Grasshopper 100m Lateral Divert Test
spacex.com
spacex.com
June 14, 2013: Grasshopper flies 325m straight up and down (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.
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?
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.
[1] http://www.usafa.edu/df/dfas/Papers/20062007/FalconSAT-2%20L...
> For years, cadets have trained falcons (the only performing mascot at NCAA division I football games). FalconSAT-2 showed its excellent homing skills in the launch failure by avoiding the sea and returning to its shipping container so it “could come home to roost.”
We constantly hear the mantra about iterating quickly, changing/breaking things, not worrying about initial quality, etc.
But, there's something to be said for investing in quality and striving for excellence every time out of the gate. And from the outside, it's certainly inspirational.
Ok, so guess I just signed up to absorb some of the downvotes. Whatevs.
But I don't think that "Move Fast and Break Things" necessarily means not striving for excellence every time. To me it or more of, since in Programming there is (usually/almost) no bad side effects of breaking the code, go ahead and try new things. Worst case, revert to your last committed version. And I have to assume that SpaceX has most definitely had ideas that didn't work, or in other words 'broke'. They just hopefully never make it to the actual rocket testing phase!
So in my opinion, you can both "Move fast and break things" and strive for excellence every time out of the gate.
And to comment on the original video, I think it's really impressive seeing a toy helicopter do stuff like this on it's own. And this is a fucking ROCKET!!
The great thing about SpaceX is that they use advanced technology very appropriately and pragmatically. They didn't design a carbon fiber body SSTO RLV or anything like that, they built a 2 stage LOX/Kerosene expendable rocket, a design that's been around since the 1950s. They built a small vehicle and spent a few years building institutional knowledge of building and operating orbital launchers. Then they used that knowledge to build products that were competitive in the market. Now they're continuing to iterate like crazy and building a lot of exiting new things off of what they've already proven: the manned Dragon, Falcon Heavy, Falcon 9 v1.1, and Falcon 9-R.
If they continue to put a consistent amount of effort into iterative R&D they'll not only own most of the orbital launch market they'll own a lot of new markets that don't even exist yet.
They're just applying common sense and building obvious designs well to compete in a market filled with companies that aren't used to strong competition.
Just ignore it.
The plan is to do a return-to-launchpad maneuver -- except that not to the actual launchpad, but to a point offshore -- followed by a controlled "landing" on the ocean. Allows them to test the entire flight profile of a Falcon 9-R (reusable) booster, using an off-the-shelf stage, absent the flight-weight landing gear (which still hasn't been tested). If this is successful, then I imagine that a series of flight-weight landing gear tests will be in order, followed by high-altitude testing at White Sands. At the rate they're going, we might see them reusing boosters on commercial missions within 18 months or so.
First team that can send and retrieve two people to each:
- $5 Billion USD for the moon
- $100 Billion USD for marsI know Google has a $30 million prize for putting a rover on the moon.
Given historical context this is as much as impressive as what SpaceX are doing right now.
It is a great illustration of the 'ecosystem effect' where adjacent technology advances move the entire frontier of a technology forward.
What blows me away is some of the stuff they did in the 60's, including the moonshots.
The V-22 Osprey does this with digital computers. The XC-142 did it with analog mechanical computers.
EDIT: One thing about the XC-142 and other tiltrotors, was that they could operate like a normal aircraft but they had ridiculous amounts of power for their weight to enable lifting in vertical mode, which made them "take off like a jackrabbit" in conventional mode. So much so, a couple of pilots tried to beat the F-4 Phantom's zoom climb record in one! http://en.wikipedia.org/wiki/Canadair_CL-84#Testing
I don't know enough about rocketry to know if you're correct. But if you are just saying this and you're not sure, please look at the Pendulum Rocket Fallacy: http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy
http://www.youtube.com/watch?v=JzXcTFfV3Ls
(DC-X crash at 2:10)
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.
