Space

SpaceX to develop a fully and rapidly reusable launch system

SpaceX to develop a fully and ...
SpaceX Reusable Launch Vehicle - stage 1 landing on the launch pad
SpaceX Reusable Launch Vehicle - stage 1 landing on the launch pad
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SpaceX Reusable Launch Vehicle - stage 2 landing on the launch pad
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SpaceX Reusable Launch Vehicle - stage 2 landing on the launch pad
SpaceX Reusable Launch Vehicle - stage 2 preparation for landing
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SpaceX Reusable Launch Vehicle - stage 2 preparation for landing
SpaceX Reusable Launch Vehicle - stage 2 reentry
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SpaceX Reusable Launch Vehicle - stage 2 reentry
SpaceX Reusable Launch Vehicle - stage 2 separating from spacecraft
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SpaceX Reusable Launch Vehicle - stage 2 separating from spacecraft
SpaceX Reusable Launch Vehicle - stage 1 landing on the launch pad
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SpaceX Reusable Launch Vehicle - stage 1 landing on the launch pad
SpaceX Reusable Launch Vehicle - stage 1 preparation for landing
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SpaceX Reusable Launch Vehicle - stage 1 preparation for landing
Falcon 9 rocket by SpaceX
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Falcon 9 rocket by SpaceX
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SpaceX, the space transport company that made history by building the world's first private reusable spacecraft, is now embarking on a quest to build the holy grail of space engineering - a reusable launch rocket. Elon Musk, the company's CEO and Chief Technology Officer, announced recently at the National Press Club that computer simulations show their design to be technically feasible. This, Musk seems to suggests, is great news for those who have been considering moving to Mars.

A document issued by the Federal Aviation Administration reveals that the reusable launch vehicle (or RLV) is to be called Grasshopper (at least throughout the testing period). Both stages of the rocket are to be capable of finding their way back to the launch pad and performing a propulsive landing. Based on SpaceX's Falcon 9 rocket, the 106-foot (32 m) tall RLV is to be fitted with a Merlin-1D engine, four steel landing legs and a steel support structure to boot. It is the weight of the additional elements required to make the rocket reusable that poses the biggest technological challenge.

If the Earth's gravity was a little bit higher, the task would be nearly impossible. A slightly lower gravity would make it much easier. However, gravity being what it is, only around 2-3 percent of the lift-off weight is actually carried to orbit. This, Musk explains, leaves very little room for error. So little, in fact, that all the previous attempts at building a fully and rapidly reusable launch system failed to produce as much as a single design that would seem viable on paper. SpaceX already has such a design - now it's time for a reality check.

SpaceX Reusable Launch Vehicle - stage 1 preparation for landing
SpaceX Reusable Launch Vehicle - stage 1 preparation for landing

That the space industry is in desperate need of a RLV is beyond doubt. It becomes even clearer if we look at the numbers. The already mentioned Falcon 9 is the least expensive rocket in the world. It costs around US$50-60 million to launch, and only around $200,000 is down to propellant costs. A reusable rocket would reduce the cost of running a space mission 100-fold.

SpaceX's CEO sees a fully and rapidly reusable space launch system as a necessary development on the way to making life multiplanetary. Musk has expressed his interest in putting man on Mars in multiple interviews, and he considers it to be the long term goal of SpaceX's existence.

While the animation below is not 100 percent accurate, it does provide a pretty good idea of what SpaceX is working on. Musk's full speech to the National Press Club can be seen here.

View gallery - 7 images
16 comments
D-Shift
Would it not be possible to use a giant linear electromagnetic motor, powerd buy mega-ultra-extremo capacitors to accelerate the vehicle into space? of course there are limits on how much G force a person can exprience, but surely in combination with a smaller booster rocket, a LEM launch would make the initial launch more efficient and the whole process a lot cheaper?
Slowburn
As the strength to weight ratio in structural materials improves all sorts of things once considered impossible have become reality. I remember being told that the Gossamer Albatross\'s flights were faked because human powered airplanes were impossible.
windykites
This is an excellent video, but what strikes me, is the amount of extra fuel/weight which is required to return the boosters back to Earth. what happened to parachutes with sea recovery? Also the payload capsule requires retro rockets. I am surprised that this system is feasible.
Stewart Mitchell
Forget the sea recovery , just parachute onto a giant air bag. Do not miss the target.
Tellurider
UP Aerospace has had numerous sub-orbital launches at Spaceport America and recovered the rocket at nearby White Sands Missile Range. Jerry Larsan has proved it all works just fine. Check out the website for the next launch (www.spaceportamerica.com) and (www.up-aerospace.biz).
VirtualGathis
If you read the original articles spaceX speaks of why parachutes to sea recovery are not working. First the vehicles are breaking up before they are low enough for chutes. Second the chutes, deployment system and sea hardening/airbags are adding more weight than the recovery fuel weight would be according their math.
YetAnotherBob
@D-Shift, No, the air resistance would be fantastic. For the near orbital velocity you would need, the muzzle velocity is around 17 Kilometers per second. But, that still requires a burn at apogee to prevent you from just coming back down very fast for a very hard landing. This has all been studied out very carefully. The sonic boom at the launch end would be fatal of you were closer than a couple of Kilometers from the muzzle.
There was one proposal for it. If the launch mechanism were built in a tube that was evacuated (Pumped down to a vacuum) then you could accelerate up to speed, if then the cap were removed very fast (a modest few hundred Kilo\'s of C4 should do it), then you could be launched into an extreme orbit. But any such orbit from ground level would then later intersect the ground again. That is why there is a need to have a \'burn\' in orbit.
If you increase the mass of the payload to allow for a much larger delta V (Change in velocity), then you can reduce the speed requirement of the catapult. This allows you to fire at a steeper angle, but there is still the little requirement for horizontal acceleration to around 17,000 KM per Hour. In all, it\'s not a simple solution.
If on the other hand you are on the moon, it\'s much simpler. There are much easier designs for such catapults to be built on the Moon. No air, and a lessening of the required velocity changes by around 36 times. In fact, if you stage it right, you could launch directly from the Lunar surface to either the L1 or L2 points, or directly to the Earth. The atmosphere makes it extremely hard to do the same from the surface of the earth.
I hope this helps you understand.
Christian Lassen
Cool to see this. My brother and two other guys built the casing for the test version of their stage two rocket. The tests were pretty cool to watch. They\'re somewhere online.
D-Shift
@YetAnotherBob- Thank you for you explanation, It was very insightful. I was unaware of the extreme horizontal velocities needed for orbit.
dugnology
This would be nice if it works, but what is the weight & complexity penalty v.s. the cost of throwaway. Since it is designed to be man-rated, I imagine that the vehicle is designed with considerable margins. The stages will be un-manned on the way back the parts involved in landing (which are beefy enough for takeoff weight) could be held to a lower standard. I imagine that the stages would be somewhat self stabilizing (all the weight is on the bottom) and very light. The descent profile could get it out of the need for a heavy heat shield. I wish him luck. We need more people like Elon.