washington & munich

Critical component: the Russian service module under construction at Khrunichev space centre. Credit: NASA

Life scientists and microgravity researchers face serious delays to the start of their experiments on the international space station as a result of proposed changes to its construction schedule being discussed this week in Moscow.

If US and Russian negotiators agree on a plan to shift part of the burden for supplying the station from Russian to US space vehicles, the need for extra space-shuttle missions could delay the seven scientific ‘utilization’ flights planned between 2000 and 2003. These would furnish the laboratory with experiment ‘racks’ that can be used for a variety of investigations.

Although the new assembly schedule has not been finalized, the average delay for utilization flights would probably be about six months, according to Mark Uhran of the US space agency NASA's Office of Life and Microgravity Sciences. Construction of the station starts next month, with the first utilization flight planned for April 2000.

The proposed schedule changes — made necessary by Russia's inability to pay for key elements it had promised to deliver — could also delay the completion of the station, now planned for 2004, by up to a year. Because the laboratory module of the European Space Agency (ESA) is among the last elements to be attached, European use of the station would probably be affected.

US space managers have been struggling for months to find a politically acceptable solution to the Russian problem, which threatens the project's schedule, if not its very survival. NASA now hopes to pay Russia $60 million immediately to finish work on a crucial ‘service module’ scheduled for launch next summer as the station's centrepiece during its early stages of assembly.

But a more ambitious NASA plan to buy an extra $600 million worth of Russian hardware and services over the next four years got a chilly reception last week from key figures in the US Congress. These included House Science Committee chairman James Sensenbrenner (Republican, Wisconsin), Senate Science Committee chairman John McCain (Republican, Arizona) and House Speaker Newt Gingrich (Republican, Georgia), who called the current US-Russian agreement on the station an “absolute disaster”.

With further slip in the schedule now almost inevitable, NASA hopes to soften the blow for space researchers by accommodating more experiments on the proposed half-dozen extra space-shuttle resupply flights.

Another possibility is for NASA to use the Russian service module, which is nearly identical to the Mir station that housed several US experiments over the past three years. But the research community would be limited by scarce funds to flying mostly repeats of past experiments, according to Uhran.

ESA, meanwhile, wants to help its small space research community weather the delay by starting up a granting programme for ground-based experiments in life-sciences space research. The proposed scheme, suggested as part of ESA's programme for exploitation of the space station from 2000 to 2004, was discussed this week by ESA's Microgravity Programme Board, which includes representatives from ESA member states.

The scheme would give researchers access to large-scale facilities such as those designed to model aspects of living in space, including bed-rest, confinement and isolation facilities, and would help them build up facilities in their own institutes.

To complement the scheme, ESA is trying to persuade the European Commission to include ground-based space biology in its fifth Framework programme (FP5), which is due to begin operation next year, to provide researchers with project money.

“More ground-based work will allow experiments to be very carefully designed on the ground, so that we can be sure they will work in space,” says Didier Schmitt, director of ESA's life sciences department.

The proposed 2000-2004 space-station exploitation programme continues microgravity work in life sciences in parallel to ground-based work, which includes sounding rocket experiments and parabolic flights.

ESA has also negotiated space for some experiments on the privately owned Spacehab, which will fly in the space shuttle's cargo bay later this month and again in 2000. “We hope the space station is not delayed”, says Didier. “But if it is we hope to have a complete strategy to keep our scientific community going.”