Freedom is the international space station planned for completion at the end of this century. NASA will assemble the station in orbit, and provide two of the four main modules. One is the habitation module, which forms the living quarters for all the crew of the station. The other is the US laboratory module, in which American scientists and engineers will carry out experiments in orbit. The other two modules are being supplied by the European Space Agency (ESA) and the Japanese space Agency NASDA. ESA's contribution to Freedom is the Columbus attached laboratory (CAT); NASDA's is JEM, the Japanese experimental module. Canada is also making a contribution to Freedom. It is supplying a robot mobile servicing system, and is building on experience with the Canadian-designed remote manipulator system, or robot arm, of the space shuttle orbiters. Freedom will be built in stages in orbit, using equipment and modules ferried up by space shuttle. As many as 20 flights may be required.
In its final configuration, Freedom will consist of the four main modules, joined by units called resource nodes, fixed to a trussed beam assembly 150 metres long.
The beam will carry huge arrays of solar cells, which will provide Freedom with electricity. The first shuttle launches to support the construction of the space station are scheduled for 1995. By the end of the following year, the space station should be in what is called its man-tended configuration. It will consist of just one main module, the US laboratory,mated to one resource node, attached to a beam assembly carrying solar-cell arrays. In this configuration, the station can be visited on short missions, using the shuttle as living quarters. Over the following three to four years, the rest of the space station will be assembled, reaching a permanently manned configuration, with all main modules in place, by the turn of the next century. Based on past experience with other ambitious space projects, it seems doubtful whether this timetable will be met.
