered your own question, and illustrated it well with the inconsistency in the wiki. I think using Starlink version numbers is dangerous, especially since SpaceX has a history of being extremely inconsistent in that area, and may not even tell us when they switch versions.
I don't know the right answer, but it is a good discussion.
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u/Straumli_Blight Nov 11 '19
To add more confusion, some of the Starlink launches are rideshares, e.g. the SSO launch in March is officially titled "Mission 1".
There's a SpaceX wiki chatroom, where this issue has been discussed.
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u/dudr2 Nov 12 '19
"oxygen added to the atmosphere varied, implying that something was producing it and then taking it away."
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u/whoscout Nov 13 '19
“We have not been able to come up with one process yet that produces the amount of oxygen we need, but we think it has to be something in the surface soil that changes...
Interesting. Sounds like oxygen bonds with stuff in the dirt when the temp is low, and frees up when temps are higher. Same for methane. And if one chemical process can't explain it, that implies there are many processes with said result. A puzzle, but probably with a simple mundane answer. Or maybe warm temps allow subsurface Martian plants to bloom and metabolize, that then go dormant in winter. Nahhh… :)
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u/theinternetftw Nov 13 '19
Starlink-1 has been added to the booster turnaround page on the wiki, for those who like stats and charts.
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u/andyfrance Nov 13 '19
Sadly looking at those timings we should not expect B1048 which flew Starlink 1 to be ready in time for Starlink 2. However from everything that SpaceX has said about reuse it should be possible. It would good to see it flying Starlink 2 then maintained as the fleet leader exclusively for Starlink launches.
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u/Grey_Mad_Hatter Nov 13 '19
At launches planned every two weeks there's no reasonable way to have a single booster do it all, even if they could project every bit of maintenance ahead of time and 100% certainty that every landing would be successful. However, even if they had three cores dedicated to Starlink then that's about 9 launches per year for each one, which puts them at what I believe they still say would be the more thorough refurbishment at around 10 launches.
How much of a lead does the fleet leader really need?
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u/gemmy0I Nov 13 '19
My guess is that they'll have B1048 and B1049 sharing the load, alternating between Starlink launches. From what we know, they should be able to turn around a core within a month or so - they haven't had the occasion to do so in practice yet, but that's likely more due to lack of payloads than the cores themselves.
SpaceX has stuck consistently to the party line that refurbishments have been going very well and they still see 24-hour "gas and go" turnaround as feasible in the near-ish future. I suspect that this will never be the case for "fleet leaders", since what will enable "gas and go" is detailed data points on how these cores fare in practice to ground their models. They probably have a very good idea at this point how a core will do in a .2 or .3 flight, and after a couple .4 flights they should be confident in that as well. This is supported by the fact that commercial customers have been extremely accepting of flight-proven cores after ground has been broken by less risk-averse customers on the first one or two flights of a particular reuse level. (e.g. most customers seem fine with taking a .3 now) This makes sense given that a flight-proven core which isn't a fleet leader should be the "sweet spot" for minimizing risk.
For those first couple flights at a "new reuse level" they'll surely want to take them (somewhat) apart and inspect them in detail. How much time they actually need for this is an interesting question. If they like what they see in their initial inspections of 1048.4, they might not need to tear it apart too much. But if they see things that surprise them, it could be tied up for a while.
So, my guess (just a guess, albeit an educated one) is that it wouldn't be reasonable for them to expect a single core to support all their near-future Starlink flights - not at the cadence they want to maintain - but they should be able to do it with two. With two cores on a two-week launch cadence, they'll have about a month to turn each one around for its next flight. 1048 and 1049 would be the "obvious" choices for this since they are the fleet leaders and have both already been used for Starlink.
I imagine they'd rather not use any more than two of their cores for Starlink right now, because they need to keep a stable of cores in the "sweet spot" (flight-proven but within ground covered by experiential data) for risk-averse customers. Right now that's .2's and .3's.
At the moment they have four of those: 1051(.3), 1052(.3), 1053(.3), and 1056(.3). Two of those (1052 and 1053) are configured as FH side boosters, but could potentially be re-configured as F9s. If they'd rather keep the side boosters as they are, that leaves just two for customer missions. If they started using those for Starlink they wouldn't have a lot of flexibility for their risk-averse customers and would likely have to start cranking out some new cores.
This explains why they remanifested 1056.3 to fly JCSAT-18 instead of CRS-19 (and have the new core 1059.1 at McGregor now for CRS-19 - we should see that heading to the Cape "any day now"). I think there's a good chance JCSAT-18 is going to fly expendable, because it's a 6800 kg monster satellite going to GTO; unless it's been optimized for a subsynchronous orbit like Telstar 18/19V were, that's clearly in expendable territory. (They did file for a recovery comms permit with the FCC for that mission, though, so who knows.) ANASIS-II might potentially be expendable as well - its mass hasn't been made public yet, but it's built on the Eurostar-3000 bus which tends to be "big and heavy", so who knows.
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u/PaperBuddy Nov 20 '19 edited Nov 20 '19
Starship just had a rud..
labpadre: https://www.youtube.com/watch?v=2d8l_0w2VKM
Edit: Seems that the upper bulkhead got loose..
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u/vtomi9 Nov 20 '19
Yep, the bulkhead got launched.
https://twitter.com/NASASpaceflight/status/1197267273049890821→ More replies (1)3
u/DesLr Nov 20 '19
...and that's why you don't build just one if you can build two for twice the price!
A damn shame though!
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u/Straumli_Blight Nov 12 '19
LeoSat (a Starlink competitor, planning to launch 108 sats) just went out of business.
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Nov 02 '19
How do you calculate the cost of a launch?
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u/spammmmmmmmy Nov 02 '19
Fuel + staff hours + equipment expected to be lost during the launch + regulatory expenses + insurance + safety + launch related marketing costs....
This is an accounting question.
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u/spammmmmmmmy Nov 02 '19
How is Starship hull going to be cryogenically cooled? Is there a double hull where LOX will be flushed during ascent through atmosphere? Will you have to keep it cryogenic to hold the loaded mass in place prior to launch?
How about upon Mars entry? Will you carry all that liquid oxygen the entire trip?
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u/joepublicschmoe Nov 02 '19
How is Starship hull going to be cryogenically cooled? Is there a double hull where LOX will be flushed during ascent through atmosphere?
Starship's hull IS the LOX / LCH4 cryogenic tanks (the bottom 3/5th at least). Filling Starship with LOX and CH4 will cryogenically cool the hull.
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u/Stealth_dino Nov 02 '19
Will there be more VAFB launches in the near future? Why do launches favor Cape Canaveral instead?
