Two spacewalking cosmonauts successfully removed a rubber seal Monday that had jammed a docking mechanism at the international space station and forced a shuttle launch delay.

The obstruction had disrupted NASA's plans last week to send space shuttle Endeavour on a space station delivery mission. Liftoff is now scheduled for Tuesday evening, five days late.

An O-ring seal, apparently left behind by the previous supply ship, prevented a new Russian cargo ship from hooking onto the space station last Wednesday. None of the hatches closed, and the unmanned ship was left hanging loosely from the orbiting outpost.

NASA feared the ship might wobble and damage the station when Endeavour pulled up with a slight jolt. As a result, shuttle managers put off the launch until after the spacewalk.

The repair job fell to Russians Vladimir Dezhurov and Mikhail Tyurin, the more experienced spacewalkers on the crew. American commander Frank Culbertson observed their work from inside.

Russia's Mission Control near Moscow backed the supply ship away about a foot so the cosmonauts could reach inside with tools and remove the stray cable. The spacewalkers reported that the supply ship was wobbling as it slowly backed out.

"Don't forget that the mass is 7 tons," Mission Control warned.

Dezhurov and Tyurin quickly identified the debris as a rubber seal, almost certainly left behind by the trash-filled supply ship that undocked Nov. 22 and, as planned, incinerated in the atmosphere as it fell.

"I can see it right there," one of the cosmonauts said. "I can see it, too," the other replied. They said the seal was twisted and described it as long -- "like a snake."

As soon as the cosmonauts cut away the seal, the supply ship was attached securely to the space station. The men took the pieces of seal into the space station at the end of their three-hour spacewalk.

"Good, guys, thank you so much," Mission Control radioed. "You did a good job."

U.S. and Russian flight controllers considered the spacewalk relatively easy. Cosmonauts performed a similar procedure back in 1987 aboard space station Mir; that time, the junk was a bag.

The space station crew could not open the supply ship and pull out the thousands of pounds of food, clothes and other gear until the vessel was firmly locked down.

Culbertson, Dezhurov and Tyurin have been living aboard space station Alpha since August. Endeavour will take up a fresh three-man crew and bring the current residents back to Earth.