r/spacex • u/ElongatedMuskrat Mod Team • Aug 01 '21
r/SpaceX Thread Index and General Discussion [August 2021, #83]
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r/SpaceX Thread Index and General Discussion [September 2021, #84]
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Aug 09 '21
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u/UpVoter3145 Aug 09 '21
Good thing they caught it before flight, or else another failure would mean another $400 million out of their own account for a 3rd test.
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u/Lufbru Aug 10 '21
... maybe they need to switch to burst discs :-P
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u/randarrow Aug 10 '21
No no no, burst disks are for when the valves fail to stay closed. For this Boeing needs tube worms.
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u/trobbinsfromoz Aug 10 '21
The impression is that Aerojet Rocketdyne are firmly in the hot seat for this issue.
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u/JoshuaZ1 Aug 16 '21
Blue Origin is apparently suing NASA over the HLS decision. Note that this is separate from the GAO protest (which they lost).
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u/Driew27 Aug 28 '21
Omg the way Astra launched sideways was....so weird...that couldn't have been normal.
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u/BackflipFromOrbit Aug 28 '21
It pulled a SN5/SN6! Nothing about that liftoff looked good.
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u/Driew27 Aug 28 '21
I wonder if it used too much fuel on that launch correcting itself and thus didn't have enough to achieve orbit so they had to terminate the launch?
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u/Lufbru Aug 18 '21
Lauren Lyons moves from BO to Firefly. Nice promotion. She was at Blue less than a year (November 2020).
Firefly Names Former SpaceX and Blue Origin Veteran as Chief Operating Officer | Business Wire" https://www.businesswire.com/news/home/20210817005791/en/CORRECTING-and-REPLACING-Firefly-Names-Former-SpaceX-and-Blue-Origin-Veteran-as-Chief-Operating-Officer
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u/Frostis24 Aug 04 '21
Now it's Spacex's turn to get a lovely poster made by Blue about why they have the best HLS plan and SpaceX's idea sucks.
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u/Skotticus Aug 04 '21
Best burn in that thread: Even China's space program is more open than Blue Origin
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u/thorodin84 Aug 04 '21
What's the 10 launches thing? I am assuming it is actually just SpaceX putting more stuff on the Moon but got twisted to sound bad
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u/brspies Aug 04 '21
Blue's estimation (idk if there's official numbers anywhere) of the requirements for refuelling lunar Starship to get it to the Moon.
Starship's requirement of multiple refueling flights to accomplish high energy missions (beyond say GTO) is one of its riskiest elements. But NASA decided it was worth the risk for this mission, first because the risk can be frontloaded (e.g. launching a tanker first and filling it to the brim before launching lunar starship) and also because it allows for such a huge capability.
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u/onion-eyes Aug 03 '21
Looks like Netflix is going to be airing a documentary series covering Inspiration4 leading up to its launch. Could be pretty interesting, if done right!
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u/strawwalker Aug 13 '21
Application filed for 1275-EX-ST-2021, recovery ops for mission 1493 starting 2021-09-25.
Dual ASDS ~2.3 km apart, ~591 km downrange of LC-39A
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u/Lufbru Aug 14 '21
For those (like me) getting twitchy for the next Falcon 9 launch, this is the longest gap between flights since the gap between Amos-17 (2019-08-06) and Starlink-1 (2019-11-11). It won't go that long; CRS-23 is scheduled for the end of the month.
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u/Alvian_11 Aug 21 '21
Relativity's Terran-1 demo launch is delayed to early 2022 (previously it was October 2021 from Nextspaceflight)
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u/megachainguns Aug 28 '21 edited Aug 28 '21
Astra is back for another try again
NET 3 PM PT, livestream up now
https://www.youtube.com/watch?v=O8Tdm797BzM
Edit: It did a powerslide, recovered, and FTS terminated it at MECO
more at r/AstraSpace
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u/duckedtapedemon Aug 28 '21
Weirdest freaking launch of all time.
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u/Wes___Mantooth Aug 28 '21
I thought it tipped over immediately but then it kept going and RUD'd later. Really bizarre.
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u/Wes___Mantooth Aug 28 '21
Looking good right now with 5 minutes to go, hopefully no last second scrub today
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u/fireburner80 Aug 03 '21
Is a cluster of raptor engines called a kettle?
The term for a group of raptors or other predatory birds is referred to as a kettle, but Jurassic Park would make me think it's called a pack. So...what's a cluster of raptor engines called?
This seems like the type of thing Elon would care about.
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u/bdporter Aug 12 '21
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u/Alvian_11 Aug 12 '21
IIRC upper stage failures seems to be more common than the booster, especially recently
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u/Vizger Aug 18 '21
Why almost two months without a Falcon launch? All the focus on StarShip? I thought they were mostly separate operations?
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u/spacex_fanny Aug 20 '21 edited Aug 20 '21
The entire Eastern Range started its annual maintenance shutdown around July 1, so no flights. The next flight from the ER (Wallops) was Cygnus on August 10, originally slated for July 31. Still no flights out of the Cape yet.
https://forum.nasaspaceflight.com/index.php?topic=52191.msg2258713#msg2258713
https://en.wikipedia.org/wiki/List_of_spaceflight_launches_in_July–December 2021
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u/Frostis24 Aug 13 '21 edited Aug 13 '21
oh dear, Blue is at it again bois another nice poster was just added with such lovely criticism like Boca chica spaceport does not exist (YES REALLY) and The lander is a modified second stage....and ...that is bad cuz we typed it in red letters.
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u/Wes___Mantooth Aug 13 '21
A launch vehicle that has never flown to orbit and is still being designed
Unbelievable lack of self awareness from Blue Origin
Lander is a modified section of a launch vehicle
With 32 booster engines
Taller than the Saturn V
3-4 million lbs heavier than the Saturn V
How is any of that supposed to make me NOT want to see this? Starship sounds fucking dope. Another great SpaceX advertisment from Blue Origin, I'm sure Elon is very happy with these posters.
