Longer Video Shows How Incredibly Close Falcon Stage Came To Successful Landing 342
Bruce Perens writes In the video here, the Falcon 9 first stage is shown landing with a tilt, and then a thruster keeps the rocket vertical on the barge for a few seconds before it quits, followed by Kabooom with obvious significant damage to the barge. It looks like this attempt was incredibly close to success. Given fixes, a successful first-stage recovery seems likely.
Larger landing area (Score:5, Interesting)
It sure seems that if a larger landing area was available, so that the rocket didn't have to lean so far to adjust to a very small target and thus could prioritize staying vertical, it would be able to land successfully. What's it going to take for NASA or the FAA or whatever to give them permission to land on, um, land.
Re:Larger landing area (Score:5, Interesting)
The ship is 300 feet long. It's a big rocket :-)
The pad area they have at KSC is made for F9 Heavy, and multiple stages are supposed to land there, the neighbors are sensitive about having other rockets come down in their yard, and there's a big building you really don't want to hit :-) . So, they probably do need the precision. There was an odd tweet from Musk, later deleted, that said there was actually a process control problem and a phase delay.
Re:Larger landing area (Score:5, Funny)
The pad area they have at KSC...
The Kerbal Space Center?
Re:Larger landing area (Score:5, Insightful)
Not until the next time we cut the NASA budget to pay for a subsidy of some incredibly rich industry. Like oil. We need more oil drilling subsidies, don't we? Or intellectual property. That's just another word for innovation, isn't it?
Re:Larger landing area (Score:5, Interesting)
Re: Larger landing area (Score:5, Interesting)
@elonmusk: @ID_AA_Carmack Looks like the issue was stiction in the biprop throttle valve, resulting in control system phase lag. Should be easy to fix.
Re: Larger landing area (Score:5, Interesting)
Certainly looked that way to me. On the last oscillation before touchdown, with the tail end moving towards the left, the thrusters keep pointing the same way as the rocket goes through vertical and only change direction a little bit afterwards. This increased the amplitude of the oscillation rather than decreasing it. The thrusters should have changed direction before passing through vertical, not afterwards. I can't imagine them getting this wrong in software, it's basic dynamic stability 101, so a sticky valve seems likely.
The rocket ended up landing almost perfectly vertical, but still rotating so the base was traveling sideways over the landing pad. No way they could stay upright like that.
Re: Larger landing area (Score:5, Informative)
Armadillo Aerospace had their own prototype hovering-gimballing single engine rocket, and Carmack was heavily involved in development of the logic and systems that made that possible.
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So can someone explain why they don't use a soft landing pad? Maybe an inflatable. It would have to be robust enough to survive the engine firing near it, but would allow the rocket to land on its side instead of having to stand upright.
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I had heard that a valve got stuck, causing the throttle and gymbaling to get out of sync. Now that I see the video, it looks like it was coming down really well until that last moment. It probably wanted to make a final course adjustment, but the rocket bits didn't work the way the computer bits expected them to. It even seemed a bit like the kind of crashes I would get in Gravitar [wikipedia.org] after getting a bit confused.
A larger landing area would have just meant no bits to fall into the water after the kaboom.
Re:Larger landing area (Score:5, Informative)
The tweet from Musk this morning used the word "sticktion", meaning static friction. And said it was the cause of a phase delay. And then the tweet got deleted.
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ty for that.
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So you're saying it wasn't hyper quantum sticktation of the flux attitude gimble during the multiphasic delay sequence?
Damn, I should write science fiction. Or maybe I could work for the media. Both string scientific sounding words that mean absolutely nothing. :)
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Now that I see the video, it looks like it was coming down really well until that last moment.
no way. for a gigantic fragile rocket it came in extremely hot. it was probably moving at 50+ MPH when reached 50 feet of the platform. it didn't slow down much until it was less than 10 feet away. it was also wobbling as it came in.
as much as i'd like to say that was close, it wasn't.
Re:Larger landing area (Score:5, Insightful)
That would be hot for an aircraft, but it was the planned vertical speed profile for the rocket. The grid fins need speed to work and they are the main control surfaces. The cold gas thrusters don't have infinite gas behind them and the engine burns are very short.