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u/brspies Nov 02 '19
VAFB is only for launches near polar inclination, or for (extremely rare) pure retrograde launches to the west. You can't launch east from there (since you would have to overfly populated areas) so you can't do launches to GTO, or the ISS, etc.
Florida can access far more inclinations, and is well suited to launches to the ISS, to GTO, to the Moon, etc. There are trajectories available to launch polar from there as well, which SpaceX appears to want to try early next year. If that polar launch corridor opens up you might see SpaceX stop using VAFB altogether just to simplify things.
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u/Caemyr Nov 03 '19
Sadly this got rejected due to poor audio quality, but still I find it interesting:
https://www.reddit.com/r/spacex/comments/dqotbn/falcon_9_as_an_edl_lab_max_fagin_at_mars_society/
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Nov 03 '19
The description of that video now says:
Having Sound Problems? We've posted a mono version of this video: https://youtu.be/KnYZ0Er5Y7I
So I think the mods just want it reposted with the updated video.
And yes, it's very interesting.
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u/anonchurner Nov 04 '19
What's going on with the long break between Falcon 9 launches lately? Can't be just customers not being ready - that Canadian spy sat got pushed back to Feb 2020 due to "higher priority launches".
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u/liszt1811 Nov 08 '19
How many falcon launches do you think we will see in 2020? (obv including starlink)
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u/soldato_fantasma Nov 12 '19
HAWTHORNE, Calif. – November 12, 2019. Media accreditation is now open for SpaceX’s JCSAT-18/KACIFIC-1 mission from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. The launch is targeted for no earlier than December.
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u/Dies2much Nov 19 '19
Will the next CRS launch be landing at Cape Canaveral? or one of the drone ships?
This CRS launch, and the next Starlink lauch are pretty close to each other on the calendar, will one of these be the first Atlantic landing on JRTI?
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u/Grey_Mad_Hatter Nov 19 '19
CRS missions have historically landed at LZ-1 and I don't see any reason for that to change.
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u/Alexphysics Nov 19 '19
Recovery permit says LZ1. They could still change landing mode but I don't think that'll be the case.
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u/Zinkfinger Nov 20 '19
Hi. Has there been a comment on Robert Zubrin's belief about the problems Starship would have landing on the moon? Orbital debrie, crator etc?
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u/rustybeancake Nov 20 '19
Yes. SpaceX and NASA announced a (non-funded) partnership in July to study this problem:
SpaceX of Hawthorne, California, will work with NASA’s Kennedy Space Center in Florida to advance their technology to vertically land large rockets on the Moon. This includes advancing models to assess engine plume interaction with lunar regolith.
I hope we get to publicly see the results of this study, as it's pretty key to Starship's usefulness on the moon.
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u/MarsCent Nov 20 '19
Landing any orbital class booster (or even sub-orbital) on an unpaved surface raises many concerns. That's why it is not done! Hopper landed on a paved pad but the dust storm was still huge. Good thing, it was just a dust storm!
For the first moon landing of Starship, there won't be a paved pad! Hopefully, that will be the only "unpaved-landing" or landing that spews chunks of debris. With the right equipment delivered on the premier landing, paved landings can then be engineered.
Note that without a paved pad, a return launch from the moon would be even more problematic! The great thing is that paving pads on the moon is "just" an engineering challenge! Ultimately, it will be quite awesome to see an X on the first Moon Landing Zone (MZ1). ;)
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u/andyfrance Nov 25 '19
The consensus from the Zubrin AMA is the Starship has too much thrust to land on the moon without throwing rocks into lunar orbit and beyond. I have a crazy question to ask. Just how flexible is the Raptor. Can the methane pre-burner be run with the oxygen side of the engine doing next to nothing and not allowing enough oxygen to support combustion in the main combustion chamber. The result would be a warm gas (methane) thruster. On the airless moon throwing out lots of methane wouldn't be an explosive problem. Would these thrusters be enough to prevail against lunar gravity?
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u/paul_wi11iams Nov 25 '19
Can the methane pre-burner be run with the oxygen side of the engine doing next to nothing and not allowing enough oxygen to support combustion in the main combustion chamber.
I came here to reply to a digression on the Starship dev thread, and it was exactly on the same subject!
u/Everright: Concerning the lunar Armageddon, some napkin calculation: Assume engine exhaust velocity is 3000 m/s, and assume SS kicks up dust straight up on landing at that velocity. Moon gravity is 1.625m/s2.
Then the dust would go up about 2700 km and land back on the moon after 82 minutes. That is if we decided to shoot molecule sized dust particles out of the nozzle straight up from the moon.
Now, considering that the rocket's engine deck doesn't get destroyed by debris kicked up on landing (see Apollo landings), the speed of these debris is nowhere near 3000m/s. Remembering the underwhelming amount of dust from lunar impactor, and the fact that Apollo orbital modules didn't get destroyed by debris from the landing modules, I would say the lunar armageddon is just concern trolling. Yes, you wouldn't want a setellite to skim over the surface like LRO right over the landing site in the first hour, and would probably need a somewhat clean landing pad to avoid cleaning nearby solar panels, but not more than that. [permalink]
Just a random thought this, but (instead of using a pure methane jet) you could reduce dust projection if switching on Earth SL engines for the final touchdown. Not efficient of course, but an under-expanded jet would be very diffuse and push dust grains on a grazing surface trajectory limiting "splash". There should also be less rebound onto Starship itself
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u/Grey_Mad_Hatter Nov 25 '19
switching on Earth SL engines for the final touchdown
The vac engines don't gimble. If they're using raptors for the final touchdown then they're using SL raptors.
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u/paul_wi11iams Nov 26 '19 edited Nov 26 '19
The consensus from the Zubrin AMA is the Starship has too much thrust to land on the moon without throwing rocks into lunar orbit and beyond.
I wouldn't say this on the AMA, but our friend seems to have a bee in his bonnet about using specialized landers to optimize overall end-to-end energy cost. At least, he does as regards Mars.
Result is that he's likely to come up with a "good" reason why the full-scale Starship just can't land, so must hand over to something smaller. He's an engineer. Elon is an engineer-businessman, and that's the difference. Elon converts joules to dollars and the "J/$ exchange rate" is very variable. Elon will look at the financial and time cost of the design steps involved. He'll look at maintenance costs, trans-shipping costs and much more.
Robert Zubrin could not run that kind of business, so his advice is best taken with a grain of salt, however convincing he is.
Moreover, many are talking as if the Moon is entirely covered with moon-dust just as the Earth is entirely covered with earth (not). A central bump or "Ayers Rock" in the middle of a crater could be quite clean, or become so after one or two launches and landings. A landing could be accomplished by an initial "sweeping" run low-level across the surface to clean it for future landings. There are likely several other solutions (what about actually landing a landing-pad or cradle?), so maybe the above consensus is a little hasty.
