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SpaceX Soft Lands Falcon 9 Rocket First Stage
- jccooper 12y agoBetter video from the first landing, despite the data corruption, than this one, due to the ice fouling. Wonder why this one got iced? Clouds? But even so, it certainly shows success. Can't wait to see 'em get a stage back. That'll be amazing.
- deleted 12y ago[deleted]
- samstave 12y agoNo, it wasn't clouds - it passed through a chemtrail.
- avenueevergreen 12y agoI speculate that this one iced up because the vehicle flew a much higher trajectory than the previous vehicle, as visually noticed from the launch webcast. This meant that the first stage spent more time higher in the atmosphere.
- fortepianissimo 12y agoFor all the rocket science, why can't they get a lens that deices itself?
- jccooper 12y agoThey will. It's not been seen to be a problem before, so they went with the simplest solution. In rockets, every ounce counts. Now they know it happens (at least sometimes) in this very novel flight regime, they'll do something about it--the linked post even says so explicitly.
- ChuckMcM 12y agoI was wondering that as well. Three possibilities come to mind; 1) Atmospheric conditions are right for it (flying a subzero steel device through clouds with moisture in them, same problem that airplanes have) 2) The burning of the cryo-propellants lead to additional ice formation (as they burn they expand from liquid to gas and pull heat out of the tanks/body) 3) "snow" which is a variation on #2 which is that ice crystals that are forming on the rocket as it burns propellant in ascent the camera is accelerating away from them, but in descent the crystals are coming towards the camera. Either way its an 'easy' fix, whether you heat the cover, add a wiper (ala nascar) or change the position.
- mmaunder 12y agoIcing is caused by supercooled raindrops freezing on the airframe. In this case the spacecraft came from a very high altitude so I'd expect the airframe to already be very cold and even if droplets aren't supercooled, they might just freeze on the cold surface of the lens. Pireps (pilot reports) are available globally where pilots report icing conditions they encounter. I suspect the SpaceX engineers anticipated this possibility and decided that they didn't want to add the extra weight and complexity of a heating or deicing system to the lens. I have a feeling someone is working there right now to come up with a quick and dirty deicing system - considering how disappointing this video is. The fluid system the Cirrus SR22 uses comes to mind.
- infogulch 12y agoI think some kind of disposable multi-layered lens cover that peels off automatically would work well. Pretty cheap, and easily replaceable. Effective against more than just ice.
- discodave 12y agoI propose a revolutionary solution: a lens cap. I'm assuming that they only need the video from when they get close to landing so the lens cap can be ejected once the rocket is low enough in the atmosphere that icing is not a problem.
- eyeareque 12y agoor some kind of heating element would work, too.
- Crito 12y agoThe video is pretty cool, but make sure to read the rest of the page. Most exciting of all is this last note: "We will attempt our next water landing on flight 13 of Falcon 9, but with a low probability of success. Flights 14 and 15 will attempt to land on a solid surface with an improved probability of success." That "solid surface" will presumably be a barge. Very exciting stuff. Edit: The "loss of hull integrity" also answers a common question of "why not use parachutes". Even if they could land the stage softly enough with a reasonable amount of parachutes, the stage has trouble surviving tipping over in the ocean after landing. It needs to land and remain upright, but using parachutes you will often get some lateral velocity that would cause a tip-over. They need more control than parachutes can provide (and that's all ignoring the problems of salt water).
- toomuchtodo 12y ago> That "solid surface" will presumably be a barge. Very exciting stuff. I get nerd chills from the level of precision needed to bring a launch vehicle from hypersonic->subsonic speeds to a target that size, and land to reuse the vehicle.
- OrwellianChild 12y agoI'm impressed with the barge concept if only from the wave action the'd have to compensate for. Anyone know wave amplitude in the area they'd be landing in? That's a flat surface that's coming up to meet you or dipping away, making for a pretty heavy drop...
- toomuchtodo 12y agoIt's apparently called "Active Heave Compensation": http://www.boschrexroth-us.com/country_units/america/united_states/en/Company/Trade_Shows_and_Events/trade_shows/otc/a_downloads/press_releases/OTC2012_Primary-Active_Heave_Compensator.pdf http://www.boschrexroth-us.com/country_units/america/united_... It's used at sea for winches, but I'm sure platforms can compensate just as well with the proper force actuators and motion reference units.
- andrewtbham 12y ago> Flights 14 and 15 will attempt to land on a solid surface with an improved probability of success. Anyone know when flight 14 is scheduled?
- washedup 12y agoIt is scheduled for October 2014: http://en.wikipedia.org/wiki/List_of_Falcon_9_launches http://en.wikipedia.org/wiki/List_of_Falcon_9_launches Flight 15 is scheduled to launch November 2014.