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It's still slowing down during the last rocket length. That is really cutting it close, yes. I think the goal is to use an absolutely minimal fuel expenditure. The current configuration is not capable of landing after a GTO insertion. When they were considering doing the test for the DISCOVR flight, they were not going to have enough fuel for the normal recovery sequence, and were planning to delete the subsonic decel burn and come up to the barge at 1 KPS rather than the leisurely 250 m/s.
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Re:Larger landing area (Score:5, Informative)
The F9 is intended to land with what they call a "Hover Slam" maneuver - the engines decelerate it to zero right above the surface in as little time as possible. The Merlin engines have a limited throttle range, and with the stage empty, just one engine firing at the lowest throttle setting has a thrust-to-weight ratio somewhere around 1.8, so it can't hover. It would decelerate to zero and then start to lift off again if the engine isn't shut off, you'd need a TWR of 1.0 to just counter gravity and make it hover.
Re:Larger landing area (Score:4, Insightful)
Rockets are capable of incredible acceleration, especially when they're low on fuel and deprived of their payload. Under those conditions, the F9 first stage could easily go from 50MPH (~22m/s) to 0 in the space of a few meters.
Also, you *want* to land fast, because for every second you spend in the air you lose another 10m/s of your limited delta-v (fuel), and the faster you're traveling the more aerodynamic control you have.
Yes, I know all this from playing KSP.
Re:Larger landing area (Score:4, Informative)
Specifically, from a starting height of 50 feet, and a starting velocity of 50 mph downward, it would require a net acceleration of ~16.5 m/s^2 to come to a stop at ground level.
Since a single (much less nine) Merlin engine can manage 654 kN thrust at sealevel, and a (nearly) empty Falcon 9 first stage masses under 20000 kg, a Falcon first stage is capable of >32.7 m/s^2 acceleration (assuming only one engine burning, of course). Which is more than plenty to allow it to come to a stop on the ground from the estimated speed/height of the OP....
Re:Larger landing area (Score:4, Interesting)
That's exactly what it is, since they don't have the throttle authority to burn lower, longer.
With that approach profile, they're aiming to have dV hit zero the same exact instant that the rocket settles into a 1g static load on its landing gear - same as if it was just sitting on the ground.
There's a good reason it's called a suicide burn.
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It's not all politics.
The first stage is a good distance downrange when it is done, as in; way out in the Atlantic when launching from Cape Canaveral.
So, to fly it back to Kennedy would take a lot more fuel than letting it come down where it is. Not to mention the 'just in case' scenarios involving Titusville, the nearby I-95, etc.
It will benefit Elon greatly if he can pull off landing it on his ocean barge. If he can do that, he can launch from anywhere in the world, with competitive fuel/payload ratios, a
Re:Larger landing area (Score:5, Insightful)
I was surprised by something in the re-entry profile. They use what they call "lift" from tilting the rocket body against the air stream to control horizontal motion. I call it "falling with style". So they can go back uprange some distance without an additional fuel expenditure.
All of their communication so far has been that they can get back to the pad with the F9 or the two outer stages of the F9 Heavy. The center stage of F9 Heavy would probably need the barge.
Re:Larger landing area (Score:4, Interesting)
Thanks Bruce, it's often in these little nuances that I catch myself staring into space, contemplating the sheer enormity of what has been achieved here. The skills of these people - to do what they're doing with the budget at their disposal - almost completely wrecks my personal 'scale of difficulty'. I thought I understood what they meant by 'It really IS rocket science,' but I'm really not even close.
We really must be living in the future: small, agile, private enterprises taking the reigns of progress from state-level actors. NASA are by no means obsolete, if anything they've adapted rather well for a bureaucracy of their size and are continuing to do amazing science.
Budgets might be tighter than we'd like but I can't help feeling like we're entering a golden era of space exploration and related technologies.
Ooooh.. uh, does this make me a Space Nutter?
Elon's King of Swamp Castle (Score:3)
When I first came here, this was all swamp.
Everyone said I was daft to land a rocket on a barge, but I built in all the same, just to show them.
It sank into the ocean.
So I built a second one.
And that one sank into the ocean.
So I built a third.
That burned down, fell over, and then sank into the ocean.
But the fourth one stayed up. And that's what you're going to get, Son, the strongest rocket in all of aerospace.
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That large explosion at the end of the longer video implies there was plenty of fuel left over.
You would assume that, yes. But a) that's mainly the fuel vapour in the near-empty main tanks, and b) the fuel the GP is talking about is the pressurisation of the hydraulic lines for the control systems that run the thrusters and fins, not the fuel that runs the rocket engine.
