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SpaceX's Grasshopper Successfully Flew 325 Metres
- xtc 13y agoHonestly I would like to see some spectacular failures. Just as Gwynne stated recently, if SpaceX doesn't generate a few craters with this program during testing it means they aren't trying as hard as they can. I'm glad Grasshopper will have its flight ceiling lifted soon with the new testing facility. Not to say a 100% flight record wouldn't be fantastic, but I'd really enjoy seeing the trend of doubling height to continue, or even greater.
- mjn 13y agoThey still have about 10x to go to hit the VTOL rocket record of 3140 meters [1], which they seem to be aiming for, so I assume some more doubling-or-greater is in the works. [1] http://www.hq.nasa.gov/pao/History/x-33/dc-xa.htm http://www.hq.nasa.gov/pao/History/x-33/dc-xa.htm
- xtc 13y agoI can't wait.
- Osmium 13y agoEh. SpaceX is very conservative in many ways. Part of the reason they've been so successful is that they've taken tried-and-tested rocket designs and just refined them to be more efficient, rather than trying something brand new and exotic, so I wouldn't say it's a bad thing they haven't had any "spectacular failures." It just means the core technology is finally getting mature enough to be reliable and cost-effective, which is a good thing.
- starpilot 13y agoWhat short memories! http://www.wired.com/science/space/news/2008/08/musk_qa http://www.wired.com/science/space/news/2008/08/musk_qa
- mikeash 13y agoFailures don't have to be spectacular to be useful. One of the nice things about a reusable vehicle (and one reason why rockets are so much more expensive than aircraft to develop) is that you can test things incrementally, such that a failure in whatever new thing you're trying won't doom the system as a whole. Look at the Apollo program, for example. I doubt anyone would say they weren't trying as hard as they could, and yet the only failure I'd call "spectacular" was the very dumb and useless failure of Apollo 1. There were lots of other failures, of course. Apollo 11 had persistent trouble with the computer during landing, nearly leading to an abort. Apollo 12 got hit by lightning on launch, twice, and the mission was only saved by quick thinking. Apollo 13, in addition to the famous explosion that happened partway through the mission, lost an engine on launch. On later investigation, it turned out that the engine loss was due to massive oscillations in the rocket that would have torn it apart within a few more seconds if the engine hadn't fortuitously shut down. Apollo 14 had docking trouble, had to have its computer reprogrammed by the crew in flight to work around a faulty switch, and finally had a radar failure, all of which threatened the mission's success if not the astronauts' lives. Apollo 15's first stage didn't shut off when it was supposed to, nearly requiring a launch abort. Apollo 16 looks to be the first one that didn't encounter major problems. I wouldn't be surprised if SpaceX didn't have a lot of similar failures, which are big deals to them but don't look like anything other than "success" to outside observers.
- startupfounder 13y agoElon and the SpaceX team are kicking ass! 2 months ago they hovered at 250m: http://www.youtube.com/watch?v=xUvbh-Z8Abk http://www.youtube.com/watch?v=xUvbh-Z8Abk 6 months ago they hovered at the height of a 12-story (40m) building: http://www.youtube.com/watch?v=Zz-NYeH-CEY http://www.youtube.com/watch?v=Zz-NYeH-CEY These guys are on a very fast learning curve. These near-ground tests are the hardest. Elon said that they will be using a fully reusable first stage in 2015, only 18 months away: http://allthingsd.com/20130530/tesla-ceo-and-spacex-founder-elon-musk-the-full-d11-interview-video/ http://allthingsd.com/20130530/tesla-ceo-and-spacex-founder-... [http://en.wikipedia.org/wiki/SpaceX_reusable_rocket_launching_system#Falcon_9_booster_post-mission.2C_controlled-descent_tests http://en.wikipedia.org/wiki/SpaceX_reusable_rocket_launchin...]
- bpicolo 13y agoNot sure I would call them the hardest. Stabilizing while traveling thousands of miles per hour in atmosphere to get to the point you can land like this seems much harder.
- mikeash 13y agoIsn't that more or less a solved problem, at least? Maybe there are aspects of it that I'm unfamiliar with which make it much harder for a rocket than for a capsule, but it seems similar, and SpaceX already has that down for Dragon.
- grinich 13y agoICBMs already do this, and we've been precisely deorbiting satellites for decades. Landing safely is the really tricky part. During the Corona spy satellite days, they used to catch the parachuting pods with a plane+hook. http://upload.wikimedia.org/wikipedia/commons/7/76/Keyhole_capsule_recovery.jpg http://upload.wikimedia.org/wikipedia/commons/7/76/Keyhole_c...
