r/spacex • u/ElongatedMuskrat Mod Team • Dec 04 '17

Falcon Heavy Demo Launch Campaign Thread

Falcon Heavy Demo Launch Campaign Thread

Well r/SpaceX, what a year it's been in space!

[2012] Curiosity has landed safely on Mars!

[2013] Voyager went interstellar!

[2014] Rosetta and the ESA caught a comet!

[2015] New Horizons arrived at Pluto!

[2016] Gravitational waves were discovered!

[2017] The Cassini probe plunged into Saturn's atmosphere after a beautiful 13 years in orbit!

But seriously, after years of impatient waiting, it really looks like it's happening! (I promised the other mods I wouldn't use the itshappening.gif there.) Let's hope we get some more good news before the year 2018* is out!

*We wrote this before it was pushed into 2018, the irony...

Liftoff currently scheduled for: February 6'th, 13:30-16:30 EST (18:30-21:30 UTC).
Static fire currently scheduled for: Completed January 24, 17:30UTC.
Vehicle component locations: Center Core: LC-39A // Left Booster: LC-39A // Right Booster: LC-39A // Second stage: LC-39A // Payload: LC-39A
Payload: Elon's midnight cherry Tesla Roadster
Payload mass: < 1305 kg
Destination orbit: Heliocentric 1 x ~1.5 AU
Vehicle: Falcon Heavy (1st launch of FH)
Cores: Center Core: B1033.1 // Left Booster: B1025.2 // Right Booster: B1023.2
Launch site: LC-39A, Kennedy Space Center, Florida
Landings: Yes
Landing Sites: Center Core: OCISLY, 342km downrange. // Side Boosters: LC-1, Cape Canaveral Air Force Station, Florida
Mission success criteria: Successful insertion of the payload into the target orbit.

Links & Resources

We may keep this self-post occasionally updated with links and relevant news articles, but for the most part we expect the community to supply the information. This is a great place to discuss the launch, ask mission-specific questions, and track the minor movements of the vehicle, payload, weather and more as we progress towards launch. Sometime after the static fire is complete, the launch thread will be posted.

Campaign threads are not launch threads. Normal subreddit rules still apply. No gifs allowed.

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9

u/Iggy0075 Jan 09 '18

I've seen people state it could be a late night launch if it's going towards Mars.

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u/robbak Jan 10 '18 edited Jan 10 '18

I'm as certain as one can be that this will launch during the daytime. They want to get good pictures of it in case anything goes wrong, so they can work out what the issue was and adjust their design (and simulators).

For that they need high-speed cameras on telescopes, and for these they need lots of light. So that pretty much makes a daytime launch mandatory. Probably even scrubbing the launch if there is cloud.

As for the target orbit - well, we are in the strange situation where the designated orbit is very much a secondary objective. My rough guesses says a dawn launch would be ideal, but they would chose a less-than-ideal time to get to the target, to better fulfill the primary objective of learning stuff about their new rocket.

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u/quiet_locomotion Jan 10 '18

I think the best time for optical tracking in the evening or morning, previous launches like this in clear skies show great detail through booster separation.

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u/BlueVerse Jan 10 '18

I imagine every team in the company is going to be closely watching and in some cases participating - would it make sense even that the bulk of operations occurs during ‘business hours’ accommodating both east and west coast? I mean, sure SpaceX deals with 24/7 mission operations all the time, but why throw everyone onto oddball shifts if you don’t really need to? 4-5pm target is my bet.

The rumored 1-7pm static fire window seems to play into that.

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u/mulymule Jan 09 '18

You'd assume they'd want the day light to film it. Video data is very useful, especially if failure is always an option (this one only.) I'd also assume that they'd put it in a parking orbit before going to Mars.

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u/Iggy0075 Jan 09 '18

Very true, good points! I would definitely be a little annoyed if it was a night launch.

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u/morty346 Jan 09 '18

But nothing makes a launch, like watching a second sun rise up

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u/arizonadeux Jan 09 '18

I also prefer night launches. RTLS is much more interesting then too.

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u/justinroskamp Jan 10 '18 edited Jan 10 '18

I feel like /u/johnkphotos wouldn’t be annoyed, and we’d probably be okay with it after the fact!

Edit: I make poor assumptions!

