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Reid: New crews arrive at the International Space Station every couple of months, so it seems like we’ve got the whole living-in-orbit thing figured out.

But America’s first space station fell apart when it launched, had a crew rebel, and crashed back to Earth before NASA could save it. Its name was Skylab, and space programs worldwide learned a lot about how to keep astronauts happy, healthy, and productive from the three crews who lived on board.

Humanity’s first space station was Salyut 1, launched by the Soviets in 1971. But the missions had some problems, and Salyut 1 was deorbited later that year after only one crew made it on board. Two years later, the US got in the game with Skylab, which launched on May 14th, 1973. Skylab was a Saturn IV-B rocket booster that was adapted so astronauts could live inside. It was much roomier than anything in space before, giving the astronauts room to shower, sleep, do experiments, and really experience microgravity like no one ever had.

Skylab’s power came from two large solar panel arrays. And shields protected it from solar radiation and micrometeoroids – the bits of dust that become shooting stars in Earth’s atmosphere and can turn an unprotected spaceship into Swiss cheese. But the mission got off to a rocky start when it launched: one of the shields fell off, which tore off one of the solar panel arrays and jammed the other one. Skylab made it into orbit, but was uninhabitable without those pieces – it basically had no power, and the Sun heated the inside to over 90 degrees Celsius.

When the first crew was sent up later that month, NASA had to figure out how the heck to do major repairs on something in orbit. Over the course of several spacewalks, the astronauts fixed the jammed solar panel and deployed a bright orange sunshade to cool down the inside. NASA learned a lot from these first big in-space repairs, which definitely weren’t the last of their kind. The ISS, for example, needs regular repairs, and the Hubble Space Telescope had a faulty mirror that needed to be fixed in space before it could take clear photographs.

Once they made it livable, Skylab’s first crew hopped on board and got down to business. Or, really, they got down to science. More than 80 experiments were conducted on Skylab, including biology, physics, and astronomy experiments that were proposed by high-school students.

But there were also experiments for professional scientists, like the Apollo Telescope Mount, which first detected things like holes in the solar corona. It was the precursor to the ISS’s SOLAR instruments that monitor the Sun’s brightness and intensity, which can affect climate down here on Earth.

Another thing NASA wanted to know was how people’s bodies responded to being in space for weeks or months at a time. Salyut 1’s crew was in space for 23 days, which was a world record at the time. But each of Skylab’s crews blew past that record, with the final crew spending a full 84 days in orbit. With that much time in microgravity, NASA could see evidence of bone density and body mass loss, which happens because astronauts’ bodies don’t have to fight against gravity and other stresses as much. Nowadays, astronauts do certain regular exercises in space to combat this problem, but space agencies are still researching ways to keep them healthy.

Skylab’s final crew launched in November 1973 – only a few months after the station was put in orbit – and they had a... rough relationship with their bosses. They hid being sick in space, which is a big no-no when you don’t have access to medical help. And they were also exhausted by the long, 16-hour work days, so they couldn’t possibly accomplish all the tasks they were commanded to do.

Eventually, they rebelled – turning off all communications with NASA for a day to relax. Of course, NASA wasn’t happy about this, and none of those astronauts ever went to space again. But the incident also taught NASA some important lessons: working in space can be slow, especially for astronauts who haven’t been there before, and you can’t treat humans like robots. So, future crews were given much more balanced schedules. But after that crew returned to Earth in 1974, Skylab stayed empty.

NASA had hoped they could send up more astronauts on an early Shuttle mission in 1977 or 1978, but the program got delayed. Plus, they ignored researchers’ predictions about more solar activity – which expanded Earth’s atmosphere enough that it started dragging Skylab down. By the time NASA considered sending a Shuttle to push Skylab into a higher, stable orbit, there just wasn’t enough time. So on July 11th, 1979, uninhabited for more than five years, Skylab re-entered the atmosphere and broke apart over Australia and the Indian Ocean.

Skylab set the stage for future space stations like Mir and the ISS, and showed that people really could live in space for a while and do important scientific research. As long as you give them time to rest, of course.

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