- anovikov 12y agoAlmost no chance these will fly this year. We will only see 3 more launches this year IMO, and 2 will not attempt stage rescue, 1 will attempt on water as the previous ones. So wait till 2015...
- namlem 12y agoWhy do you say that?
- anovikov 12y agoBecause the 3 launches are densely packed for August-September, and delay in one means delay of following ones, and delays almost always happen. Then there is a big hole and next launch is for late November. That alone is enough to move the 4th launch after the most recent one into 2015. So nah, we will not see attempt of land recovery this year. I am not a naysayer. I am very enthusiastic about what SpaceX does. Especially the reusability. But i just want to remind that they never stick to their schedule (that's generally hard to do in the rocket business), and their current schedule for the rest of 2014 looks in a way it will be almost certainly broken even if slightest issues arise.
- HarryHirsch 12y agoWhere do you find a solid surface to land on except in Russia and China? You would like to fly across water or at least unpopulated areas in case a problem develops during flight and range safety needs to go for self-destruct. The USA, Europe, India and Japan all do that, because no one wants a re-run of the Long March desaster in 1996. Flying back the opposite direction is no good because you are fighting the rotation of the Earth and are paying with extra fuel to carry the fuel needed to go back, besides coastlines are always the most densely settled areas of any country. I can't imagine that the economics will work out, but perhaps someone else has genuine numbers to prove me wrong.
- crb 12y agoWill there be a video of the landing, as seen from Earth? Is the rocket currently aimed "at the Atlantic", or are they operating with the precision they need to land back where they took off from: and in that case, do they have a camera pointing at the landing point from a ship?
- dba7dba 12y agoProbably no video from the earth. We won't be getting it for awhile. But I think maybe in about a year or 2 we will get to see the video.
- lefrancaiz 12y agoWhy does the rocket tipping over cause a loss of hull integrity? Does that mean that it actually exploded, just from going horizontal?
- geetee 12y agoThink belly flops on a rocket scale.
- icegreentea 12y agoProbably not exploded, just that the lateral stresses that the rocket is designed for. Rockets have to withstand a lot of different types of forces (axial, all sorts of vibrational, probably hoop type stresses), but massive lateral shocks aren't really one of them.
- mbell 12y ago> Probably not exploded I don't know about that: https://twitter.com/elonmusk/status/488718649515986944 https://twitter.com/elonmusk/status/488718649515986944 Even with minimal fuel, the tanks are still highly pressurized, a loss in hull integrity would result is a rapid depressurization of those tanks. It may not have been a fiery explosion, but I would bet it made a hell of a bang.
- bashinator 12y agoI think it just meant that because it was wholly immersed in water, it's not worth refurbishing.
- rspeed 12y agoCompare the amount of force it takes to crush an aluminum can from the sides vs. from the top and bottom. A rocket is the same basic shape and material.
- nickhalfasleep 12y ago"it fell over, as planned"... great attribution of the fundamental nature of gravity. But mad props to SpaceX for working towards recycling their boosters.
- m_mueller 12y agoI had a laugh at that as well. Idiocracy seems near if things like that need to be mentioned in press releases.
- elements 12y agoThe shuttle SRBs floated vertically after splashdown, so I don't know why someone would be dumb for thinking the Falcon 9 booster might do the same.
- axman6 12y ago"This was a COMPLETE failure! It FELL OVER! THEY'RE JUST TRYING TO SAY IT WAS SUPPOSED TO DO THAT AFTERWARDS! SELL ALL SpaceX STOCK PEOPLE!" We've all seen this sort of crap to one degree or another. Sadly a lot of it right here on HN.
- larrydag 12y agoI've been super impressed with how efficient SpaceX is in getting launches into orbit. I did a visual comparison to the Space Shuttle program. It looks like SpaceX will overtake the Space Shuttle launch efficiency by the end of the year. http://snag.gy/wUTD7.jpg http://snag.gy/wUTD7.jpg sources: http://en.wikipedia.org/wiki/List_of_space_shuttle_missions http://en.wikipedia.org/wiki/List_of_space_shuttle_missions http://en.wikipedia.org/wiki/List_of_Falcon_9_launches http://en.wikipedia.org/wiki/List_of_Falcon_9_launches
- bellerocky 12y agoThe space shuttle launches are manned missions. I don't think it's a fair comparison.
- tnorthcutt 12y agoThat graph might be a little more intuitive if you swapped the axes, FWIW.
- hughes 12y agoDefinitely. Also choose colours that aren't almost identical.
- Dylan16807 12y agoThe blue and black don't look very close to me, and they're pretty color-blind safe. Odd.