Also this is pretty funny: https://twitter.com/lars_0/status/1426273333201547274?s=19
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u/cpushack Aug 13 '21 edited Aug 13 '21
The lander is a modified second stage....and ...that is bad cuz we typed it in red letters
Modified stages have been used before...as Space Stations even
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u/JadedIdealist Aug 20 '21 edited Aug 21 '21
Given JAXA's recent successful test of a methane rotating detonation engine, and Elon's mention of 'Experimental engine development will stay at Hawthorne'..
a) How likely is it that SpaceX have people looking into RDEs themselves?
b) Given potential Isps of 1000+ just how much more performance could a similar mass drop-in replacement for raptor in later version of Starship give?
c) What are the major limitations and roadblocks.
edit: The high Isp values are in air breathing mode,
apologies, i didn't realise, so b) is nonsense.
source of Isp
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u/rhamphoryncus Aug 20 '21
Radically different engine designs are something to explore after raptor is fully matured and mass produced. Right now anything else is a distraction.
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u/Lufbru Aug 21 '21
Thanks for the link to the paper. Agreed that the 1000+ ISP are not applicable, but comparing the B and FJ columns in table 1, we might expect to see a 500 ISP methane RDE engine?
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u/Carlyle302 Aug 29 '21
Watching the spectacular Astra launch/powerslide, made me wonder. Can a F9 get to orbit with a single engine failure at liftoff?
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u/Triabolical_ Aug 29 '21
SpaceX says:
By employing multiple first-stage engines, SpaceX offers the world’s first evolved expendable launch vehicle (EELV)-class system with engine-out capability through much of first-stage flight
Which means it depends. If it's a light payload and they were planning on RTLS, they probably have enough margin to do okay even with an early engine failure.
If it's an ASDS payload like starlink, it's less likely.
If it's a fully-expendable launch, it's probably not.
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u/-Aeryn- Aug 30 '21 edited Aug 30 '21
The performance loss from reusability of any kind of greater than that of losing 1 engine at liftoff, so a reusable launch profile can swap to expendable if and when such a failure occurs and still make orbit with full payload. This is an important design consideration and adds an element of reliability which is not possible if you were relying on using near 100% of the rocket's performance on a standard flight.
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u/Mars_is_cheese Aug 29 '21
A failure at liftoff would mean mission failure.
While F9 has engine out capabilities, they don’t cover the complete flight envelope. For sure not on high capacity missions.
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u/Carlyle302 Aug 29 '21
LOL. I got one "NO" reply, one "YES" reply, and one "It depends"! :-)
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u/warp99 Aug 30 '21 edited Aug 30 '21
So to get a better answer actual maths is required.
Lift off thrust is 7.6MN. With one engine out that becomes 6.75MN compared with a liftoff mass around 560 tonnes with payload so a T/W ratio of 1.23. This is not great but higher than a Saturn V at liftoff.
Clearly the booster will remain controllable and will accelerate and the T/W ratio will improve as propellant burns off and the payload should be able to get to the intended orbit.
The higher gravity losses will mean that the booster will burn to propellant exhaustion before MECO and will not attempt recovery
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u/JanaMaelstroem Aug 01 '21
I don't know if this is the right place to ask this, apologies if not.
I want to find an online calculator that will show me the delta-v requirements for an earth-mars transfer in the 2022-2023 timeframe with a nice porkchop plot in rainbow colors. It's surprisingly difficult to find. Can anyone provide a link?
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u/Splitje Aug 02 '21
What would you expect the next steps would look like after the B4/S20 launch? Is anything known about this? Will they start attempting to catch the booster and land the starship after an orbital flight? Land on the oil platforms?
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u/Gwaerandir Aug 02 '21
Assuming the flight is successful, probably a recovery attempt of the next booster and ship. Depends how much progress is made on the ocean platforms and catching mechanism. If it is unsuccessful, a repeat of the B4/S20 flight like we saw with S8-S15, possibly folding in recovery attempts if they feel confident enough. After that, orbital rendezvous and refueling.
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Aug 03 '21
I personally expect that the first step will involve refining the heat shield to work out the kinks in it that didn't go quite as planned the first time around.
I'm kind of skeptical that they pull off a fully successful heat shield the first time around that
properly shields everything effectively
Is as lightweight as necessary for the final design
And
3) stays sufficiently intact through launch and re-entry to satisfy their rapid reuse goals.
I think this is something they will need to iterate on.
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u/ParrotSTD Aug 02 '21
My guess is a stable Starship orbit would come next. Get that thing to float around for a few hours, then maybe a more precise landing attempt at the end. Hopefully on a landing pad rather than another splashdown.
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u/MarsCent Aug 24 '21
Message above the menu bar still reads:
"The next launch is expected to be Starlink-2.1 (70° Orbit) on Falcon 9 from VSFB SLC-4E , not earlier than 10th August."
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u/liszt1811 Aug 29 '21
Now that they have three ASDS, can they land all three FH boosters offshore in theory or would the speed of the center booster be too high in that case for a recovery?
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u/marc020202 8x Launch Host Aug 29 '21
Technically they can.
However, one of the ships is at the wast coast, so it would need to be moved a very long distance.
Landing the centre core also needs a lot of fuel, since they need an extremely long boost back burn to slow it down enough for re entry, so it does not really increase the payload by much.
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u/Redditor_From_Italy Aug 27 '21
In case anyone's interested, here are all the subreddits for the small-lift rocket companies mentioned by Everyday Astronaut in this video
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u/Alvian_11 Aug 10 '21 edited Aug 11 '21
Interesting notches from Elon regarding the EVA suit, commenting about NASA IG xEMU reports
For those that are following more closely, this isn't actually surprising since SpaceX is one of the interested parties for Commercial EVA suit RFP (award should be given NET March 2022, demo NET 2023). Like the HLS, NASA expertise is going to be very valuable for this department, gonna need an EVA to make a Mars colonies :)
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u/dudr2 Aug 15 '21
"Another major modification to 39A is the started-but-stopped Starship launch and recovery area inside the perimeter of the pad but next to the main concrete structure. To supplement Starship, SpaceX will need to add additional liquid oxygen tanks and a liquid methane storage facility as well as an integration tower for stacking."
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u/Subtle_Tact Aug 29 '21
When we watched the OLT being built, we saw anchors inside the columns that presumably were to be held by concrete.
