Two officials refused to approve the launch from Russia aboard a Soyuz rocket of a new two-man crew for the ISS and signed a dissent warning about "the continued degradation" of the environmental monitoring and health maintenance systems and exercise equipment aboard the station, the daily said quoting documents and interviews.

However NASA spokesman Don Mirelson later told AFP the defective equipment was destined for replacement by upcoming resupply flights.

"The international partners are working together to replace some of the equipment, the monitoring equipment and send up some other new equipment on a subsequent supply flights," he said.

"The international partners and the United States agreed that they felt there is no immediate safety danger to the crew related to the environment of the International Space Station. So the decision was made to go ahead and launch the expedition."

NASA administrator Sean O'Keefe also told the Post there was no immediate hazard to the crew, but that conditions aboard the space station could deteriorate in the next six months and force the crew to leave.

"If there is any indication whatsoever that this [situation] is hazardous to their continued existence, or to their health longer term, the answer is: Get aboard the Soyuz, turn down the lights and leave," he said in an interview with the daily.

The dissenting scientists, who were not identified, said that the February 1 disaster of the US space shuttle Columbia, which disintegrated on reentry, killing all seven astronauts on board, has made it impossible to repair or replace faulty equipment on the ISS.

They said a growing array of hardware problems was preventing NASA's flight team from assessing the quality of air, water and radiation levels aboard the

Some NASA medical officials told the daily the equipment problem had been festering for more than a year, with ISS astronauts complaining of headaches, dizziness and, according to one official, "an inability to think clearly."

The Soyuz rocket launched Saturday docked on Monday with the ISS. American Michael Foale and Russian Alexander Kaleri will replace the current US-Russian ISS crew, Edward Lu and Yuri Malenchenko.

Spaniard Pedro Duque, who also traveled to the ISS, will remain aboard the space station for 10 days to carry out experiments.

Russia has been the only country servicing the ISS since the United States grounded its shuttle program following the Columbia disaster.

The 16-nation ISS project was launched in 1998.

SPACE.WIRE