Landing vs splashdown (Score:2)
One would think lifting off with all that fuel needed for the landing is inefficient compared to a splashdown parachute recovery like the shuttle's boosters. And the damage caused by landing on water with parachutes has got to be less than the explosions from the landings on the barges.
Re:Landing vs splashdown (Score:5, Insightful)
Probably not when they figure out how to land on the barge without exploding... at that point the damage from hitting the water and amount of cleaning & service required to be read for launch will be much more.
Re:Landing vs splashdown (Score:5, Insightful)
Remember: seawater ruins everything.
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Remember: seawater ruins everything.
One of those occasions where I wish I had mod points but don't. Mod the parent post up!
Seawater is extremely corrosive. Engineering the rocket engine to survive sudden immersion in seawater when very hot would add a great deal to the complexity and cost (and probably weight). And that's before you add the cost of engineering the rest of the vehicle to resist corrosion.
Re:Landing vs splashdown (Score:5, Funny)
We could start with our already phallic looking rocket and then have it come down into something that looks like the world's largest inflatable sex toy. Elon Musk might have trouble living that one down. :-)
Yes, there have been many proposals to somehow catch the rocket.
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Re:Landing vs splashdown (Score:4, Interesting)
They have talked about refueling on the barge and flying the booster to land! That's really difficult to do after a salt-water dip :-)
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Where I used to live they had trucks dump salt on the road!
Re:Landing vs splashdown (Score:5, Informative)
Close to where I live are large intertidal mudflats. Every other summer some tourist drives a brand new four by four out there and gets stuck. And then, of course, the tide comes in. When the vehicles are recovered two or three tides later, they are insurance write-offs - the electrics, interior, and engine are all beyond repair.
You do not want to immerse something complex and expensive in salt water unless you really, really have to.
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I've heard this point before, with the obvious comparison of Shuttle wings. The counter is that wings are absolutely dead weight on liftoff, plus you've added an entirely new structural mode to the airframe. It has to have the correct structural strength for both vertical ascent and horizontal landing. Both wings and bimodal structure add weight.
Landing the F9 on it's tail, it's practically empty, a fraction of it's initial weight. I'd be interested in seeing the math between F9 and Shuttle, but I suspe
Re:Landing vs splashdown (Score:5, Interesting)
A couple of months ago I was having a discussion with a fellow from Space X who designs the hydraulic systems and we spoke about a number of issues. This was right after the failed landing due to it running out of hydraulic fluid. I asked about how reusable the engines are and he said that they run test burns lasting hours. The launch is only a few minutes. According to what he said, it should just be a simple matter of refueling and adding more hydraulic fluid and probably some other simple things without having to do a major overhaul. The engines are very reliable.
I asked about why they don't reuse the hydraulic fluid and he said that it was cheaper and lighter to not reuse it. He also said that they knew it could run out and that the next version would have more.
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It's lighter to not reuse the hydraulic fluid.
It's an open loop system with pressurized gas pushing the fluid out and then it's dumped in the air. Pumps and whatever powers them have weight.
Remember that big fuel-required multiplier in getting any weight at all to 78 miles height and suborbital speed.
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Sorry.
I guess then you were not so lucky as to have rocket scientists in the family. I guess I'm not unlike many techies my age, whose dads worked in aerospace. My dad worked on the lunar module at Grumman. My father in law worked in the blue cube for Lockheed.
People think of me an the Open Source guy. But I have been getting space spoon-fed to me since before first grade.
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Every time there's a thread about this, someone says the same stupid thing you're saying, and it's still wrong.
There's a huge difference in power requirement in getting a fully fuelled and loaded rocket up in the sky, and slowing the descent of a nearly-empty, lightweight fuel tank. You need very little fuel to accomplish the latter. Don't forget that parachutes have mass too and it's very hard to make a controlled descent with them (especially if you need to carry the rocket a significant distance). All in
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They have fuel to spare on board anyway (so they can launch with eight of nine engines working)
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If one engine fails, the fuel cross feeds from that fuel tank into the other engines. I could be wrong, but I do not believe each fuel tank automatically includes more fuel to burn that particular engine for longer just in a case another engine fails. That would be an awful lot of redundant weight for very little benefit. Being able to cross feed the fuel from a broken engine's tank into the others would make far more sense then constantly launching with a bunch of dead weight that is not going to be used.