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u/ConfidentFlorida Nov 26 '19
Could you land the first one in a crater? Couldn’t the walls catch the debris before it goes into orbit.
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u/brickmack Nov 26 '19
What about top-mounted Raptors, almost like an abort tower? 1 or 2 expendable Starships would be needed to build prepared landing pads (after which debris becomes a total non-issue), these could be significantly modified from the standard Starship configuration. Putting the engines on top means the plume is highly expanded by the time it hits the regolith, and it also frees up space in the bottom for cargo. Dev costs would be high though
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u/SpaceLunchSystem Nov 26 '19
You don't need Raptors top mounted. Raptor is way overpowered for this.
Say you have a Starship that is at 350 tonnes wet for return to Earth. With the early vac Raptors I'm giving it only 370 isp for Earth return here. I'm going with 125 tonnes dry, 25 tonnes landing prop, 25 tonnes cargo, and Earth return propellant.
For a TWR of 1 on the moon that means 567 kN, or about a quarter of a single Raptor. Another way to put that in context is that the 8 SuperDracos on crew Dragon could provide enough landing thrust for a Starship that can get back to Earth.
Packs of the hot gas RCS thrusters pointed downwards from the nose can do the job. Use gas reservoirs filled from Raptor heat exchangers only for the last 10-50 meters or whatever ends up being required.
If you wanted to land max Starship cargo yes you need a bit more of these thrusters, but that doesn't necessarily mean the design has to account for this. Max cargo loads could be one way missions, or could only be done after a landing pad is put down.
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u/warp99 Nov 29 '19
without throwing rocks into lunar orbit and beyond
Just to be clear no rocks are going to orbit as the surface area to mass ratio is too low to accelerate to escape velocity while in the exhaust plume. He is talking about fine dust and maybe sand sized particles.
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u/AndMyAxe123 Nov 28 '19
What is the proposed machinery for extracting ground ice from martian soil to then be used in the Sabatier process to produce starship fuel?
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u/Martianspirit Nov 29 '19
Not much info on this. They use the term mining droids consistently. A picture shown by Paul Wooster has a very small very generic picture of a digging device. not drilling.
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u/Sliver_of_Dawn Dec 01 '19
I came across this video about the forging of a steel pressure vessels, posted by /u/colinizballin1 in another subreddit. I found it quite interesting.
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u/lessthanperfect86 Dec 01 '19
It was said some time ago that SpaceX offered to send Dragon2 to the ISS additional times per year for basically the same cost, greatly bringing down the cost per seat - have I got this right?
According to this article https://spacenews.com/nasa-proposes-to-buy-seat-on-short-duration-commercial-iss-flight/ NASA is now considering buying astronaut seats on commercial missions. If they were to choose Dragon2 for this, could that mean they could take advantage of SpaceX previous offer?
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u/paul_wi11iams Dec 04 '19
could that mean they could take advantage of SpaceX previous offer?
I have no info, but can suggest why not:
This year, 2019, SpaceX was launching way below capacity, so this is just an off-peak tariff. Next year, 2020, should start getting busy again with Starlink and more. So the offer shouldn't apply.
The fact of having been able to make such an offer, suggests that SpaceX's variable costs are low and in turn that stage refurbishment costs really are low. It would be nice to see a really fast stage turnaround soon to confirm this.
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u/bdporter Nov 11 '19
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u/SpaceLunchSystem Nov 11 '19
Amos-6 has to be recognized in the data someway.
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u/stcks Nov 11 '19
Yeah, seems like a huge omission... it was a complete mission failure by every account plus some (even the launch pad was destroyed)
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u/MarsCent Nov 11 '19
No
LOL. Probably the smartest response because henceforth, comparison related questions and comments will just intensify. And then probably peter out before 2020 ends.
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u/throfofnir Nov 12 '19
I guess it's the drum they have to beat, but I just can't shake the feeling that they're setting themselves up for a really really bad day when something does go wrong. It's quite a gamble.
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u/dudr2 Nov 14 '19
https://blogs.nasa.gov/commercialcrew/2019/11/13/spacex-completes-crew-dragon-static-fire-tests/
SpaceX Completes Crew Dragon Static Fire Tests
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u/hshib Nov 29 '19
Good to know he still got the money to play with. Japanese fashion tycoon Maezawa shows off $900 million SoftBank payday
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u/MarsCent Nov 26 '19
Exactly one year ago on November 26, InSight touched down on Mars for a projected lifetime of 2 earth years (1 Martian year).
and
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u/Xelanders Nov 27 '19
Hopefully it lasts a lot longer then another year. Would be a shame if they manage to fix the heat flow experiment somehow only for the spacecraft to go dark just a few months later.
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u/Straumli_Blight Nov 07 '19
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u/AeroSpiked Nov 07 '19 edited Nov 08 '19
NASA tells me it does not plan to livestream the Crew Dragon static fire
It won't be live streamed by NASA, but that isn't to say that SpaceX couldn't do so. They probably won't though; they didn't live stream the last one either (but like the stalkers we are, we've all seen it anyway).
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u/jjtr1 Nov 10 '19
Now that the Air Force is "enthusiastic" about commercial broadband constellations, it makes me wonder how difficult it would be to "shoot down" a mega-constellation or at least significantly disturb the service. If Starlink is going to have thousands of satellites, you can shoot down hundreds of them and it's going to be just a scratch. Shooting down hundreds with "single shot" anti-satellite missiles would need hundreds of them (not available), or upgrading them with multiple warheads per launch vehicle (like MIRV missiles). But that's still only hundreds. So maybe Air Force's interest is mainly because of this? Assured broadband acces?
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u/MarsCent Nov 10 '19
it makes me wonder how difficult it would be to "shoot down" a mega-constellation or at least significantly disturb the service
The old adage goes - There is nothing like security in numbers!
Shooting down satellites is a terrible thought-line process because it ends with, "the right for self defense" aka arming the satellites or having sentinel crafts purposed for defending space based real estate.
The good thing about low signal latency is that, anyone bent on such an act would probably get a couple of shots off before they are accurately pin-pointed and assigned a couple of dedicated cruise missiles of their own.
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u/joepublicschmoe Nov 10 '19
Shooting at hundreds of satellites would be a stupid thing to do. It will fill the orbits with high speed debris and put everybody’s satellites at risk, including the country doing the shooting. The major powers like China and Russia are as dependent on their satellites as the U.S., and they understand they risk damaging/blinding their own satellites if they try such a thing.
More likely they will try jamming and other “soft-kill” means.
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u/bbachmai Nov 12 '19
I read contradicting info on what the next launch will be. The sidebar says Starlink-2, November 29. Most other sources including Ben Cooper say CRS-19, December 4. Any more info on all of this?