1. http://nasawatch.com/archives/2013/07/composite-cryog.html
Sort of like how the Saturn V is considered a 3-stage rocket, even though during the later Apollo missions it had on top a service module, a command module, and a (two stage!) lunar module.
Also, if the mission is something like transport astronauts to the ISS, why eject any stages at all? Why not just make the rocket capable of flying to the ISS, let the whole thing dock to the ISS, exchange astronauts, then detach and land back on Earth?
(Of course, if there are tons of missions happening around the same time, all requiring a first stage rocket, and each mission has a period that doesn't require any rocket, then I see the point of letting the rocket go back and be used for other things.)
Because that requires a single-stage-to-orbit vehicle, which has never been done before. Yes, in the future that might be possible.
Staging is done because not doing it ("SSTO" or "single stage to orbit") is extremely hard. In fact, it has never been done before from earth. When that second stage burns, it is only accelerating the mass of itself and the Dragon spacecraft on top. Having it accelerate the mass of the lower stage as well would be massively inefficient, requiring much more fuel to be used. So much more fuel that there most likely would no be any mass left over for the Dragon spacecraft. Without staging we wouldn't be able to put things in orbit at all (today and in the past anyway), let alone reuse rockets.
It's not a complete waste though. I believe at the ISS they usually pack those sorts of parts (parts that burn up that is. Other examples being the Russian "Progress" spacecraft or the ESA's ATV) full of garbage before sending them off. Intact reentry volume/mass is valuable (currently only the Soyuz and the Dragon can do that) so they just let all of their trash burn up. Here's a neat picture of the first ATV, carrying a bunch of ISS trash, burning up: http://en.wikipedia.org/wiki/File:Jules_Verne_Automated_Tran...
Essentially, Physics. To a lesser extent, practicality and cost.
See The Tyranny of the Rocket Equation[1] or the "Model Rocketry" entry of xkcd What-If[2]
[1] http://www.nasa.gov/mission_pages/station/expeditions/expedi...
Also, the lower stage engines are optimized for working in the low atmosphere while the second stage only needs to operate in a vacuum and therefore, has a different design.
An SSTO--single stage to orbit--vehicle would be safer, more reliable, and above all cheaper to operate than a multi-stage vehicle, but every attempt to make something light enough that it can reach orbit with all its fuel tanks still aboard has failed. A two-stage rocket where the stages return to the pad under their own power is still a big improvement over the traditional model, with three or more stages that are simply dropped into the ocean to be recovered later.
TECHNICAL FEATURES
* Linear aerospike engine [first ever tried]
* Conformal composite LH2 tank [first ever tried]
* Integrated advanced metallic thermal protection [first ever tried]
* Subcontractors in 38 states and 122 congressional districts
One of the secrets is dense propellants which increases mass ratio considerably. It also makes higher thrust to weight ratio engines easier to implement (because pumps primarily pump volume rather than mass), and with identical initial acceleration, the dense propellant higher mass ratio lower impulse vehicle gets lighter faster and thus has higher acceleration towards the end of the flight, meaning less gravity losses. (Also air drag is less with a smaller vehicle, but it's not a big effect, though it is proportionally bigger for smaller vehicles.)
Hydrogen has the best specific impulse but it is non-dense. It is also hard cryogenic, meaning potential complexity in the vehicle, ground infrastructure and operations.
Also, big vehicles might be more expensive, even if their contents (the propellants) don't weigh much.
Edit: as mikeash points out in the reply, I'm plain wrong. You could use multi-stages to accomodate different gravities when launching Earth-Mars-Earth (2 stage E->M, reusable as standalone second-stage, so single stage M->E).
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.
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.
Typically, businesses are described as "private," with governments being labeled as 'public.'
That's starting to be a pretty moot point given the Nissan Leaf.
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-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
They could license Tesla's battery technology, but I doubt Musk would help set up competition to the future Model E.
This computer is great, except for the storage space and processor speed.
It's the most affordable electric car out there.
