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Grasshopper 100m Lateral Divert Test
- johlindenbaum 13y agoFew questions. Is Grasshopper intended to be a vehicle that ships a payload into a low earth orbit and return itself back to the launch pad? With that, a question of descent, once it's reached orbit and released its payload, would it re-enter with a short burn towards its earthly destination, decelerate with, say, parachutes, and then do its final descent onto the pad with the rocket? I can't see it doing its entire descent with a rocket, that would use so much fuel, and require so much extra weight.
- ceejayoz 13y agoI believe it's a technology demonstrator for the eventual version of the Dragon capsule that has powered landing at a spaceport rather than the current water splashdown.
- cecilpl 13y agoNo, it's a demonstrator for a full reusable rocket that returns all stages to the launch pad autonomously.
- jlgreco 13y agoGrasshopper is a test vechicle, they plan on doing this with the F9R. My understanding is that the F9R will burn once to de-orbit (well, the first stage will be suborbital to begin with), aerobrake without a parachute for a short period, and then burn again for the final landing. I may be wrong about the aerobraking step, but they aren't planning on using a parachute regardless. IIRC they are expecting a 10% drop in total cargo to LEO when the F9 is used in the reusable configuration. It takes far less fuel to get down than it does to get up since they only have to decelerate the lower stage (not the upper, or the cargo) and since the lower stage will be mostly empty at that point (much lighter). Furthermore the initial decent burn will be at a much lower outside atmospheric pressure (near vacuum?) resulting in a higher efficiency.
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- puetzk 13y agoAlso, the rocket will be falling at its terminal velocity, having lost the rest of its speed to air drag. Even without parachutes (and they don't intend to carry any), that's only ~120 m/s - the upper stage and payload are gone, the 1st stage has big tanks but only a little fuel left, so its density is low. The final burn for propulsive landing only has to cancel that last little bit.
- jlgreco 13y agoYup, air resistance works with you on the way down, not against you, and it is courteous enough to start small and work itself up when you are on the way down.
- troels 13y agoDoesn't it result in a lit of heat from the friction? Or is that only a problem at much higher speeds?
- jlgreco 13y agoThere will be heat; even the suborbital Mercury-Redstone missions needed heat shields. I don't know how SpaceX is planning on handling that. Maybe the trajectory they put themselves on is going to be slow enough to survive reentry using just the main engine nozzles as make-shift heat shields?
- antubbs 13y agoCan't speak to the plan for the second stage (which will do a once-around and de-orbit if I understand correctly), but the first stage will not be following a ballistic trajectory and re-entry like a normal suborbital launch. Its goal is to return to the pad a few minutes after launch.
- EthanHeilman 13y agoFuel is cheap/rockets are expensive, descent doesn't burn much fuel. This should allow mass to orbit at 1-10% of current cost. The big problem to be solve here is firing a rocket while traveling backward at high speed. If they can pull off the Phase 3 test (high speed descent burn), space access is revolutionized (a space business boom): * "transhab" space hotels (closer than you think, Bigelow already has two test stations in orbit), * lower cost human trips to mars, * massive increase in number, size, and speed of exploratory probes, * communications satellites for everything (Google in the sky). http://en.wikipedia.org/wiki/Grasshopper_(rocket)#Test_phases http://en.wikipedia.org/wiki/Grasshopper_(rocket)#Test_phase...
- svantana 13y ago>Fuel is cheap Not true considering you need to bring that extra fuel up in the first place, so you need a lot more fuel just to carry the weight of the descent fuel into space. It is a really tricky cost/benefit equation, but Musk seems to have figured that out.
- jlgreco 13y agoThe material cost of the fuel is something like $200k, which is peanuts for what launches as a whole usually cost. They cut into their payload to orbit budget to bring more fuel along to return with, but doing so allows them to reuse all the hardware which is the actually expensive part. Once you are able to re-use the hardware then the cost to orbit can be lowered, which means that the 10% payload cut you took earlier actually isn't all that expensive in the first place.