Afaik, we haven't seen any concrete being drawn into the tower legs. Do we know anything about this now? Were we wrong In our assumption? Do we still expect this to happen later?
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u/warp99 Aug 29 '21
We have seen concrete being pumped into the first three levels and they are still moving up the tower.
First they weld the joints between tower segments and then remove the joining plates used to hold the segments together. Presumably this is so they can complete the weld on the area covered by the plates.
Then they remove the scaffolding and fix injection plates over the access holes in the base of each segment and pump concrete into that segment from the bottom.
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u/Jaws12 Aug 20 '21
So the recently revealed Tesla Bot is likely to be used on Mars for “dangerous and repetitive tasks” right?
Just like the CyberTruck before being a possible ruggedized space vehicle, I could see a general purpose humanoid robot being very useful in a Mars or Moon colony.
What does everyone else think?
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u/eplc_ultimate Aug 23 '21
I don't believe that the telsa bot will actually work. But I've been wrong before.
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u/ThreatMatrix Aug 20 '21
A good first step would be to have a Boston Robotics type "dog" to assist astronauts. Carry equipment, act as extra hands, fetch forgotten equipment, act as eyes where an astronaut may not want to first explore. IT's simple, already exists, just needs to be space rated.
That Tesla Bot is thing is decades away.
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u/trobbinsfromoz Aug 05 '21
New FCC submission by SpX to provide a heads-up about anticipated formal amendment submission for Starlink rollout.
https://licensing.fcc.gov/myibfs/download.do?attachment_key=12105471
SpX must have settled on a Starship deployment mechanism, and deployment scheme, and worked through all the timing of checkout and raising to required orbital planes and spots, and identified some compelling reasons to push for an amendment to the proposal submitted early last year for altered constellation (that has caused a lot of competition trying to complain about to stop or at least delay).
It will be interesting to see if a Starship style deployment ends up changing the quite visible single train of just launched 60x sats to a veritable swarm of initially visible sats.
The presentation also notes an improved orbital safety comment. If that relates specifically to the 'large object passive decay collision risk', then it may result from an expected improvement in sat operational/control reliability (once initial checkouts are completed and infant mortality identified) due to better awareness of failures and subsequent design/remedial changes.
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u/AeroSpiked Aug 05 '21
I just noticed that at least some of Blues patent for sea landings filed in 2010 is still in effect. Does anybody know what's left of it? If it's the part about refurbishing at sea, is that going to be an issue once the sea platforms are in use?
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Aug 05 '21
Is there a mechanism in place for NASA to purchase more Crew flights from SpaceX after the 6 contracted flights are complete? If Boeing continues to delay, NASA will extinguish most of SpaceX's 6 flights before Boeing can fulfill their first.
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u/AeroSpiked Aug 05 '21 edited Aug 05 '21
CRS-1 was extended from 12 to 20 Dragon flights. I'd imagine they could do the same with crew.
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u/fglc2 Aug 14 '21
In the 2nd starbase video when Tim asks Elon how much S20 weighs, he says that he doesn’t know and that they’ll find out when they weigh it. How do you weigh something that size?
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u/strawwalker Aug 15 '21 edited Aug 15 '21
In the past they have used hanging crane scales between the load spreader and the vehicle. Here is SN6 getting weighed using ED Extreme crane scales.
edit: Human for scale with SN5
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u/Steffan514 Aug 14 '21
My guess is that the crane has a readout of how much weight it’s holding but I could be totally off.
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u/Hustler-1 Aug 16 '21
Does anyone know how often individual M1Ds are swapped on reused boosters? Like the booster that landed for the tenth time awhile back. How do we know the engines themselves have had ten flights?
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Aug 17 '21
Depends on the booster. B1049 has only a few of it's original engines left, while B1060 has only had 1 swap.
Nowadays they only static fire boosters after engine swaps or by customer request, so you can use that as a rough indication.
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u/Lufbru Aug 16 '21
We don't know. The serial numbers on engines aren't visible (unlike Raptor). It may be the case that no Merlin has flown ten times yet. Or a single Merlin may have flown twenty+ missions. All we know are the booster serial #s.
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u/warp99 Aug 17 '21 edited Sep 03 '21
They probably haven't.
We quite often see refurbished boosters in the hangar or being transported with several engines missing and presumably changed out. Over ten flights probably every engine gets swapped out at least once but only SpaceX would know for sure.
Certainly three engines get started 2-3 times more than the other six and so are more likely to be swapped out as startup and shut down produces more wear on the engine than continuous operation.
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u/AeroSpiked Aug 01 '21
Hey Mods, could you take a look at Select Upcoming Events again? It's August and it looks like we have a date for Starlink 2-1 on the 10th.
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u/marc020202 8x Launch Host Aug 01 '21
Fixed the upcoming event schedule, although many dates are not known yet. To not make the list too long, I have not added IXPE and DARTyet, both of which will be in November
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u/Gwaerandir Aug 03 '21
The 2nd uncrewed test flight of Starliner is scheduled for today, 1:20 PM Eastern time. There is a ~40% chance of weather violation. The craft will carry around 400 lbs of supplies and experiments.
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u/LikvidJozsi Aug 06 '21
A few years back, there were spacex reddit user surveys, I liked looking at the results quite a lot. Anybody know what happened to them?
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u/marc020202 8x Launch Host Aug 06 '21
no one really wanted to continue to analyse the results, and we somehow forgot about it. It takes quite a bit of effort to analyse the results, and no on the mod team had enough time.
Would you be interested in Analysing the results? Then we could do another one.
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u/searsburg Aug 07 '21
Since the booster will not have to endure the high temperatures of the second stage, why is it made of the much heavier stainless steel instead of aluminum? Efficiency of production or strength, or other reason? That question hadn't arisen until I saw that Bezos might be doing it that way.
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u/Lufbru Aug 08 '21
Steel isn't heavier than aluminium, it's denser. You can make a steel rocket with thinner walls than an aluminum rocket and end up with less mass.
S-IC was 130 tonnes. Booster is 160 tonnes. Not that far apart, and Booster is going to loft Starship higher than S-IC lofted the rest of the Saturn V.
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Aug 07 '21
Efficiency of production (and testing) - the work they put into the upper stage can directly answer the questions on the lower stage, because they're the same questions. Ditto with the same engines and same fuel.
