Skylab 4 Launches for the Final Skylab Expedition

In Brief

Skylab 4 launched on November 16, 1973, carrying Gerald Carr, Edward Gibson and William Pogue. They would conduct the final crewed expedition to America's first space station. The mission combined solar observations, studies of Earth and experiments on long-duration life in orbit. Its lengthy stay helped build experience needed for later space stations. Skylab 4 was the mission name, not a fourth Skylab station.

A Third Crew Leaves for Skylab

On November 16, 1973, Gerald Carr, Edward Gibson and William Pogue launched toward Skylab. The mission, Skylab 4, was the last crewed expedition to the station. The name counts the station launch in the sequence, so Skylab 4 was not the fourth crew to live aboard. The astronauts traveled in an Apollo spacecraft and used a Saturn IB for launch. Reaching the station meant navigating to a vehicle already in Earth orbit and docking with it. Once aboard, they would be responsible for maintaining a workshop whose useful life depended on what successive crews could keep working.

A Longer Period of Work

NASA planned a stay longer than those of the previous crews. The astronauts examined the Sun, observed Earth and took part in biomedical studies. They also observed Comet Kohoutek, which offered a target on a schedule set by its motion rather than by the station's ordinary workload. Different instruments made different demands on pointing, power and crew time. Exercise and rest had to fit the same schedule. The mission was a test of endurance in that practical sense: could a small group repeat productive work for weeks without using up its ability to manage new tasks?

The Story About Workload

Accounts of Skylab 4 often repeat a story that the crew stopped work for a day in a space strike. The record supports disagreement and adjustments about workload and communication, but does not support that popular account of a planned strike. Treating it as fact obscures the more interesting issue. A schedule planned on Earth can underestimate the time required to find equipment, make records or recover from an interruption in orbit. The crew and the controllers had to compare their expectations and change the plan where necessary. Negotiating those differences was part of learning how to operate a station.

The Final Return

The crew returned on February 8, 1974, after about eighty-four days in space. Skylab remained in orbit without another crew and reentered in 1979. The launch did not immediately end the Skylab program; it began its longest crewed expedition. Its value for later stations lay in evidence gathered across many repeated days about observation, maintenance, workload and health. An orbital workshop became familiar enough to reveal problems that a shorter visit might not have exposed, making the final expedition useful well beyond the record it set.