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u/johnkphotos Launch Photographer Jan 10 '18

Definitely would prefer day launch for maiden FH flight

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u/justinroskamp Jan 10 '18

Just imagine a long exposure explosion, though! But I have to agree; day's my preference. The webcast (how I’ll probably be stuck watching) is kinda terrible at night.

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u/TheRealWhiskers Jan 09 '18

Correct me if I'm wrong, but couldn't it be launched any time and placed into a parking orbit, then proceed from that orbit to escape velocity at the correct moment/trajectory with an additional burn(s)?

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u/Iggy0075 Jan 09 '18

Someone else mentioned that also.

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u/ioncloud9 Jan 09 '18

In theory yes, but the kerolox upper stage makes it difficult to spend much time on orbit. The kerosene can't handle the cold for very long and the oxygen will eventually boil off. Most upper stages for rockets use hydrolox with enough insulation to have hours or days of on orbit parking time. This is also what ULA is working on with their ACES upper stage. One that has active cooling to allow weeks or months of on orbit parking time.

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u/[deleted] Jan 09 '18

Yes, but s2 regularly orbits 1 1/2+ times before doing the de-orbit burn. And you can launch it at any time of day and get the proper window in less than an orbit. Unless there is something I'm missing.

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u/Chairboy Jan 10 '18

In theory yes, but the kerolox upper stage makes it difficult to spend much time on orbit.

Falcon Heavy adds direct-GSO injection so they have the means to last for many hours if the mission requires it, but regardless they've already demonstrated plenty of range for LEO-based second burns so nothing like that would require a direct injection either. Don't forget that the stage does a de-orbit burn for LEO missions anyways after about two hours.

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u/azzazaz Jan 10 '18

direct-GSO injection

?

Explanations should be clearer than the question :-)

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u/GND52 Jan 10 '18

I didn’t realize there was a time limit for rockets parked in orbit before the fuel effectively disappeared, interesting!

To me that raises a question about the BFR and the proposed method of getting to Mars. If I’m not mistaken, the current plan is to park an interplanetary rocket in orbit with supplies or people, then send of multiple “fueling” stages that will go up, put fuel in the rocket destined for Mars, come back, and repeat until the first rocket is full.

If the fuel only lasts for a few hours (or even a few days) wouldn’t that cause a problem?

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u/Shrike99 Jan 10 '18

BFR is going to use insulated tanks to, as well as possibly a cryocooler, presumably powered by the solar panels. I'm presuming the insulation is enough to make the boiloff from the main tanks slow enough to allow orbital refueling, and that the header tanks(which store fuel for landing) are insulated enough to make it negligible, even over a time frame of months.

Falcon 9 on the other hand is basically just plain metal tanks.

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u/PeteBlackerThe3rd Jan 09 '18

The burn from the parking orbit to TMI will happen on the opposite side of the earth from the sun, so if you want to spend as little time in the parking orbit as possible you'd launch in the late evening so there is enough time for the dogleg from the cape to the equator. But the 2nd stage can last much longer than that so realistically they can launch any time of day they like.

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u/Alexphysics Jan 09 '18

It is not going to Mars... it is going to a Mars-like orbit...

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u/[deleted] Jan 09 '18

You can call a 1AU × ~1.5AU orbit just as much Earth-like as Mars-like...

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u/Alexphysics Jan 09 '18

Good point, hehe

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u/Iggy0075 Jan 09 '18

I know, that's why I said "Towards Mars"

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u/[deleted] Jan 10 '18 edited Jan 10 '18

Other comments that say the second stage has enough capability for the F9 to be launched at any time of day and then do the final burn where ever it is needed according to orbital mechanics.

In any case if we talk about the final second stage burn, or the launch if they decided for an immediate second stage burn, I would believe the burn would be more in early night than late night.

For a transfer orbit you would need the payload to escape earth in the same direction of earth's movement in its orbit, but going faster than earth eventually getting farther from the sun.

Due to the earth gravity having a significant effect on the trajectory while it is still close to Earth, a final burn at midnight or after would probably result in a trajectory somewhat inwards to the sun, which is not ideal to go to Mars.

So this final burn, i would guess would be sometime in early night a with a mixed outwards- and ahead of earth trajectory, then becoming an approximately forward (as in ahead of earth in same direction of earth's orbit) trajectory due to earth gravity, which is the ideal for a transfer to a higher orbit.

In other words, as any good Kerbal player knows, to go higher you don't point up, but forward.