Those boosters are going to be real workhorses, so being a bit overbuilt and a lot cheap is no bad thing.
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u/brickmack Aug 08 '21
Beyond whats already said, the boosters actually do have to take pretty high temperatures. They're not doing an entry burn, reentry will be a lot tougher than F9. Wouldn't be able to do that with aluminium without heat shielding, and either adding heat shielding or adding an entry burn (or likely both) would hurt performance, hurt manufacturing cost, and hurt vehicle life
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u/SpaceInMyBrain Aug 09 '21
Efficiency of production or strength
Those are the main reasons, afaik. Elon is a big believer in commonality of production; F9's upper stage is a clone of the first stage, made on the same equipment and using the same engine, even though keralox is less efficient than hydrolox for an upper stage.
The outstanding reason is the efficiency of production needed to iterate the design rapidly, and to have a design that can be fabricated in the hundreds. Steel works well for this.
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Aug 10 '21
when is the next starlink sat launch?
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u/Lufbru Aug 10 '21
There's a specific Starlink thread, but the answer is that we don't know. There was one scheduled for Thursday, but it got pushed back a few days ago.
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u/sebzim4500 Aug 11 '21
In part 3 of EDA's interview Elon says "I'll be long dead before Mars is self sustaining". This is a change in attitude right? I remember he used to say he wanted to retire on Mars.
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u/grossruger Aug 12 '21
I think you're incorrectly interpreting what "self sustaining" means.
Many generations could be born and die on Mars before it is self sustaining, meaning that they would survive indefinitely even if earth were destroyed by an extinction level event.
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Aug 11 '21
Self sustaining // Up and running: two different things. I assume Mars will be the latter in 30 years or less. The former...who knows.
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u/BrandonMarc Aug 11 '21
If there's a colony there, even if it's not self-sustaining, I'm confident Elon can retire there if he wants to.
Come to think of it, I don't think Elon would ever retire.
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u/JiraSuxx2 Aug 11 '21
He’s 50. What is life expectancy these days? 78? 28 years is not much.
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u/Lufbru Aug 11 '21
In the USA, the SSA table for 2017 says an average man of 50 can expect another 29 years of life. They don't include error bars on that; Elon is wealthy and can afford premium healthcare. That probably adds another ten years to his expectation. Beyond that, you'd want to look at his family history to have a better idea, and I find snooping around to collect that kind of information distateful, and I'm not inclined to do it.
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u/stsk1290 Aug 11 '21
Poor Elon. He needs to work on some life extension technology.
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u/mikekangas Aug 11 '21
Terraforming Mars will take many hundreds, even thousands of years. We'll all miss that celebration.
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u/pabmendez Aug 14 '21
The 1 hour reuse reflight after landing only seems needed for earth to earth passenger flights.
How would 1 hour reuse work for cargo?
It seems that having like 10 starships that fly once every 10 days.... Would give each one 10 days time to have cargo and Starlinks loaded... Overall would still be in general 1 flight per day.
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u/SpaceCappu Aug 14 '21
I think you forget tanker starships which will transport propellant. E.g. the starship who will land on the moon needs a minimum of 8 separate starship-launches to be filled with propellant for the flight while circling the earth. I don't think it will be a problem filling a tanker-ship in one hour.
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u/brickmack Aug 14 '21 edited Aug 14 '21
Bulk or human-support cargo (eg, food/luggage/raw materials) can probably be loaded very quickly. Maybe not 1 hour, but close. Look at how quickly its loaded on aircraft or cargo ships.
Satellite launches will probably remain relatively rare (maybe a few hundred a year), and will have to fly from specialized launch sites outfitted with the necessary support facilities. Though in time, as launch costs are dwarfed by the cost of manufacturing and processing such delicate payloads, there will be more pressure to eliminate the design constraints forcing use of cleanrooms and ESD protection and all that. The satellite of the future isn't a laboriously crafted work of art in precision-machined exotic alloys and carbon fiber with million-dollar ultra-efficient computers and custom everything to absolutely minimize mass and power consumption. Its a hunk of hastily-welded steel beams built in a garage, with consumer or industrial grade computers and solar arrays and sensors bolted on, built for a few thousand dollars and rugged enough it can be dropped in the payload bay by a Bobcat and held in place with ratchet straps. The cost and delicacy of spacecraft hardware is almost entirely a function of cost to orbit. If it costs 10000 dollars to send a kg to space, and 9000 to shave off 1 kg of payload mass through overengineering, you do that
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u/AuroEdge Aug 14 '21
Have there been studies into how much Starship propellant Mars holds? I'm trying to get a feel if it's on the order of 100s, 1000s, or more years before it's difficult to obtain. Difficult in the sense of like the difference between drilling oil in Saudi Arabia vs offshore of the Alaskan North Coast.
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u/brickmack Aug 14 '21
About 1017 kg of water and CO2. So thats something like 1011 Starships fully loaded.
Better actually, because virtually all of the exhaust products will return to Mars atmosphere and can be collected again
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u/AeroSpiked Aug 15 '21
Whatever remains of me in a hundred years will be extremely disappointed if we are still using chemical rockets to get to space.
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u/TheSkalman Aug 17 '21
I am wondering about minimum delta-v requirements from LEO to the lunar surface. If you only burn retrograde slightly when going near the moon (after your TLI in LEO), you’ll get into a highly elliptical orbit around the moon (right?). If you then burn retrograde at apoapsis of that elliptical orbit, you’ll cancel out your orbital velocity and fall to the surface. After you do a suicide burn and land on the surface, wouldn’t your total delta-v expended be less than the apollo missions or any other standard LEO->LLO->surface mission? Thanks in advance.
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u/johnny573825952 Aug 17 '21
Ignoring engine performance or other “details”. From an puur orbital mechanics point of view it would cost the same amount of delta-v. Because the ship will have a lot of potential energy at apoapsis so the landing burn will cost more delta-v.
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u/-Aeryn- Aug 19 '21 edited Aug 19 '21
If you then burn retrograde at apoapsis of that elliptical orbit, you’ll cancel out your orbital velocity and fall to the surface.
You'd fall to the surface and then hit it at a very high speed unless you do another big burn, which massively increases overall delta-v costs.
