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Slide 99 of 99


Mars habitation module undergoing tests at I.S.S. The Space Station was originally regarded as a staging base or assembly node for manned missions to the Moon and Mars. The 1991 redesign removed most of the necessary features, e.g. power and attachment points for a "spacedock" facility, and most recent NASA lunar/Mars plans have assumed the Station only would used for crew training and as a technology testbed. However, an expanded version of the International Space Station may well be able to serve as a "space harbor" for reusable manned lunar spacecraft. Earlier studies from the 1980s suggest the necessary modifications would be relatively inexpensive. NASA planners currently believe the assembly operations in low Earth orbit would be too complicated and that it would be better to use large expendable spacecraft and launch vehicles specifically designed for the mission, much like the 1960s Apollo lunar project. History suggests such programs would not survive politically, though. Commercial launch vehicles are not large enough to launch an entire lunar or Mars spaceship, so some kind of assembly node in space would be required to assemble the pieces. Since manned interplanetary spaceships typically cost up to one billion dollars per copy, it might make sense to recover and re-use them after each mission even if the direct and indirect servicing cost is high. There is no obvious reason why the International Space Station should not be useful for this. True, the old Freedom space station's low equatorial orbit (28.5 degree orbital inclination) would have been slightly more suitable than the ISS 51.6-degree orbit. There will be fewer and shorter launch opportunities ("launch windows") to and from the International Space Station, but it is not a showstopper.

Manned lunar convoy departs from the "Power Tower" Space Station. This lunar lander & reusable space tug configuration was proposed at the Lunar Bases and Space Activities of the 21st Century conference in 1984. The lander is carrying a moonbase module derived from the Space Station's habitation module. NASA expected to build and launch such spaceships in 2003-2005 after completing the Space Station in 1995. The schedule turned out to be optimistic, but a small manned lunar outpost still makes sense as a realistic and affordable "next logical step" in manned spaceflight, perhaps by 2015. It now looks as if the International Space Station actually might accomplish some of the commercial space-related goals outlined in the 1984 plan after all, e.g. as a market for commercial services. Hopefully, the Space Station will also play an important role in future manned lunar and Mars exploration activities.