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I really like the idea of using our own Moon for a fuel-saving gravity assist. http://svs.gsfc.nasa.gov/vis/a000000/a003300/a003364/ http://svs.gsfc.nasa.gov/v
by otikik 4y ago
I really like the idea of using our own Moon for a fuel-saving gravity assist.
http://svs.gsfc.nasa.gov/vis/a000000/a003300/a003364/ http://svs.gsfc.nasa.gov/vis/a000000/a003300/a003364/
Unfortunately it's not usable for a lot of targets because it closes the window of opportunity too much (a three week window for hitting Mars becomes a handful of days with a Luna assist).
Main source for all this: https://space.stackexchange.com/questions/4027/has-luna-been-used-for-gravity-assist-for-interplanetary-probes https://space.stackexchange.com/questions/4027/has-luna-been...
- midasuni 4y agoDon’t all lunar journeys start with a low earth orbit? Couldn’t you launch into LEO a week or two before hand, then do the lunar assist at the proper time, eliminating the delay concerns of launching from the ground (weather etc) Or will the fuel needed to boost to escape velocity boil off over the wait?
- lmm 4y ago> Don’t all lunar journeys start with a low earth orbit? No, at least they don't have to. It's more efficient to boost directly into an orbit that's eccentric enough to bring you close to the moon, if you started from LEO you'd lose a lot of the gains. > Or will the fuel needed to boost to escape velocity boil off over the wait? No, but relighting an engine is a relatively high risk procedure, so it only makes sense if the gains are large.