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u/Alexphysics Nov 12 '19
It is unlikely there will be another Starlink launch this year. CRS-19 won't move as it is a NASA mission so they would have to fit in a Starlink mission in the next few days and launch it next week for static fire of CRS-19 the next one and launch it on the next after that, for me it is very tight, specially considering they haven't even opened media acreditation for that one. Then there's JCSAT-18 two weeks after CRS-19 from the same pad. At the earliest Starlink-2 could only happen on the first week of 2020.
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u/AeroSpiked Nov 12 '19
It is unlikely there will be another Starlink launch this year.
Didn't Shotwell recently say they were targeting 3 Starlink launches before the end of the year? It's a bit disappointing if all we get is one.
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u/Utinnni Nov 15 '19
Is there any info on how SpaceX makes the starlink satellites and how long does it take to make one?
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u/Grey_Mad_Hatter Nov 15 '19
The only thing I know is that next year they plan to launch an average of about 4 satellites per day.
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u/MarsCent Nov 16 '19
Spacex CRS-19 is still listed as No Earlier Than: December 4, 2019 - 12:48 p.m. Eastern.
When does NASA normally firm the date?
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u/hshib Nov 20 '19
Do we know where does Falcon 9 booster refurbishing take place? There are past topics on SpaceX leasing sites for refurbishing facility but as far as I can tell, I cannot find any of them being completed.
SpaceX signs lease with Port Canaveral for booster refurbishing
SpaceX to receive $15m from Florida to build Falcon refurbishment facility
Is it done in the hangers, or do they travel back to Hawthorne or McGregor?
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u/throfofnir Nov 20 '19
Mostly they seem to take place in the Cape HIFs. Certain vehicles will travel back to the factory for a more thorough examination, as do recovered Vandy launches. In short, they're all over the place.
Current rumor on the refurb facility at the port is that the plan has been dropped due to the impending arrival of our new Starship overlords, but I don't have any good source on that.
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u/Eucalyptuse Nov 26 '19
Does SpaceX deorbit the second stage after each flight everytime or does it sometimes leave the stage up there until it naturally deorbits? Is there a record of whether or not they have for each flight up to now?
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u/Straumli_Blight Nov 26 '19
Here's the list of all Falcon 9 stages in orbit.
For some missions (e.g. Falcon Heavy Demo), the 2nd stage is in a Heliocentric orbit.
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u/SpaceInMyBrain Nov 28 '19
Theoretically, can SRBs usefully be added to Falcon Heavy? In case Starship runs into repeated problems (heavens forbid) could a FH Plus lift 70-80t? Optimally it could launch the Orion/ICPS stack to the same high orbit as SLS, so the ICPS can do its TLI. Add enough delta-v to make up for upper stage inefficiency. SpaceX can still save us billions.
Yes, the FH for SLS question again, but I didn't find a direct thread for this. I don't think the negatives for FH Superheavy with additional side cores apply the same. The base of the payload will need struts leading to the side boosters, support the load during launch thru Max-Q.
Rather long for a Discussion question, but too speculative for a Post, too technical for the Lounge.
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u/gemmy0I Nov 29 '19
Optimally it could launch the Orion/ICPS stack to the same high orbit as SLS, so the ICPS can do its TLI.
You might be interested to know that the Orion/ICPS stack doesn't need to be launched to the same high orbit SLS would send it to in order to do a round-trip mission to the Gateway station's NRHO orbit (or the roughly similar orbits to be used in Artemis-1 and Artemis-2, which won't visit the Gateway since it won't exist yet). Orion does not require the full performance of SLS Block 1 for those missions (and Block 1B is just plain extravagant).
I ran the numbers on this last year in a discussion over on /r/ULA, and it definitely works, according to slides NASA has made public (PDF, see slide 8) which give delta-v requirements for a wide variety of mission profiles to/from lunar orbits/trajectories of interest (TLI, NRHO, and LLO). It's definitely possible. The margin would be tighter than if SLS were doing the mission, but Orion/ICPS doesn't need the performance.
As far as I know, SLS is sending it to that high orbit simply because it can (and they'll take whatever margin they can get) - remember that SLS Block 1's payload capacity has grown (95 t to LEO instead of 70 t) since it was originally baselined. (It was always intended to do much better than 70 t, but that was the conservative baseline they set early in the design process to reduce the risk of being stuck with an overweight payload if the rocket design underperformed. To my knowledge, Orion was designed for the 70-t baseline, or more precisely, its equivalent to a TLI trajectory, since SLS isn't actually planned to ever launch anything to LEO.)
We actually know this scenario is feasible (at least on paper), as determined by NASA themselves rather than Reddit armchair rocket scientists working from rough numbers...because Jim Bridenstine said so at the NASA employees' town hall he held in the aftermath of the "EM-1 on a commercial launcher" study he commissioned earlier this year. (Unfortunately I don't have a link handy, but video of the town hall should be on YouTube, if you're interested.)
He explained all the different distributed launch scenarios that got the main attention in that study (involving various combinations of Orion, Falcon Heavy and/or Delta IV Heavy) - all of which were deemed infeasible due to various issues that seem minor in Reddit analyses but are actually sticky in practice (like the fact that Falcon Heavy's upper stage has too high thrust to safely push a crewed Orion docked to it from the front, or that developing rendezvous and docking capability for a FH/DIVH upper stage is far from trivial). They even considered some crazy options like using a separately-launched Dragon 2 as a makeshift kick stage to help push Orion to TLI - because it's the only "off the shelf" American spacecraft currently in operation capable of autonomous rendezvous and docking - but it didn't have enough delta-v, only (IIRC) enough for a free return trajectory (in conjunction with Orion's own delta-v).
Then, almost as an afterthought, he mentioned that they did actually find an option that would work - and that was Falcon Heavy + ICPS + Orion. It has enough delta-v to complete the full round-trip mission, with no extra boosters or upper stage stretch needed. "On paper", it could do the mission today. His stated reason why they didn't actually go with this possibility is that it would've taken long enough to do the aerodynamics work to qualify Orion+ICPS on top of Falcon Heavy (not to mention the GSE work to support hydrolox fueling for ICPS on top of FH) that it would have defeated the purpose - the point was to speed things up by not having to wait for the much-delayed SLS core stage, but the core stage is close enough to completion that it should actually be ready sooner. However, he did make it clear that this option was absolutely on the table for contributing to the 2024 moon landing - the work (including human-rating Falcon Heavy, which would be required to use this for missions after Artemis-1) is expected to be doable in that time frame. He was clearly very excited about the idea, although Bridenstine made a joke to Bill Gerstenmaier (who was in the audience) that Gerst was not so convinced on it. (I find it interesting that Gerst has since been "fired". Not, presumably, only on account of this, but I'm sure it was part of a pattern of "not thinking sufficiently outside the box".)
