Author Topic: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion Thread 1  (Read 586527 times)

Offline Flying Beaver

Interesting detail from the pad pics are these three points on all the cores, facing the same way, even with the west booster being rotated 180degs. I assume these are telemetry transmitters? As they would be facing downwards as the vehicle pitches over during accent.
Watched B1019 land in person 21/12/2015.

Offline oiorionsbelt

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #781 on: 01/03/2018 03:34 AM »
Interesting detail from the pad pics are these three points on all the cores, facing the same way, even with the west booster being rotated 180degs. I assume these are telemetry transmitters? As they would be facing downwards as the vehicle pitches over during accent.
Speaking of one booster being rotated 180degrees. Couldn't help but notice these.

Offline ChrisC

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #782 on: 01/03/2018 03:58 AM »
But yes, I'll happily take charge of organizing something surrounding Falcon Heavy.  I'll be at KSC press site for the launch, but as we'll likely have A LOT of people coming for this, maybe I can dust off the old Shuttle dinner gatherings I used to organize and we can see who all wants to meet up for dinner/drinks the night before the first launch?

Mods, split these meetup posts to a new thread, like the old STS launch days?

EDIT -- the new thread is here: https://forum.nasaspaceflight.com/index.php?topic=44587.0
« Last Edit: 01/04/2018 04:00 AM by ChrisC »
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Offline allio

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #783 on: 01/03/2018 05:14 AM »
Was thinking the other day, How cool would five foot plushies of Jebediah, Bill, Bob and valentina strapped into the front of the tesla be?

AWESOME!

Offline ugordan

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #784 on: 01/03/2018 08:44 AM »
Interesting detail from the pad pics are these three points on all the cores, facing the same way, even with the west booster being rotated 180degs.

Note also something that looks like a wire in the leftmost two cores coming out of that same section. Wonder if its some instrumentation for the static fire because it doesn't look secure enough for a flight environment, but then why paint the wiring white?

Offline bdub217

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #785 on: 01/03/2018 01:59 PM »
I am interesting in seeing how big the initial launch window will be when the launch date is posted. Clearly there should be no operational restraints for launching a tesla in the general vicinity of a martian heliocentric orbit. I'd also imagine they'd want plenty of time to call a delay if anything should look unusual. That said - wouldn't an especially  lengthy active launch window negatively impact air and sea navigation around the cape?

Offline Ben the Space Brit

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #786 on: 01/03/2018 02:06 PM »
Are there any viable slingshot orbits to enable trans-Martian injection coming up (via Venus or the Moon perhaps)?
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Offline cscott

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #787 on: 01/03/2018 02:52 PM »
AIUI the inclination-from-the-ecliptic difference between Earth and Mars is "maximally bad" this month, so you'd either have to do something fancy---or else refire S2 after a couple months of coasting.

I'm starting to be persuaded that the "fancy" orbit is just a "simple" apogee-at-Mars-distance elliptical orbit, and the inclination difference is going to be sold as a planetary-protection "feature".

Offline jacqmans

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #788 on: 01/03/2018 03:19 PM »
That moment when you find a poll with your name on it and you've got the most votes and you go "What?"

But yes, I'll happily take charge of organizing something surrounding Falcon Heavy.  I'll be at KSC press site for the launch, but as we'll likely have A LOT of people coming for this, maybe I can dust off the old Shuttle dinner gatherings I used to organize and we can see who all wants to meet up for dinner/drinks the night before the first launch?

Dixie Crossroads like with the shuttle, you might want to count me in ;)

Offline envy887

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #789 on: 01/03/2018 04:28 PM »
Are there any viable slingshot orbits to enable trans-Martian injection coming up (via Venus or the Moon perhaps)?

There's no particular reason to do this. SpaceX can define a reference orbit that is similar to a TMI, and see how close the actual injection is relative to that target. No point in running any chance of actually hitting Mars down the road.

Offline ChrisGebhardt

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #790 on: 01/03/2018 06:07 PM »
But yes, I'll happily take charge of organizing something surrounding Falcon Heavy.  I'll be at KSC press site for the launch, but as we'll likely have A LOT of people coming for this, maybe I can dust off the old Shuttle dinner gatherings I used to organize and we can see who all wants to meet up for dinner/drinks the night before the first launch?

Always meant to go to one of these. As long as it doesn't conflict with remotes, I'll definitely try to join in.

It definitely won't as it'll have to be around all the media events that I'll be at, too.

Offline ChrisGebhardt

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #791 on: 01/03/2018 06:30 PM »
With confirmation that there's a good deal of interest in having an NSF member meet up for Falcon Heavy's debut, I've started a dedicated thread for that.

https://forum.nasaspaceflight.com/index.php?topic=44587.new#new

Offline CyndyC

AIUI the inclination-from-the-ecliptic difference between Earth and Mars is "maximally bad" this month, so you'd either have to do something fancy---or else refire S2 after a couple months of coasting.

I'm starting to be persuaded that the "fancy" orbit is just a "simple" apogee-at-Mars-distance elliptical orbit, and the inclination difference is going to be sold as a planetary-protection "feature".

