SPACE CENTER, Houston, July 4 -- The shuttle Atlantis unberthed from the Mir space station Tuesday after a five-day visit to swap crews, replenish supplies and test a budding U.S.-Russian space partnership. 'Happy Independence Day,' astronaut David Wolf, speaking from NASA's Mission Control Center, told the Atlantis crew as they readied their 100-ton ship for departure. The shuttle eased away from Mir on-time at 7:10 a.m. EDT (1110 GMT), the second craft to depart Mir Tuesday morning. Cosmonauts Anotoly Solovyev and Nikolai Budarin strapped themselves inside a Soyuz space capsule and left Mir 15 minutes earlier, getting into position to film Atlantis' undocking. Whizzing 17,500 mph around the planet, Mir, Atlantis, and Soyuz flew in an unprecedented orbital formation while astronauts and cosmonauts hovered at the windows, aiming cameras at each other. 'This is quite a scene,' said shuttle commander Robert 'Hoot' Gibson. 'The phrase 'cosmic ballet' comes to mind.' After 44 minutes, the Soyuz redocked with Mir, depositing Solovyev and Budarin at the station for a two-month stay. The outing was cut short by about five minutes because of a computer problem that shut down Mir's automatic positioning system. The glitch also forced the cosmonauts to transmit their video of Atlantis' undocking to the Russian control center through a ground communications station rather than the more sophisticated Altar satellite system. The tape was to be retransmitted when Mir's computer is back in operation. In the interim, the station's attitude is being handled remotely by ground controllers.
Solovyev and Budarin, who flew into space aboard Atlantis a week ago, will reboard the Soyuz for a return trip to Earth. Their seats on Atlantis, meanwhile, are occupied by their colleagues Vladimir Dezhurov and Gennady Strekalov, who had been stationed on Mir since mid-March. The shuttle, scheduled for landing on Friday, also carries an eighth passenger: astronaut and physician Norman Thagard, the first American to be stationed on Mir, who now holds the U.S. record for the longest spaceflight. Since boarding Atlantis, Thagard, Dezhurov and Strekalov have been the subjects for a series of medical and biochemical tests to gain understanding of how microgravity has changed their bodies. Tests in the shuttle's Spacelab module were to continue throughout the remainder of Atlantis' flight. The shuttle is scheduled to fly to Mir six more times over the next two years, including a flight in late October to install a permanent shuttle docking port at Mir. The missions are expected to be followed by a U.S.-Russian partnership to build and operate an international space station. 'It's been an inspiring visit with our neighbors in space,' said Wolf. 'We look forward to returning.' Added Tommy Holloway, manager of the shuttle-Mir program: 'The spirit and capability of NASA is still alive. This is NASA's finest hour.'