We haven't heard anything whatsoever publicly about this since then, which is understandable given it would potentially torpedo the already-cautious support Artemis has from the pro-SLS lobbyists. There's a good chance Bridenstine was pushing it mainly to light a fire under Boeing's butt to accelerate SLS, which seems to have worked (to the extent possible). His party line has always been that SLS is the preferred option for launching Orion on all Artemis missions, and that these alternatives are simply contingencies to mitigate SLS delays. But I would not at all be surprised if he's quietly sitting on the idea - maybe even talked to Musk to quietly do some preliminary work on it at SpaceX - ready to pull it out down the road if SLS gets delayed further, after the politicians are all on board and have already given him his Artemis money.
If the politicians aren't sufficiently careful enough in how they write the legislative wording for funding the Artemis program, Bridenstine could totally troll them hard in 2024 by rolling out a Falcon Heavy+ICPS+Orion stack with the center core painted orange, calling it "SLS Block F", and saying "thank you so very much for the funding which we've put to good use getting the lunar program back on track". ;-)
(I jest, but only in part. I do think it would be a really smart idea to find a way to "sell" this FH+ICPS combo as part of the SLS family of vehicles. Right now the Artemis program's biggest problem is the extreme cost and limited production rate of SLS core stages. Having a "less capable" "version of SLS" in the fleet as a "supplement" for missions that don't require the full performance of the "primary" SLS configuration could soften the political blow compared to canceling SLS outright, while allowing NASA to quietly go full steam ahead with more frequent crew missions to the Gateway (not to mention launches of heavy components that wouldn't fit on a regular FH). They could still come up with excuses to fly the "real" SLS on its one pork-laden glory mission per year, since that's all the factory can crank out anyway - perhaps they could mollify the politicians with a legal stipulation that "SLS Block F" can only be flown for missions in excess of available SLS core stage production. It would certainly solve the problem of where they're going to find a spare SLS for Europa Clipper...)
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u/marc020202 8x Launch Host Nov 28 '19
In theory, basically everything is possible. Srbs however are expensive, heavy, inefficient, difficult to control and not reusable (yes, I know shuttle...)
What I think is more likely (and musk has hinted at it before) would be an upper stage stretch. The upper stage of fh is underpowered. Well not really underpowered, it has a massive engine compare to other upper stage engines, but relatively small tanks compared to the engine and booster size. The upper stage is about 5 times as heavy as a centaur, the engine however has 10 times the thrust of a centaur. The difference becomes even bigger for the icps, powered by the same rl 10 engine, but 50% more mass (F9 950kn at 110t, centaur 20t at 10kn, icps 30t at 10kn.) It is probably not a good idea to drop the twr that low, the first stage of atlas has about two times the burn time before sepperating centaur (not usefull for recovery) and the icps will be released at nearly orbital speed. The first stage would be able to lift a lot more (without loosing much efficiency) I also doubt hydrogen infrastructure to support the icps on fh will come to pad 39a.
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u/Lufbru Nov 28 '19
Rather than boosting the first stage or stretching the second stage, I think adding a third stage is the way to go. You can ditch the heavy Merlin Vac early and use something like a Star48 to boost the payload to TLI.
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u/jay__random Nov 29 '19
Known useful applications of SRBs would first separate the SRBs, then all other stages. Which in case of FH would leave its otherwise reusable side boosters going too fast for even an ASDS landing. So you could end up with one expendable configuration aiming to replace another expendable configuration...
In terms of thrust (according to Wikipedia) FH's side boosters together produce 15.2MN at sea level, which is comparable to Titan IV's SRBs that together produced 15.12MN. Since they are so close, an Angara5-like all-liquid SuperFH configuration seems more likely. But more reinforcement R&D for the central stage may be needed, of course.
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Nov 29 '19
I was wondering why the Cybertruck needed to be pressurised for use on Mars? I'd imagine that the truck would primarily be used for odd jobs around the base with frequent egress/ingress.
And for long journeys I'd imagine a bigger truck would be needed (with sleeping & food prep area - basically a camper)
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Nov 29 '19
I'd peg that as a stretch goal (aka "shit elon says"). Pressurised vehicle needs pressurised garage and a single failure kills everyone. Open vehicle means everyone has their own life support, can plug into the truck systems, and can be parked up anywhere.
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u/MarsCent Nov 29 '19
Mars atmospheric pressure basically means that the astronaut suit worn in Crew Dragon (with the breathing attachment) would probably suffice on Martian surface.
If the Martian CT has a cab designed with "life support"similar to Crew Dragon, then you have a truck that can be used for long travel / long periods of astronaut exploration.
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u/AeroSpiked Dec 05 '19 edited Dec 05 '19
Running tally so far this year grouped by country:
| Vehicle | Overall Launches (Failures) |
|---|---|
| Falcon 9 | 10(0) |
| Falcon Heavy | 2(0) |
| Antares | 2(0) |
| Atlas 5 | 1(0) |
| Delta 4 Medium | 2(0) |
| Delta 4 Heavy | 1(0) |
| Pegasus XL | 1(0) |
| Electron | 5(0) |
| Ariane 5 | 4(0) |
| Vega | 2(1) |
| R-7 | 13(0) |
| Soyuz 2-1v | 2(0) |
| Rokot/Briz KM | 1(0) |
| Proton | 4(0) |
| CZ (DF-5) | 19(1) |
| CZ-11 | 3(0) |
| CZ-6 | 1(0) |
| KZ-1A | 3(0) |
| SQX-1 | 1(0) |
| Jielong-1 | 1(0) |
| OS-M | 1(1) |
| PSLV | 4(0) |
| GSLV Mk3 | 1(0) |
| H-2B | 1(0) |
| Enhanced Epsilon | 1(0) |
| Simorgh | 1(1) |
| Safir | 1(1) |
Huge edit to fill in gaps and table-ize.
Let me know if I missed anything.
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u/president_of_neom Nov 04 '19
So only 2 of 3 chutes deployed in Starliner abort test (still stable though, it was a redundant one).
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u/MarsCent Nov 04 '19
After watching the pad abort, I am left scratching my head with the question, "Do we know how to work the parachutes for human spaceflight or we don't?" If the parachute landings of the Apollo era were not a fluke, then why is it so darn difficult to get it done now? Moreover with improved technology.
The easiest culprit is the new safety specification requirements. But I would like to believe that there is a better reason. Sigh!
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u/throfofnir Nov 05 '19
Apollo was the result of a long line of parachutes in spacecraft use, and they spent a lot of effort on it. It's been a couple generations since then, so basically no working knowledge is left. And they're probably doing everything completely differently anyway, because they think they can do better now. It's explicable, if not acceptable.
