Cosmonauts complete space walk for repairs

Cosmonauts Mikhail Tyurin, left, and Vladimir Dezhurov, right, repaired the docking mechanism during the spacewalk. Astronaut Frank Culbertson, center, observed the work from inside.

(CNN) -- Russian Cosmonauts Vladimir Dezhurov and Mikhail Tyurin finished a successful space walk in 2 hours and 26 minutes -- less than half of the time the crew estimated it would need to repair a docking port.

The walk began seven minutes early at 8:20 a.m. EST Monday. It was a retrieval mission to get an errant rubberized o-ring seal that was hampering a hard dock between the Progress cargo ship and the international space station.

The 30th space walk ended at 11:06 a.m. EST.

Space agency officials had correctly theorized that an obstruction was preventing hooks and latches from fully engaging to fasten the supply ship Progress to its docking port.

That failure to dock properly prompted shuttle flight engineers to scrap liftoffs last Thursday and Friday of Endeavour. NASA managers expressed concern that had the shuttle attached to the station, the unmanned Progress vessel, which is "soft-docked" to another part of the station, might shake and damage the multibillion dollar modular complex.

The new departure time of Endeavour is set for 5:45 p.m. EST Tuesday, since it appears the space walkers succeeded on their makeshift repair job.

The Progress, which arrived Wednesday, contains about 1.5 tons of supplies, none of which could be delivered until the vessel could tightly docked.

Col. Sam Dick, a U.S. Air Force officer in charge of security for the NASA mission, said the delay would not compromise safety during the launch, the first since the September 11 terror attacks.

The military has taken unprecedented steps to protect the $2 billion orbiter. Fighter jets and attack helicopters have increased patrols over Kennedy Space Center in Florida.