xiv changed. With costs again projected to greatly exceed the budget, President Clinton ordered a rescale of the platform in 1993 with the requirement to keep the project under a $2.1 billion annual cap. As a result, NASA developed three options that were called, in true NASA fashion, options A, B, and C. Option A was basically a restructuring of the Space Station Freedom modules. This option had a crew of about five that spent 1-month intervals on orbit. Option B was larger and could allow two shuttle orbiters to dock simultaneously. However, it would only have a human presence during shuttle missions with the science payloads operating untended in between. Although producing a capable station, this option required a large number of launches. Finally, Option C was thrown together from “spare” parts of the Space Shuttle Program and Space Station Freedom Program, including using the Columbia orbiter as a permanent module. This would get the program going quickly and more cheaply, but it did not really support a good platform down the road. Option C was essentially a modern Skylab option. All three options, however, did call for a strong international cooperation, including the European and Japanese space programs. In fact, the first two options even included using Soyuz spacecraft for the crew’s emergency return vehicles. Option A was selected and the project was now called ISS Alpha. The plan called for the first element to be launched in 1997, with “assembly complete” status slated for 2002. What was the Space Shuttle? The term Space Transportation System referred to the entire program, which included the Space Shuttle, the mobile transportation launch pad, and even the assembly buildings. The Space Shuttle consisted of the external tank, which contained the liquid propellant, solid rocket boosters, and winged orbiter that launched like a rocket but landed like an airplane. The orbiter contained the crew in a pressurized area and an unpressurized payload bay. The fleet was composed of five orbiters, two of which (Challenger and Columbia) were destroyed during launch and reentry, respectively, resulting in the loss of 14 astronauts. Although not strictly correct, the terms shuttle and orbiter are used interchangeably. At the same time, the world was undergoing a marked change. In particular, 1991 saw the collapse of the Soviet Union. In late 1993, it was announced that Russia would be full partners in the ISS project. This decision was made as much out of engineering necessity as political reality, but it has proven to be a robust partnership that has enabled the ISS Program to be a success. However, it presented some interesting challenges, which were to be expected when essentially splicing together two different space stations. Even basic infrastructure such as power was different, as every American traveler has experienced when trying to plug an American electrical device into a foreign socket. Even the planned orbit around the Earth was adjusted to accommodate the Russian rockets, which had less lifting capability than the Space Shuttle. Because of this history, the ISS is separated into two segments—US and Russian. The United States On-orbit Segment (USOS) includes all the non-Russian partners, most notably the European Space Agency (ESA) module, the Japanese modules operated by Japan Aerospace Exploration Agency (JAXA), and the Canadian robotic systems operated jointly between NASA and the Canadian Space Agency (CSA). The remainder is the Russian Segment. Although different countries built the various modules of the USOS, NASA integrated them all from the beginning therefore, the modules all have the same look and feel (e.g., use the same base power standard). The assembly sequence was laid out in three phases. Phase one was to be the learning interval. To make the project work, Russia and the US would have to learn how to cooperate in order to merge two very different programs. During this interval, US astronauts would spend time on the Russian space station Mir, and several cosmonauts would fly on the Space Shuttle. Due to the Iran Nonproliferation Amendments Act (2005), NASA could not pay for the