>Given a little time the tech will come close to Tesla's.
What tech?
>They could license Tesla's battery technology
Why would they? My understanding is that there's nothing special about Tesla's battery technology. Leaf just has less batteries (in kg) in them, so the range is lower.
It's the most affordable electric car out there.
In other words, they released 1 gen too early!
To get an access to Tesla's charing network, for example.
The Leaf has been received well.
Wikipedia: "The Leaf has received awards from multiple organizations. Notable awards include the inclusion by Time magazine as one of the 50 best inventions of 2009.[386] At the 2010 Washington Auto Show, the Leaf was given the 2010 Green Car Vision Award by the Green Car Journal (GCJ), who noted that the Leaf "will provide the features, the styling, and the driving experience that will meet the needs of a sophisticated and demanding market, while producing zero localized emissions and requiring no petroleum fuels."[387] Popular Mechanics, upon awarding the Leaf its 2010 Breakthrough Award, explained that the Nissan Leaf is "not the first pure EV, but [...] hits the mainstream like none of its predecessors." Popular Mechanics also alluded to the Leaf's 160 kilometres (100 mi) range, which is said to be "enough for most commuters for the price of an average vehicle – and with a much lower operating cost than gasoline-powered vehicles."[388]
Other awards received by the Leaf include the 2011 European Car of the Year,[389] EV.com’s 2011 EV of the Year,[390] 2011 Eco-Friendly Car of the Year by Cars.com,[391] 2011 Green Fleet Electric Vehicle of the Year,[392] it was listed among the 2011 Greenest Vehicles of the Year by the American Council for an Energy-Efficient Economy,[393][394] also listed by Mother Earth News among its "Best Green Cars" of 2011,[395] and also was ranked first in Kelley Blue Book Top 10 Green Cars for 2011.[396] The Leaf won the 2011 World Car of the Year,[397] and was a finalist for the 2011 World Green Car.[398] Ward's Auto listed the Leaf's 80 kW electric motor in Ward's 10 Best Engines for 2011.[399] Until October 2011 the Leaf was ranked as the most efficient EPA certified vehicle for all fuels ever.[400][401] In December 2011 the Leaf was awarded with the 2011-2012 Car of the Year Japan at the Tokyo Motor Show.[402]"
>Nissan has to continue to slash the price to move them,
Nissan Leaf is the best selling electric car in history.
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.
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.
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?
Maybe they are going to push the gravity turn later into the flight so that the first stage doesn't participate in that as much?
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_phase...
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.
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.
A Falcon 9 lower stage also isn't a spaceplane covered in very expensive and fragile tiles, sitting next to a rocket. That helps.
The SpaceX project suffers from none of these problems. A relatively conventional rocket with medium-performance engines, no crazy DoD requirements, and a sane budgeting process should do a whole lot better when it comes down to being actually reusable.
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.)
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.
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/1...
EDIT: In case you are not sure, it's a fiction book. It's interesting because it presages some things SpaceX did later.
Aside: does Amazon not categorize its books by "fiction" or "nonfiction"?
So you love rockets and have plenty of time on your hands?
Here is Kerbal Space Program, enjoy!
KSP was mentioned to Elon in some post-talk Q&A session - he hadn't heard of it and seemed unimpressed.
> > 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_s...
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'.
I think posting a video of a rocket crashing would be way beyond any reasonable expectation. That's not contributing to any public learning. That's just doing significant damage to your brand with extremely small upside (gaining "honesty" cred with some small subset).
https://www.google.com/maps/preview#!q=spacex&data=!1m4!1m3!...
https://developers.google.com/youtube/player_parameters#colo...
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'?.
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.
In general, rocket technology is missile technology.
Wernher von Braun agrees.
Even if you could somehow add high maneuverability to a MIRV, it wouldn't be close to matching how well an ABM can maneuver.
This technology allows a rocket to maneuver while slow and close to the ground. The military terms for an object that is slow and close to the ground is "target".