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The required longer burn to make up for a shut down engine does use extra fuel. It also changes the orbital injection point.
Re:Landing vs splashdown (Score:5, Insightful)
Re: Landing vs splashdown (Score:5, Insightful)
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Re:Landing vs splashdown (Score:4, Informative)
fuel needed for the landing is inefficient compared to a splashdown parachute recovery
The barge/ocean is just a temporary measure. The vision [youtube.com] is twenty rockets launching a day and returning to the launch site to prep for the next launch.
There were about 120 rocket launches last year. SpaceX's mission statement is to reduce the cost of launches by 100x, and utilization rates go up as costs fall, so it's not just 100x more launches - twenty a day is probably very conservative if they hit their price targets.
Queue the folks who can't imagine what anybody would do with more than 640 launches a year.
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One would think that if they didn't know that the shuttle's boosters are made of inch-or-more-thick steel, while the Falcon's tanks are millimeter thick aluminum-lithium. And that the booster splashdown still tended to leave the boosters slightly out of round (which contributed to the problem Challenger had).
The extra fuel almost certainly weighs less than the necessary parachutes would.
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The first stage is most of the rocket by weight. The second stage has one engine, while the first has 9. And as you can see from a photo, the second stage is much smaller.
What makes it recoverable is that it doesn't take much fuel to bring an empty first stage back down. It's really light when empty. They only use one engine out of the 9, for very short burns, to do that.
No I don't agree (Score:3)
The falcon can't throttle down enough to hover before landing so it has to approach the pad at high speed, and high acceleration. While doing this it has to rotate the entire vehicle to control lateral movement. It has to coordinate lateral and vertical acceleration to achieve near zero in all three axes at touchdown, with only one chance to get it right.
I doubt this can be done without extra thrusters for fine control over velocity and position.
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But we've seen Grasshopper and Falcon R9 position properly on land. Nobody's told us what the maximum wind was in those tests.
Musk alluded to a process control issue this morning and then deleted the tweet. It will take time to find out what the deal is.
Merlin 1D can throttle to 70% and the old 1C could go to 60%. Perhaps there's room for deeper throttling. I would expect that they'd try that before adding a new system and its weight.
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In those tests, both Grasshopper and R9 were coming down much more slowly. But it appeared they could come down slowly. Pretty close to hover.
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I suspect they just need to tweak some PID loops at this point. I don't think throttling is an issue. Unlike the Lunar Lander, the target of the landing is a concrete point. Hovering should not be needed. Drop it on the spot, done.
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>Perhaps there's room for deeper throttling.
Indeed. It might even make sense to use a different design for the central engine if deeper throttling interferes with efficiency or maximum thrust. Of course if they can get the control systems working properly with the standard engines that would be the optimal solution.
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Came here looking for the armchair rocket scientists, left unsurprised but disappointed. Dunning-Kruger lives.
Re:No I don't agree (Score:5, Funny)
We have Kerbal players now.
Try HD mode (Score:5, Informative)
You can see a lot more if you go to 1080 HD and full screen. There's some large piece of equipment, perhaps the motor head for one of the barge's corner thrusters, being thrust off of the barge in flames.
It looks like they'll need to do a lot of work on the barge. The support ship Go Quest and the tug Elsbeth III seem to be back in Jacksonville according to vessel tracking sites. There is a Carnival cruise ship that parks next to the barge's dock every 4 days, so we will probably see photos from its bow netcam if we don't see them otherwise.
Oh, check out this newscast [youtube.com]. At 2:43, CBS News uses a sequence a SpaceX fan produced with Kerbal Space Program to illustrate how the landing is supposed to work.
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I don't think that was Scott Manley's video, but he's hardly the only well-known person making KSP videos. Given the effort it takes to recreate it that well I doubt someone on their staff did it. I wonder who they ripped off without credit if that's the case.
Re:Try HD mode (Score:5, Insightful)
Oh, they're Canadian. That explains everything!
(Ducks and runs for cover)
:-)
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The Hard Way (Score:2)
Why do it the hardest and most fuel inefficient way imaginable. Split seam the fuel tank, then swing out and rotate the elements and create a massive autogyro. Sure you have to be careful with the seal of the seams in the tank and wind could be a problem requiring on the fly change of landing zone but overall a whole lot less additional fuel required and even a bad landing will still be soft by comparison.
