Here is a cost differential analysis just for the cost of the propellant delivered to L1 of Hydrazine and LH2/LOX. A small fully reusable lander L1 to lunar surface and back using 27mt of Hydrazine propellant or 10mt of LH2/LOX propellant (I said it was a small human lander on approximate scale to the LEM, size is used just to show costs differentials for the propellant used) that does 2 missions per year over 5 years of operations would experience for a cost of propellant delivered at L1 at the price range of $10,000-$20,000/kg (that’s equivalent to being able to put something in LEO for <$3,000-$6,000/kg) would have a cost difference of $1.7B to $3.4B.

Quote from: oldAtlas_Eguy on 01/15/2012 05:09 PMHere is a cost differential analysis just for the cost of the propellant delivered to L1 of Hydrazine and LH2/LOX. A small fully reusable lander L1 to lunar surface and back using 27mt of Hydrazine propellant or 10mt of LH2/LOX propellant (I said it was a small human lander on approximate scale to the LEM, size is used just to show costs differentials for the propellant used) that does 2 missions per year over 5 years of operations would experience for a cost of propellant delivered at L1 at the price range of $10,000-$20,000/kg (that’s equivalent to being able to put something in LEO for <$3,000-$6,000/kg) would have a cost difference of $1.7B to $3.4B.I'm fine with the size, number of missions, and number of years, for purposes of discussion. But how did you come up with $10k to $20K/kg of prop costs? And that cost differential?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120001435_2012001131.pdf

Is the journey from L1 Depot to the Lunar surface really '~2-3 week' or should it say '~2-3 days'?

All of the other missions in Figure 1 appear to give time and delta-vee for a round-trip.

Earth to LEO-Ken 9.3-10LEO-Ken to GEO 4.33LEO-Ken to L1 3.77L1 to Moon 2.52

Earth to LEO 10LEO to GEO (total) 6.5(I presume "total" means round trip?)LEO to L1 (total) 4.1L1 to Moon 2.52

Quote from: deltaV on 02/15/2012 04:02 PMAll of the other missions in Figure 1 appear to give time and delta-vee for a round-trip.Wait a sec. Delta-v from Earth to Leo is readily rounded from 9.8 to 10 km/s. That's one way. From Wiki:http://en.wikipedia.org/wiki/Delta-v_budgetThe values shown at Wiki don't seem to jive with this chart on this thread.Earth to LEO-Ken 9.3-10LEO-Ken to GEO 4.33LEO-Ken to L1 3.77L1 to Moon 2.52The chart shows one way these values:Earth to LEO 10LEO to GEO (total) 6.5(I presume "total" means round trip?)LEO to L1 (total) 4.1L1 to Moon 2.52Again, what is it that I'm not getting about delta-v?

The trip back can brake non-propulsively using the atmosphere. I.e. aerocapture/aerobraking.