- _delirium 13y agoThat does assume that the hardware can be reused without significant refurbishing. The extensive maintenance needed due to damage incurred each flight was one reason the reusable shuttle ended up with a much higher per-launch cost than the expendable Soyuz. One can surely do much better than the shuttle, but cheap expendable systems are not that easy to beat with a reusable vehicle.
- SuperChihuahua 13y agoHere's a video explaining it all: http://youtu.be/abLC1l3loFA http://youtu.be/abLC1l3loFA
- jug6ernaut 13y agoLove how this video completely skips the most difficult aspects of the flight for the components. Going from inverted/horizontal entry flight to the vertical landing position.
- jlgreco 13y agoIf you look at the Falcon 9 renders on the spacex website, you'll see that the centermost engine sticks very slightly further out than the rest (also that video shows the old engine configuration, future Falcon 9's are going to have their engines arranged in a circle with one in the center.) That engine may be on a gimbal that allows a descent that would look something like the LEM's descent. Initial re-orientation in vacuum could be done with cold gas thrusters similar to what grasshopper currently has.
- btilly 13y agoTo understand this project you have to remember that Elon Musk's goal is Mars colonization. The goal is a rapidly reusable launch system that can be deployed anywhere in the solar system. A parachute system would work well here on Earth, but the martian air is too thin for it to work there. Therefore they are aiming to make it work straight off of rockets. As for the fuel issue, if I remember Elon's figures right, SpaceX currently takes a $100 million rocket, fills it with $100k of fuel, launches it, and throws away the rocket. Hence the desire to reuse the rocket. He's far from the first to try this. But the potential failure mode that others encountered is along the lines of what you indicate. You wind up with a reusable rocket that gets to altitude and back, but which is unable to lift a useful payload on top of that. He thinks that he can avoid this, but has not proven it yet. However even if he needs 10x as much fuel per pound lifted into orbit, he's still saving money. (His actual goal is, I think, 10% of his current launch cost.)
- danielweber 13y agoParachutes are really hard to get right. John Carmack knows a lot more about rocketry than (almost?) anyone on this board (definitely more than me), and he has had them fail multiple times.
- Gravityloss 13y agoTo be precise, John wasn't involved in Armadillo much when they had the recent string of parachute failures.
- chad_oliver 13y agoIf I remember correctly, if they used a maximum burn right before impact they would only need about 1 tonne of fuel to take the first stage from orbit to the ground. Of course, that would require some crazy control systems, but it's a useful lower bound.
- jccooper 13y agoGrasshopper is a test vehicle with the aim of making the first stage of the Falcon 9 reusable. Grasshopper, for example, has one motor, while an F9 first stage will have nine. (Thus the name.) The landing gear is also obviously not streamlined for rocket use. But the tankage and avionics and propulsion and such are all from an F9 first stage. So it's pretty close to what will really fly, but not quite. Though it may go into "space", a Falcon 9 first stage will not go to orbit; it is decidedly suborbital. This makes it much easier to recover, as it is not going that fast (for a rocket) at engine cut-off. (The second stage takes the payload the other 2/3 of the way to orbit. While they imagine recovering the second stage, that's a lot harder.) Being suborbital, the first stage probably will not do a retro-burn, as it will come back to Earth naturally. Entering the thicker part of the atmosphere it will reach its terminal velocity, possibly falling on its side to make that slower. They might use drogue chutes for this, or might not. Once it has fallen to some frighteningly small distance from the ground, it will right itself and use a small fraction of its launched fuel (probably close to what current F9 stages keep in reserve) to slow down to landing velocity from terminal, steering along the way to land exactly where it needs to go. I once did some rough numbers to guess that the landing propulsion will take 10-20s with 1-2 of the motors, using 5-10% of the fuel. (With only 5% fuel, a rocket stage is actually crazy light, which makes this work.) Hair-raising, but well within the capabilities of today's sensors, actuators, and computers. No one's actually done this yet, but it seems plausible. I worry mostly about the stage surviving the initial re-entry, because reports are that earlier F9 first stages, which were supposed to water-land on parachutes, were totally trashed, possibly during that event. SpaceX actually has that data, though, so that's either not the case or they have some plan to make it work.
