Backgrounder: State of the Station
The International Space Station is on hold while NASA answers calls for attention in the order in which they are received.
- By Tony Reichhardt
- Air & Space magazine, November 2003
AFTER ALMOST 20 YEARS OF DESIGN, REDESIGN, re-redesign, and, finally, construction, the International Space Station is very nearly finished. Tentative applause. Now the bad news: For all the time and money ($24.4 billion and counting) spent so far, the station will have little use as a research laboratory until a full crew arrives to conduct experiments and serve as test subjects—or so says just about every scientific advisory group NASA has asked for an opinion.
Just what constitutes a “full” crew has been a matter of debate. A task force led by astronaut-turned-chief-NASA-scientist Shannon Lucid recently concluded that a full research load will require 5.6 astronauts. When those 5.6—call it six—people will move in is far less certain. First they’ll need lifeboats that can evacuate all six in an emergency. (The Russian Soyuz, the station’s current lifeboat, holds only three.) That means NASA has to design, build, and fly a brand-new vehicle—the Orbital Space Plane—something it hasn’t done in 30 years.
Despite this enormous hurdle, station managers had to be feeling pretty good going into 2003. Sixteen of 23 assembly flights, and more than 50 spacewalks, had come off with barely a hitch, and no one could deny the project’s astonishing success in purely engineering terms. Astronauts had delivered 200 tons of hardware to orbit, and most of the rest was built and awaiting launch at the Kennedy Space Center in Florida. Even the program’s chaotic finances were finally being whipped into shape.
Then: Columbia. Today a skeleton crew of two astronauts is marking time on the station, performing essential maintenance instead of running the busy program of scientific research they had trained for. About the only noteworthy thing that’s happened onboard since the shuttle accident—other than the July celebration of the 1,000th day of astronaut occupancy—was the August 10 video-link wedding of cosmonaut Yuri Malenchenko with his Earthbound bride. A space first, but hardly what NASA had been wishing for.
At least the station is in no imminent danger of falling from orbit or being shut down. The international partners, including Russia, whose Soyuz is the only vehicle currently ready to reach the outpost, agreed after the accident to take whatever steps are necessary to keep the station supplied and operating until the shuttles return.
When that will be is anyone’s guess—NASA hopes next summer. Station managers also desperately hope to pick up where they left off, and to stick with the pre-Columbia order of assembly flights. That plan could unravel if the three shuttles left fly less frequently as a result of recommendations by the Columbia accident investigation board. But assuming the schedule holds, here’s how things will go:
The next assembly flight will carry up research “racks” and other equipment to outfit the inside of the station’s laboratory module, Destiny. Then for the next five flights the action shifts outside: Astronauts will add sections to the station’s 356-foot backbone, or truss structure, and unfurl giant solar arrays to increase electrical power on the station. When finished, the backbone will support almost an acre of solar panels, generating 100,000 kilowatts. The Tinkertoy-style assembly job is hardly Tinkertoy-easy, however. Multiple spacewalks will be required to connect electrical and fluid lines, and the segments need to be positioned delicately, with clearances often measured in inches.
The last of these assembly flights will be the most challenging, as astronauts, with the help of the shuttle’s robot arm and a larger one on the station, detach one of the giant truss/array segments—labeled P6 for port side 6— that has supplied power since 2000. Originally positioned at the center of the station for balance, it will now be moved to its final resting spot: the end of the backbone. NASA engineers don’t relish the idea of scrolling up the arrays and then unfurling them again, especially since the original unfurling didn’t go smoothly. But it has to be done.