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SpaceX Breaks Down Its Rocket Landing Attempts
An anonymous reader writes: Twice now, SpaceX has attempted to land one of its rockets on a barge in the ocean after it delivered a payload to orbit. Each attempt came very close, and provided some fascinating imagery. In a new post on their website, SpaceX explains where they're at with rocket landing technology, and what went wrong with the earlier trials: "That controlled descent was successful, but about 10 seconds before landing, a valve controlling the rocket's engine power (thrust) temporarily stopped responding to commands as quickly as it should have. As a result, it throttled down a few seconds later than commanded, and—with the rocket weighing about 67,000 lbs and traveling nearly 200 mph at this point—a few seconds can be a very long time. With the throttle essentially stuck on 'high' and the engine firing longer than it was supposed to, the vehicle temporarily lost control and was unable to recover in time for landing, eventually tipping over." They believe they've solved the issues that cropped up in the earlier tests, and they're looking forward to the next attempt, which will happen on Sunday if the weather cooperates.
Space X break a lot of rockets while landing.
I just got an image of them using Java as their primary control language and the gc decided to collect at the last moment...
If you were me, you'd be good lookin'. - six string samurai
Motion control is as much an art as a science, and PID loops can be a bitch to tune on the bench, I'm not in the least bit surprised they dented a few rockets trying to get this stuff to work reliably. Keep trying and keep posting video of a spectacular fuckups.
The whatchamacallit came away from the doohickey and the widget fell into it. From that point it got all fucked up.
Fuck yeah science
FFS, get those damn icons off the friggin artical title!
Why don't they just build a big net on the barge? If it doesn't land straight up and down, or if it falls over it won't matter. And if the rocket thing doesn't work out maybe they can still catch some nice tuna.
SpaceX Breaks Down... (crap, what happened now?)
its rocket landing attempts. Ah, alright then, never mind. Got me worried for nothing.
On the run for what seemed like decades, the infamous D.B. Cooper has been captured. He was mortally wound in the capture, and his body was eaten by wolves before the remains could be gathered by local LEO.
This is a genius stroke of marketing. Rocket launches are nothing special anymore (besides figuring which of the next three next Russian launches will fail due to incompetence). By focusing on the part of the launch that is wholly inconsequential, people pay them far more attention than they would for an otherwise uninteresting successful launch.
If this software can bring down a rocket safely, could it bring down a plane safely? Could completely self-fly planes be in the wings?
> but about 10 seconds before landing, a valve controlling the rocket's engine
> power (thrust) temporarily stopped responding to commands as quickly as it should have.
"The OS support engineers at Microsoft still maintain we are not one of the very few applications that really need true real time."
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Check out this video of Falcon Heavy. They plan to land and reuse all 3 boosters at the landing site they have leased at the Kennedy Space Centre. Saving 9 engines from a Falcon 9 is a considerable savings but saving all 27 engines from a Falcon Heavy launch would bring the cost per kg down to perhaps $100.
Today's vices may be tomorrow's virtues.
space technology then - Trampolines!
Could somebody explain the reasoning for this? Landing on the ground would make more sense to my limited knowledge. Thanks
CrazyOldMan
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I'm going to assume you've been doing the /. equivalent of living under a rock, since this question comes up (and gets answered) every single time this topic is discussed, and that's a lot. But what the hell...
Landing on solid ground is, generally, preferable. However, unlike the ocean where you can tell all the boats to get out of a safety zone, land has these inconvenient things like buildings and infrastructure that can't simply be told to stay away for their own safety. Until it was clear how precisely SpaceX could bring the rocket down - and remember, we're talking about something returning from the edge of space, at supersonic speeds, with barely any fuel remaining, in a maneuver that had never been attempted before - it would have been foolish to bring the rocket down anywhere near any inhabited regions. Given the geography around the launch sites they use, that means the ocean is the best bet by far.
Also, sometimes they may not have a choice. The rocket *really* doesn't have a lot of fuel left as it returns, and it's going really, really fast in a direction that is decidedly away from the launch site (but not fast enough to make it all the way around the world, or the second stage wouldn't be needed to actually achieve orbital velocity). SpaceX pulls a lot of cool tricks to guide the rocket's return, like using the stage as a lifting surface (with a truly abysmal lift/drag ratio, I assume, but they're also trying to scrub speed) while controlling it with little folding grid fins (which are quite effective at those speeds). However, at the end of the day, even Falcon 9 may not have the fuel margin to return to the spaceport after launches even though it has enough fuel to launch *somewhere*. The center core of the Falcon Heavy - which flies for much longer than the F9 first stage - will be much too far downrange to boost back to the spaceport in most cases. Thus, for FH's center core, the barge may be the only landing option. Landing on a ship may be harder than landing at a conventional spaceport, but the ship can be almost anywhere there's ocean, while land-based spaceports are not noted for their mobility.
Now, with all that said, the goal is to, eventually, be able to land at the spaceport. The next F9 launch after this one will, according to a cool site called SpaceX Stats, attempt to return to the launch site and land there. This presumably demonstrates that SpaceX has been found to have sufficient precision in the first-stage landing attempts so far for it to be safe to land near people and expensive buildings. I wish them the very best of luck!
There's no place I could be, since I've found Serenity...
It's nigro, dammit.
... is why they insist on trying to land it on its feet. It's not like it's going to be taking off seconds after. Why not land it in a material or construction that can take a hit and not care so much about whether it is perfectly upright at the last seconds? It almost looks like Hollywood putting rocket shoes on their stuntmen, instead of having them land in a net, on cardboard boxes or a nice air cushion...
Slashdot is filled (at least theoretically) with smart people... so why do I have to keep explaining this?
It's virtually impossible to determine how much recovery will bring down the costs of launch because we don't know how much it will cost to refurbish the recovered vehicle. Certainly it will be cheaper than building a new one, but how much cheaper is impossible to predict... especially in the beginning with zero experience.
The case with the Shuttle is instructive... it took dozens of flights to go from removing and dismantling the SSME's after every flight to only removing them for inspection every third to fifth flight and only dismantling them for cause. (And they were on the second or third block of engines by the time they reached that point.)
Falcon has the additional problem of figuring out how to inspect and re-certify the tank.
It's Pull the Tregros, Negros
I love that they found time to name the drone ships in true Iain M. Banks' Culture style: “Just Read the Instructions” & “Of Course I Still Love You”
That sound you heard was my point zooming over your head.
Estimates are not reality - even if you do have the experience to base your estimate on. Experience SpaceX lacks.
Plans are not reality. See above about experience.
You say that as if it's relevant. It's not. The structure is still highly stressed and the engines still run at full power. These things matter.
That falls under the category of "no shit Sherlock". Anyone who has actually studied the issue knows this. That's why NASA was trying for a week turnaround back in the 1970's.