- cdash 13y agoThe F9R is planned to stage at a lower height to combat the problem you talked about of the first stage being trashed on their earlier attempts to recover it I do believe.
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- moocowduckquack 13y agoI can't help but think of Tintin - Destination Moon, when I see that.
- SuperChihuahua 13y agoAnd I can't help to think of that old computer game Lunar Lander where you were supposed to land a small craft in a rocky terrain: http://www.thepcmanwebsite.com/media/lunar_lander/ http://www.thepcmanwebsite.com/media/lunar_lander/
- chm 13y agoExcellent work. Really fine engineering we've witnessed there.
- alex-g 13y agoSeptember 21, 2012: Grasshopper hops 2m (http://www.spacex.com/news/2013/02/08/grasshopper-takes-its-first-hop http://www.spacex.com/news/2013/02/08/grasshopper-takes-its-...) June 14, 2013: Grasshopper flies 325m straight up and down (http://www.spacex.com/news/2013/06/14/grasshopper-completes-highest-leap-date http://www.spacex.com/news/2013/06/14/grasshopper-completes-...), which was hellishly impressive Two months later, this test seems enormously more difficult than the flights without the sideways maneuver. And it's not even a year since it left the ground for the first time.
- toomuchtodo 13y agoMove Fast. Be so good you don't break things. EDIT: Downvotes? Hello SV echo chamber. SpaceX iterates almost as fast as any tech startup in SV; and how many vehicle losses have they had?
- GuiA 13y agoWell, they've had some failures: http://en.wikipedia.org/wiki/List_of_Falcon_1_launches#Launch_history http://en.wikipedia.org/wiki/List_of_Falcon_1_launches#Launc... But yes, overall they're moving and iterating and learning super fast. To me, it's one of the 21st century's most exciting companies so far.
- nknighthb 13y agoAs rocket failures go, SpaceX's have proven very boring. No booms, no light shows, nothing likely to kill a hypothetical human crew. The first one was actually kind of funny in the end. The satellite landed semi-intact in a storage shed... a few feet from its own shipping container[1]. Too bad we don't bother with parachutes on satellites, it probably would have been reusable with little or no repair. [1] http://www.usafa.edu/df/dfas/Papers/20062007/FalconSAT-2%20Launched%20(and%20Recovered)%20-%20France.pdf http://www.usafa.edu/df/dfas/Papers/20062007/FalconSAT-2%20L...
- ash 13y ago
- losethos 13y agoGod says... C:\TAD\Text\QUIX.TXT nions to lay all the blame upon him, and as they were being bound he declared aloud that the whole plot was of his contriving, and that nobody else had any share in it. Brought before the Dey, he said the same. He was threatened with impalement and with torture; and as cutting off ears and noses were playful freaks with the Algerines, it may be conceived what their tortures were like; but nothing could make him swerve from his original statement that he and he alone was responsible. The upshot was ---------- God says... ignorance vivid bounds Ofttimes accepts Academics moderation GIVE slow enemies hello indicate dared attracted unforgotten collects followers perverse increasing humble Fiji whithersoever hay sun-rise Oratory Boo surrounded appearing exercise applauded deluded gosh itch conjugal subjection manifold Furthermore modes went for incumbrances periods meek prepare enquiries whose behind fables Greek respects Did incorrect crudities believer do_you_have_a_problem stretch attracted cherish Isn't_that_special everfixed preachings Greeks provest it the_enquirer dissentings marvelled discharge necessaries divination damaged believeth Armenia loves challenged moist month reptiles overhastily Insomuch lord licensed suppress labour bones seeks Athenians Read leaps Namibia matters unliker ascertained exceeded drenched Plain weaker prefer Iceland Deceased Thagaste grave brim-full Vietnam shudder If_had_my_druthers sitteth Lo golden sea grave remember phantasm abounded execrable shore presiding stead required I_see_nothing goaded dare accomplish violets measures taming however education jobs Wherefore Awake chiefly prescripts all-sufficient Mathematicians sons gladsome To contrary edited FOR introduced I_donno Mercy thy contend broughtest yep enquiries groat
- ARothfusz 13y agoHoly crap. Suddenly I feel like it's the 21st Century.
