Correction. When I mentioned the Long March 4 booster I should have said the CZ-2F booster which is the booster for the manned Shenzou spacecraft.

On mission architecture…

I know your original 2-man lunar scheme was to squeeze the most out of the fewest launches and using only existing hardware, but I think your launcher economy forces too tight design margins. And in a minor way you recreate the ESAS priority of minimal lunar launches.

If instead your lunar achitecture is split into three phases — prepositioning on the moon the habitat, prepositioning into LLO the lunar lander, and following up with the manned launch, you gain several advantages. The first advantage is the amazing similarity that lunar architecture would share with the notional ESAS Mars plan. That would give a ring of endorsement (and magnify the arbitrariness of the ESAS lunar plan rationalizations) and if actually carried out give vital experience towards a successful Mars mission. But the most important advantage of splitting the lunar mission into multiple phases is the abiltity to take full advantage of different trajectory and propulsion schemes to increase the payload capability of your launchers.

That WSB trajectory is amazing. Taking advantage of that 3-month trajectory for as much of the unmanned component of the lunar mission as possible increases payload. Plus the flight time is slow enough so that perhaps an off the shelf supplemental electric propulsion system could also boost the payload delivered. It just makes too much sense to send the minimum payload as possible on the speedy trajectories which the manned component of the mission requires.

Opening up the design margins might also allow off the shelf propulsion systems for some flight elements. Right now your lunar plan requires LOX/LH2 propellants for almost everything. I’ve seen some of the Lockheed documents and talk about work they are doing on a long-storage passively-cooled Centaur and it’s very exciting, but it’s not currently available. With a three phase architecture I suspect the margins open up enough that even storable propellants would be adequate for the lunar lander and the TEI burn.

So I’m imagining something like a total of 3 Delta IV heavy + 1 Atlas V 401 launches. One Delta IV sends the habitat to lunar surface, One Delta IV sends a lander into LLO, and One Delta IV sends it’s upper stage into LEO. The Atlas V launches the manned capsule + service module into LEO which then rendezvous with the Delta IV stage.

I think it’s interesting to note that should the Chinese actually field the Long March 5 booster they have been talking up, they could launch an extremely similar mission to the moon using the 3 x LM 5 + 1 x LM 4 and a modified Shenzou spacecraft.

It could be light, cheap and disposible.

Build your own ultra-Spartan descent module for Earth return and landing but attach to a Bigelow made orbital module for living space during passage between Earth & Moon and back.

why build a new capsule?

we already have the Soyuz and Shenzhou for that job

one year ago I’ve suggested to use them for moon mission, here: http://www.gaetanomarano.it/LSAMshenzhou/lsamshenzhou.html

their thermal shield already is ready for a direct reentry from the moon

the internal space and (one week) life support of both capsules are for three astronauts

with two astronauts their life support will be sufficient for 10 days

their internal space is sufficient for two astronauts and 200 lbs. of moon samples (same of Orion)

the Soyuz/Shenzhou SM propellent can be used only for TEI

we only need a smaller LSAM and a booster for TLI

the LSAM may be around 20 mT (or less) and must include the propellant for the LOI of the full convoy

last, the flight must be planned for a “fly around the moon” trajectory, so, if something goes wrong the LSAM+Shenzhou convoy will come back to earth without enter the lunar orbit

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