Debris Forces Station Crew To Take Shelter

Frank Morring, Jr. morring@aviationweek.com

Debris from a spent rocket motor passed within 4.5 kilometers of the International Space Station Thursday, forcing the crew into the Soyuz capsule as a precaution.

The crew -- Expedition 18 commander Mike Fincke and flight engineers Yuri Lonchakov and Sandra Magnus -- spent about 10 minutes in the Soyuz, which serves as the station lifeboat. Had there been a collision requiring the station to be abandoned, Lonchakov would have been able to pilot the Russian vehicle to an emergency reentry and landing.

Before entering the capsule the crew closed hatches to compartmentalize the modules in the U.S. side of the station, and they "soft-docked" the hatches leading to the Soyuz in case they needed to make a quick departure.

NASA received a warning of the close approach from U.S. Strategic Command on March 11, too late to plan and execute an avoidance maneuver. The crew remained in the Soyuz from 12:35 p.m. EDT until 12:45 p.m. EDT, bracketing the estimated time of closest approach at 12:39 p.m.

NASA said the debris was from an old PAM-D payload assist motor from an earlier satellite launch. Strategic Command tracks thousands of pieces of space debris down to the approximate size of a baseball. Among them are some 700 objects scattered by the collision last month of an operational Iridium communications satellite and a defunct Russian military communications spacecraft, which added slightly to the debris risk at the station's orbit (Aerospace DAILY, Feb. 12).

Photo: NASA