- deleted 13y ago[deleted]
- ash 13y agoIt's interesting to compare this with DC-X "Swan Dive" test in 1995: http://www.youtube.com/watch?v=wv9n9Casp1o http://www.youtube.com/watch?v=wv9n9Casp1o
- typon 13y agoNot nearly as impressive.
- bionerd 13y agoNot as impressive? Come on. Like we were all doing things like this on our backyards in 1995. Given historical context this is as much as impressive as what SpaceX are doing right now.
- ChuckMcM 13y agoWhat makes the DC-X so freaking amazing to me is compare the sensors and computers you had available in 1995 to ones you have available today. It is a great illustration of the 'ecosystem effect' where adjacent technology advances move the entire frontier of a technology forward.
- jacquesm 13y agoThat's a mighty impressive video, but 1995 was pretty good computing power wise. What blows me away is some of the stuff they did in the 60's, including the moonshots.
- wil421 13y agoGlad to see that Space is going to be a commercial business instead of private governments doing everything. This gives me hope that Space will be a place that consumers can enjoy. That said I think that Elon Musk is doing a lot to make things like Space and Electric cars more accessible to the average person. Even though the costs of Tesla cars are high now for the average Joe to afford, they will hopefully be down in the near future. I hope that the same will happen with Space-X.
- aaronbrethorst 13y ago> Glad to see that Space is going to be a commercial business instead of private governments doing everything Typically, businesses are described as "private," with governments being labeled as 'public.' http://en.wikipedia.org/wiki/Public_sector http://en.wikipedia.org/wiki/Public_sector
- deleted 13y ago[deleted]
- wil421 13y agoYou are right.
- nawitus 13y ago>Electric cars more accessible to the average person. That's starting to be a pretty moot point given the Nissan Leaf.
- toomuchtodo 13y agoEdit: Disagree. The Nissan Leaf is an atrocious electric vehicle, with the same baggage the GM EV1 had. 80 mile range. Barely. If you don't use the heat or AC. http://www.digitaltrends.com/cars/how-does-gms-fabled-ev1-stack-up-against-the-current-crop-of-electrics/ http://www.digitaltrends.com/cars/how-does-gms-fabled-ev1-st... Nissan has to continue to slash the price to move them, while people will pay top dollar for Tesla vehicles (and, I argue, will continue to do so, not only for the high end but also the lower priced models when they're announced/produced). Disclaimer: I'm super long TSLA
- PhasmaFelis 13y agoOMG, is this actually supposed to be single-stage-to-orbit? Ah, Wikipedia says it's two-stage-to-orbit. That's still impressive, but a ship that can reach orbit in a single piece without having to jettison anything is the Holy Grail of spaceflight. And watching that blazing titan set down on the landing pad as gently as a butterfly is awe-inspiring in any case.
- deleted 13y ago[deleted]
- trafficlight 13y agoWith the eventual goal of returning the second stage, as well.
- ColinDabritz 13y agoI believe, particularly, one of the major reasons for developing the systems in these tests is to create a system where there the first stage can land itself after being jettisoned, to be reused.
