Space Station Walk Mired in Complications

June 24, 2004 -- -- There have been 52 spacewalks so far to build or fix the International Space Station. But spacewalk No. 53 is showing how complicated it is to conduct international affairs in orbit.

Today's space walk has one objective: to replace a broken power unit on one end of the station. It happens to be an important one — it supplies one of the four gyroscopes that keep the space station oriented in orbit — but replacing the power unit, at first glance, would seem to be simple. The box that holds it is held in place with a single bolt.

"This EVA [extra-vehicular activity] is one that we can do, and should do," said Mike Suffredini, NASA's deputy program manager for the space station project, at a news conference in Houston. The loss of the gyroscope, he said, "does put us at some risk posture."

But here are the hurdles faced by the station's two crew members, American Michael Fincke and Russian Gennady Padalka:

The spacewalk is happening now because another of the four gyroscopes has failed, and a replacement can only be delivered by an American Space Shuttle. The fleet has been grounded since last year's Columbia accident.

The men were originally going to wear American space suits to fix American equipment, but two of the three suits on board had coolant problems. "Those suits were past their expected lifetimes and needed to be refurbished, and we just couldn't get them up and running in time," astronaut Fincke said from orbit on June 15.

So they switched to Russian space suits — but that brought new complications. The Russian airlock, from which the men will now head outside, is 80 feet from the part that needs replacement. The American airlock is fewer than 20 feet away.