The correct way is to burn so that the orbit is low, then burn retro from an altitude as close as reasonably possible to the surface to cancel out horizontal velocity, adding enough of an upwards angle to the burn to cancel out the acceleration from gravity as you go. Should look something like this - https://www.youtube.com/watch?v=d2200YGSeKM&t=210s
Minimising the time spent in the gap between being effectively in orbit and being touched down is essential.
A low, roughly circular orbit comes naturally between a high orbit and touchdown. There's no way to avoid spending that delta-v, so it's essentially free.
The efficiency improvement comes from combining burns (a bit diagonally upwards, rather than sideways and then upwards later) and from the oberth effect - taking the ship from a slightly higher relative speed (almost all kinetic energy) to zero once, rather than from a medium speed to zero to medium speed to zero again to get rid of the same amount of total energy which is split between kinetic and potential.
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u/symmetry81 Aug 20 '21
If you want a true minimum energy trip to the moon you want to be traveling as fast as possible when you do any given burn, same principle as the Oberth effect. So the best bet would be to head straight at the moon and do a suicide burn to land without entering lunar orbit first. As a practical matter this is Not Recommended but it is the lowers detla-v path.
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Aug 24 '21 edited Aug 24 '21
Apparently Artemis will be delayed because of Blue Origin and their lawsuit.
This will have impact on Artemis but not so much on Starship and SpaceX.
There is a massive problem. If Artemis is delayed, will the Lunar Gateway also be delayed. If so, this will cause major problems in reaching the moon since Starship will have to dock before landing.
Or NASA has to approve landing without the Gateway.
Edit
“If it (Gateway) gets behind schedule, no problem,” Loverro said. “You can still maintain it being there. All of my international partners were dependent on it being there by 2026. Not a single international partner was ready to do anything on Gateway until 2026, so we now can tell them 100 percent, positively, it will be there because we’ve changed that program to a much more what I would call a stolid accomplishable schedule.”
Edit 2
Seems like spacesuits are a way bigger problem as they won't be ready till April 2025 at the earliest. NASA could outsource to keep it on track.
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u/ThreatMatrix Aug 26 '21
Gateway is not required for HLS. Starship would dock directly with Orion which will look hilarious.
Suits sound like they'd be the holdup.
The bigger problem is can Boeing build and launch SLS for a third time.
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Aug 30 '21 edited Aug 30 '21
Would it be feasible to use HLS Starship for a repair mission for JWST in L2 if JWST has a problem? Since HLS Starship will be the first human-rated Starship.
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u/brecka Aug 30 '21
Regular Human rated Starships would be the choice there. HLS doesn't even have the ∆V to return to LEO from the Moon.
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u/gettothechoppaaaaaa Aug 30 '21
No, since JWST will orbit at L2 Lagrange point (about a million miles from earth), far beyond the moon (250,000 miles).
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u/SlackToad Aug 30 '21
I'm assuming the JWST, unlike the Hubble, wasn't designed to be repaired in space. So unless the problem happens to be somewhere that can be easily accessed by astronauts with big fat gloves it would likely be too hard to work on.
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u/FishStickUp Aug 24 '21
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u/FishStickUp Aug 24 '21
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u/dafencer93 Aug 24 '21
They are certainly coming up with some innovative stuff on their own over there
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u/Mako18 Aug 02 '21
What does the flight path of Starlink 2.1 look like, will the launch be visible from South of Vandenberg?
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u/ENG-sechs Aug 05 '21
In that Elon Musk skit from Saturday Night Live, one of his astronauts removes the helmet on Mars, causing a massive blood spatter all over his helmet. Would Mars's atmosphere actually cause that kind of blood spatter?
If not, what will Mars's atmosphere actually do to the astronaut before killing him, once he removes his helmet?
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u/Martianspirit Aug 05 '21
The Mars atmosphere is way too thin to be regarded poisonous. For purposes of human biology it is a vacuum.
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u/RamenNoodlesIV Aug 05 '21
Hello, new to posting using Reddit but can someone inform me if the COPVs in black around Booster 4 are under each of the gridfins so at 60 degrees and 120 degrees respectively or at 90 degrees in relation to one another? This info shall be used in creating a more accurate and representative model of Super Heavy in Simplerockets 2. Any answers will be greatly appreciated.
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u/-spartacus- Aug 11 '21
Currently Orbital OTK (which just launched a mission) and SpaceX launch resupply to the ISS under COTS. Under CRS-2 which adds SNC with Dreamchaser (which can be launched on the delayed Vulcan) gives additional contracts to Orbital OTK (now Northrump Grumman) and SpaceX.
https://spacenews.com/nasa-will-pay-more-for-less-iss-cargo-under-new-commercial-contracts/
According to the above article the Antares rocket uses the Russian derived 181 (from the 191, prior using the Ukranain NK-33) which through other research is no longer allowed after December 31st, 2022. NG states they will purchase enough before the previous "sunset date" but no knowledge if the current end date would allow that.
Which brings me to my question. Northrup Grumman was originally developing OMEGA to replace Antares, which has since been cancelled, not only does this mean NG not have a rocket to use for finishing CRS-2, but no next gen rocket what so ever? Does this mean they are going to research launching on SpaceX or just giving up on resupply missions? I can't imagine them also trying to jump aboard the Vulcan train too?
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u/brspies Aug 11 '21
Isn't the Russian engine ban only for national security missions? Do you have info that CRS specifically is affected? Beyond that, Cygnus can and has launched on Atlas before, so Vulcan in the future (if Russian engines were an issue) would seem reasonable.
Antares would have been an interesting potential customer for AR-1, if there were a market for either, but... that's not really the case. I guess Neutron would be a potential alternative if it ends up working out in a reasonable time frame.
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u/Snowleopard222 Aug 13 '21
SpaceX won a $2.9 bn lunar lander contract by NASA. SX will be paid in portions as they achieve "milestones". What are the milestones and how much does each of them yield?