- nawitus 13y agoThe problem with single-stage-to-orbit (SSTO) is mainly weight. I think using composite tanks is enough to make a SSTO rocket. X-33 was supposed to use a composite tank, but the fuel tank failed during testing in 1999. Recently, NASA has succesfully tested a composite tank[1]. 1. http://nasawatch.com/archives/2013/07/composite-cryog.html http://nasawatch.com/archives/2013/07/composite-cryog.html
- lobster_johnson 13y agoI was confused by this video [1], which looks like it shows three stages. All three stages are able to land on their own. Can you explain? [1] http://www.youtube.com/watch?v=abLC1l3loFA http://www.youtube.com/watch?v=abLC1l3loFA
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- cindaydavilla 13y agomy classmate's mother-in-law makes $69 every hour on the laptop. She has been fired for eight months but last month her check was $19742 just working on the laptop for a few hours. Here's the site to read more,, www.max38.com
- kilroy123 13y agoLaunching a ten story tube into the air, and safely landing it on the ground really is impressive.
- adamwong246 13y agoBeautiful!
- bionerd 13y agoThis is incredible. Yes, it would be insanely cool to live in 2500s with all that privately affordable faster-than-light travel and everything but still... it's very exciting to see the progress being made by private/commercial space programs. I wish them all luck. It must be an amazing feeling to be a part of all this. This is actually the only thing that's giving me hope that man could really step a foot on Mars or mine valuable resources on asteroids in a (hopefully) not too distant future.
- dclowd9901 13y agoMaybe life extension will progress as well? :P
- vecinu 13y agoI don't mean to stir controversy but I am curious how many countries are thinking 'I want one of these for my military'. Hear me out, wouldn't this technology allow for more advanced ballistic flight across Earth and perhaps even become more efficient than anti-ballistic missiles, evading any 'danger'?.
- omni 13y agoMy understanding is that the main improvement here is that the rocket is sophisticated enough to land itself gently and intact. Why would a missile ever want to do that?
- ljd 13y agoI don't know anything about military strategy or missile technology but I'm having a hard time seeing how a missile making a turn that slow would really be effective at evading any kind of supersonic defensive weapon. Also, missiles have to explode to be useful; a safe relaunch would be a bit worthless. Just to add a pedantic remark, if the missile is guiding itself then it's not a ballistic missile anymore.
- nobodysfool 13y agoYes, it's a guided missile not ballistic so those anti-ballistic things would be useless anyway. The best defense against guided missiles would be to disrupt the guidance system. However, there is technology being developed with the accuracy to allow a missile to use inertial navigation systems in the absence of gps.
- greedo 13y agoIt's already been developed in the 1980s with the Pershing 2 systems. They used inertial navigation, then terminal homing via a radar transmitter.
- jlgreco 13y agoThere is a reason so much of what they do is covered by ITAR. ;) In general, rocket technology is missile technology.
- vpayette 13y agoWow, amazing
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- cwkoss 13y agoNow I want to see what Kerbal Space Program ships the SpaceX guys are making when they are goofing off.
- alexhawdon 13y agoProbably none. KSP was mentioned to Elon in some post-talk Q&A session - he hadn't heard of it and seemed unimpressed.
- ash 13y agoSpaceX software engineers on Reddit AMA: > > First question: do any of you guys play Kerbal Space Program? > Are you kidding? That’s how we design our rockets! http://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_software_engineers_we_launch/c8bp6sx http://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_s...
- stcredzero 13y agoTwo Stage to Orbit, with vertical rocket-thrust tail-landing for both stages, eschewing carbon fiber for aerospace aluminum and using friction stir welding, rejecting exotic engine designs for proven ones, and financing from dot-com tycoons: I'm not affiliated, and the end is kinda corny, especially if you are a typical skeptic/rationalist Silicon Valley type. It's not exactly how it happened with SpaceX, but there are quite a few parallels: http://www.amazon.com/The-Rocket-Company-Library-Flight/dp/1563476967/ http://www.amazon.com/The-Rocket-Company-Library-Flight/dp/1... EDIT: In case you are not sure, it's a fiction book. It's interesting because it presages some things SpaceX did later.
- tantalor 13y agoIn case anybody else was as confused as I was, this is a story about a fictional rocket company. Aside: does Amazon not categorize its books by "fiction" or "nonfiction"?
