What was the name of the first U.S. space station?

The first U.S. space station was named Skylab. Launched in 1973, Skylab represented a significant milestone in American space exploration, as it was the first space station operated by the United States. It facilitated various scientific experiments and observations in microgravity and served as a platform for astronauts to live and work in space for extended periods.

Skylab hosted three crewed missions, allowing astronauts to conduct research in fields such as biology, materials science, and solar studies. Its establishment marked a shift in the approach to long-duration spaceflight and contributed to our understanding of life in space, which was crucial for future missions. The successful functionality and diverse research conducted aboard Skylab laid the groundwork for subsequent space stations and initiatives, such as the International Space Station.

The other options pertain to significant space missions or satellites but do not represent space stations. Explorer I was the first successful U.S. satellite, Friendship 7 was the mission in which John Glenn became the first American to orbit Earth, and Sputnik I was the first artificial satellite ever launched, by the Soviet Union.