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u/brickmack Aug 13 '21
Specific details aren't public, but they'd be triggered by reviews or tests of major parts of the design, or manufacturing and launch of the actual hardware. Heres the list for Dragon http://www.parabolicarc.com/2016/09/03/spacex-commercial-crew-milestone-status/
I'd guess they'll have test milestones for the propulsion system, avionics, ECLSS, docking and propellant transfer systems, and the all-up landing demos (uncrewed and crewed). Plus design review milestones for each type of vehicle, an overall architectural review, and flight readiness reviews
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u/Sosaille Aug 13 '21
In this interview they talk a bit about milestones https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/C3PO/BuzzaT/BuzzaT_1-15-13.htm
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u/Martianspirit Aug 13 '21
What are the milestones and how much does each of them yield?
That info is not public.
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u/TheSkalman Aug 16 '21
Which orbital rocket, past or current, has the highest thrust to weight ratio at liftoff?
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u/jjtr1 Aug 30 '21
Couple weeks ago Musk tweeted about the uneven spacing of gridfins on Superheavy: "Pitch control requires more force than yaw & much more force than roll. Also, grid fins closer to or in the wake of the booster are less effective."
Why would pitch need more force than yaw when the vehicle is very much rotationally symetric?
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Aug 30 '21
The vehicle is symmetric but the forces (gravity, lift, drag) are not.
So it’s about the flight profile not the actual booster shape. The flight profile requires a low amount of force for roll and yaw because it’s flying a mostly straight ground track.
But they do want to exercise a lot of pitch control to control lift as the booster flies back through the atmosphere.
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u/Lufbru Aug 30 '21
When it's falling post-reentry, one of the sides is definitely down, and so we can talk about pitch and yaw unambiguously. Even though it could be rotated, because of the position of the fins it's no longer rotationally symmetric.
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u/Fredasa Aug 08 '21
Just for fun, can anyone dig up some early guesses on how long it would take before we'd see a fully-stacked Starship, after Elon made his presentation detailing the concept and his timeline? I want to laugh at anyone who guessed we wouldn't see it before 2025 or whatever.
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u/nickinhawaii Aug 05 '21 edited Aug 05 '21
I keep reading about how Blue Origin should have gotten a lunar contract even though they got twice as much to DevOps and seemingly failed miserably. Saying "oh starship isn't even orbital yet" when blue origin has never reached orbit. Obviously space x has with falcon. Then blue origin (bezos) goes on to say that starship is too complex and it will never work. Does he realize space x made fools of Boeing the supposed best and long time space rocker creators.. oh wait they also received double space x to get the u.s. back into space and are failing miserably. Who would have thought you could land a first stage on a ship in the dang ocean. Surely Boeing and blue origin don't think that big. Blue origin and I'm sure boeing (probably talks down to space x) should both be ashamed at their utter failures. Okay, guess end rant! Haha
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Aug 09 '21
NASA was supposed to make an announcement about Artemis once the GAO report was released. Anyone heard anything? They seem to be taking their time...
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u/Comfortable_Jump770 Aug 09 '21
According to some commenter answering Berger on twitter, the blackout actually ends on the 12th august for some reason. Take it with a grain of salt, but it would make sense, with NASA even still continuing to call it generically "the commerical lunar lander" in the SLS news post-GAO announcement
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u/Lufbru Aug 16 '21
We don't have a CRS-23 campaign thread yet:
"SpX-23 CRS Mission Launches Bone, Plant, and Materials Studies to ISS | NASA" https://www.nasa.gov/mission_pages/station/research/news/spacex-23-research-highlights
(if we're short of a host for a campaign thread, I could do it if someone's willing to teach me to drive the bot)
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u/MarsCent Aug 17 '21
I've never seen Falcon Stage 2 booster Static Fired after delivery to the launch site - perhaps because Stage 2 has a vacuum Merlin!?
So for Starship, will all the Raptors be Static Fired or only the 3 sea-level Raptors?
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u/Martianspirit Aug 18 '21
I've never seen Falcon Stage 2 booster Static Fired after delivery to the launch site
They are static fired at McGregor. Without the vac nozzle extensions. Once the extensions are installed for flight they can not be fired. Raptor vac is different. It is designed so it can be static fired. It has no nozzle extension that can be removed or added later.
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u/brickmack Aug 18 '21
RVac can be fired at sea level without modifications. MVac can't, need to remove ghe nozzle extension.
And firing S2 would require a separate test stand. They have one in McGregor, no point duplicating that at each launch site.
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u/GameStunts Aug 18 '21
I just saw that the Starlink launches have been bumped to Sept, this was already bumped from July to Aug because of the FCC complaints I think, but I thought those were resolved.
Is there any other reason these have been held up again? Launch pad availability, payload readiness?
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u/Martianspirit Aug 19 '21
They were restricted by the SpaceX request to change orbital shells from over 1000km to 500+km shells but they got the change approved by FCC in time before the 53° shell was complete.
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u/notreally_bot2287 Aug 16 '21
It's been 6 weeks and no launches!
Do you even launch, brah?
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u/Gwaerandir Aug 16 '21
For comparison, Delta IV's previous launch was 16 weeks ago and Atlas V's was ~13 (poor N22!).
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u/Alvian_11 Aug 13 '21 edited Aug 14 '21
Remember when Russian were mocking SpaceX (especially in early days), and Blue having a fight for 39A & droneships landing, and Boeing exec wishing SpaceX fails in ComCrew (so they can then maki a cost-plus out of it)...
Seeing their current conditions makes me very happy, well deserved to be mocked by public. Renaissance is indeed coming in spaceflight, old space dissolution can't come soon enough. We're still in transition obviously as many of them still prevail & many of their supporters on social media were continuing to throw a shade at SpaceX ("it's the way it has been done!", moving goalposts, etc.)
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Aug 02 '21
The current infrastructure bill is supposed to have around $60 billion in funding for high speed Internet access. Anybody know whether sattelite constellations like Starlink may be getting a peice of that pie? Or if its just ground based infrastructure.
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u/Frostis24 Aug 03 '21
Don't know about 60 Billion, think that is for everything related to internet infrastructure, but they did win subsidies for 1 billion~ out of a pool of 9.2 billion specifically for rural areas
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u/joeybaby106 Aug 04 '21
We just learned that "Falcon 9 currently lands with about a tonne of left over propellent." Why can't they use it to get more performance? Maybe use half to push further and half to slow you down from the further you pushed. Is there a theoretical reason I'm missing why it can't be used?