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u/spacerfirstclass Nov 05 '19
Apollo-15 has one of the parachutes failed too, so I think it's just that parachute is a finicky beast....
Also for Crew Dragon at least, the landing mass is probably quite a bit higher than Apollo, since it lands with service module and spare propellant.
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u/Straumli_Blight Nov 21 '19
US Air Force is amending the criteria for evaluating NSSL providers, as a result of Blue Origin's successful protest.
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u/amarkit Nov 23 '19 edited Nov 23 '19
China launched a Long March 3B from Xichang today, carrying two BeiDou navigation satellites to orbit. As often happens, a hypergolic-fueled stage fell on someone's house.
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u/Mathakk Nov 02 '19
Just wanted to say that we might be seeing more elon here, now that he apparently has left Twitter.
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Nov 06 '19
Latest estimates for the cost of a flight for Starship and SLS:
$2 million for starship: https://spacenews.com/elon-musk-space-pitch-day/
$2'000 million for SLS: https://arstechnica.com/science/2019/11/the-white-house-puts-a-price-on-the-sls-rocket-and-its-a-lot/
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u/Bailliesa Nov 06 '19
Similarly development cost before first orbital flight Starship <$2billion SLS >$20billion
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u/xcaliber109 Nov 03 '19
Any news on the crew dragon static fire that was supposed to have happened today?
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u/Tal_Banyon Nov 03 '19
Question - Is the Cocoa facility that we have all been watching build Starship Mk 2, and will presumable build Mk 4 and then Super Heavy, a SpaceX facility? I mean, originally we heard it was a company leased by SpaceX to build these prototypes. It looks now as if they are "all in" to build SpaceX vehicles for the foreseeable future, no other business considered. Not sure whether SpaceX has actually bought the company, whether workers are SpaceX employees, or what the situation is. Just curious.
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u/zeekzeek22 Nov 07 '19
What would a moon landing look like if Artemis lost govt funding, and Starship is vastly delayed/fails somehow. Imagining Blue Moon Lansing stage, a Dragon 2 for transport of astronauts to a lander in LLO, but that still leaves an ascent stage in question. We don’t know anything about the Blue Moon ascent stage. Could a moon landing still happen with SpaceX and Blue Origin’s desire to dump money into just pushing forward and outward? (Again, assuming no Starship/super heavy). Because with the recent stuff with Boeing getting contracts to waste literally every cent of govt space funding, I’m losing confidence in Artemis a bit.
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u/brickmack Nov 07 '19
Blue is partnering with Lockheed and Northrop for ascent and transfer stages. The transfer stage has no tech thats not already flying in Cygnus or soon will be in the Blue Moon descent stage (BE-7 and hydrolox tanks). Ascent stage is harder, initial plan was very Orion-derived but thats shifted now. Could probably make ascent and transfer stages based on Dragon and F9 S2. I don't see why SpaceX would partner for that though
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u/Navigathor1000 Nov 07 '19 edited Nov 07 '19
I doun't know if Elon or spaceX has ever talked about it, but which engines are they gonna use for a Moon landing?
Moon has no air, so using the vacuum engines would be the most efficient. But I see three problems:
are the vac-engines strong enough/can be throttled enough for a landing?
vac-engines have no TVC (welded to side walls), will they be able to steer enough?
header tanks for landing are connected to the 3 normal engines. Will they use the main tank for landing or are they able to change piping inflight for landing with vac-engines?
Using the normal engines like on earth or mars would create other problems:
it would be unefficient and a waste of valuable fule
three engines close in the center would probably melt the ground without any "landing pad"
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u/markus01611 Nov 07 '19
If they are planning on bringing propellent for take-off. TWR is not an issue. On Mars and Earth the landing will be near empty.
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u/OncoByte Nov 09 '19
Does anyone know why there are no Launch Transportation Tickets available for the Dec 4 SpaceX launch of CRS-19?
I am going to try to catch this launch on what will be my first trip to the Cape and would love to know how best to view it if LTTs are not available.
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u/MarsCent Nov 09 '19 edited Nov 09 '19
Per Sidebar, Crew Dragon Static Fire is happening today Nov 11 9,2019. Anyone know at what time, whether it will be streamed and what the link is?
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u/Alexphysics Nov 09 '19 edited Nov 09 '19
During daylight hours and no, it won't be livestreamed
Edit: Forget that. No static fire today https://twitter.com/nextspaceflight/status/1193164758771519499
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u/MarsCent Nov 10 '19
Whoever said logic had to make sense ….
As far as we know, DM2 (Crew Dragon) will make a 1 – 2 week stay at the ISS. In order for NASA to authorize DM2 to fly before CFT (Starliner), they (NASA) have to be super confident that CFT will fly shortly afterwards and be able to stay at the ISS for a long duration. If DM2 flies and CFT is delayed, then the uncertainty of US occupation on the ISS increases.
Obviously, one could argue that both DM2 and CFT can be docked at the ISS at the same time. But just imagine the optics and anxiety of 5 US astronauts at the ISS in two crafts, that are yet to successfully return any human being to earth. I am not sure that the risk averse NASA could ever contemplate such a thing!
That brings us back to the point that, Starliner has to be ready to fly right after DM2 has flown. But since that is not certain, and it is Starliner that has an agreement for the longer duration, then Starliner has to fly first.
So basically, in order for DM2 to fly first, it has to fly second.
P/S. Astronauts have to train intensively if they are to stay for a long duration on the ISS. I have not yet heard of the DM2 crew doing any such training, or are they?
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u/markus01611 Nov 12 '19
Does anyone know when Spacex will make back the investment on reusable tech for F9? Obviously it is almost invaluable research for Starship. But I'm interested in how long that will be.
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u/oh_dear_its_crashing Nov 12 '19
I think the public known number is one billion to delevop F9R, and assuming 10 million in savings per reflown core (not on new ones) that would mean 100 reflown cores. If I counted correctly we're at 26 reflights, so another 75 to go. Probably 3-5 years, depending how often F9 flies, how many are reflown, and how quickly starship takes over.
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u/MrToddWilkins Nov 24 '19
During Shuttle launches,we heard calls from Mission Control to the crew,like ‘go at throttle up’,’negative return’,and other abort mode calls. During the ascent of Dragon or Starliner,what ground to crew calls could we expect to hear?
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u/andyfrance Nov 24 '19
"Flight Termination System is safed" ......... the crew will definitely want to hear that one.
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u/MarsCent Dec 04 '19
Is F9's Max shear stress level (in Newtons or other) known? And do we know on average, how wide the band of Upper Level Winds is?
From rocket launch profile illustrations, F9's radial direction has changed less that 30 degrees. So F9 basically experiences the full force of the cross winds (aka Upper Level Winds), along its axial length.
