Skylab Paved Way for International Space Station

May 18, 2021

As the crew of Skylab 2 departs, the gold, parasol-like Sun shield covers the main portion of the space station. The solar array at the bottom was the one freed during a spacewalk. The four, windmill-like solar arrays are attached to the Apollo Telescope Mount used for solar astronomy. — As the crew of Skylab 2 departs, the gold, parasol-like Sun shield covers the main portion of the space station. The solar array at the top was the one freed during a spacewalk. The four, windmill-like solar arrays are attached to the Apollo Telescope Mount used for solar astronomy. Photo credit: NASA

America’s First Space Station – Part 1

By Bob Granath

The International Space Station has been in operation with research ongoing since Nov. 2, 2000. America’s first space station was Skylab. Launched 48 years ago, it was a complex orbiting scientific laboratory that helped pave the way for permanent operations in low-Earth orbit.

*The Skylab orbital workshop arrives in the transfer aisle of the Kennedy Space Center’s Vehicle Assembly Building on Sept. 26, 1972. Photo credit: NASA*

Skylab orbited from 1973 to 1979. The 169,950-pound space station included systems to allow three crews to spend up to 84 days in space. While the orbiting complex lifted off unpiloted atop a powerful Saturn V launch vehicle as Skylab 1, the astronaut crews were launched by Saturn 1B rockets.

Skylab was hailed as a “bold concept” by Rocco Petrone, who served as director of launch operations at NASA’s Kennedy Space Center before becoming director of the agency’s Marshall center during 1973 and 1974.

*The Skylab space station is mated to a Saturn V rocket in the Vehicle Assembly Building on Sept. 29, 1972. Photo credit: NASA*

“The program demanded innovation and ingenuity,” he said in Skylab, Our First Space Station, a NASA report published in 1977. “Experience and knowledge gained from earlier space programs provided a solid foundation on which to build, but the Skylab Program was truly making new pathways in the sky.”

Nine highly trained astronauts in teams of three lived and worked in shirtsleeve comfort aboard the orbiting home and scientific laboratory. It was a program of unparalleled scientific scope that continues to yield highly valuable information about the universe and life within it.

Lessons in living and working in space learned from the Skylab Program paid dividends throughout the Space Shuttle era, and now are being applied during International Space Station missions. NASA now is developing plans for future long-duration missions well beyond Earth orbit such as the agency’s Artemis exploration program designed to land the first woman and the first person of color on the Moon.

Birth of an Idea

Concepts for a space station began in the mid-1950s as part of an overall program to place a human on the Moon. Among the first plans for an orbiting laboratory were proposed by Dr. Wernher von Braun, then director of the Development Operations Division at Redstone Arsenal’s the Army Ballistic Missile Agency in Huntsville, Alabama. He later served as the first director at Marshall.

In 1956, Dr. Wernher von Braun, then chief of Redstone Arsenal’s Guided Missile Development Operations at the Army Ballistic Missile Agency, describes an early concept for an Earth-orbiting space station. Photo credit: U.S. Army/Walt Disney Co.

As NASA worked toward meeting President John F. Kennedy’s goal of landing a man on the Moon by the end of the decade of the 1960s, agency officials considered using Apollo era hardware to build a prototype space station to follow the lunar landing effort.

In a meeting at Marshall on Aug. 19, 1966, the initial concept was drawn by Dr. George Mueller, NASA’s associate administrator for Manned Space Flight. The project formally began as the Apollo Applications Program in 1968 with an objective of developing science-based human space missions. The effort later was re-named Skylab.

As plans for Skylab moved from concepts to reality, Marshall developed and integrated most of the major components including the orbital workshop, where the astronauts lived and worked and an airlock module, which served as a doorway to space for extravehicular activities, or spacewalks. It also had a multiple docking adapter so that the Apollo crew capsule could dock with the lab delivering people and equipment.