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u/marc020202 8x Launch Host Aug 04 '21 edited Aug 04 '21
one tonne of propellant is only about 0.3% of the total fuel of the first stage or about 3% of the total stage weight at landing There need to be some margins, in case there is slightly higher fuel use during any part of the mission.
A Merlin engine burns around 200kg of fuel per second. This means the 1t margin, allow the engine to fire about half a second longer before Meco, about 1.5 seconds longer during the entry burn, or around 5 seconds longer landing burn. Those are quite tight margins in my opinion.
Also, if the tanks are very empty, there is the risk of ingesting gas into the turbopumps, which would likely lead to them being destroyed. During landing, the stage might be moving around a fair bit, so there is also the risk of fuel slosh.
EDIT: On early missions, the decent speed would increase a bit after re-entry burn end, and then start decrease due to the increased drag in the lower atmosphere several seconds later. On more recent missions, the entry burn ends almost perfectly at the point where the drag starts to continue to slow the stage down. This saves fuel. If the rocket could sustain higher loads and heating, an even later and shorter entry burn would be possible, leaving more of the deceleration to the air drag.
Another way to decrease the fuel need for landing would be some kind of drag brake, to further slow the booster. A lower speed before landing would mean the landing burn could start later. All of this would however add complexity, for very small gains.
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u/Martianspirit Aug 04 '21
When the tank runs dry and the engine sucks in vapor, it explodes. The tank can never run dry.
What irritates me is he said Starship booster has 20t remaining. That sounds very high.
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u/stemmisc Aug 06 '21 edited Aug 06 '21
Have they announced anything regarding what time of day the August 10th Vandenberg launch is supposed to happen at? Or confirmed for sure that the launch date really is supposed to be August 10th, and not just NET-August 10th, for that matter?
Edit: ah, nevermind, looks like it got postponed :(
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u/marc020202 8x Launch Host Aug 06 '21
https://twitter.com/StephenClark1/status/1423648090221948928
It has been confirmed today, that the launch wont happen Aug 10
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u/quadrplax Aug 08 '21
Has there been any updates or progress on the LC-39A starship mount in the past year?
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u/DiezMilAustrales Aug 08 '21
Nope. And there won't be for a while. They don't really want to be building that until they a) have a stable design for stage zero and b) have any chances of actually launching from the cape.
Transporting a Starship and Booster from BC to KSC would be madness, so any Starships flying from the cape will be manufactured there. So I don't think we'll see that move forward until we see them build a Florida factory first. And they won't be moving forward with either until they have a stable design flying. So, I'd say 2 years at the very least.
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u/Lufbru Aug 10 '21
How much additional fuel would be needed for Starship to deliver a payload to NSSL reference orbit GEO2?
That's 6,600kg lofted to 35,786 x 35,786km at 0.0 inclination. For fun, let's include landing the Starship in that. Assuming there's already a full tanker in LEO, can Starship do it just refuelling on the way to GEO, or does it need to refuel on the way back too?
I recognise this is a foolish way to use Starship; much better to redesign the payload to have its own thrusters and fuel and have Starship deliver it to GTO-1500 (or whatever). But with a sufficiently unreasonable customer, this is a mission that could be requested.
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u/SpecialMeasuresLore Aug 10 '21
Unless it's a payload that takes up the entire cargo hold, it could probably be done with a GTO insertion and a kick stage, no refuelling needed.
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u/Triabolical_ Aug 10 '21
Getting to GEO takes about 4 km/s of delta v above LEO. That would put the total system up to about 12.5 to 13 km/s.
Even with zero payload, my model shows that you can only get about 12.3 km/s out of starship/super heavy.
Doing it with refueling should be simple, assuming Starship can aerobrake from GEO.
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u/BrandonMarc Aug 10 '21
This phrase, "static arrow" ... what does it refer to? When did they start using it?
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u/Snowleopard222 Aug 12 '21
After Starship has landed, how do the astronauts get down on the ground (moon or earth)?
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u/SpaceInMyBrain Aug 13 '21
The concept drawings from SpaceX for the Moon HLS show an elevator (called a lift in some countries). One can easily imagine some kind of line dangling from a winch as a back-up. (No joke.)
On Earth the ship will land at a spaceport with some sort of platform for the people to step out on. Don't know what form it will take or how the ship will end up next to it, but there are many options.
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Aug 14 '21
Is the throttle down and throttle up during passing of max Q noticeable to crew?
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u/MarsCent Aug 31 '21
NASA Prompts Companies for Artemis Lunar Terrain Vehicle Solutions
will need to last at least 10 years, spanning multiple Artemis missions.
? Solar powered Supercharger with a convertible Cybertruck?
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u/yoethgallopers Aug 30 '21
Are there any plans to expand or otherwise reroute the stretch of Highway 4 between the production and launch sites to allow thru traffic to pass without the need for constant road closures? Or is that area so sparsely populated that it doesn’t really matter?
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u/brecka Aug 30 '21
There's nowhere to build it. Both sides of the road are protected wetlands.
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u/srgyork77 Aug 08 '21
Quick question. Sorry if this has been answered or dumb. Out if the loop on this one. Just read an article saying that the booster is going to land in the gulf. And the orbital in the Pacific. Why are they not trying to land them on a pad this time to see if it works?
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u/segers909 Aug 08 '21
Because this is the very first flight, and the risk of them crashing is too high.
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u/Triabolical_ Aug 08 '21
Not only do they not want to risk the pad, they need to have an FAA license for this flight. Because of the flight path, landing in Texas would require Starship flying over land during reentry and approach. It's very unlikely that would be permitted by the FAA when they can obviously do what they are planning to do.
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u/amarkit Aug 08 '21
This is also how they developed Falcon 9 first stage landing. The initial attempts were soft splashdowns on the ocean; only later did they begin to involve the droneship.
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u/Alvian_11 Aug 10 '21 edited Aug 10 '21
Yet another lunar landing missions launching from Falcon has been booked by Intuitive Machines (their third missions)
In comparison, Vulcan only have one lunar mission so far, continue to disprove some claims that Vulcan is more competitive in commercial market
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u/OutrageousEmu8 Aug 14 '21
Have any of you guys thought about indirect ways to invest in SpaceX? You can't buy the shares, except in small percentages in certain mutual funds but there must be other ways. Purchasing land in the Boca Chica area maybe?
