SpaceX to Send Privately Crewed Dragon Spacecraft Beyond the Moon Next Year

Post by schiffern » Tue, Feb 28, 2017, 4:29 AM UTC

Retric wrote: post #131

homerowilson wrote: post #115

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Mostly CO2 and CO, see for instance https://en.wikipedia.org/wiki/RP-1

The H in hydrocarbons mostly ends up as water, so ideally it's about 50/50 H2O + CO2. But, you do get a little bit other stuff. https://en.m.wikipedia.org/wiki/Kerosene The combustion reaction can be approximated as follows, with the molecular formula C12H26 (dodecane): 2 C12H26(l) + 37 O2(g) → 24 CO2(g) + 26 H2O(g); ∆H˚ = -7513 kJ

Post by greglindahl » Tue, Feb 28, 2017, 4:39 AM UTC

Retric wrote: post #318

jessriedel wrote: post #253

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Right. SpaceX doesn't have a craft capable of lunar orbit rendezvous https://en.wikipedia.org/wiki/Lunar_orbit_rendezvous so they would need to return to the Earth directly from the surface of the moon https://en.wikipedia.org/wiki/Direct_ascent Direct ascent requires a much larger initial launch mass, i.e., a larger rocket than has ever been built. Since it took the massive Saturn V to complete the Apollo missions u…

SpaceX is already docking with the space station which is similar difficulty as launching from the moon and docking in lunar orbit. The problem is getting a rocket with enough fuel on the surface of the moon without damaging it, not the docking in orbit. Which is even easier than doing the same thing from the surface of Mars. The only advantage of Mars is you don't need to burn fuel slowing down but that's more than…

Post by astrodust » Tue, Feb 28, 2017, 4:46 AM UTC

rlanday wrote: post #301

dperfect wrote: post #232

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> China has been working up to getting a space capability to send people to the Moon with the full backing of the government funding, by 2035[1]. They started in 2003. SpaceX was founded in 2002 and they are saying they will fly someone around the moon next year? I don't want to downplay SpaceX at all because I'm a huge fan, but isn't flying someone to the moon (and presumably back) more complicated than just flying…

It's not a greater achievement than the Apollo moon landings (it's basically the mission flown on Apollo 13, swinging around the moon without going into orbit and then coming back), but it's still something that hasn't been done since the Apollo 17 mission in 1972.

Post by dwg » Tue, Feb 28, 2017, 4:53 AM UTC

astrodust wrote: post #346

rlanday wrote: post #301

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It's not a greater achievement than the Apollo moon landings (it's basically the mission flown on Apollo 13, swinging around the moon without going into orbit and then coming back), but it's still something that hasn't been done since the Apollo 17 mission in 1972.

Hurray for progress! We're able to repeat what was done in 1972!

Post by gpm » Tue, Feb 28, 2017, 4:54 AM UTC

BWStearns wrote: post #178

gravypod wrote: post #121

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The Earth has a full atmosphere with winds, an expansive array of magnetic and electric fields, and a much much higher gravitational pull then Mars or the moon. About a factor of 10 removed from mars and about a further factor of 10 removed from the moon. You'd obviously need more fuel, and fuel that can burn in a completely different atmosphere then it's intended to run in. It's an invalid test for the kind of usefu…

I wonder if there's an altitude you could do a "landing" at that would be thin enough atmosphere and weak enough gravity to get close to Martian conditions.