Re:The Hard Way (Score:5, Funny)
They have a job for you in the ULA marketing department.
Re:The Hard Way (Score:5, Insightful)
Why am I not convinced your way sounds like the "easy way"?
I can't event think of the mechanical stresses involved in opening this thing up to spin it around.
In fact, it sounds outright crazy.
And that's before we start considering a fuel tank designed to open up. Because, what could possibly go wrong there?
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What's the worst thing that could happen? The fuel tank leaks and explodes shortly after takeoff, showering the ground nearby with burning wreckage, or leaking rocket fuel higher up in the atmosphere, without igniting it, coating everything around with toxic, un-burnt fuel, ready to set half a state on fire?
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Who cares about the fuel efficiency of landing? A Falcon 9 launch costs about 50-56 million dollars - the fuel itself only costs about 200,000, or 0.4% of the launch costs. The cost of increasing the fuel load by a few percent to allow for landing barely even qualifies as a rounding error.
Meanwhile, all the extra mechanisms needed to turn a simple high-strength fuel tank into a transformer is almost certainly going to increase the mass so much that you'd need far more fuel to get the thing to the second-s
I Disagree with the Summary (Score:5, Interesting)
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I was shocked at how abrupt and extreme the pitch changes were. I think so long as it needs such gross adjustments so close to landing, landings will be unreliable with a significant chance of failure. It is not at all like the tidy landings made by the Grasshopper test vehicle.
Two engineering changes which could make a big difference are lower minimum thrust (so it can approach the landing with lower acceleration) or lateral control rockets (RCS) at the top of the stage.
Re:I Disagree with the Summary (Score:5, Interesting)
Someone in the Youtube comments says "The flight profile veers the booster off to the side on purpose so the exhaust from the final burn isn't directed at the barge where it could do damage"
If this was a planned manoeuvre, I'm much happier. Can anyone confirm this statement?
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It *has* RCS at the top of the stage. One of them fires for a good 4-5 seconds trying to hold the stage upright after the touchdown (it failed, obviously). Were you watching in really low quality or something?
Re:I Disagree with the Summary (Score:5, Insightful)
They hit a barge in the middle of the ocean with a gigantic rocket that was nearing orbital velocity. I think we need to cut them some slack :)
"Close" Only Counts (Score:5, Insightful)
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In combat it's called "walking your fire". Sure, the first 30 rounds aren't close enough to matter in themselves, but they give you enough information so that the 31st round hits home.
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Not that great with a 30 round magazine.
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I must confess that most of my programs have bugs the first time I write them. I don't start over from zero when that happens.
The Wright Flier didn't get to San Francisco, but it started the path that led there. Actually touching down on the planned point, at the planned vertical velocity, is pretty good. They'll fix the rest.
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If you think that's bad, read some of the comments to nontechnical news site articles on the recovery failure. Ignoramuses whining "how much of my taxes did this failure use". They aren't even smart enough to realize that it launched the Dragon to ISS successfully, and that NASA isn't footing the bill for recovery attempts. It's really enough to kill one's sympathy for the common man.
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Well, it did what SpaceX was paid for reliably, which was to send the Cargo Dragon up to ISS in an expendable rocket. All of the NASA demo and supply flights they have done have been successful.
Recovery is so far a secondary and private mission of SpaceX, and Musk did say it had less than a 50% probability of success for this attempt (but a 75% to 80% probability of success for the year).
Me, I'm damned impressed that they can bring that thing from 78 miles high and suborbital speed, and touch the landing ge
Re:"Close" Only Counts (Score:4, Interesting)
Armstrong was an exceptional pilot, I read on old NASA report about him regaining control of a space capsule that started spinning before it could kill them. Something to do with a malfunctioning thruster rocket.
Here it is:
"And, make a decision he did. In a rule-breaking move, Armstrong manually disabled the OAMS thrusters and activated the re-entry control system (RCS) thrusters to stabilize the spacecraft. With hand controllers aboard the spacecraft now functioning properly, correct motion of the capsule was restored."
http://www.spaceline.org/fligh... [spaceline.org]
Yeah, they were 'hands on'
Alternative Idea for Landing (Score:3, Interesting)
Re:Alternative Idea for Landing (Score:5, Informative)
The forces required are enormous, and even 10m away the rocket thrust would toast most materials. It still has to be caught in a specific orientation to minimize stresses, which means stabilization. As for stopping further, a 10m fall would probably far outstrip the capacity of the structure. (For comparison, more heavily built high power / amateur rockets are designed for touch down forces equivalent to a drop of about 2 meters). The fuel difference is near zero since the full motion of the rocket must be arrested prior to that final "fall".
