Why Moon-El-Too is so great - Mars, the easy way!

[Kibble]

The bad thing about cryogenic fuels, is that even thou they are the most efficient, they are not storable. Any mission involving rendezvous and docking prior to a large rocket engine burn has to use less-efficient storable fuels instead. But what I have realized about EML2, the reason it is so important - it allows you to store energy. That way you can use your fancy hydrogen to send up individual pieces, and they are already 90% of the way to Mars, before rendezvous even happens, and only a small amount of the work has to be done by hypergolics.

2 launches of formerly-named Space Launch System Block IB to EML2, first the lander, unpiloted, with an attached hypergolic rocket stage for TMI, MOI, and lander deorbit. Waits on lunar orbit for a year or so until launch of astronauts. Second launch, piloted, Orion and habitat for journey to and from Mars, Orion does TEI.

[Bill Phil]

Then why not build a full fledged base at EML-2? Because that's what I would like to see... And one in LEO.

You see, EML-2 is so great because it can act like a gateway to the Moon and even interplanetary space.

The only trouble I see with your plan, is inclination. But even that wouldn't take much energ that far out...

And another problem is where the moon is. It needs to be at the right place at the right time.

Edited August 30, 2015 by Bill Phil

[PB666]

Then why not build a full fledged base at EML-2? Because that's what I would like to see... And one in LEO.

You see, EML-2 is so great because it can act like a gateway to the Moon and even interplanetary space.

The only trouble I see with your plan, is inclination. But even that wouldn't take much energ that far out...

And another problem is where the moon is. It needs to be at the right place at the right time.

Hmm, At that orbital radius it shouldn't make that much difference, earth mars cycle is something like 2 years and the monn is 1 month so there are 24 1 month periods in 2 years, 360/24 = 15' Thus the EML2 would never be more than 7.5 degrees from optimal. That means only a tiny amount of delta-radial velocity would need to be added. One way to counter the problem would to be to shuttle to ESL2 at the previous EML2 crossing of ESL1-ESL2 transect then wait for optimal transfer, this would speed up the trip anyway.

[How2FoldSoup]

Hmm, At that orbital radius it shouldn't make that much difference, earth mars cycle is something like 2 years and the monn is 1 month so there are 24 1 month periods in 2 years, 360/24 = 15' Thus the EML2 would never be more than 7.5 degrees from optimal. That means only a tiny amount of delta-radial velocity would need to be added. One way to counter the problem would to be to shuttle to ESL2 at the previous EML2 crossing of ESL1-ESL2 transect then wait for optimal transfer, this would speed up the trip anyway.

Would it not also be optimal to drop down from moon l2 to slingshot around Earth. You don't have to worry about missing the optimal angle and one would take advantage of oberth? I haven't done the math however and I'm not sure how much dV one might save(or lose).