Skylab: The Troubled Mission

The sunlight glinted off the object looming larger in the command module window, and Astronaut Charles ("Pete") Conrad Jr.'s exuberant voice came crackling across space: "Tallyho! Skylab!" As he maneuvered the Apollo spaceship closer to the windmill-shaped orbiting laboratory, Conrad gave crewmates Joseph Kerwin and Paul Weitz--and millions watching their TV screens on earth--a closeup look at the damaged Skylab.

Barely more than a minute after the orbiting laboratory was launched two weeks ago, ground controllers knew that Skylab was in trouble. Telemetered signals indicated that the meteoroid-and-heat-shield protecting the workshop and living quarters of the craft had been ripped away. The telemetry also seemed to confirm that one of the workshop's twin electricity-producing solar panels had sheared off, and the other had been jammed by debris from the shield.

Now Conrad was able to confirm what the telemetry had suggested. But after surveying the jammed solar panel and the remnants of the meteoroid shield, the skipper was reassured. "I think we can take care of it," he told relieved flight controllers in Houston. Several hours later, it appeared that NASA'S ingenious salvage operation--and indeed the entire $2.5 billion Skylab mission--might end in failure.

Conrad's optimistic appraisal, following the flawless launch of the Skylab astronauts and their successful rendezvous with the space lab, had raised high hopes that the trouble-plagued ship could be put back in order. Thus, after Apollo docked with the orbiting laboratory and the astronauts had dinner, word was flashed to Conrad to begin the first phase of the repair operation:

an attempt to free the solar panel that had been jammed by Skylab's meteoroid shield.

Conrad undocked and maneuvered Apollo to Skylab. Wearing a bulky space suit, Weitz leaned out of Apollo's hatch (while Kerwin held onto his knee to keep him from drifting out into space) and attempted to pull the jammed panel loose with a long-handled tool resembling a boat hook. The panel would not budge. After an hour of pushing, shoving and tugging--interspersed with streams of obscenities clearly audible to millions--the task seemed hopeless. "I hate to say it," said the exasperated Weitz, "but we ain't going to do it with the tools we've got."

That judgment was a severe blow to the prospects for a full Skylab mission.

Without the electrical power from the inoperative panel, Skylab would have to depend on its windmill solar panels and on Apollo's fuel cells, which would be depleted in about three weeks. That meant that many of Skylab's planned experiments would have to be curtailed.

The worst was still to come. When the disappointed astronauts moved Apollo back to the nose of Skylab to dock for a rest period, another glitch developed: Apollo's docking mechanism, which had worked the first time, suddenly balked. Several times Conrad bumped Apollo's nose into Skylab's docking adapter; each time, Apollo's docking mechanism failed to engage.

Determined to avoid aborting the entire mission, the astronauts suited up again, depressurized their cabin, removed the probe assembly and attempted to make repairs. After two hours of effort they finally managed to dock successfully. On Saturday, they were to try to enter Skylab and attempt to put a sun screen over the orbital workshop's exposed skin.

Despite the dubious outlook, the very fact that the repair mission got aloft at all was something of a triumph.

Toiling round the clock, scores of technicians and scientists at NASA'S centers --Cape Kennedy, Houston, Huntsville, Ala., and Langley Research Center, Va., as well as in the labs and workshops of the space agency's private contractors --worked feverishly to put together the assortment of gear and tools that was needed to repair Skylab. The astronauts themselves practiced the various repair possibilities. Indeed, these activities continued until the very eve of last week's launch; so many new and untried procedures were involved that the command module was not fully loaded until four hours before Friday's liftoff.

Never before had a spacecraft gone up amid such an atmosphere of last-minute improvisation.

The preparations involved an extraordinary race against the clock. If the repair kit had not been ready in time, the launch would have had to be postponed for another day, until Skylab again moved into favorable position for a rendezvous. Meanwhile, the condition of the orbiting laboratory might have worsened to the point where any thought of salvage would have had to be abandoned. In fact, despite all efforts to bring down the temperatures inside the orbital workshop by changing the ship's angle relative to the sun, the heat again soared to more than 125DEG (after hovering around 105DEG). That created fears of additional food spoilage, and the astronauts were warned to be on the lookout for bad odors when they began sampling Skylab's delicacies, which include such items as roast beef, lobster Newburg and Conrad's favorite butterscotch pudding. The space agency was also worried about the buildup of potentially lethal fumes from the decomposition of the heat-sensitive polyurethane foam used to insulate the interior walls of the ship. As an added precaution, the astronauts planned to don gas masks before entering the ship.

By far, the greatest attention was devoted to developing the various sunshades. That effort required the skills and ingenuity of a wide assortment of specialists, ranging from pipefitters and seamstresses to space physicists and polymer chemists (who were needed to evaluate the effect of solar radiation on the thin, aluminized Mylar and nylon sheet used to construct the canopies). Because plastics are notoriously vulnerable to the sun's ultraviolet radiation, technicians taped a thin, gold-colored protective material on the outside of one of the shades. But they quickly discovered that the coating made the canopy too bulky to fold and pack. So they pulled the coating off.

Two different kinds of canopies were tested underwater in the big tank at Huntsville, where conditions of weightlessness can be simulated; the astronauts found that it was possible to deploy the devices. But NASA gave top priority to a third, untested device: the so-called "parasol" canopy. One reason: the astronauts would not have to leave Skylab to put it in place. Resembling a beach umbrella, the canopy is made up of a 22-by-24-ft. sheet of aluminized Mylar and nylon attached to a long pole consisting of seven 4-ft. sections. An astronaut could extend the pole and sheet out of a small airlock in the middle of the Orbital Workshop's exposed area. Springs in the umbrella's "spokes" would automatically snap the covering into a rigid rectangle that could be positioned close to the skin of the shieldless spacecraft. Major drawback of the parasol: the airlock mechanism would prevent the astronauts from seeing how the operation was proceeding outside the spacecraft.

As their second option, the astronauts also carried into space a canopy rigged to a makeshift A-frame. But its deployment would require a more difficult space walk from the exit in Skylab's airlock module. As a third option, the Apollo command module carried the "Spinnaker Shade," which had been the original first choice of space officials. They had second thoughts about the sail-like canopy, because they feared that the light jet plumes from the command module's thrusters might fog the still functioning solar wings on the telescope mount. As he hung out of the open hatch of the command module, an astronaut would have to fasten the canopy in place while the ship hovered at Skylab's side. The final decision about which technique was to be used was left to the astronauts--the first time that so important a responsibility had been given to a crew in space.

Successful deployment of the canopy would not immediately solve all of Skylab's problems. At best, space officials expected some three or four days to elapse before the shading effect of the shield would reduce the temperatures inside Skylab to a near normal 70DEG. Meanwhile, the crew would have to wait out the time in the cramped confines of their command ship, making occasional forays into the stifling heat of the orbital workshop only to bring out food and perhaps scientific equipment.

If all went well, and the workshop cooled, the astronauts were to begin their scientific chores, hoping to complete a good part of their originally planned 28-day mission.

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