Space stations


Having recently written about the Human Genome Initiative and the Superconducting Super Collider, it behooves me to write about the third “big science” project now in the works, Space Station Freedom.

There was some question last year whether Space Station Freedom would ever be built–the U.S. Congress was considering dropping it from the budget. Fortunately for us space buffs, reason prevailed.

A space station, as the term is generally understood, is a permanent inhabited base in Earth or planetary orbit. People have been talking about space stations for as long as they’ve been talking seriously about going to space: in other words, since the 1920s, when Hermann Oberth, the father of modern astronautics, explored the possibility and problems of building such a station.

In 1929 Herman Noordung of Austria postulated a doughnut-shaped station that would rotate to provide artificial gravity. The rotating, doughnut-shaped space station is still what many people think of, not least because that’s what the space station looked like in 2001: A Space Odyssey and in countless other popular treatments of space flight.

Real space stations, however, don’t look like that–at least, not yet. The U.S.’s first space station was Skylab, which was manned in 1973 and 1974 for a total of 172 days by three three-man crews. (It later fell out of the sky and landed on Australia.)

NASA was planning a larger station even then, but decided it would be impractical without a re-usable space transportation system, and so shifted priority to the space shuttle. Freedom was officially born in 1984, when President Ronald Reagan announced a project to establish a permanent manned, international space station within a decade.

The international element of Freedom is the participation of the European Space Agency, Japan and Canada. Japan and the ESA will contribute modules to the station, while Canada has agreed to build a Mobile Servicing System, basically a larger and more complex version of the current Canadarm, which will be used to move equipment and supplies, release and capture satellites, support astronauts in space, service equipment, dock the shuttle and load and unload its cargo bay. All of the countries will also provide astronauts, with Canada to have a crewmember on board for six months every two years.

(The international flavor of the project is one reason Congress decided to keep funding it: with these countries having already committed considerable resources to preparing for their roles in the space station, they would not have been happy had it been cancelled.)

The reason NASA wants Freedom (aside from the institutional one of giving its employees something to do!) is to provide a laboratory for scientific research that cannot be carried out during the short duration or cramped conditions of a shuttle flight. The main focus will be on the life sciences, especially the long-term effects of space travel, important knowledge that will have impact on future travel to other planets.

Material sciences will also be an important area of research. It may be possible to manufacture exotic substances in space that would not be possible in Earth gravity, ranging from revolutionary metal alloys to ultra-pure and ultra-effective pharmaceuticals. Many other kinds of previously impossible scientific research will also be undertaken.

The actual design of Freedom is still undergoing revision–rather drastic revision, actually, because while Congress kept the station alive, it insisted it be scaled down.

As currently planned, the first elements of Freedom will be launched in 1996, and “man-tended capability” will be achieved in 1997, after six shuttle flights. The station will become permanently manned in 2000 (after 17 shuttle flights) and will consist of three laboratories (U.S., European and Japanese), a habitat (initially supporting four crewmembers), the Canadian Mobile Service System, and three sets of solar arrays furnishing 65 kilowatts of electrical power. The laboratory and habitat modules are about 9.5 metres long and five metres wide, about 40 percent smaller than originally planned. Overall, the space station will be 124 metres wide (down from 173).

The elements will be held together by truss segments which were originally supposed to have been assembled in orbit by space-walking astronauts but will now be built, preassembled and checked out on the ground, halving the number of spacewalks required.

Freedom is being designed to be expanded, with the eventual goal of increasing its crew to eight, adding another solar array and possibly another laboratory module.

Like the other “big science” projects I’ve written about, Freedom is not without its critics, who feel it will absorb resources better spent on smaller, more cost-effective projects and that it will undoubtedly run over-budget and behind schedule, to boot.

These arguments are probably valid, especially if you’re a scientist whose own project has been cut in favor of Freedom, but frankly, they leave me cold. Humans have always longed to see beyond the horizon, to explore the next frontier, and Space Station Freedom is the first rung of a ladder leading us back to the Moon, out to Mars, and beyond.

It’s time we started climbing.

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