On 9/13/2011 3:14 PM, Eric Funk (antispam) wrote:
a reason I laugh at "Despicable me"...
At late TL 8, acceleration isn't really the issue, drive types that are useful over periods of less than thousands of hours are chemfuel rockets that will burn all their fuel in minutes, so it's a matter of how much delta-V you have. The moon is 384,000 km, so you need a velocity of 7.1 km/sec leaving the moon. At low earth orbit gravity will have increased your velocity to 13.2 km/sec but you only need to slow down to 7.9 km/sec so that's 5.3 km/sec. A total mission delta-V of 12.4 km/sec, using a 450s LOx/LHd rocket, requires a 93% fuel fraction, which is doable if stupid most of the time, since there's rarely need to get it down that short. The L3 and L5 points are at the same distance as the moon.
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