Re: SpaceX's Grasshopper
Oh, I didn't know about DC-X, I actually like how it looks. But as far as I can tell all the tests have been limited in duration, and it neither has actually gone to orbit, nor it has had a big enough version capable of doing so?
As for the SuperDraco and the Moon –
I don't think that gravity is as important as air drag here. For landing on Earth, the delta-v required from the engines is far less, because the atmosphere does most of the job. For the Moon, you have less gravitational acceleration to deal with, but your initial speed will be a problem anyway. So unless you pick some crazy trajectory, I have some doubts that the Earth SuperDraco engines will do it, but I'm sure they can be upgraded for the Moon.
Unless I'm missing something?
Edit: Hm, I guess someone who has worked more with celestial mechanics could clarify that, but now that I think about it, when Dragon is inserted into lunar orbit, it has to deal mostly with cutting horizontal speed, at least initally, and if I understand correctly you would have more time to do it, so thrust might be not as important as fuel? I'm still not sure that it would be enough though.
Edit 2: Right, I think I figured that out, the lack of air would make almost no difference, except for the fuel expenses. Gosh, I'm stupid. You only need thrust force to cancel out the force of gravity. If it can do it on Earth, the Moon would be a piece of cake. At the speed you'd be touching down, air resistance doesn't play a role at all. Feel free to laugh at me.
Now, having learnt this, I'm betting on a private moon landing in 2013.
R.I.P. Admiral James T. Kirk (2233-2267, 1969, 2267, 1930, 2267-2268, 1968, 2268-2269, Serpeidon Middle Ages, 2269, 2237, 2269-2286, 1986, 2286-2293, 2371)
Last edited by YellowSubmarine; September 26 2012 at 07:29 PM.
Reason: mispelled landing