Olivia Cavallaro Science 07.28.2022 06:Jul AM EDT

Today in History: NASA Launches Skylab 3 Mission, What Happened to Skylab?

The second crewed mission to Skylab, the first American space station, launched 49 years ago.

On July 28, 1973, NASA began Skylab 3, the second crewed mission to Skylab, the first American space station that was launched on May 14 that same year. The Skylab 3 mission was manned by astronauts Commander Alan Bean and Pilots Owen Garriott and Jack Lousma upon a Saturn IB rocket and lasted 50 days, 11 hours, and nine minutes.

According to the NASA Life Sciences Data Archive or LSDA, the Skylab 3 crew performed scientific experiments involving "medical activities, solar observations, Earth resources," and many others in the span of 1,084.7 astronaut-utilization hours. The Skylab 3 mission also carried on the comprehensive medical research program that widened scientists' understanding of human physiological adaptation and readaptation to space flight using data collected from the previous Skylab 2 mission.

Astronauts Conduct Experiments and Research Aboard the Skylab

Skylab 3 mission crew stayed in space from about 30 to 60 days, enabling scientists to examine the effects of flight duration on physiological adaptation and readaptation among astronauts. Several core medical investigations were conducted in all three Skylab missions, but in-flight photographs from Skylab 2 revealed "puffy face syndrome."

This prompted scientists to add in-flight torso and limb girth measurements to ensure they collect more data on the headward fluid shift on Skylab 3. Astronauts also conducted tests on arterial blood flow measurements using an occlusive cuff placed around the leg, as well as facial photographs taken before and during the flight to study "puffy face syndrome" more closely.

Skylab 3 biological experiments also considered the effects of microgravity on single cells as well as the stability of the circadian rhythm of a mammalian system during space flight.

But Skylab 3 was not without its challenges. According to Spaceline.org, all three crew members of the mission experienced motion sickness shortly after docking and entering the Orbital Workshop (OWS), causing a delay in activating the OWS on-board equipment. On the fifth day of the mission, two of the four thruster quadrants of the Command Service Module (CSM) reaction control system had failed.

This failure could have caused the mission to end early or could have increased the risk of safely carrying the astronauts back to Earth. Kennedy Space Center launch crews were then placed on a 24-by-seven work schedule to prepare the Skylab 4 Saturn IB launch vehicle for flight in the event a rescue operation was required.

Skylab 3 mission crew conducted three spacewalks, on August 6, 24, and September 22.

What Happened to Skylab?

Skylab was the first US space station launched by NASA in May 1972. For about 24 weeks, the space station was occupied and operated by three separate crews made up of three astronauts. The missions were labeled Skylab 2, which launched on May 25, 1973, Skylab 3 on July 28, and Skylab 4, on November 16 that same year.

As per NASA, Skylab space station was equipped with an Apollo command and service module (CSM), a workshop, a solar observatory, and a few hundred life science and physical science experiments. It also featured the Apollo Telescope Mount, a multi-spectral solar observatory, a multiple docking adapter with two docking ports, and hatches for extravehicular activity. It was powered by solar arrays and fuel cells on the Apollo CSM and also contained a habitable space inside for its crew.

Skylab's orbit decayed through the years and on July 11, 1979, it began its atmospheric reentry amid media attention all over the world. Before it reentered Earth's atmosphere, NASA ground controllers attempted to adjust its orbit to minimize risk of damage from falling debris. It eventually landed in the south Indian Ocean, while debris reached Western Australia.