It also means that the rockets could never land on an arbitrary location, which would be a future goal. Solving it now is a Good Thing (TM).
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While I think your idea would still leave some damage ... I'm thinking similar ... something like a safety loops that snare it at multiple heights once it touches the barge.
Re:Alternative Idea for Landing (Score:4, Insightful)
A booster is really a pretty fragile thing. It's designed to be really strong in one axis only. It also has to be lightweight. Grabassing the thing from the sides is going to make for a bunch of expensive scrap metal.
Any ideas for improvements? (Score:2)
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Speed and distance are the big problems. Rockets can do both. Things that are tied to ships or the ground have trouble keeping up with the rocket.
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Rotating a thousand ton barge at 60 rpm would be interesting.
Re:Any ideas for improvements? (Score:4, Insightful)
I suppose magnetic/sticky harpoons might help (you don't want to damage it after all), sort of like guy-lines on an airship. I don't know about a shock-absorbing landing pad (your catcher's mitt) though - in the moments before landing the backwash would be subjecting it to forces exceeding those of the weight of the rocket itself - probably at least as difficult to tune any "give" to occur at the proper moment as i is to land the sucker in the first place.
Plus, as others have mentioned, Musk seems to have his eye on Mars. Landing a colony ship can probably only be done by rocket, and there won't be any special landing pads on Mars. Plus, for more terrestrial concerns, if he can master landing on a simple barge, he can land pretty much anywhere, which dramatically improves the value of his rocket design onte international market: any bit of flat, stable land is a potential cheap spaceport that his rockets can service.
why dont they spin it? and land it in a silo? (Score:2)
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It doesn't have to be a big heavy concrete silo. Picture something like a big playland plastic thing, like a too deep skateboard well at the park. Maybe 15 degree angles; the rocket at rest can lean against it without undue mechanical stresses. It covers the whole barge, and it's tall, but light; so it is still a viable ship.
But a huge target, that can't be missed, and you won't tip over.
Downside; can't relaunch from the barge now. Have to just ferry it back to the Cape.
Seems like a pretty good idea though.
Some Additional Details (Score:2)
New product (Score:4, Interesting)
Musk's claim is that the barge didn't sustain any serious damage.
Screw self-landing boosters. What I want is a house made out of whatever the barge is made of, easily shrugging off what are essentially two direct rocket hits complete with massive explosion.
obvious damage (Score:2)
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Only a billionaire can say that damage from an exploding rocket booster landing on top of something is 'minor'.
Funnel (Score:3)
Build a large funnel, or infundibulum, on the barge.
All you have to do is hit the wide top of the funnel at a non-clusterfuck angle.
Then you let the structure of the funnel contain and guide the rocket as it continues on down.
If you fuck up badly, you won't lose everything. And if you do very well for 98% of the landing but tip toward the end, damage from impacting the walls of the vertically will be incidental and minor as the rocket is still thrusting to lower its velocity (and thus the force of the impact).
And if you do it successfully the funnel isn't touched.
Alternatively, do the same but instead of a solid funnel, use closing arms so you can actively catch and assist the rocket if need be, or drop the arms and let the rocket fall into the ocean if you have to abort.
You could also put 8 electromagnets in a circle with the target in the center. If the rocket leans north west, increase power to the southeast magnet and decrease power to the northwest magnet.
Another idea would be to have a guy with a long stick on the barge ready to nudge it just a bit if it starts to tip.
Not 'close' (Score:3)
1. Hit the target location
2. Minimal vertical velocity
3. Vertical orientation.
They met #1. It was coming in tilted (for varying amounts of tilt), and way too fast.
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They planned the fast approach. Consider that the main control surfaces are the grid fins. They don't work at slow speeds. It's all about landing with the minimum use of weight (thus fuel).
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They got #2 as well, it was just that #3 wasn't quite there.
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You're just jealous 'cuz you're mom won't by you a quadcopter.
Speaking about getting a life ....