Will SpaceX Successfully Land a Rocket on a Boat?

[GiantSheeps]

So SpaceX is going to try to land a rocketship on a boat... That's pretty amazing, if you ask me. Does anyone know of a TV station that will be broadcasting the event live? I know I could watch it here http://www.spacex.com/webcast/ , but it would be nice to be able to see it on the big screen with the whole fam

 

[phinds]

Geez ... that IS amazing. Very surprising that they are even going to try it and even more surprising that they put the odds of success at 50% (at best). Still, they know its capabilities a lot better than we do and wouldn't be trying it if there were not at least some reasonably chance of success.

Seems that landing leads to another problem though ... say it works. THEN what ? How do they get it back onto land?

 

[GiantSheeps]

Seems that landing leads to another problem though ... say it works. THEN what ? How do they get it back onto land?

Ooh I hadn't thought of that. That whole process might actually be as exciting as the landing (if the landing is actually a success of course). That would be horrible if the landing was successful and they damage the rocket when they are trying to bring it back onto land

 

[enorbet]

Actually it seems they have accounted for that by recognizing this is a process and that there are bound to be failures along the way, but that also we often learn more from failures than successes. People can say whatever they want to about Elon Musk but I like his cool blend of dreamer and practical "hands on". He sees Problem - Booster stages are where much of the money goes and we throw it away because it is difficult to not throw it away Solution - Find out just how difficult that really is and see what that reveals for a 2nd step and narrow down. The payoff is quite literally astronomical.

 

[Garth]

we often learn more from failures than successes.

Thanks! That makes me the cleverest man in the world...
Garth

 

[berkeman]

Elon Musk -- "Close, but no cigar..."

http://www.cnn.com/videos/us/2015/01/16/orig-space-x-launch-crash-landing.cnn

 

[enorbet]

Despite the crash ( or RUD, if you prefer :P ) it appears a simple problem to repair. As anyone could see there was a problem with attitude as it was at nearly a 45 degree angle rather than perpendicular. Apparently a simple hydraulic system or it's controls failed to do it's job at fin guidance. Redundancy caused the engines to attempt to compensate but it was too little, too late. It is praiseworthy that they hit the barge on target. I doubt it will take much to fix this last wrinkle. Overall as experiments go, quite successful as it lends credibility to the idea that it is by no means an insurmountable problem even with present technology.

Here's the link -> http://www.popularmechanics.com/how-to/blog/spacex-falcon-9-reusable-rocket-failed-landing

 

[GiantSheeps]

Yeah, and from what I understand they're going to make another landing attempt on the 29th, it seems like the chances of success on this one are wayyyy higher than they were before.

I might have misread that though and I don't remember where... Can anyone verify that they are in fact going to attempt another landing on the 29th? I know that they do have a launch scheduled for that day...

 

[mheslep]

it appears a simple problem to repair.

Musk identified the problem as a 10% shortage of hydraulic fluid. If this was a simply problem to fix, then why wasn't it identified earlier, i.e. add an ample margin of fluid, unless the vehicle mass margin is too tight allow such? If that's the case, then adding more fluid won't be simple.

 

[cjl]

They probably thought they did have an ample margin, and more control effort was required than expected. They'll probably just add more for the next flight.

 

[mheslep]

They probably thought they did have an ample margin, and more control effort was required than expected.

I could see that being the case if the control profile left expectations; that is, PID control degenerated into some kind of bang-bang oscillation. If that's the case, then fluid store is not the fundamental problem.

 

[cjl]

It's also possible if their plant or dynamic models were a bit off. It doesn't require a dramatic oscillation to eat into aerospace-style margins.

 

[mheslep]

SpaceX launches again tomorrow 4:33pm eastern to ISS, and will have another go at landing the booster.

http://www.usatoday.com/story/tech/...onal-space-station-resupply-mission/25682539/

 

[mheslep]

13 mins 35 34 33 ...

 

[berkeman]

Looks like they had to scrub due to weather: http://www.cnn.com/2015/04/13/us/spacex-rocket-landing-on-platform/index.html

Next try is tomorrow...

 

[mfb]

And liftoff!

The first stage separated, the second stage is firing, they will try to land the first stage again in a few minutes.

Edit: Second stage engine cutoff and separation.
Dragon has unfolded its solar arrays.

 

[berkeman]

Ack, they stopped the live feed and said to check social media for the live landing site action. Facebook is not showing me an obvious live feed. Anybody got a link to a live landing site feed?

 

[berkeman]

Maybe here: http://www.vox.com/2015/4/13/8383151/spacex-watch-live-launch-landing-stream

.

 

[mfb]

Ascent successful. Dragon enroute to Space Station. Rocket landed on droneship, but too hard for survival.

