Re:SpaceX to Send Privately Crewed Dragon Spacecraft Beyond ...
by robszumski on Tuesday February 28, 2017 @02:12AM
(#13751908)
A lot of the devil here is in the details. You need long term life support that Dragon hasn't proven yet. Deep space communications on the transmit and receive side. Abort scenarios for most or all phases of flight. All of this is untested and requires a huge amount of engineering and manufacturing work. Since this will likely share the same design as the NASA-contracted capsules, these systems will need to pass muster with them. And they don't cut corners.
Re:SpaceX to Send Privately Crewed Dragon Spacecraft Beyond ...
by CydeWeys on Tuesday February 28, 2017 @08:57PM
(#13760268)
Minor quibble: you don't need deep space communications. The Moon is laughably close. I am quite confident that we can easily make contact with the existing unmodified Dragon capsules by using something like one of these bad boys: https://www.nasa.gov/sites/default/files/goldstone.jpg
Of course it's laughably overkill for the purpose -- amateur radio operators using much smaller equipment can already send and receive signals to each other by bouncing them off the Moon, which has four times the signal attenuation owing to the doubled distance plus a good deal more in losses from the poor reflectivity of the Moon to radio waves.
Why not? Their Dragon capsules can dock with the ISS; why wouldn't they be able to dock with each, possibly with some kind of adapter? You can imagine one Dragon and a trunk docking with another upper stage that's all fuel tank, heading to the Moon, undocking in orbit, landing, ascending, and rendezvousing in orbit to return home.
The total dv requirements of landing on the Moon and ascending again starting from low Moon orbit is 4 km/s. I haven't done the math, but I suspect that you can put together a workable mission using two Falcon Heavy launches. Now, granted, they don't have all the exact pieces put together quite yet, but I suspect they've been thinking about it.