Returning S2 will be 'similar to Dragon' in that it comes in from orbital velocity and will involve the use of Pica-X heat-shield material, but there are also many differences. The shape and mass characteristics are totally different.Are you thinking S2 comes down nose first ~vertically? The stock S2 is tail (engine) heavy but I suppose a big parafoil stored in the nose will weigh something, perhaps enough to make it fly nose first. Would it be a lifting-entry a la Dragon for steering?Or... the ITS fans would be happy if it had TPS on the side and it came in ITS/shuttle-style! But then you'd need a flap or something to protect the MVac - as recent posts have suggested.Looks like guesstimate of S2 dry mass is <5mT before re-use hardware is added. At what mass does helicopter capture become too hairy, I wonder.Edit to add:A couple of years ago I threw out the possibility of landing something S2-like (ESA's IXV) at very high speed on a runway. FWIW: http://forum.nasaspaceflight.com/index.php?topic=36856.msg1335557#msg1335557
Quote from: launchwatcher on 04/07/2017 09:07 pmElon's latest on twitter:QuoteFairing is ~$5M, but that should be reusable this year. Am fairly confident we can reuse upper stage too by late next year to get to 100%.I'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?
Elon's latest on twitter:QuoteFairing is ~$5M, but that should be reusable this year. Am fairly confident we can reuse upper stage too by late next year to get to 100%.
Fairing is ~$5M, but that should be reusable this year. Am fairly confident we can reuse upper stage too by late next year to get to 100%.
Quote from: philw1776 on 04/07/2017 10:28 pmQuote from: launchwatcher on 04/07/2017 09:07 pmElon's latest on twitter:QuoteFairing is ~$5M, but that should be reusable this year. Am fairly confident we can reuse upper stage too by late next year to get to 100%.I'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?Surprise! Hey....wait....why is no one surprised?
Quote from: deruch on 04/09/2017 01:53 amQuote from: philw1776 on 04/07/2017 10:28 pmI'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?Surprise! Hey....wait....why is no one surprised?Maybe it's part of Block 5, now.
Quote from: philw1776 on 04/07/2017 10:28 pmI'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?Surprise! Hey....wait....why is no one surprised?
I'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?
Quote from: Robotbeat on 04/09/2017 01:54 amQuote from: deruch on 04/09/2017 01:53 amQuote from: philw1776 on 04/07/2017 10:28 pmI'm floored.1) Does this mean that the Block 5 design freeze slated for this year is NOT a design freeze?Surprise! Hey....wait....why is no one surprised?Maybe it's part of Block 5, now.If so, I would have much larger concerns about SpaceX meeting their schedule goals for Commercial Crew certification. I could sort of see it as part of a Block 5.5 update that included planned changes/updates to the upper stage to address some DoD needs related to direct GEO insertion that they will eventually fold in after a while. But, I can't see them including the mods I expect will be needed in time to achieve their stated flight rate goals for CC prior to their deadlines.
Here's what you can do: * add autonomous cold gas thruster packs * add autonomous drag devices * means to link/coordinate them * payloads that attaches to the payload adapter. Possibly a TPS? * stuff that only becomes active following primary mission * surface application TPS of marginal weight/drag to primary mission
How about using the real upper stage to carry a reentry demonstrator upper stage on top of the payload adapter and inside the fairing? Doesn't need a real Merlin or anything like that, just a needs to reproduce the weight distribution. Add TPS and hypergolic propulsion and so forth to the demonstrator. There's no way a Falcon Heavy couldn't handle launching that.
S2 and aerospikes are a match made in engineering heaven.
Quote from: Space Ghost 1962 on 04/09/2017 02:25 amHere's what you can do: * add autonomous cold gas thruster packs * add autonomous drag devices * means to link/coordinate them * payloads that attaches to the payload adapter. Possibly a TPS? * stuff that only becomes active following primary mission * surface application TPS of marginal weight/drag to primary missionHow about using the real upper stage to carry a reentry demonstrator upper stage on top of the payload adapter and inside the fairing?
Doesn't need a real Merlin or anything like that, just a needs to reproduce the weight distribution. Add TPS and hypergolic propulsion and so forth to the demonstrator.
There's no way a Falcon Heavy couldn't handle launching that.
Wacky idea but... Could Stratalaunch perform air-recovery of a large parachuting payload like S2?
Quote from: rakaydos on 04/09/2017 03:18 pmWacky idea but... Could Stratalaunch perform air-recovery of a large parachuting payload like S2?No need to think that wacky when it comes the Falcon second stage: the Erickson S-64 Skycrane has an advertised max payload of 9mT. I doubt you'd want to catch 9 tonnes in mid-air, but it a Falcon second stage might be doable. (For arguments sake, call it ~5 mT.)I recently learned that mid-air capture is simplified by fitting the target with a parafoil that's designed to leave it with a fairly high horizontal speed. Or course that's not helpful if you want to land, but for mid-air capture it means smaller gusts have relatively less effect on it's path due to its momentum. The same is true for the helicopter that's matching it's speed. Plus the helicopter downwash trails the target rather than interfering. Smoother, more predictable motion makes for easier capture.
Quote from: adrianwyard on 04/08/2017 05:35 pmWhat makes this so fascinating is Musk saying they may try to bring the FH demo S2 back this summer! No-one expected that. Presumably that rules out anything but the simplest modifications. And definitely not a Raptor. ...This line of reasoning is flawed; you are assuming that EM didn't decide to bring back the second stage until that event 1-2 weeks ago. Us not knowing about his plan (and it is likely much more mature than he is letting on) doesn't have any bearing on him having a plan. His time constraints as you've outlined them don't exist... FH has been on drawing boards without a paying customer for years. IIRC, five years ago, he asked -- if you could launch anything into space, what would it be -- he was referring to the FH demo launch. The 'silly' payload and the hardware to return the second stage was probably ready last year when AMOS disrupted all plans.
What makes this so fascinating is Musk saying they may try to bring the FH demo S2 back this summer! No-one expected that. Presumably that rules out anything but the simplest modifications. And definitely not a Raptor. ...