Launcher Option 6: Independent LEO Transportation Node

The final alternative is to launch a whole new space station into orbit, and assemble the spacecraft there. The space station will be expensive, but this is the only real long-term solution to the problem of Low Earth Orbit (LEO) assembly. The Space Shuttle will not always be available when we need it, and the ISS requires a considerable fuel cost. A transportation node in Low Earth Orbit will not only be an opportunity to make money and carry out useful science and manufacturing, but it will provide a permanent foothold in space for private enterprise. A LEO transportation node is necessary for cislunar (and beyond) manned spaceflight.

For the first mission, all that is needed for a transportation node is some pressurized tubing to connect the stack to two Soyuz capsules, an airlock, a manipulator arm, some girders and solar cells, and some expansion ports to add a SPACEHAB module later (image). This shouldn't mass more than 15,000 lbs (7,000 kg), which would leave a couple of tonnes over the 120,000 lbs (55,000 kg) required for the actual translunar spacecraft.

The Ariane 5 has a payload of about 42,000 lbs (19,000 kg), and the Proton can deliver 53,000 lbs (24,000 kg) to orbit. With one Ariane 5 carrying the SPACEHAB modules, and two Protons with most of the equipment and fuel (including the space station), the total orbited mass would total 137,000 lbs (67,000 kg). Two Protons at $60 M each, and an Ariane 5 for $105 M totals $225 M, plus the space station (maybe another $150 M, for a very frugal set of girders, Common Berthing Mechanisms, and a robot arm; no habitat volume).

Whether the Ariane 5 is man-rated or not, the crew will have to go down in two Soyuz capsules. This will also provide extra habitation room during assembly, as well as functioning as extra service modules or even lifeboats. That's another $50 M.

Another possibility is to have the assembly node include a SPACEHAB module and support systems for the space station from the beginning (image). This would add about $150 M to the cost, and for the first mission, costs should be avoided as much as possible. It would, however, make the station far more capable, and the two Soyuz pilots would not have to stay in two connected capsules for two weeks while the crew goes to the moon and back. Another possibility with the extra mass, aside from making the Lunar Habitat more massive, is that it would be possible to add a Pressurized Mating Adapter (PMA) to the space station to allow a shuttle to dock at a later date. However, the addition of another launch and the SPACEHAB module raises the price far beyond that of a simple assembly station, and on the second mission, there will be room for a second SPACEHAB where the Lunar Transfer Vehicle was for the first mission, without a fourth cargo launch.

Launcher	Payload	Cost
Ariane 5 + 2 Protons + 2 Soyuz	148,000 lbs (67,000 kg)	$275 M (for subsequent missions)
Ariane 5 + 2 Protons + 2 Soyuz + Assembly node	148,000 lbs (67,000 kg)	$425 M ($305 M if amortized over 5 flights)
2 Ariane 5's + 2 Protons + 2 Soyuz + Node with Habitat	190,000 lbs (86,000 kg)	$680 M

This is the cheapest ticket to the moon yet. It costs considerably less to make a space station of our own than to rent the Space Shuttle, and this is the most capable option yet considered. The staging base will have many opportunities to pay for itself through research, industrial, and entertainment value. With a reflight costing only $275 M, this seems to be the best option, especially in the long-run.