|Assembling a World-Class
Phase One of the International Space Station Program
Commencing in February 1994, the Shuttle-Mir program, also known as Phase I of the International Space Station program, consisted of a series of Space Shuttle-Mir rendezvous and docking missions and stays of seven U.S. astronauts on the Russian Mir space station. Nine Russian cosmonauts flew on the Space Shuttle during Phase I. The Phase I program concluded in June 1998.
The Phase I program provided the U.S. with the opportunity to conduct long-term experiments in microgravity aboard Mir for durations far beyond the capability of the Shuttle. Prior to the four-year Phase I program, the U.S., with the exception of the Skylab program, was able to send astronauts into orbit for only limited periods of time-primarily stays of up to about two weeks aboard the Space Shuttle. Phase I enabled U.S. astronauts, in four years, to spend 975 days on Mir, more time in orbit than had been accumulated since the Space Shuttle program began in 1981.
Important, on-orbit life science, microgravity and environmental research was performed during Phase I in preparation for the International Space Station. More than 140 scientific experiments were conducted by leading scientists from Canada, France, Hungary, Japan, Russia, the United Kingdom and the United States.
In the life sciences, research was conducted into human metabolic, neurosensory, cardiovascular and pulmonary systems. In the microgravity sciences, research was conducted on Mir in fluid dynamics, materials science and combustion science.
In addition to conducting scientific research, another important objective of the Phase I program was to learn how to reduce risks associated with assembling and operating the International Space Station. Actual space operations on Mir have led to improvements in the design of the space station, and U.S. astronaut experience on Mir has led to software, hardware and procedural modifications for the space station including single-command shutdown of ventilation systems to prevent fire from spreading, simplified location of medical kits and fire extinguishers, and a quick disconnect capability for cables in the event of a module depressurization.
Analysis of the events following a fire on Mir has resulted in a modification to the station's software so that all intermodule ventilation can be shut off with a single command. Also, a protective coating has been added to the space station's cooling lines to prevent corrosion, and additional tracking lights will be added to the space station to provide better use of navigation systems during rendezvous operations.