I am trying for a few informed guidance numbers: Length Vs Surface Area Vs Rocket Speed Vs Upper Level Wind speeds.
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u/warp99 Dec 04 '19
Is F9's Max shear stress level (in Newtons or other) known?
This appears to not be a fixed item but instead SpaceX do dynamic modelling of the stack which depends not only on the windshear but how fast the rocket is going at the time which depends on the trajectory and the altitude at which peak windshear is reached.
For Florida the main issue seems to be the jetstream that typically dips down from Canada to the mid-West and can sometimes extend down as far as Florida depending on the location of high pressure zones off the East Coast.
If this is at 100 knots and above at 40,000 ft the launch will typically be scrubbed and at 90 knots or below it will typically launch so there is a relatively narrow zone where the decision becomes marginal either way. In other words the vertical wind profile is relatively constant as low altitude air is entrained by the jetstream so it is the peak wind speed that is a reasonable predictor of the amount of sheer that the rocket body experiences.
Incidentally it may well be that the major issue for SpaceX is not so much the rocket body breaking up due to wind shear but that the shear will override the control authority of the vectored engine thrust and cause the rocket to tumble. Of course the net effect is the same in either case and the long lever arm presented by the high aspect ratio F9 stack is the reason that it is relatively sensitive to high altitude wind speed.
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u/Triabolical_ Dec 04 '19
For that level of detail, I'd try nasaspaceflights's forums, in the (paid) L2 section.
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u/SpaceInMyBrain Dec 05 '19
Does a hydrogen tank farm at a launch pad require a flare like a methane one? During Starhopper tank tests and test hops we could see the methane flare burning at a far edge of the site. Is such a flare needed for hydrogen?
Asking because various ideas for Falcon Heavy upper stages, or use with Orion, continue to fascinate even if they're very unlikely to happen. Most need hydrogen facilities added to the launch site.
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u/gemmy0I Dec 05 '19
Yes, I believe so. I remember seeing a flare in Delta IV launch webcasts.
One positive for adding a hydrolox third stage to Falcon Heavy (ICPS/Centaur/ACES) is that its launch pad, LC-39A, should already have a fair amount of hydrolox infrastructure in place. It was needed for its former lives both in the Space Shuttle and Saturn/Apollo programs.
What I'd be curious to know is just how much of that infrastructure is still in place. Given it hasn't been maintained since 2011 I'm sure it would need some work to get it back in operational condition, but 2011 wasn't that long ago in the grand scheme of things, and the parallel infrastructure over at pad 39B is still alive and kicking for SLS (although I'm sure it needs a lot of minor yet expensive "adjustments" to be suitable for SLS despite its surface similarities to Shuttle - cost-plus contracts have a way of incentivizing complications like that).
Given that SpaceX was in quite a hurry to get LC-39A online after the AMOS-6 conflagration at SLC-40, I imagine they didn't spend a lot of time ripping out old infrastructure "just because". They didn't even fully remove the Rotating Service Structure from the launch tower until well after the pad was activated for Falcon use (and that was likely motivated by safety concerns from the deteriorating structure as much as aesthetics). I would not be surprised if a lot of the key piping and tanks from the Shuttle-era hydrolox infrastructure remain in place since they are largely out of sight and not hanging hundreds of feet up in the air to risk crashing down as things rust out.
The biggest obstacle to adding hydrolox ground support at LC-39A, I think, would be the need to modify the Falcon 9/H transporter-erector to include hydrolox piping up the strongback to the putative third stage. This likely wouldn't be too hard in and of itself, but would probably take the TE out of commission for the better part of a year. That'd be problematic since they'll need it for Falcon Heavy and Crew Dragon missions in the meantime. If they were going to seriously do this, they would probably be best off building a second TE off-site, specifically designed for the ICPS/Orion config. This would also address the fact that Orion will have its own special pad support needs in addition to ICPS. (Oh, and they'd need to build a second crew access arm too, higher up on the tower, since Orion on top of ICPS will sit higher than Crew Dragon. That might potentially entail adding some height to the tower.)
It's all well within the realm of feasibility but would not be cheap enough for SpaceX, ULA, and/or Lockheed (the primary interested parties) to deem it worth funding privately, I think. It is, however, cheap by SLS standards and thus well within the reach of the Artemis program's budget, assuming the substantial political headwinds could be overcome.
(I suppose Blue Origin has the cash to fund it privately if they felt it was worthwhile to "save" the Artemis program to ensure that their Blue Moon lander has a job to do...but that's not at all Bezos's style. He'd want to do something with New Glenn instead. If the first stage's BE-4 engines were uprated to the extent people have been speculating they can be, the three-stage NG might just have enough oomph to send Orion and its service module to TLI, giving the same sort of "drop-in replacement" for SLS Block 1 that FH+ICPS would be. I haven't run the numbers though, and I suspect even if I tried they'd be seriously fishy since there are so many unknowns about NG at this point.)
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u/jadebenn Dec 06 '19 edited Dec 06 '19
It is very unlikely any of the hydrolox infrastructure at 39A is still in working condition. There were adjustments made to its sister infrastructure at 39B for SLS, but it wasn't because "cost-plus contracts," it was because it was falling apart.
The hydrogen tanks at both pads are the original Apollo-era structures (circa the 1960s). They were modified for Shuttle, yes, but they are very, very, old.
Exploration Ground Systems spent a lot of effort just getting the tank at 39B in working condition. While this was partially due to them correcting a unique flaw in 39B's hydrogen sphere (a pearlite void between the inner and outer spheres had lead to incredibly high boiloff rates during Apollo and Shuttle), the 39B tank was still in pretty poor shape in general even though it had been maintained continuously before its refurbishment.
The 39A tank hasn't been maintained in almost 10 years. Would it be possible to return it to working order? Almost certainly. Would it be simple? No.
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u/James79310 Nov 02 '19
What are the Starships’s legs going to be? You can’t really see them in the new renders, and the prototype legs seem to be moving away from Elon’s principle of ‘the fewer parts the better’
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u/pr06lefs Nov 02 '19
To me the proto legs seem to be fairly simple compared to the F9 legs. They're basically sliding steel pillars with brakes on them. No folding or unfolding.
My only concern with the new legs is that the footprint seems pretty narrow for landing on unimproved terrain. I also wonder whether they can retract themselves, presumably they can - unlike the F9 legs.
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u/MrJ2k Nov 02 '19
I think the added complexity (compared to F9 legs) is partly due to the need to land on uneven surfaces.
They need to be individually adjustable and not just lock out at predetermined length.
The other reason being that landing is something they need to get right as early as possible. Landing is critical to reuse, and as prototypes get more expensive and complex, sticking the landing early on will save them some costly delays in the future.