- stcredzero 13y agoSorry, I thought "the end is kinda corny" would be enough indicator that this is fiction. It does predate SpaceX getting on the public radar, though.
- Gravityloss 13y agoThe book was originally released online in parts, and I read it. The parts were then taken offline when the book appeared. I remember they used jet engines for thrust assist in the first stage.
- marshc1 13y agoAnyone else seeing the youtube loaded bar as gray? Is this a custom overlay? see: http://imgur.com/wKOB6jh http://imgur.com/wKOB6jh
- xnxn 13y agoIt's an option in the embedded player API. https://developers.google.com/youtube/player_parameters#color https://developers.google.com/youtube/player_parameters#colo...
- Gravityloss 13y agoI wonder how useful the Lunar Lander Challenge was in being a trailblazer. Here's one of Masten Space's 2009 flights. Rock solid transfer from one pad to another, with a 90 second hover. They had hired a guy from Draper Labs to do the control code and won, snatching the big price from Armadillo. Impressive control. http://www.youtube.com/watch?v=oaXW5TaFwAE http://www.youtube.com/watch?v=oaXW5TaFwAE
- agumonkey 13y agoEach videos is more awesome than the previous one, but one thing remains constant, the incredibly short time between low altitude and stable landing.
- kfury 13y agoDoes SpaceX document all their tests publicly? Or are we just seeing the successful ones? (If they've all been successful ones, will we see unsuccessful ones if they come in the future?)
- lutorm 13y agoWell, it's kind of hard to keep the tests secret: http://youtu.be/i9n6rYoSGNQ http://youtu.be/i9n6rYoSGNQ
- kfury 13y agoAhh, yes. A little digging shows that these tests are done at their McGregor, TX test site, and McGregor is well within hearing and visual range of the tests. https://www.google.com/maps/preview#!q=spacex&data=!1m4!1m3!1d4031!2d-97.459888!3d31.400645!2m1!1e3!4m10!1m9!4m8!1m3!1d4556!2d-97.4079412!3d31.4347774!3m2!1i1293!2i909!4f35&fid=7 https://www.google.com/maps/preview#!q=spacex&data=!1m4!1m3!...
- SuperChihuahua 13y agoForgotten the unsuccessful Falcon 1 flight 1,2,3? They are available online on youtube
- kfury 13y agoA launch is completely different from a private short-range test on a closed site. You could watch a launch live, and they are very public about the timing, purpose, and location of launches before they happen. The Grasshopper tests (to my knowledge) are not open for public observation, and I haven't seen any media coverage prior to tests, so if there was an unsuccessful test it wouldn't be as obvious as an unsuccessful launch attempt. My question was whether this is by design, and if there was an unsuccessful test whether they would showcase that as well, in the manner that unsuccessful launches are well documented public 'learning experiences'.
- resu_nimda 13y ago
- ondross 13y agoThis is also using a fairly new engine, the Merlin 1-D http://en.wikipedia.org/wiki/Merlin_1D#Merlin_1D http://en.wikipedia.org/wiki/Merlin_1D#Merlin_1D. It is designed for mass production, using nearly 50% fewer components than the 1-C, and it seems to be flying great! Can't wait for the next launch!
- abalone 13y agoPretty cool how the lens flare forms an "X" around the exhaust.
- amorphid 13y agoUseless speculation: Hyperloop is a red herring meant to distract us from the rocket that will get you from LAX (not Sylmar) to SFO in 15 minutes!
- ballard 13y agoElon gets that humans need to go to the stars to ensure our survival. That's the big idea. The neat part is writing history along the way.
- joss82 13y agoHello, fellow HNers. So you love rockets and have plenty of time on your hands? Here is Kerbal Space Program, enjoy! http://kerbalspaceprogram.com/demo.php http://kerbalspaceprogram.com/demo.php
- iotakodali 13y agothis should make space travel more affordable