Significance

While the Apollo-Soyuz mission did contain scientific experimentation, its main accomplishment was crushing the political boundary between the United States and the Soviet Union. By proving that nations could overcome technological, linguistic, and political differences to work together in space, the Apollo-Soyuz mission laid the foundation for future international collaboration in space.

The most famous of these collaborative missions was the founding of the International Space Station, or ISS, formed in 1998, as a merging of the individual space station projects of the United States and the Soviet Union. Skylab, a NASA station launched in 1973, and Mir, a Soviet space station launched in 1986, were both doomed to fail due to lack of funding. Cooperation between the United States and Russia, however, using a docking system similar to the one used in the Apollo-Soyuz Test Project, made the combined project a huge success.

Since then, other countries have contributed to the ISS and made this a successful international effort to further important scientific research in peaceful, gravity-free space.

Mr. Clinton called to congratulate the astronauts. "We're all so impressed," he said. "This really proves, I think, that Russians and Americans can work together and that we can make this international space station project successful."
(Broad)

MSNBC

After the project ended, there was a period of sporadic cooperation. However, in 1995, the United States and Russia were able to come together again to combine their ships in space. Since then, there have been no major problems, and the countries have been able to cooperate in space.