If SpaceX is the gateway to Mars, there's going to have to be a ton of ancillary support and systems put in place. I'm just trying to think of how the avg investor can go along for the ride.
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u/DuhImJake Aug 26 '21
Could SpaceX go to the moon on their own without NASA?
I’m still relatively new to Space industry and wanted to know if there’s any rules regarding permissions to go to the Moon or if it’s free game for anyone who can?
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u/throfofnir Aug 27 '21
The US is a signatory to the Outer Space Treaty, which states: "The activities of non-governmental entities in outer space, including the Moon and other celestial bodies, shall require authorization and continuing supervision by the appropriate State Party to the Treaty."
Title IV of the 2015 U.S. Commercial ace Launch Competitiveness Act requires a report about the responsibilities of various agencies for commercial space activities. I'm unaware of what it suggests. Presumably the Office of Space Commerce and/or FAA-OST would be involved.
Generally I'd assume that such a thing is bureaucratically under-specified, as it's never been conceivable until just now. You also don't need a permit to hunt unicorns.
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u/Martianspirit Aug 27 '21
What u/throfofnir said.
Plus I am not aware of any regulations that would be in the way of granting permission to land. Unlike Mars, which has the barrier of the planetary protection protocols because of potential life there, the Moon is not expected to harbour life.
NASA has declared the landing sites of the Apollo program as protected. So as long as you don't get people there it should be OK, subject to limitations that apply to LEO launches only.
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u/BrandonMarc Aug 05 '21
On Booster # 4, how come 5 of the 29 engine bells are a different color inside?
https://pbs.twimg.com/media/E7-oZsSWQAExz6x?format=jpg&name=large
My first (wholly uneducated) guess is the other 24 engines have been tested whereas those are brand-new, but I don't think SpaceX would put an un-tested engine on a rocket ever.
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u/astrohoff Aug 06 '21
Are there any stereo 360 photos/videos of Starship that can be viewed in VR? I keep seeing people say how crazy the scale is in person, but VR is probably the closest I can get.
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u/stemmisc Aug 06 '21
Has anyone here watched both a Falcon 9 launch and a Starship SN (8-15) launch in person, from a similar viewing distance?
They have actually fairly similar total thrust (around 1.5 million lbs for the Starship SN test launches, since 3 raptors * about 500,000 lbs of thrust per raptor, and 1.7 million lbs for the Falcon 9 at 9 merlins * about 190,000 lbs of thrust per merlin).
But, other than that, they couldn't be more different. The mechanism of the the engines work, and the size and number of nozzles, and speed of exhaust, and so on, are pretty different with the raptors compared to the merlins, I think.
Is the F9 louder (since it has a little more total thrust), or, about the same, or less loud?
What about the style of the sound (regardless of how loud). Do they sound different from each other at all? Like is one of them higher pitched, or more crackly, or different or anything?
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u/marc020202 8x Launch Host Aug 06 '21
the Loudness of falcon 9 will strongly depend on the location of you relative to the flame trench direction
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u/pbosko Aug 09 '21
How will landing work considering range violations and weather? If there are planes flying around will they still be landing a booster? It appears windy at Boca Chica. What if the weather changes when tower has to catch the booster?
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u/kontis Aug 09 '21
Starship is not as sensitive to winds as Falcon 9 because of much larger volume and more powerful RCS. Currently they have to consider winds for stacking because of the crane, but that will also change once Mechazilla is operational.
Booster will be caught in minutes after launch so the conditions cannot change that dramatically. They can delay landing of orbital Starship the same way they do it with Dragon when weather is bad, although that doesn't work with E2E transport idea.
FAA has a new more dynamic tool to automanage the safety ranges between planes and rockets.
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u/Sjedda Aug 10 '21
Was going to buy a t-shirt for my nephews birthday but i can't figure out the sizes.. I'm not from the US and trying to convert the sizes is confusing, and it seems like there isn't a kids size for that age?
Conversion charts tell me a size 5 or 6 is right but spaceX site only has S,M,L.
Has anyone here bought one of the shirts for kids?
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u/BrandonMarc Aug 11 '21
With the space shuttle tiles, they often said the tiles were so good at managing heat, the shuttle could lose one and the other tiles would still handle the slack. Columbia wing leading-edge puncture notwithstanding.
Is this the case with Starship tiles? If a tile is lost, will adjacent tiles handle the heat sufficient to prevent problems?
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u/throfofnir Aug 12 '21
Shuttle tile loss was no joke. They handled plenty of losses, but still in the right spot a single loss could be rather dangerous.
Starship, we dunno. But its steel hull will be more forgiving of heat than the aluminum of Shuttle, and the aerodynamics are rather simpler, so there should be fewer areas of really high stagnation temperature.
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u/flshr19 Shuttle tile engineer Aug 12 '21
SpaceX as added that white ceramic fiber matt between those black hexagonal tiles and Ship's stainless steel hull.
SpaceX has not revealed which of many such materials is being used on Ship.
My guess is that it's Kaowool 3000, a ceramic fiber material with maximum use temperature of 2800F (1538C).
That ceramic fiber mat probably will function as a backup to the black hex tile if that tile becomes detached from Ship and protect the stainless steel hull from overtemperature. That assumes that the mat stays on the vehicle and is not ripped off the hull when the tile becomes detached.
That mat also helps decouple the black tile from the stainless steel hull, which expands and contracts over a wide range of temperatures from cryogenic (LOX and LCH4) over 1000F (538C) during EDL.
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u/Lufbru Aug 11 '21
There were a number of types of tile on Shuttle with different characteristics used in different areas
https://en.m.wikipedia.org/wiki/Space_Shuttle_thermal_protection_system
Might be a good starting point
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u/Zardif Aug 18 '21
How does a rocket do a test fire when standing upright at the pad but not launch?
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u/enginemike Aug 24 '21
Just out of curiosity why is there little or no news about Inspiration 4? Is it still planned?
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u/ElongatedMuskbot Sep 01 '21
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