Any info on how much damage the barge took from that explosion?
Space X CR6 First stage landing
131–140 of 205 posts
Re: Space X CR6 First stage landing
#132I wonder what happened there. Looks at 4 seconds the guidance system figured it needed to pull an ultra manoeuvre to slow the the horizontal speed(was drifting left) but ended up with a solution putting the rocket upright again at nearly 0m. If it would have left some altitude for stabilizing I think they would have had it. Arm chair rocket science is fun.
According to Elon's tweet that seems to have disappeared by now, they had static friction in bipropellant valves introduce a lag that the control system couldn't handle.
Can you or someone else please explain what that means in slightly less technical terms without dumbing it down too much?
Re: Space X CR6 First stage landing
#133Any info on how much damage the barge took from that explosion?
"Droneship is fine. No hull breach and repairs are minor. Impact overpressure is closer to a fast fire than an explosion."
Re: Space X CR6 First stage landing
#134As if this weren't impressive enough already, according to a comment made by Scott Manley[1] it sounds like the final maneuver (where it appears the rocket is making a fairly strong lateral correction) is entirely intentional. Not sure if anyone here can confirm or deny the claim, but apparently the trajectory prior to landing is not supposed to be exactly above the barge as one would expect - I understand it may be…
This is pretty fascinating and makes a lot of sense. You obv want to land very slowly, but going slow means less control to keep it vertical. So the clever work around is use thrust at the last second which will allow it to also be vertical and stable. And that means coming in from a non vertical angle beforehand which is exactly what they do.
Re: Space X CR6 First stage landing
#135Come on people, have a go at it yourselves:
Re: Space X CR6 First stage landing
#136Is there a reason you couldn't have things on the side of the landing pad that "grab" onto it and secure it? It could be as simple as a huge ring of cable that just closes around the top of the rocket, then pulls it tight on all sides- like the guidelines on a tower to keep it stable. Maybe they don't want to do that because they think they can do it without it?
> Maybe they don't want to do that because they think they can do it without it?
If they master vertical landing without external support equipment, they can pull it off on Mars as well. I think that's their other goal here.
Re: Space X CR6 First stage landing
#137Why did it explode in such a dramatic fashion? I thought the booster was almost entirely empty when it returns to the barge.
The rocket is, at the very least, a thin pressurized tube full of kerosene vapor and oxygen, and probably some decent amount of liquid kerosene and liquid oxygen. Crack it open and it's gonna make a pretty good flash. But as rocket explosions go, that wasn't very big. Get to YouTube if you want to see some real rocket explosions.
Check out, for instance, Proton-M going full Kerbal in 2013: https://www.youtube.com/watch?v=Zl12dXYcUTo.
Re: Space X CR6 First stage landing
#138I can't help but feel bad for that one poor little RCS thruster doing its level best to keep the first stage upright, but ultimately running out of fuel.
Judging from the ensuing explosion there was still fuel left over.
Making it a little puzzling ask to why the engines didn't try harder to lower the vertical velocity on approach. Perhaps there are improvements to be made in the control systems.
Re: Space X CR6 First stage landing
#139It's interesting to think that if you are building rockets, up til now you've never really gotten to take the rocket apart _after_ flying it - it's burnt up in the atmosphere or at the bottom of the ocean somewhere. I imagine there will be lots of interesting insights that come out of recovering, undamaged, a flown first stage and taking it apart to see what's experienced wear etc.
NASA has been recovering their rockets from ocean landings for some time. See: https://www.youtube.com/watch?v=Gbtulv0mnlU
But only after getting them totally messed up by salt water. Also, those were solid-fuel rockets, which are significantly simpler than liquid-fuel ones. There's probably a lot to learn from an undamaged liquid-fuel first stage that went to space.
Re: Space X CR6 First stage landing
#140Question: Why don't they land into the water instead of a hard surface? (Wouldn't this give them more leeway in terms of impulse?) Edit: i.e. landing on a net stretched (under the lake/ocean-surface) by 3 or 4 ships - reel the net it in to raise stage out of the water, I'm pretty sure seawater is not significantly corrosive from 2-3 hours of exposure.
This how NASA recovered the SRBs. They landed upright, much like SpaceX's rocket. They were bouyant and floated vertically. The tender would approach the SRB, hook onto it, pump more water into it so it would sink. It would then carry it horizontally back to land. Seawater is incredibly corrosive and as it evaporates it leaves behind a fine layer of sea salt. Since these were SRBs, they had few moving parts. They wer…
Correct me if I'm wrong, but AFAIR SRBs weren't really reused, it was cheaper to make new ones than refurbish those they fished out.