That is an... interesting, at best, proposal for S2 recovery. It does, however, seem possible that a Dragon could be mounted inside the fairing like this for a circumlunar flight, while still keeping fairing validation for the USAF.
If the Falcon Heavy Demo Mission flies this year, there is not much time to develop a payload.
Quote from: OneSpeed on 04/25/2017 03:48 amIf the Falcon Heavy Demo Mission flies this year, there is not much time to develop a payload. As noted above, a false assumption. SpaceX has had years to decide on and develop a payload. They have even refused to launch someone else's payload so the statement that it will be just a mass simulator does not add up to me.
... SpaceX has had years to decide on and develop a payload ...
I don't think a Dragon is silly enough.
A mass simulator or boilerplate spacecraft makes perfect sense. SpaceX has plenty to work on just getting FH flying with no payload on it.
But they have said there will be a 'Hail Mary' attempt to return a second stage on the demo flight.
Quote from: OneSpeed on 04/25/2017 09:58 pmBut they have said there will be a 'Hail Mary' attempt to return a second stage on the demo flight. Funny how "may be" becomes "will be" in the private little game of "Telephone" we have going on here...
Quote from: rpapo on 04/25/2017 10:02 pmQuote from: OneSpeed on 04/25/2017 09:58 pmBut they have said there will be a 'Hail Mary' attempt to return a second stage on the demo flight. Funny how "may be" becomes "will be" in the private little game of "Telephone" we have going on here...Fair enough, "may be". Still, the question is, how could it be done?
However they plan to recover the upper stage has to be compatible with real payloads or it's pretty useless. So go up with a simulator, sep, and come back without it.
Quote from: envy887 on 04/26/2017 12:42 amHowever they plan to recover the upper stage has to be compatible with real payloads or it's pretty useless. So go up with a simulator, sep, and come back without it.The topic of this thread is not the long term plan for S2 re-use. Rather, it is asking what could realistically be achieved by the FH demo mission. If the mission could provide new data regarding the re-entry from orbit of a Falcon second stage, then it would have been anything but useless. If it could return a second stage, even if damaged, even with a 'silly' payload, the results obtained would be invaluable. Those results would inform the longer term design of a truly re-usable second stage.If you were to just 'go up with a simulator, and separate', how would you then return the second stage? Where on the upper stage would be the Dragon heatshield? How would you provide thrust, both for attitude control, and for landing? Would it have a moveable mass for controlling AoA? Would it have landing legs? What would be the flight control system? How would you create all of these new features before the FH demo launch? To my mind, using the Dragon2 to provide all of this functionality massively simplifies the problem, and does so in the shortest possible timeframe. But I'm keen to listen to any alternatives.
what if they were to build an instrumented boilerplate 2nd stage with a heat shield, thrusters, and just an mvac mockup, and carried that up inside the payload fairing.that would allow them to get data on a cylindrical reentry vehicle without the risk of a 2nd stage failure due to reentry modifications.I'm pretty sure that launching a 2nd stage on top of a 2nd stage counts as pretty silly.
The second stage already has avionics and a RCS system. It will need some mods for recovery, like a parachute, some extra TPS for the side walls, and probably rear flaps, so it's not like they can claim it's a standard upper stage. They may be bolt-on mods like the S1 recovery hardware, but the stage function still has to be validated with them.
If they do use an upside-down Dragon 2 heatshield with its legs, tanks, and superdracos, they still need some way to mount the payload adapter on top - likely using the Dragon-to-trunk fittings and discarding the payload adapter before reentry. And they need to show that the payload adapter works with all the new stuff under it. The only way to do that is to carry a realistic massive payload up and demonstrate separation. Thus: carry a mass simulator up, separate, return the stage.
To my mind, using the Dragon2 to provide all of this functionality massively simplifies the problem, and does so in the shortest possible timeframe. But I'm keen to listen to any alternatives.
It does none of those things as explained before. Dragon is not flying in a fairing.