Skylab Becomes a Reality

On June 15, 1972, astronauts Karol Bobko, left, and Bob Crippen, go over a menu in the food preparation area during a simulation of a Skylab mission. They, along with Dr. William Thornton, participated in a 56-day Skylab Medical Experiment Altitude Test. Photo credit: NASA

As development was underway, astronauts Bob Crippen, Karol Bobko and William Thornton took part in a 56-day activity called the Skylab Medical Experiment Altitude Test, or SMEAT. The effort took place between July 26 to Sept. 19, 1972 helping NASA evaluate equipment and procedures proposed for the long-duration Skylab missions. While the trio did not fly aboard Skylab, all went on to be members of Space Shuttle crews. Additionally, from January 1992 until January 1995, Crippen served as director of NASA’s Kennedy Space Center.

Liftoff of the unpiloted Skylab 1 complex came on May 14, 1973, but within minutes it was apparent that there was trouble. NASA’s Skylab Program Manager William Schneider, filled in the details at a post-launch news conference.

“At approximately 63 seconds into the launch of Skylab 1, there was an indication of premature deployment of the meteoroid protective shield,” Schneider said. “If that has happened, the shield was probably torn off. The thermal indications are that it is gone, and we have some indication that our solar array on the workshop also did not fully deploy.”

Prior to launch in May 1973, the Skylab space station, foreground, awaits liftoff atop a Saturn V on the Kennedy Space Center's Launch Complex 39A. To the north, is the Saturn 1B with an Apollo command-service module being prepared to launch the first crew to Skylab. — Prior to launch in May 1973, the Skylab space station, foreground, awaits liftoff atop a Saturn V on the Kennedy Space Center’s Launch Complex 39A. To the north, is the Saturn 1B with an Apollo command-service module being prepared to launch the first crew to Skylab. Photo credit: NASA

The station was, in fact, damaged during liftoff when the micrometeoroid shield separated from the workshop and tore away. It also took one of two main solar panel arrays with it and jammed the other one so that it could not deploy. This removed protection from intense solar heating and deprived Skylab of most of its electrical power threatening to make it unusable.

Because of the uncertainty, launch of Skylab 2 with the crew of Pete Conrad, Joe Kerwin and Paul Weitz, scheduled for the next day, was postponed.

It would be up to the first crew to save Skylab in the first ever in-space major repair by deploying a replacement heat shade and freeing the jammed solar panels.

The NASA-industry team around the country went into action to develop plans and hardware necessary to save Skylab. The astronauts practiced using special tools to remove material that jammed the remaining solar array to allow it to provide Skylab with the needed electrical power. A square thermal shield, which operated like a sunshade, also was developed to protect the station from the heat of the Sun.

‘We Fix Anything’

*The Skylab 1-Saturn V space vehicle is launched from Launch Complex 39A, on May 14, 1973. Photo credit: NASA*

The Skylab 2 astronauts launched May 25, 1973 aboard an Apollo command-service module and mission commander Conrad expressed confidence that their preparations would pay off right away.

“This is Skylab 2, we fix anything,” he said at the moment of liftoff.

The crew deployed the new solar shield through a small scientific experiment airlock, located in the side of the workshop normally facing the sun. Once outside, the shield popped open like a parasol, with four struts extending outward from a segmented center post. Temperatures inside the lab soon diminished to near-normal levels.

Freeing a stuck electricity-generating solar array was the next priority.

During a spacewalk on June 7, 1973, astronaut Joe Kerwin uses a cutting instrument to remove metal that had jammed the solar array in a partially opened position. The successful effort by Kerwin and Pete Conrad allowed the solar panels to fully deploy and provide the needed electricity for Skylab. Photo credit: NASA

After considerable work, Kerwin was able to cut the metal that had jammed the solar wing in a folded position. Using a rope sling, Conrad forced the array beam to deploy. Full extension of the solar panel occurred later, providing electrical power crucial for the three planned piloted missions.

The repair effort was an important milestone in human spaceflight as it was the first time astronauts completed a major repair of an orbiting spacecraft.

According to Skylab 2 pilot Weitz, the spacewalk in which Conrad and Kerwin completed the repair was crucial in order to continue the mission.

“Pete and Joe’s successful deployment of that solar array was an extraordinary endeavor,” he said.

Skylab now was ready for months of research by three crews.

Check back in mid-June 2021 for the concluding feature article on how Skylab laid the groundwork for long-term operations in space.