Spacewalking Soviets Run Into Trouble : Technology: Two cosmonauts are forced to use an emergency hatch to get back into their space station.

Two spacewalking cosmonauts had to use an emergency hatch to re-enter their spacecraft because their normal hatch malfunctioned and their life-support supplies were running out, Soviet media said Wednesday.

The incident, which Soviet television called life-threatening, occurred while Anatoly Solovyev and Alexander Balandin were trying to fix a torn thermal insulation blanket on the outside of their spacecraft.

It was the latest in a series of problems plaguing the cosmonauts’ six-month mission.

Despite the danger, the cosmonauts joked about it afterward. Solovyev quipped that flight controllers “need to put road signs there” on the outside of the huge craft, Soviet television’s evening news program “Vremya” said.

“Was there a threat to the crew’s lives? Yes, there was,” the “Vremya” broadcast said.

“Midnight Emergency in Outer Space,” was the headline of a front-page story in Wednesday’s Izvestia newspaper. The article raised the possibility that human error could be behind the hatch problem and that the cosmonauts might have to take another spacewalk for more repairs before they can return to Earth.

A U.S. specialist on the Soviet space program said the hatch problem may prevent Solovyev, the 42-year-old flight commander, and Balandin, the 36-year-old engineer, from taking another spacewalk.

The Soviet Union’s manned space program, which for decades has been a source of national pride, has been plagued the past two years by equipment malfunctions, mistakes by cosmonauts and budget cuts.

The cosmonauts on Tuesday left Mir, the space station orbiting for four years, to fix thermal insulation around the capsule they must use to return to Earth.

Nearly half the insulation on the Soyuz TM-9 capsule, which is docked to Mir, has peeled off, news reports have said.

After repairing some of the damaged insulation, the cosmonauts, who were working without tethers or hoses connected to the ship, encountered the hatch problem.

“During their return to the spaceship, the crew experienced unexpected difficulties,” Radio Moscow said. “The cosmonauts had to make use of an emergency door to enter the station.”

James Oberg, author of several books on the Soviet space program, said that although the cosmonauts managed to climb back into Mir safely, the hatch problem could complicate future spacewalks.

“The general crisis was not fully resolved,” Oberg said in a telephone interview Wednesday from his Texas home.

He said the cosmonauts may be unable to take another spacewalk because equipment needed to recharge their spacesuits with air and other vital supplies is now inaccessible in the damaged air lock.

Izvestia said it took Solovyev and Balandin three hours to reach their damaged capsule after crawling out of Mir and scampering along its outer skin using fasteners like mountain climbers. They managed to fold part of the damaged insulation using clamps but another damaged piece wouldn’t budge.

Izvestia said life support resources of the cosmonauts’ spacesuits approached their six-hour limit.

They were running so low on air that they had to “feed” their spacesuits outside the ship, Izvestia reported, apparently drawing oxygen from the vessel.

In their rush, the cosmonauts apparently did not remove their ladders from the outside, Izvestia reported. It said ground controllers “cannot rule out” that Solovyev and Balandin will have to take another spacewalk in the next few days. It did not say whether the walk would be needed to remove the ladders or to repair the balky hatch.