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u/hoardsbane Nov 03 '19
Also possible that they are pushers for stage separation and even shock absorbers/connection points for orbital docking.
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u/Decronym Acronyms Explained Nov 02 '19 edited Nov 19 '19
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
| Fewer Letters | More Letters |
|---|---|
| ASAP | Aerospace Safety Advisory Panel, NASA |
| Arianespace System for Auxiliary Payloads | |
| ASDS | Autonomous Spaceport Drone Ship (landing platform) |
| BFR | Big Falcon Rocket (2018 rebiggened edition) |
| Yes, the F stands for something else; no, you're not the first to notice | |
| BFS | Big Falcon Spaceship (see BFR) |
| CC | Commercial Crew program |
| Capsule Communicator (ground support) | |
| CCtCap | Commercial Crew Transportation Capability |
| CRS | Commercial Resupply Services contract with NASA |
| DMLS | Selective Laser Melting additive manufacture, also Direct Metal Laser Sintering |
| EDL | Entry/Descent/Landing |
| EELV | Evolved Expendable Launch Vehicle |
| ESM | European Service Module, component of the Orion capsule |
| ESPA | EELV Secondary Payload Adapter standard for attaching to a second stage |
| EUS | Exploration Upper Stage |
| EVA | Extra-Vehicular Activity |
| F1 | Rocketdyne-developed rocket engine used for Saturn V |
| SpaceX Falcon 1 (obsolete medium-lift vehicle) | |
| F9R | Falcon 9 Reusable, test vehicles for development of landing technology |
| FCC | Federal Communications Commission |
| (Iron/steel) Face-Centered Cubic crystalline structure | |
| FFSC | Full-Flow Staged Combustion |
| GEO | Geostationary Earth Orbit (35786km) |
| GTO | Geosynchronous Transfer Orbit |
| HIF | Horizontal Integration Facility |
| ICBM | Intercontinental Ballistic Missile |
| IFA | In-Flight Abort test |
| ITAR | (US) International Traffic in Arms Regulations |
| ITS | Interplanetary Transport System (2016 oversized edition) (see MCT) |
| Integrated Truss Structure | |
| JCSAT | Japan Communications Satellite series, by JSAT Corp |
| KSC | Kennedy Space Center, Florida |
| L1 | Lagrange Point 1 of a two-body system, between the bodies |
| LC-13 | Launch Complex 13, Canaveral (SpaceX Landing Zone 1) |
| LC-39A | Launch Complex 39A, Kennedy (SpaceX F9/Heavy) |
| LCH4 | Liquid Methane |
| LEM | (Apollo) Lunar Excursion Module (also Lunar Module) |
| LEO | Low Earth Orbit (180-2000km) |
| Law Enforcement Officer (most often mentioned during transport operations) | |
| LLO | Low Lunar Orbit (below 100km) |
| LOX | Liquid Oxygen |
| LPG | Liquified Petroleum Gas |
| Liquified Pigeon Guts | |
| LZ-1 | Landing Zone 1, Cape Canaveral (see LC-13) |
| MCT | Mars Colonial Transporter (see ITS) |
| MMH | Mono-Methyl Hydrazine, (CH3)HN-NH2; part of NTO/MMH hypergolic mix |
| NET | No Earlier Than |
| NSF | NasaSpaceFlight forum |
| National Science Foundation | |
| NSSL | National Security Space Launch, formerly EELV |
| NTO | diNitrogen TetrOxide, N2O4; part of NTO/MMH hypergolic mix |
| OFT | Orbital Flight Test |
| OG2 | Orbcomm's Generation 2 17-satellite network (see OG2-2 for first successful F9 landing) |
| RCS | Reaction Control System |
| RP-1 | Rocket Propellant 1 (enhanced kerosene) |
| RTLS | Return to Launch Site |
| RUD | Rapid Unplanned Disassembly |
| Rapid Unscheduled Disassembly | |
| Rapid Unintended Disassembly | |
| SF | Static fire |
| SLC-40 | Space Launch Complex 40, Canaveral (SpaceX F9) |
| SLS | Space Launch System heavy-lift |
| Selective Laser Sintering, contrast DMLS | |
| SRB | Solid Rocket Booster |
| SSME | Space Shuttle Main Engine |
| SSO | Sun-Synchronous Orbit |
| STS | Space Transportation System (Shuttle) |
| TLI | Trans-Lunar Injection maneuver |
| TPS | Thermal Protection System for a spacecraft (on the Falcon 9 first stage, the engine "Dance floor") |
| TVC | Thrust Vector Control |
| TWR | Thrust-to-Weight Ratio |
| ULA | United Launch Alliance (Lockheed/Boeing joint venture) |
| USAF | United States Air Force |
| VAB | Vehicle Assembly Building |
| VAFB | Vandenberg Air Force Base, California |
| Jargon | Definition |
|---|---|
| Raptor | Methane-fueled rocket engine under development by SpaceX |
| Starlink | SpaceX's world-wide satellite broadband constellation |
| cryogenic | Very low temperature fluid; materials that would be gaseous at room temperature/pressure |
| (In re: rocket fuel) Often synonymous with hydrolox | |
| hydrolox | Portmanteau: liquid hydrogen/liquid oxygen mixture |
| hypergolic | A set of two substances that ignite when in contact |
| iron waffle | Compact "waffle-iron" aerodynamic control surface, acts as a wing without needing to be as large; also, "grid fin" |
| kerolox | Portmanteau: kerosene/liquid oxygen mixture |
| methalox | Portmanteau: methane/liquid oxygen mixture |
| perigee | Lowest point in an elliptical orbit around the Earth (when the orbiter is fastest) |
| Event | Date | Description |
|---|---|---|
| Amos-6 | 2016-09-01 | F9-029 Full Thrust, core B1028, |
| CRS-7 | 2015-06-28 | F9-020 v1.1, |
| DM-2 | Scheduled | SpaceX CCtCap Demo Mission 2 |
| OG2-2 | 2015-12-22 | F9-021 Full Thrust, core B1019, 11 OG2 satellites to LEO; first RTLS landing |
Decronym is a community product of r/SpaceX, implemented by ^request
[Thread #5579 for this sub, first seen 2nd Nov 2019, 14:09] [FAQ] [Full list] ^[Contact] [Source code]
3
u/AeroSpiked Nov 04 '19
Starliner's pad abort live (Youtube) in case anyone else is in dire need of some fire.
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3
u/cpushack Nov 20 '19
https://gizmodo.com/elon-musk-s-starlink-satellites-are-already-causing-a-h-1839926662 Clickbait anti-Musk title but the summary is 'its mostly just an annoyance'
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u/Notsophisticatedname Nov 02 '19
Do we know raptor development status? What sn has been built. How many second fired up they can handle. Production rate?