International Space Station I 20th Anniversary
This view of the Space Shuttle Atlantis still connected to Russia’s Mir Space Station was photographed by the Mir-19 crew on July 4, 1995.
NASA, with the support of Vice President Al Gore, ordered yet another redesign. There were three configurations considered, called Alpha, Beta, and Charlie. Alpha used some 75 percent of the Space Station Freedom hardware, and subsequently most of the hardware that had previously been deleted was added back. While one segment of truss was removed from each side, it was essentially the same as Space Station Freedom in appearance and capability, envisioned as a world-class research laboratory in three fields: microgravity, life sciences, and technology. Meanwhile, within a month of taking office in April 1992, NASA Administrator Daniel Goldin was contacted by Yuri Koptev, his counterpart at the Russian federal space agency, who suggested the two agencies might combine their resources to build and operate a space station. Russia had already begun building modules for its planned Mir-2 station, but the future of the Russian program, given the new
16
country’s political and fiscal circumstances, was precarious. Shortly after, in June 1992, Boris Yeltsin and Bush signed an expanded space exploration agreement that considered flying Russian cosmonauts on a U.S. Space Shuttle mission, sending a U.S. astronaut to Mir for an extended flight, and pursuing the possibility of docking the Space Shuttle with Mir in 1994 or 1995. This joint effort was called the Shuttle-Mir Program. The advantages to including Russian hardware and expertise in the space station program were clear, for both geopolitical and pragmatic reasons. In terms of the station’s capabilities, NASA claimed Russian participation would allow it to be built a year sooner, cost $2 billion less than the Alpha design, have 25 percent more usable volume, generate 42.5 kilowatts more electrical power, and accommodate six crew members instead of the planned four. The ability to park two Soyuz capsules permanently at the station (one Soyuz would
be required for each three crewmembers) took pressure off NASA and its partners to develop their own crew return vehicle. Progress spacecraft, the expendable Russian cargo carriers, could aid in supplying the station. On Sept. 2, 1993, Gore and Prime Minister Viktor Chernomyrdin signed an accord merging Mir-2 and Space Station Alpha into a single project that would soon be known simply as the International Space Station (ISS). On the American side, NASA’s Johnson Space Center took the lead, and Boeing signed on as the prime contractor. The existing Shuttle-Mir program was expanded to become Phase 1 of the new ISS program, and added a whole series of shuttle flights to the Mir Orbital Station. A few months later, in February 1994, cosmonaut Sergei Krikalev – who had been stranded in orbit when the Soviet Union fell and forced to stay an extra six months aboard Mir after a cancelled Soyuz flight – joined the crew of the Space Shuttle Discovery to become the first cosmonaut to fly aboard an American orbiter. About a year later, astronaut Norman Thagard became the first American to serve aboard Mir, joining a threemonth expedition whose crewmembers were brought home aboard the Space Shuttle Atlantis. In November 1995, Atlantis delivered a Russian-built docking module to the station, marking a milestone: the first addition of a module to a working space station in orbit. The revamped ISS design had already taken shape. It was based on a modified Space Station Alpha, somewhat bigger, with some of the formerly deleted pieces added back. It comprised a horizontal truss perpendicular to the station’s flight path, and modules clustered near the truss’s centerline, mostly at right angles to the truss. The truss was arranged symmetrically, with four pairs of solar arrays extending from each end. The Russian-built but U.S.-funded Functional Cargo Block, named Zarya, was the primary early Russian contribution, along with the Zvezda Service Module (the same as the Core Module or Base Block of the earlier Mir and a direct successor of the earlier Salyut stations). The main thing to disappear from the U.S.-provided systems was the propulsion system. The station was now totally reliant on Russian-provided propulsion. Early on, Russia would also provide the habitation and life support functions, and the Soyuz would provide the emergency return capability. By 1997, NASA had begun shifting funds from
