How Skylab Was Saved: The Stuck Solar Array and Chance Tools

Skylab reached orbit crippled: during its Saturn V launch, airflow got between the stage structure and a heat shield mounted on the exterior and ripped the shield away. The documentary tells how engineers, a Missouri tool maker and an astronaut crew turned that damage around.

What the launch damaged

Tearing the heat shield away did two things. A solar array that the shield had been holding in place deployed and was ripped off at speed. The array on the other side began to deploy, but a small strap of metal from the torn shield wrapped around it. That kept it from being ripped off, but also kept it from extending once the station was in orbit. The workshop was also heating up because the thermal shield had been lost, which would make it uninhabitable if not fixed.

A call to Centralia

Chuck Lewis, a crew systems engineer working on spacewalk activities in the operations control center in Huntsville, recalls that his boss told the team to do a spacewalk they had earlier said they could not do. Engineers considered a pole to extend the reach so the command module would not have to come close to the array. A McDonnell Douglas colleague handed Lewis a note: A. B. Chance company, Centralia, Missouri.

Lewis made a cold call, and was passed to product manager Cliff Bosch, who said, "give me 15 minutes", walked through the stock room and filled a box with tools off the shelf with no paperwork. Bosch was flown on a NASA Lear jet to Huntsville. In a high bay with a one-G mockup of Skylab, the team opened the box. Bosch was then sent on to the Cape to help work out how to stow the tools in the command module.

Planning the repair

When the crew did a stand up spacewalk and flew around the cluster, they reported a strap holding the solar array down. It was a strap on the bottom of the micrometeoroid shield and had embedded a 5/16 bolt into the skin of the array cover. A cable cutter could not be used then because there was not enough clearance. The images they brought back helped over the next nine days.

Marshall engineers worked on a mylar fabric to spread over the sun side of the workshop using two long poles. They modified the cable cutter from Chance with the same quick disconnect fastener used for those poles. The idea was to use it on about 25 ft of poles. A bone saw from the dental kit was also considered.

Freeing the array

Outside, the crew attached the cutter to the strap. Pete Conrad tethered himself to the pole and carried a rope with small hooks to hook into relief holes on the vent cover on the top of the solar array beam. After the strap was cut, the tether was snubbed down. Conrad put his feet on the hinge end and stood up while Joe Kerwin pulled tension. The array began to move out.

During a loss of signal of about an hour, mission control then reported amps from the array. Conrad came back on and said they had got her done. Lewis later sent Bosch a cigar.

Three crews

Three crews lived and worked on Skylab: the first for about 28 days, the second for about two months and the third for a record 84 days. The work covered biological science, human adaptation to spaceflight, material science, solar astronomy and an Earth Resources program.