Quote from: Okie_Steve on 03/09/2013 02:53 pmFinally, anyone have a good speculation about what contact with cold water will do to the engines?It is a safe guess that the working engine will be ruined, for everything else it depends on actual temperature. I passed my metallurgy exam long ago, but still remember that quenching makes steel harder but more brittle. So may be the thrust structure wont be reusable after such quench-splash...
Finally, anyone have a good speculation about what contact with cold water will do to the engines?
Quote from: simonbp on 03/09/2013 03:16 pmIt's not supposed to reused after the water landing, just prove that it can impact the ocean in one piece (something v1.0 never did). The killer is side loads, so they have to prove they can orient the vehicle tail first before the rest of the recovery sequence can work. If they do a relight and softly land in the water, great, but that's nothing Grasshopper can't do.I was thinking more in terms of how much damage a water landing would do vs a grasshopper style dirt landing. At a minimum I would expect the center nozzle to implode once the bottom is sealed by water and chilling begins. But, that still leaves lots of forensic knowledge to be obtained about the flight hardware if they get it back. The physical landing environments are different enough that I don't have a good feeling for what will happen on water. Ergo the question.
It's not supposed to reused after the water landing, just prove that it can impact the ocean in one piece (something v1.0 never did). The killer is side loads, so they have to prove they can orient the vehicle tail first before the rest of the recovery sequence can work. If they do a relight and softly land in the water, great, but that's nothing Grasshopper can't do.
Robert Truax studied water effects on rocket engines a lot, fired pressure fed engines underwater etc.See http://neverworld.net/truax/I'd speculate the most dramatic effect on recently running engine being immersed in water would be that surfaces get wet
ugordan, thanks for remembering me.
Quote from: Jim on 03/09/2013 03:40 pmQuote from: KSC Sage on 03/09/2013 03:29 pmI've been told that the v1.1 will become SpaceX's "workhorse" launch vehicle. SpaceX has told NASA they plan on producing up to 40 v1.1 cores/boosters a year for the F9 and F-H vehicles.That was a givenI bet you are meaning the first sentence, because there's no way that SpaceX has the launch demand needed to produce 40 cores/boosters per year (currently the most produced almost-completely-same core stages must be the Soyuz rockets, and they are only flying up to 20 flights per year).
Quote from: KSC Sage on 03/09/2013 03:29 pmI've been told that the v1.1 will become SpaceX's "workhorse" launch vehicle. SpaceX has told NASA they plan on producing up to 40 v1.1 cores/boosters a year for the F9 and F-H vehicles.That was a given
I've been told that the v1.1 will become SpaceX's "workhorse" launch vehicle. SpaceX has told NASA they plan on producing up to 40 v1.1 cores/boosters a year for the F9 and F-H vehicles.
I wonder if they would add a camera on the first stage to record the water landing, which we could watch afterwards... That would be epic.
I was thinking more in terms of how much damage a water landing would do vs a grasshopper style dirt landing. At a minimum I would expect the center nozzle to implode once the bottom is sealed by water and chilling begins. But, that still leaves lots of forensic knowledge to be obtained about the flight hardware if they get it back. The physical landing environments are different enough that I don't have a good feeling for what will happen on water. Ergo the question.
If they do a relight and softly land in the water, great, but that's nothing Grasshopper can't do.
Right now, SpaceX views their manifest is basically a self-funding technology development program (not something that customers love, I'm sure) but so far it seems to have a good chance of working out for both sides.
So if the center engine creates a bowl wider than 3.3 m, the rocket could descend into the bowl, which would then get deeper. I wonder how deep it could descend before the top of the bowl collapses and swallows the booster!
So if the center engine creates a bowl wider than 3.3 m, the rocket could descend into the bowl, which would then get deeper. I wonder how deep it could descend before the top of the bowl collapses and swallows the booster!Sounds like an xkcd what-if topic.
Quote from: smoliarm on 03/09/2013 03:44 pmIt will displace some water - proportionally to the engine thrust, but not 100%. So, just before "touchdown" there should be a bowl of about several dozens cubic meters volume, I'd love to see that Hmmm, maybe they will try to "touchdown" at a negative altitude of a couple of meters for this test then, depending on how deep the "bowl" is, the effects of the bowl collapsing on engine shutdown, and the floating stability of the stage. Falling over and buckling can't be good for recovery prospects.
It will displace some water - proportionally to the engine thrust, but not 100%. So, just before "touchdown" there should be a bowl of about several dozens cubic meters volume, I'd love to see that
don't focus on the water landing or miss the real test.