SpaceX Developing Orbital Crew Capsule

iamlucky13 writes "Private aerospace firm SpaceX has revealed that it has secretly been working on a crew and cargo vehicle since late 2004. Development of the capsule, named Dragon, has so far been funded by SpaceX and its partners, which includes the Canadian company that built the robotic arm for the International Space Station. Dragon would be launched atop a SpaceX Falcon 9 and dock at the ISS with assistance of the robotic arm. While SpaceX founder Elon Musk is prepared to complete development of the capsule with his own resources, SpaceX is seeking funding from NASA's Commercial Orbital Transportation Services program, which makes up to $500 million available through 2010 for private spacecraft development."

Comments

What's with the naming???

[ssummer]

Scaled Composites has the "White Knight", SpaceX has the "Dragon", what's next? The "Grand Wizard" orbiting space station?

Re:Slightly OT: Kerosene?

[cmowire]

Kerosene is not the most efficent, in terms of mass, but it is rather efficent in terms of density. It's rather much like jet fuel, so there's already hardware to deal with it.

Hydrogen is more efficent in terms of mass, but it's not very dense, so you need huge tanks to store it. Also, it's cold enough to give you nasty materials problems that you don't get with just LOX.

So usually it makes more sense to use kerosene + LOX on the first stage because you are going to need a lot of fuel and you are going to have to push it through the atmosphere and stuff. Then once you are above the atmosphere and have ejected the first stage, the rest of the stages work better with hydrogen as the fuel.

Re:Slightly OT: Kerosene?

[Jonathan_S]

Could someone briefly explain why liquid kerosene and liquid oxygen are one of the preferred fuels for orbital rockets, at least for the first stage? I know the F-1 engine on the Saturn V used kerosene, but I never understood why; the J-2 engines on the second stage of the Saturn V used liquid hydrogen and LOX -- why the mix?

Liquid kerosene / LOX is more efficient energy per volume, while liquid hydrogen / LOX is more efferent energy storage per mass.

For 1st stage rockets that aren't going to burn for very long, the reduced tank volume possible with kerosene / LOX can be enough of a total weight savings to offset the lower ISP and greater mass of kerosene / LOX over hydrogen / LOX.

On upper stages, where you are going to carry the fuel higher, and burn the engines longer, the mass efficiencies and higher ISP of hydrogen / LOX win out.

Hence the Saturn V switched fuels as it went through its stages.

Re:SkyRamp FFS

[QuantumG]

Very true. If you want to attribute anything to Von Braun, attribute in-orbit assembly. His proposals for military installations on the Moon in the late 50s were elegant and advanced. He relied on what today we would call medium-lift launch vehicles and in-orbit assembly. At the time the army had a proven capability to fire off hundreds of these rockets a month and had shown they can man and supply outposts in much harsher conditions. The only thing lacking was a mandate. From an economical point of view medium-lift launch vehicles make a lot of sense. See The case for smaller launch vehicles in human space exploration by Grant Bonin, part 1 and part 2.