- ilaksh 12y agoThe hardest part is not running out of fuel on the way down. Old-school science fiction often assumed something like nuclear power where that wouldn't be a concern. Seems like for many years most people haven't even attempted this full recovery/landing thing because of fuel and weight issues. Has SpaceX really cracked that problem? What portion of flights on this smaller rocket can do it? It says some missions won't have enough fuel left over. Will the Falcon 9 Heavy be able to do all or almost all missions with a landing and full recovery at the end? How much fuel will Heavy have left on average after a return? Theoretically it would not wait until the last possible second to start slowing, and therefore use up almost all of the fuel in order to give the descent a larger margin of error and also reduce the possibility of damage, I assume.
- jpgvm 12y agoUntil now most information out of SpaceX has suggested it needs roughly 30% propellant left in the first stage of Falcon 9 to attempt a retrieval. Numbers are not yet known for the 2nd stage retrieval or Falcon Heavy. One could probably assume a similar number for the first stage but possibly a bit less given the Falcon Heavy's higher thrust/weight ratio.
- deleted 12y ago[deleted]
- grecy 12y agoIs SpaceX's long term plan to also have 2nd stage retrieval? (I didn't know that)
- jccooper 12y agoYes; in fact they have videos showing the whole stack re-entering and doing a propulsive landing (one at a time, of course.) The second stage will need a re-entry heat shield, but otherwise can land like the first. Tricky part is getting enough margin in the second stage for the landing fuel and legs and heat shield. Usually the top stage is the one you optimize most heavily. So plausible, but tricky. Good news is that the second stage is much cheaper than the first, at least on the F9. Eight fewer engines, for one.
- russell 12y agoI did see a launch north over my town, about 80 miles north of Vandenberg. It looked like the path was over the ocean all the way. The first stage was still burning, so it was pretty spectacular. Edit: oops. This was supposed to be a reply to the comment below about launches from Vandenberg being mostly to the south.
- sargun 12y agoI'm curious as to why SpaceX, or their competitors haven't utilize Sky Cranes, a la Mars Science Laboratory: http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Sky_crane_landing http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Sky_cra... - basically, it seems to be a powered parachute.
- mmcnickle 12y agoThe sky crane solves a very particular set of problems with landing a (relatively) small, functional rover on Mars. It's not really a general solution to returning a large payload intact to Earth.
- danielweber 12y agoThe sky crane will probably never be used again. It was an engineering marvel but the requirements that brought it into being were a management nightmare. (Requirements to not use any carbon-based propellant directly on the surface of Mars, which probably got violated anyway because you can still see blast marks from the sky crane where MSL landed.) And it was only useful for one very particular mass window -- much lighter and it wouldn't be useful, much heavier and it couldn't work.
- JulianMorrison 12y agoThe main difference between a sky crane and a soft-landing rocket stage is whether the braking/hovering engines are inside the thing landed (SpaceX) or outside and discarded after landing (sky crane). Since SpaceX is doing their best to not discard things, a sky crane is the opposite of what they want.
- anovikov 12y agoWhat i don't understand is how are they going to solve the problem of landing precision. The stage is passive from the retroburn (just after the stage separation) for the several hundreds seconds it is flying back, and large part of that trajectory is in atmosphere, and stage has a high sail factor: it is big and, being almost empty, lightweight. So it might be dragged by wind too far from the landing site to compensate in hover mode which is i assume only 100-200 meters or so, even if original entry trajectory is perfect. Ballistic missile warheads for example, accumulate about 100 meters or error due to this factor despite they are much smaller/have higher density and fly several times as fast. A an additional short mid-flight engine burn to compensate may be a solution but so far i haven't heard of that. Anyone has an idea?
- ceejayoz 12y agoBallistic missile warheads aren't slowing down for a soft landing. Try landing a helicopter at Mach 1 and see how accurate it is compared to a normal landing.
- Symmetry 12y agoI believe that's what the new grid fins they've been testing out on the Grasshopper are for. Those are there to let the rocket steer even at the speeds it comes in at. http://en.wikipedia.org/wiki/Grid_fin http://en.wikipedia.org/wiki/Grid_fin
- toomuchtodo 12y agoThey are! And they work well at both subsonic and supersonic speeds, just not transonic speeds.
- anovikov 12y agoNo, these things are just for improvement of stability when descending. But it seems that answer is aerodynamic control by partially (and differentially) extending the LEGS. Which appears brilliantly smart and should work. Same hardware, zero additional weight or cost, additional function.
- Jacky800 12y agoI wish there is someone in the medical domain equivalent to Elon Musk.
- mtm 12y agoElizabeth Holmes is taking a stab at it: http://seattletimes.com/html/businesstechnology/2024121844_valleyphenomxml.html http://seattletimes.com/html/businesstechnology/2024121844_v...