There is also the question is that going to be close enough to Mars orbit for Elon Musk and enough SpaceX employees? If they delay the launch further just to get closer to Mars orbit, till late February as you said in a previous post on this topic, employees who don't care as much where the Roadster ends up and the public would only be disappointed for another 50 days, whereas if they don't delay the launch, Elon and employees who do care where the Roadster ends up would be disappointed for a billion years. I'm serious  ;)
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Offline Space Ghost 1962

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #793 on: 01/04/2018 02:58 AM »
AIUI the inclination-from-the-ecliptic difference between Earth and Mars is "maximally bad" this month, so you'd either have to do something fancy---or else refire S2 after a couple months of coasting.

I'm starting to be persuaded that the "fancy" orbit is just a "simple" apogee-at-Mars-distance elliptical orbit, and the inclination difference is going to be sold as a planetary-protection "feature".
Mars is quite far away at the moment - 16.15 light minutes distance, in a telescope 4.8 arc seconds, about 3/4 of the furthest it can get from earth. Visible low in the morning sky.

Opposition is July 26th, when they will be 3.22 light minutes apart and 24.2 arc seconds. Insight will launch May 5th to transit optimally.

If you want to make it to Mars, you'll wait on your launch to later this year. Now, if you want the long transit time with an encounter (no props to assist capture),  you don't need to wait to May to do so, but you still need to wait.

(Yes you could conceive of an aerobrake by skimming the Tesla through the low atmosphere, possibly melting portions of it, which might lose enough delta-v to be captured into an orbit around Mars, but given that you'd like to minimize encounter velocity you'd have to wait close to a year and a half so as to launch and encounter Mars 180 degrees apart (too late for this opposition, would have had to happen many months ago - see more in Earth--Mars Transfers with Ballistic Capture). As it's the wrong shape for entry, the tumbling would be unpredictable so you'll have a large sheaf of possible trajectories depending on how the payload gyrates during entry and ends up exitting the atmosphere, likely to re encounter it again with similar instabilities.)

In any event, you'd need a GNC with thruster package around center of mass, to do mid course corrections. And, in keeping with planetary protection protocols, you'd have to insure a clean miss with your mission operations team until your final commit to encounter, likely a month or so out. Oh, and you'll need DSN time to track/communicate such corrections and to monitor.

So much for bringing "Mars the planet" into the picture - work, work, work. Much better to just transit it's heliocentric distance from the sun, and not have to worry about all that and niggling things like being in the plane of the orbit, at a time when that might complicate ascent and ground tracking from the same location as launch ...

Offline freda

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #794 on: 01/04/2018 02:33 PM »
Interesting detail from the pad pics are these three points on all the cores, facing the same way, even with the west booster being rotated 180degs. I assume these are telemetry transmitters? As they would be facing downwards as the vehicle pitches over during accent.

Similar artifacts also shown on S2.

Offline nacnud

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #795 on: 01/04/2018 02:38 PM »
We're gonna need a four picture split screen to watch all those downlinked vids! Plus one for the Tesla!  8)

Offline Surfdaddy

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #796 on: 01/04/2018 05:20 PM »
1 - Do we know if this is going to a direct TMI (or Mars-distance orbital injection) or whether they'll coast in earth orbit for a bit?
2 - I would assume for publicity purposes that Elon will have arranged an epic live video shot of the Tesla payload separating from the upper stage. Or do we think that they'll just have it remain attached to stage 2 for total simplicity?

Offline cscott

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #797 on: 01/04/2018 05:41 PM »
Consensus seems to be direct injection and no separation, but there's no a lot of evidence either way. Only: longest S2 coast was for DSCOVR (30 min) & it would require S2 modifications for significantly longer; and no obvious hardware on the roadster (solar panels, comm antennas) to support a mission apart from the S2. Of course there could be surprises.

Offline Space Ghost 1962

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #798 on: 01/04/2018 05:46 PM »
1 - Do we know if this is going to a direct TMI (or Mars-distance orbital injection) or whether they'll coast in earth orbit for a bit?
2 - I would assume for publicity purposes that Elon will have arranged an epic live video shot of the Tesla payload separating from the upper stage. Or do we think that they'll just have it remain attached to stage 2 for total simplicity?
1. They won't coast because they need to stay in range as long as possible to get tracking from Florida assets nothing elsewhere.
2. Very likely it'll remain with F9US because it's easier to track, has active control/telemetry for the life of the stage, and deals with disposal of stage.

Consensus seems to be direct injection and no separation, but there's no a lot of evidence either way. Only: longest S2 coast was for DSCOVR (30 min) & it would require S2 modifications for significantly longer; and no obvious hardware on the roadster (solar panels, comm antennas) to support a mission apart from the S2. Of course there could be surprises.
Attitude controls for a Tesla?  :o

Offline Brian45

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Re: SpaceX FH : Falcon Heavy Demo : early 2018 : Discussion
« Reply #799 on: 01/04/2018 06:00 PM »
Someone mentioned here that under a certain scenario, the S2 might need to fire for a Mars course correction quite a while after launch. Seems to me this would be an excellent opportunity to gather some more data points for the performance of the S2 engine under unique conditions.

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