Slide 48 of 99
Notes:
After the 1986 Space Shuttle Challenger accident, a number of space policy reports (“Pioneering the Space Frontier”, “Leadership and America's Future in Space”) advocated an aggressive manned lunar/Mars program to restore America's lead in space. NASA now embarked on a number of studies to see how the downscaled Space Station Freedom could assist this goal. This 1988 illustration depicts a large "Drive-thru" spacedock facility for assembly and checkout of manned lunar spacecraft.
The "Drive-thru" spacedock would have weighed more than twice as much as the
basic Space Station Freedom, which had an in-orbit mass of 200 metric tons.
Lunar transfer vehicles would have been assembled, serviced and refueled in
the rectangular enclosure on top.
The "Atrium" spacedock would also have utilized the same type of
modules and structures as Space Station Freedom.
Finally, the "Platform" spacedock would have featured a large
gravity gradient-stabilized extension at the bottom. The Canadian Mobile
Servicing Center would have been capable of moving up and down this structure,
transporting the lunar spacecraft stack along the way. The "Platform" and
"Atrium" versions would be bigger than the "Drive-Thru", but their overall
operation (e.g. attitude control/stability) and maintenance might be easier.
Most NASA studies preferred to develop a separate spacecraft assembly & checkout facility in order to minimize the impact on sensitive experiments onboard Space Station Freedom. This “spacedock” would be connected to the Space Station by a long tether. The space tug (top) will receive a free boost from the centrifugal forces when it releases the tether
This free-flying “spacedock” would be constructed from Space Station subsystems such as solar thermodynamic power generators, radiators, truss segments etc.. The white tanks contain rocket propellant for the space tug.
The second illustration shows a space tug being assembled from elements launched from Earth by a large robotic arm. The large walls on the side of the spacedock's box-like structure provide thermal protection.
