Discovery Expands US, Russian Cooperation in Space Exploration

WHILE cosmonaut Sergei Krikalev circles Earth on the space shuttle Discovery, two American astronauts start cosmonaut training at Star City outside Moscow.

What the National Aeronautics and Space Administration (NASA) calls ``Phase 1'' of ``the rapidly expanding United States/Russian human space flight cooperation'' is under way.

Its next milestone is a shuttle mission in January when Cosmonaut Krikalev's backup, Vladimir Titov, will be on board. Then, in March 1995, either Norman Thagard or Bonnie Dunbar - the astronauts now at Star City - join two cosmonauts to ride the Soyuz 18 spacecraft to the Mir space station.

Meanwhile, back at the space shuttle Discovery some 200 miles above Earth, Krikalev and his American colleagues are making the most of their remaining time on orbit before their scheduled return to the Kennedy Space Center in Florida midday Friday. Failure to deploy the 3,700-pound Wake Shield Facility satellite - one of the main feature's of this mission - was disappointing. But they can still fulfill the mission's primary objective of operating the Space Habitation Module (Spacehab) commercial laboratory mounted in Discovery's cargo bay. It's loaded with life-science and materials experiments and support equipment for still other experiments installed on Discovery's middeck.

The Wake Shield features a 12-foot diameter stainless steel platform on which equipment is mounted. This platform is designed to act literally as a shield to push aside dust and stray atoms and produce an ultrahard vacuum in its wake. Alex Ignatiev and his University of Houston team that are developing the wake-shield concept hope to use that vacuum to grow highly pure wafers of the semiconductor gallium arsenide.

Problems with indicator lights, glare, and radio interference from the shuttle, which had prevented deployment Feb. 5 and Feb. 6, were overcome. But uncertainties about the satellite's on-board guidance system forced NASA to abandon deployment Feb. 7. This failure of a guidance system that has worked well on many previous craft was a ``snake'' lurking in space that ``we didn't expect,'' Dr. Ignatiev said.

The experimenters will try to make the most of what they can learn from working with the equipment in the cargo bay. They may have a second chance on a later shuttle mission, since NASA had originally intended to fly the facility - whose current mission cost $13.5 million - more than once.

It also was a disappointment for Krikalev, who had trained to retrieve the satellite. But, since he has had two duty tours on the Mir station lasting, respectively, 151 days and 312 days, he is used to dealing with the challenges of space flight.

NASA expects to give some American astronauts sustained space flight experience in the Phase 1 stage of the US/Russian program. Either Dr. Thagard or Dr. Dunbar are to spend three months on Mir. Then, in June 1995, a shuttle carrying a replacement crew consisting of an astronaut and two cosmonauts will bring Thagard or Dunbar and their Russian teammates back to the United States.

All told, the Phase 1 program is planned to include four or more US-astronaut Mir duty tours totaling over two years of on-orbit time. With up to 10 shuttle-Mir missions between 1995 and 1997, American spacecraft will take on a significant role in assisting with crew transfers, resupply, and payload activities for Mir, according to a Feb. 3 NASA statement.

Phase 2 of the cooperative effort follows with development of the core elements of a new international space station.

Phase 3 opens around the beginning of the new millennium with expansion of the station to include the other partners - Canada, Japan, and the European Space Agency.