(Cont’d from Part 1)

On May 14, 1073, NASA launched Skylab 1, America’s first space station using a Saturn V rocket.  The Orbital Workshop, or OWS, as it was called, was unoccupied at launch; the first crew, comprising Pete Conrad, Paul Weitz, and James Kerwin, was to follow the next day in an Apollo Command and Service Module (CSM) launched by a Saturn IB rocket.  About 63 seconds after the OWS lifted off, a solar and micrometeoroid shield wrapped around the station tore away, taking one of the two solar panels with it.  The other panel was jammed shut by debris. When Skylab reached orbit, the sun’s rays beat mercilessly on the OWS and temperatures inside the station soared.

Skylab 2 was postponed for ten days as NASA and contractor engineers worked on ways to salvage the station.  Working around the clock, teams devised several makeshift sun shades and created a tool kit to release the remaining solar array.  One of the biggest challenges was that nobody knew precisely what the astronauts would find, so three different shields were needed to handle various contingencies.

Conrad, Kerwin and Weitz left Earth on May 25.  In addition to three different sun shades and tools to free the solar panel, the crew carried food and drugs to replace those believed already spoiled by the heat.  “We can fix anything!” declared an exuberant Conrad during the launch.

When they approached Skylab, they found the Sun had discolored and blistered the gold foil that covered the OWS.  They also confirmed that one solar array was completely gone and the remaining one was partially extended.  After docking, they had dinner and prepared for the first attempt to unfold the solar array.  Their meal finished, they undocked and flew along the side of the workshop.  While Conrad brought the CSM close to the solar panel, Weitz opened the hatch and stood up.  Kerwin held Weitz by the legs so the latter could attempt to pull the array into its deployed position with a 10-foot pole with a hook on it.  Each tug made the CSM drift towards the station, so Conrad had to carefully monitor and correct their position.  After several attempts, the array remained stubbornly in place.  A strap of metal caught on the wing proved too strong, and the solar cells remained folded.

When they tried to redock with the workshop, the capture latches balked.  Despite repeated attempts by Conrad, they could not get a secure attachment.  Once again the astronauts depressurized the Command Module, this time to open the top hatch, disassemble the docking mechanism and put it back together.  On the next attempt, they successfully docked.  Finally, the astronauts could settle in for the night and get some sleep.

On May 26, they boarded Skylab for the first time.  Weitz went first, wearing an oxygen mask.  Polyurethane insulation lined the inner walls of the OWS and there were fears the heat had made it release toxic vapors.  Before the crew arrived, ground controllers vented and replenished the OWS atmosphere several times but there were still concerns about lingering fumes.  Testing the air, Weitz reported:  “We pass with flying colors.”  The next priority was to erect a sun shade, called the “parasol,” to shield the workshop from the Sun.  Finding the outer surface of the OWS clear of debris from the micrometeoroid shield, the crew opted to deploy the parasol because it did not require an EVA.

Skylab had two small airlocks, on opposite sides of the OWS, for scientific experiments.  One faced the sun; the other faced the earth.  Conrad and Weitz attached a canister containing the folded parasol to the sunward scientific airlock.  They extended the makeshift shield and opened it like an umbrella, then retracted the parasol so it was only a few inches above the OWS.  Temperatures inside Skylab began to drop almost immediately.  Eleven days after the 20- by 24-foot shield was unfolded, the temperature was a comfortable 75 degrees.  The astronauts began Skylab’s agenda of scientific experiments, but they were still hampered by a lack of electrical power.

On June 7, Conrad and Kerwin performed a space walk to free the jammed solar array.  Before their launch, NASA engineers created several tools for them to use and packed them aboard the Command Module.  Given the nature of the problem — a metal strap that held the solar array down — they decided to use a modified set of lineman’s cutters.  Once the jaws were closed as tightly as possible around the strap, Conrad worked the cutter from side to side while Kerwin maintained tension on the rope.  After a short time, the astronauts worked through the strap and broke a restraining bolt.  The solar array was free, but it did not spring open.

This had been anticipated — the hydraulic actuators that should have pushed the array into position were expected to be frozen — so Conrad and Kerwin had a length of rope to pull the wing open.  The procedure had been worked out in the neutral buoyancy simulator at the Johnson Space Center, and the precise length of rope provided.  Anchoring one end of the rope on the OWS and the other on the solar array support boom, Conrad was to simply put the rope over his shoulder and stand up.  The problem was, the tests had been conducted by Rusty Schweickert, one of the tallest astronauts, and the length of rope provided according to his height.  Conrad was considerably shorter, and he had to stretch to get enough tension in the rope to pry the wing open.  Suddenly the support boom snapped open, but the three sets of solar cells that comprised the wing still did not unfold.  After Conrad and Kerwin were back inside the OWS, Mission Control pitched Skylab upward to direct sunlight on the frozen hydraulic system.  Once the hydraulic fluid thawed, the panels extended.  Skylab’s energy crisis was over and the crew settled into the planned research agenda.

By the time the first Skylab crew splashed down on June 22, Conrad, Kerwin and Weitz had set a new record for space flight duration.  During the four-week flight, they collected more than 30,000 solar images with the ATM, including real time observations of a moderately strong solar flare.  The trio also brought back 7,000 photographs of the Earth covering 31 of the United States and six other countries.  But, perhaps most importantly, they demonstrated what a motivated and determined flight and ground support crew could accomplish to save an otherwise lost mission.

Written by Greg Kennedy on May 23rd, 2013 , Space History

Leave a Reply

Your email address will not be published. Required fields are marked *