- InclinedPlane 13y agoICBM warheads have about a 90% chance of landing within a circle with a radius of about half a kilometer, at least according to declassified info, the actual accuracy is likely higher. Even so, that hardly compares to a precision landing on a small landing pad.
- leeoniya 13y agoArmadillo did this, and cooler already :) https://www.youtube.com/watch?v=9u0qlIoSSkQ https://www.youtube.com/watch?v=9u0qlIoSSkQ http://www.youtube.com/watch?v=k_Xiq3dYJlM#ws http://www.youtube.com/watch?v=k_Xiq3dYJlM#ws
- trafficlight 13y agoWhile it's awesome that they've done this, the scale isn't exactly the same. The Super Mod is about 12 feet tall. Grasshopper is 106 feet tall and has considerably more power.
- jevinskie 13y agoI haven't seen the flight where they cut the engine and restart it. Very impressive!
- grinich 13y agoSpaceX is orbital. Armadillo is suborbital (at least Super Mod). It's like the difference between an ultralight and a 747. Both are impressive, but on completely different scales.
- medde 13y agoin addition to all previous replies: they are also missing the camera from above (ie: hexacopter at ~325m), which was very nice to see
- malkia 13y agoOne is Wolfenstein, the other one is Quake!
- GravityWell 13y agoI was glad to notice the lack of Johnny Cash drowning out the rocket sounds. I have nothing against Cash, but these rocket landings are impressive as they are, without treating them like an MTV video.
- marcosscriven 13y agoVery cool. I'm surprised that the turbulence/vibrations coming back from the pad on landing don't damage it.
- bnchrch 13y agoI am really routing for SpaceX, I would love to see the commercial possibilities (and scientific) if we could reduce the cost of getting to space. Luckily it looks like they're already making some pretty impressive steps if you consider that only 6 months ago they were hovering at 40m.
- jloughry 13y agoDUCK DODGERS: Whoops! Had the silly thing in reverse.
- spiek 13y agoCould anyone explain why this is a good way to fly a spacecraft/what they are aiming for with this? It seems somewhat inelegant, considering the challenges having to do with stabilizing a vertical rocket.
- Game_Ender 13y agoIt's elegant because you "just" have to strap landing gear and some parachutes to your existing rockets and you can reuse them. You lose some payload capacity, but you get to use your rocket again (which is the expensive part). We have tried engineering more complex re-usable lifting body type designs, only the shuttle ended up flying, and it wasn't cost effective.
- adrianpike 13y agoHow much fuel does it take to control a descent from the altitude they separate the stage? I mean, obviously it's worth it, but I'm curious just how much of a game changer this is.
- jccooper 13y agoNo one quite knows, as no such system exists yet, though I imagine SpaceX has some internal numbers. You need enough to slow your mostly-empty (and thus fairly light) stage from its terminal velocity to 0, and however many seconds margin you need to be comfortable. Let's do some very rough numbers to get a ballpark... Say terminal velocity is 100 m/s, which is fairly fast, but a rocket is a skinny streamlined thing. (It could fall slower, maybe even 50 m/s, on its side or with parachutes, but parachutes are heavy and complicated, and falling sideways may be difficult to control, but seems quite possible.) Say an F9 "1.1" first stage weighs 28,000 kg. The landing components mostly are already there: the engines are already gimballed and the additional software weighs nothing. Unless you're so awesome you can land in a cradle--which is not impossible--you need some landing gear, so let's add 3000kg, for a dry weight of 31,000 kg. Amongst all its engines, our F9 has some 300,000kg of thrust. Just one engine is around 33,000kg thrust, so we'll probably only use one or two. Two engines will get us easily about 10m/s slower per second, so we need to retro-fire for minimum 10 seconds. You probably want some margin over that; let's reserve 20 seconds fuel. F9 1.1 stage 1 will have a burn time of 185s; our retro burn is only at about 25% capacity, so 20s of two engines is worth, oh, 5s of normal burn time. Say about 3% of the fuel. Of course, it's not that simple, because (1) we've made the stage heavier with the landing gear, which requires more fuel and (2) to avoid losing performance we'll want to add enough fuel to add our extra burn time, which also requires more fuel, and (3) we need more fuel to lift all that fuel and mass we added. The rocket equation strikes again! (Of course, it may not be that bad, because usually first stages have plenty of margin, and most payloads are not max. Maybe if you encounter a really heavy payload you just agree to throw away the rocket that time; use an old one or something.) Most of my assumptions are pessimistic (I think) but in the real world they may turn out optimistic. I would guess you're looking at 3-5% of the fuel load for a recoverable VTOL stage. A lot depends on details, as with rockets weight scales very badly against performance.