 

[mheslep]

Arg. Wind responsible for "excess" velocity? A 10 m/s wind places more than a half ton of force on that cylinder (~3.7mx30m), meaning it might have to come in with a tilt into the wind. I don't recall any indication of wind velocity on those multiple ground landing tests in Texas.

Barge drift with current/wind? Though barge station keeping is routine.

 

[mheslep]

The vehicle appears to have incurred a ~20deg tilt from vertical with a single vehicle height remaning above the platform. Last moment positioning correction, or wind forcing? I see white caps on the water so there was at least 10 m/s wind on the surface, higher a couple hundred meters up. I can't see how they avoid some maneuvering thrusters (couple hundred N) at the top of the lander if wind is the problem, as gimballing the engine has against the rotational moment of that lander must be too slow? Only minimal thruster fuel required, in the last few hundred meters before landing. I suppose the mass of the thrusters (minimum two?) would be no trivial matter when every kilo of payload means 98 kilos of rocket.

Descent velocity also seems a bit faster than the Texas tests. Looks like ~30 m/s at 30 m if the video is real time. Descent velocity did zero (apparently) by the time it hit the pad, but that velocity at 30 m also means almost no time to correct lateral velocity - which Musk noted was high. Lateral velocity correction means a vehicle rotation with this scheme, which per above is not quick.

blob:https%3A//vine.co/b77664ce-5826-4c4f-b694-4fe24a0ac215

 

[Astronuc]

Almost - Awesome New SpaceX Video Shows Rocket Landing Try and Crash
http://news.yahoo.com/awesome-spacex-video-shows-rocket-landing-try-crash-223927085.html

 

[donpacino]

Almost - Awesome New SpaceX Video Shows Rocket Landing Try and Crash
http://news.yahoo.com/awesome-spacex-video-shows-rocket-landing-try-crash-223927085.html

We watched this at work. Everyone cheered at first...

 

[Dotini]

Space X has exploded a few minutes after launch.

Watching the press conference, I gleaned the following:- They have a serious problem. They have 4 months of supplies left on ISS. The crew will be returned when they are down to 45 days.

- Water and water filtration and provisions are probably the biggest loss to the ISS. And the docking adapter and radio system. Russian Progress and Soyuz flights are pending, as is one from Japan later in the summer.

- The ISS water processor is reaching its limits.

- All three commercial vehicles to ISS (Orbital, Progress and Space-X ) were lost in a one year time frame.

- Stand-down of Musk's rocket until problems are understood.

- FAA will have oversight of the investigation which will be conducted by Space-X, which operates on an FAA license.

- Commercial crewed vehicles are paused and under scrutiny, as are budgets. But they want to continue with the concept. Boeing is working on one.

- The Russian Progress launch which adds crew to the ISS is still on for next month.

 

[phinds]

Space X has exploded a few minutes after launch.

Damn !

 

[Dotini]

Damn !

No kidding.

I was watching very carefully on a 27" HD screen. At about 2:19, the 2nd stage appeared to ignite while the 1st stage was still thrusting. I could be wrong about that, but the ensuing explosion filled my screen, and the sky filled with smoke and debris. Musk identified a 2nd stage oxygen tank overpressure, but not as the root cause.

 

[mfb]

SpaceX had such a good track record :(. The first stage landing looked like a problematic part, but I didn't expect that.

One failure out of 19 launches is still the average ratio, but it will certainly delay several things significantly (including the idea of manned launches).

 

[tom aaron]

SpaceX had such a good track record :(. The first stage landing looked like a problematic part, but I didn't expect that.

One failure out of 19 launches is still the average ratio, but it will certainly delay several things significantly (including the idea of manned launches).

It's 2015.

There are 3 humans in LEO on the ISS. Another rocket failure.

A much needed reality check as people talk about a successful Mars mission by 2040. Our technology is nowhere near any such time line for a trip to Mars. We can barely service 3 astronauts in LEO.

The Shuttle was touted as the most advanced machine ever made. Buzz Aldrin criticized it for exactly that reason. The ISS, the Shuttle, the JWST...victims of technologies that have frenzied and eaten up resources far beyond what they were designed for.

 

[rootone]

... the 2nd stage appeared to ignite while the 1st stage was still thrusting.

It looked like that to me as well, but it could be just 'appearance of'.
If that actually happened, it's hard to believe. That is that something as simple as an incorrect timing of scheduled events could explain it.

 

[mfb]

A much needed reality check as people talk about a successful Mars mission by 2040.

You can stop progress completely with reality checks that are pessimistic enough.
2040 is 25 years away. 25 years before Apollo 11, the first unmanned V2 rockets reached space (but not orbits).

We can barely service 3 astronauts in LEO.

3 to 6. We can, but sometimes we might have to send more rockets than planned because no technology is 100% reliable.