An August 21, 2013 article in NASASpaceflight.com has some good news and some bad news for advocates of a return to the moon. The good news that it is certainly technically feasible, especially since two elements of lunar surface missions, the Orion spacecraft and the Space Launch System, are already in development. The bad news is that a lunar return program would cost more money than either Congress, which seems to want it, or the White House, which had rejected it, is currently willing to spend.
There are two cost drivers for a return to the moon program. One is the building of a lunar landing vehicle, similar to the Constellation era Altair, capable of taking four astronauts to the lunar surface and maintaining them there for a week. The second is the necessity of launching two SLS rockets every year, about six months apart.
The plan would be to launch a lunar landing module on top of an SLS and insert it into lunar orbit. It would have the capability to loiter for the six months it would take to prepare Pad 39B to launch a second SLS with an Orion and a four person crew. The Orion would assume lunar orbit, rendezvous and dock with the lander. The crew would transfer to the lander, undock, and land on the lunar surface, leaving the Orion to loiter in lunar orbit. The crew would conduct operations on the lunar surface for about a week, then take off, dock with the Orion, and then return home.
How much additional money that would be required for a return to the moon program is unknown. However the Augustine Commission report recommended that NASA’s budget be increased by $3 billion to allow for either a “Moon First” strategy or what it called a “Flexible Path” approach that would focus on asteroids. It would be a large increase in NASA’s budget, but not a lot of money in comparison to the almost $4 trillion federal budget.