Remembering Skylab’s launch, 50 years on

The eventual success of America’s first space station, Skylab, was masked by a troubled launch that almost halted the mission in its tracks.
By | Published: May 17, 2023 | Last updated on May 18, 2023

On May 14, 1973, watched by 25,000 rapt spectators, the last Saturn V patiently sat on Launch Pad 39A at Florida’s Kennedy Space Center (KSC). Atop the rocket was Skylab, the biggest, heaviest single object ever to be put into space and the nation’s first long-term, off-planet homestead.

At 12:30 P.M. EDT, the Saturn’s five F-1 engines came alive, churning out 7.6 million pounds (3.4 million kilograms) of thrust. A harsh guttural growl and a river of fire rolled, lava-like, across the marshy landscape. “And we have liftoff,” gushed a NASA launch commentator as the 36-story rocket, the mightiest ever flown at the time, lumbered airborne. “The Skylab, lifting off the pad now, moving up.”

Thirty seconds later, the behemoth vanished into a low-hanging canopy of iron-gray cloud, its trailing tongue of flame offering reassuring certainty of a nominal ascent. “Range Safety gives Saturn a green,” came the update as the rocket powered onward. “Good, stable thrust on all five engines.”

Skylab: America’s first space station

Among the watchers lining Florida’s coast that dreary Monday five decades ago were NASA astronauts Charles ‘Pete’ Conrad, Joe Kerwin, and Paul Weitz. These three were slated to ride a Saturn IB rocket from neighboring Launch Pad 39B the next morning for a four-week stay aboard Skylab, which was the United States’ first attempt at a space station. Their 28-day mission would be the longest anyone had ever spent in orbit.

“It looked great,” Kerwin said of Skylab’s launch, despite the gloomy visibility.

Fellow astronauts Owen Garriott and Jack Lousma, assigned to fly the second of three missions to Skylab, were inclined to agree. After turning their gaze away from the rapidly receding rocket, they headed for nearby Patrick Air Force Base to fly home to Houston, Texas. But while walking to their rental car, they met senior NASA official Rocco Petrone, who told them that Skylab had exhibited some telemetry issues during ascent.

The ominous data suggested that Skylab’s micrometeoroid shield — which also facilitated thermal control — and one of its twin solar arrays had prematurely unfolded. If this was accurate (and not an instrumentation glitch), it signaled very bad news: With zero micrometeoroid protection, no thermal defense, and half of its power-producing potential gone, the 170,000-pound (77,000-kilogram) Skylab was as good as dead in space.

Nonetheless, a trio of three-man crews ultimately would occupy the station between 1973 and 1974, residing for four, eight, and 12 weeks and running numerous experiments in life sciences, solar physics, Earth observations, astronomy, and materials processing.

As Conrad, Kerwin, and Weitz watched the Saturn vanish from view that murky Monday, they awaited news of Skylab’s safe arrival in orbit and their own launch to join it. But the news, when it came, was ugly.

Skylab’s rocky start

Skylab separated from the Saturn rocket on time and deployed its Apollo Telescope Mount (ATM) and a suite of X-ray, visible-light, and ultraviolet solar physics instruments. Next, its twin solar arrays were supposed to unfurl and start generating some 12.4 kilowatts of electricity. But the station’s actual power levels averaged a measly 25 watts.

Telemetered data indicated that the arrays had begun to open but did not fully extend. Rising temperatures — 179 degrees Fahrenheit (82 degrees Celsius) on Skylab’s hull, 100.4 F (38 C) in its habitable interior — looked set to double. And the ‘outgassing’ of materials on the internal walls at extreme temperatures threatened to ruin the astronauts’ food, spoil photographic films, and poison the station’s atmosphere with lethal toluene and carbon monoxide.

Conrad, Kerwin, and Weitz clearly were going nowhere soon. But matters worsened, as engineers battled to stabilize Skylab’s temperatures against the razor-edge of maintaining adequate power levels.

Hurried plans to fabricate a makeshift sunshade parasol to protect Skylab’s crippled hull were developed. New cameras, new food, and new tools were crammed aboard the astronauts’ Apollo command module to support a totally rewritten flight plan.

“Most of the team…never slept for four days,” remembered astronaut Rusty Schweickart. “It was all the resources of the whole aerospace industry. Anything we wanted, you simply called somebody, and they turned inside out. It would be there on the company’s Learjet the next morning.”

Amid the high-pressure drama, there were still light moments. An engineer lent a center director’s car keys to a colleague, forgot to return them, and got a severe verbal roasting. Another NASA employee, working late one evening after the security gates had been locked, scaled the space center’s perimeter fence to get home, earning “a big gash in my butt” for his trouble.

Elsewhere, however, a clear picture was emerging about the calamity that befell Skylab during its launch. Sixty-three seconds after liftoff, as the Saturn passed through the dense clouds, the micrometeoroid shield inadvertently deployed, standing just proud of the hull and getting torn off in the supersonic airstream. Blame fell on imperfect seals and fittings in an ‘auxiliary tunnel’ that was intended to alleviate pressure during ascent.

Part of the heat shield’s debris wrapped itself around the Skylab’s No. 2 solar array and damaged the No. 1 array’s latches. And to make matters worse, the Saturn’ final stage was discarded at 10 minutes after launch and fired separation motors to achieve a safe distance from Skylab. But the motors’ exhaust sheared the ailing No. 1 array right off its remaining hinge. And the other array was so clogged with debris that it remained stuck fast, barely able to wheeze open.

Astronauts get Skylab back into shape

When Conrad, Kerwin, and Weitz finally launched at 9 A.M. EDT on Friday, May 25, their Apollo spacecraft was packed with repair tools, all bagged and secured by a sea of brown ropes. These tools included modified tree-loppers to free the jammed No. 2 array, face masks to guard against toluene, carbon monoxide, and other invisible nasties, extra cameras to inspect Skylab, and makeshift parasols and sails to effect repairs to the bruised and battered station.

“We can fix anything!” yelled Conrad as their Saturn IB roared aloft from KSC’s Pad 39B. And over the next 28 days, this record-setting first crew of Skylab did just that, successfully installing the solar parasol, freeing the No. 2 array (to exuberant laughter from the astronauts), and snatching success from the jaws of ignominious defeat.

Conrad, Kerwin and Weitz were followed by two other record-breaking crews. Astronauts Al Bean, Owen Garriott, and Jack Lousma spent 59 days aboard Skylab in July through September of 1973, while Gerry Carr, Ed Gibson, and Bill Pogue logged a further 84 days between November 1973 and February 1974.

Although never intended to be inhabited again, hope sprang eternal for a time that Skylab might be revisited (and its ailing orbit perhaps boosted) by the Space Shuttle. But the Shuttle’s first flight, planned for 1978, did not take place until April 1981. And heightened solar activity in the late 1970s and its corresponding impact on Earth’s atmosphere further impaired the stability of Skylab’s orbit.

Amid great public fanfare, the old space station plunged back home, showering the Australian outback with blazing debris,in July 1979. Skylab had travelled 890 million miles (1.4 billion kilometers) in its six-year life, circling the globe 34,981 times. And its contribution not only to science, but also the ingenuity of the human spirit surely paid dividends for the missions that were to follow.