With cooling problems affecting the American spacewalking suits stashed aboard the International Space Station, mission managers on Monday significantly revised plans for next month's critical excursion to replace a failed electronics box in the outpost's orientation system. The station's two-man crew will wear Russian suits and exit through an airlock farther away from the worksite, making the repair job more time-consuming.

"Two out of the three U.S. spacesuits aboard the International Space Station have been declared 'no-go' for EVA," NASA spokesman Rob Navias said Monday.

"As a result, the Mission Management Team met this morning here at the Johnson Space Center to discuss the current status of EVA preparations to try to be in a posture to safely and successfully replace the remote power controller unit in the S0 truss and to regain the use of Control Moment Gyro No. 2.

"The decision by the (Mission Management Team) this morning was to curtail any further troubleshooting activities with the U.S. spacesuits for now and to press ahead with the plans and preparations to conduct this repair spacewalk in Russian Orlan spacesuits."

The latest problem with the U.S. spacesuits occurred last week as the Expedition 9 crew of commander Gennady Padalka and NASA flight engineer Michael Fincke conducted a dress rehearsal inside the American Quest airlock module. Although Fincke's suit worked properly, Padalka's suit suffered cooling problems that the crew could not correct during troubleshooting over the weekend.

A third suit has shown cooling problems dating back to Expedition 7 last year.

"Well, we tried our best with the (U.S.) suits both on the ground and up here and now we'll just go with the Orlans," Fincke told mission control after hearing management's decision today. "That shows the strength of our partnership and the strength of the flexibility that we have with the International Space Station."

There are four Orlan suits presently aboard the station, Navias said, two of which were delivered by a Russian Progress ship earlier this year. A Russian spacewalk by the last resident crew was cut short when the cooling system in a cosmonaut's suit stopped working.

Station officials wanted the upcoming spacewalk to begin from the Quest airlock since the electronics box being swapped out is nearby on the front-facing side of the S0 truss segment. The new plan with Russian suits means the walk will be staged from the Russian Pirs module of the station.

In order to travel the extended distance from Pirs to the S0 truss, a telescoping crane called Strela will provide a path for the spacewalkers to climb from the Russian segment of the station to the U.S. portion.

"It will take longer for us to go from the Russian airlock in Russian Orlan suits all the way over to the worksite to repair the power module. It won't be difficult, it's just going to take time," Fincke said in an interview with The Associated Press on Monday.

NASA says the box removal and replacement will be the only objective of the spacewalk due to time constraints.

"We only stay outside for roughly six hours due to oxygen and carbon dioxide removal concerns," Fincke said. "The trade-off with the Orlan suit is that part of that six hours is going to be used just getting to the American side of the space station and getting to the worksite. So that will definitely change the flavor of the EVA."

Fincke, a spaceflight rookie making his first EVA, said the spacewalkers must be mindful not to harm external equipment during the trek to and from the worksite.

"There are things we need to watch out for like important radio antennas, things like that. But we know where those are, and we will have a chance to review those before we go outside. It's not as dangerous as a mine field by any means. It's just going to take a fair amount of time to get there and to come back."

A firm date for the spacewalk has not been established, Navias said. But it is expected sometime around June 16.

The station has four massive Control Moment Gyroscopes that are used to stabilize and re-orient the complex. At least two are needed to keep the station flying correctly or else Russian thrusters must take over, which would require their fuel supply to be replenished.

A gyro failed two years ago and is awaiting replacement on the next space shuttle mission. When the electronics box, called the Remote Power Control Module, malfunctioned a month ago, it shut down a second gyroscope. With no margin for further problems, NASA decided the Expedition 9 crew would perform this unscheduled spacewalk to replace the electronics unit to get the gyroscope restarted.