Mir Space Station

In 1994, the United States made an historic $400 million deal with Russia to place six American astronauts on Mir for durations of up to six months. Ostensibly an arrangement designed to prepare American crews for duty on the International Space Station (ISS) by exposing them to long periods in orbit, the deal also had political implications. With the collapse of the Russian economy, the Russian space program was in jeopardy, and with it, Russia's commitment to provide crucial elements for the ISS, such as the habitat module. Although NASA officials insisted the Mir deal brought important experience and data to the ISS program, many viewed it as a thinly disguised subsidy for the Russian space program.

Despite the wear and tear of more than a decade in space, the station functioned surprisingly well until 1997, the year that contained a number of mishaps. In February, an oxygen canister burst into flames, filling the living module with smoke. When the astronauts, turned to extinguish the flames, they discovered that the launch restraints on the firefighting equipment had never been removed, and spent valuable time searching in near darkness for tools to free them prior to extinguishing the flames.

In subsequent weeks, the main carbon dioxide removal system failed. Then the cooling system malfunctioned, leaking coolant into the air and forcing the shutdown of the drinking-water reclamation system due to contamination. Temperatures in the modules remained at 96°F (36°C) for weeks.

In June, the station suffered the most dangerous setback. During the test of a new docking system, an unmanned rocket collided with the Spektr module, piercing the hull and crumpling solar panels. During the scramble to seal off the module, the astronauts were forced to disconnect cables that snaked from Spektr's solar panels into the other modules of the station, leaving Mir with only partial power. Days later, the steering units broke down, then a power surge knocked out a computer. The astronauts were forced to use precious fuel from the Soyuz escape pod to reposition the station, turning the solar panels toward the Sun.

In July, the cooling system failed again, then the main computer crashed, an event that would repeat itself time and time again in coming months. In September, the U.S. Space Command center sent out a warning that a military satellite was in an orbit that would pass dangerously close to Mir. About the same time as the warning was received, the main computer on the station failed, leaving the astronauts aboard to simply watch tensely from the Soyuz escape pod as the MSTI-1 satellite passed 1,000 yd (910 m) away.

As the month dragged on, the station suffered repeated computer failures, as well as failure of the carbon dioxide removal system and leaks of mysterious brown fluid. Amid reports that the Russians were ignoring scheduled parts replacements as a cost-cutting measure, concern for the safety of American astronauts aboard the station mounted. The four year collaboration ended in mid-1998, as the seventh American astronaut came back to Earth.

With the launch of the ISS approaching, and the continued problems at Mir, the Russians initially announced plans to intentionally de-orbit the station in September 1999, dropping it into the sea. As the appointed date drew near, however, the space agency seemed less and less inclined to terminate the station. Mir was actually owned and maintained by privately held RKK Energia, which pledged to dig up the $100 million annually required to keep the station in orbit. Eventually the effort to maintain the station became resource exhausting and a decision to make a controlled deorbit was inevitable.

Almost 100 astronauts spent time on the space station during its lifetime, and countless experiments provided data to help scientists better understand the effects of the space environment on man and materials. The ISS has and will continue to benefit from the lessons learned with Mir.