Skylab 3

Background

By the summer of 1973, NASA's Skylab program had already demonstrated that human beings could live and work productively in space for extended periods. The first crew, launched in May of that year, had overcome a serious launch emergency — the loss of a micrometeorite shield and one of the station's two solar-array wings — and had remained aboard the orbiting workshop for 28 days, a national record at the time. Their success set the stage for a more ambitious second mission, which would push the boundaries of human endurance considerably further. The crew selected for that mission brought a compelling combination of experience and specialist knowledge. Commander Alan Bean had walked on the Moon during Apollo 12 in 1969. Science Pilot Owen Garriott was a Stanford-trained electrical engineer and one of the scientist-astronauts recruited by NASA in 1965. Pilot Jack Lousma, a Marine aviator making his first spaceflight, rounded out a team well suited to the program's twin goals of solar astronomy and biomedical research.

Launch and Rendezvous

Skylab 3 lifted off from Kennedy Space Center on 28 July 1973 aboard a Saturn IB rocket. Orbit insertion was achieved approximately six minutes after liftoff, placing the Apollo command and service module on a trajectory toward the already-occupied — if currently dormant — Skylab station. The crew docked with Skylab at just under eight hours into the mission, taking up residence in the 85-ton workshop that had been unoccupied since the first crew's departure weeks earlier. The station required reactivation and inspection, but the spacecraft and its systems were found to be in satisfactory condition. What no one knew at the time was that the mission would soon face its own serious technical crisis.

A Mission Tested by Crisis

Shortly after arriving at Skylab, the crew discovered that two of the three thruster quads on the Apollo service module were leaking propellant — a potentially life-threatening problem that raised questions about whether the command module could safely return the crew to Earth. For a period, NASA seriously considered launching a rescue mission using a modified Apollo spacecraft reconfigured as a two-person vehicle that could carry all three stranded astronauts home. The crew prepared contingency procedures and continued their work while engineers on the ground analysed the situation. After careful assessment, flight controllers concluded that the two remaining healthy thruster quads were sufficient for a safe return, and the rescue mission was stood down. The crew pressed on.

Their scientific programme was extensive. Working with the Apollo Telescope Mount — a cluster of solar telescopes that constituted the most capable solar observatory ever placed in orbit to that point — Bean, Garriott, and Lousma logged a substantial number of hours observing the Sun in wavelengths invisible from Earth's surface, including ultraviolet and X-ray. They captured imagery and data related to solar flares, coronal structure, and other dynamic phenomena, contributing to a body of solar physics knowledge that would take years to fully analyse. Garriott, as science pilot, was particularly active in this work.

The biomedical research conducted aboard was equally significant. One of the central scientific questions of the entire Skylab program was how prolonged exposure to weightlessness affected the human body — its cardiovascular system, its musculoskeletal structure, its fluid distribution, and its sensory and vestibular function. The crew participated in a structured programme of exercise, medical testing, and data collection designed to answer these questions. Early in the mission, all three astronauts experienced nausea and discomfort associated with space adaptation syndrome, which temporarily reduced their productivity. The episode prompted important discussions about crew scheduling and workload management in long-duration spaceflight — lessons that would inform planning for years to come.

To support continued operations and address maintenance needs, the crew conducted spacewalks outside the station. Among the tasks accomplished was the installation of a replacement sun shield — a twin-pole sunshade deployed to supplement repairs made during the first mission and to better protect the station's thermal environment. The extravehicular activities were physically demanding and logged considerable time outside the station's hull.

Splashdown and Legacy

Retrofire occurred at just over 1,415 hours of mission-elapsed time, and the crew splashed down in the Pacific Ocean at approximately T+1416 hours, completing a flight of 59 days. At that moment, Bean, Garriott, and Lousma had set a new world duration record, more than doubling the mark established by their predecessors just weeks earlier. Recovery teams reported that the crew was in reasonable physical condition, reflecting the value of the exercise protocols maintained throughout the mission.

The significance of Skylab 3 extended well beyond its record duration. The solar data returned by the Apollo Telescope Mount represented a landmark contribution to the understanding of solar physics and space weather. The biomedical findings — concerning bone density loss, cardiovascular deconditioning, and fluid redistribution in microgravity — established a scientific baseline that shaped human spaceflight medicine for decades. The mission demonstrated that human crews could adapt, problem-solve, and perform high-quality science over multi-month durations, a finding that would prove foundational to the planning of future long-duration programmes including Mir and the International Space Station.

Skylab 3 also illustrated the importance of crew autonomy and the capacity to manage unexpected technical crises far from Earth. The propellant-leak emergency, handled calmly and methodically by both the crew and mission controllers, reinforced principles of redundancy and contingency planning that remain central to human spaceflight operations today. It remains one of the most consequential missions of the early American human spaceflight era.