Looking back on the second decadeЁ2121ЁЁЁЁЁЁ3

There were significant developments during the second decade of manned space flight operations, which progressed the program forward as the emphasis changed from pioneering missions and lunar exploration to extended duration space flight and international cooperation.

During the final Apollo missions (14-17), the emphasis switched to more extensive surface activities and orbital science operations. The use of the Lunar Roving Vehicle and more mobility in the pressure suits helped the efficiency of the astronauts but one thing that became abundantly clear from the surface activities was that the disturbed lunar material would be a significant factor in planning any future lunar excursions (although at the time no one really thought this would be over 50 years in the future). The lunar dust found its way into everything, cover­ing the suits, the equipment, and cameras. It was carried inside the LM at the end of the moonwalks and, in the one-sixth gravity, lingered in the environment inside the LM. When the next-generation lunar spacecraft or scientific research base appears, it will likely include an airlock-type facility, or at least an airflow barrier, to isolate the outside environment and EVA equipment area from the living quarters. Another important lesson learned from the later Apollo missions was that back-to-back EVA operations were tiring for the crew concerned, something that would have to be factored into planning for extensive EVA operations from the Shuttle.

From Skylab, the Americans experienced a totally new learning curve. Prior to the space station missions, the longest U. S. flight had been the 14-day Gemini 7 mission of 1965, with little mobility available in the close confines of the crew compartment. Even the three final Apollo landing missions with a packed timeline only lasted 11 to 12 days. There had been a gradual buildup of U. S. duration records over the first decade of operations, but Skylab extended the experience significantly over a period of just nine months. The Skylab missions set the achievement bar high for the rest of that decade and beyond.

Skylab has been an often overlooked program, in the shadow of Apollo, but like Gemini before it Skylab established some of the most important and influen­tial experiences and achievements in U. S. space flight history. The program has more in common with today’s space station program than with the historic Apollo lunar missions. In some respects, Apollo could be considered a diversion from the logical progression of early manned space flight activities, from the first attempts through to experience of extended space flight operations in low Earth orbit, prior to the expansion of human exploration away from Earth. It could be argued that, like the Concorde supersonic passenger plane, and perhaps even the Space Shuttle, the Apollo missions were ahead of their time and suffered accord­ingly. Mastering operations in low Earth orbit and establishing a firm foothold there before moving outwards seems to be the way the global program is being directed for the 2020s. Perhaps without the distraction of the Space Race, we may have already gone farther along this path. But, then again, without that back­ground of competition, we may not have gone very far at all. Once again, future history will reveal just how important these early programs were in establishing permanent human presence in space and far from the Earth.

One of the key lessons learned from the Skylab missions was the importance of scheduling the crew’s time and workload. There was an eventual realization that introducing new activities or objectives for which the crew had little or no prior experience would be less productive than allowing the crew to have the choice to follow a basic flight plan, with a “shopping list” of priorities. Tasks needed to be flexible, so that they could be completed on the day, added to a list of things that would be desirable to complete as soon as possible, or which could be slipped into the schedule as and when time allowed. Trying to micromanage the timeline, as was the case on Apollo, was not the best way to plan longer missions on a space station.

Skylab also highlighted the need for the crews flying the missions to be capable generalists rather than necessarily dedicated specialists. Each of the three missions included a scientist astronaut who had worked on the program for some years, but few of the pilot astronauts had been on the program for that long, many of them having moved over from the Apollo program. Skylab 4 Commander Jerry Carr, a Marine pilot on his first space flight, soon realized that, while learning to operate and monitor the Apollo Telescope Mount and its suite of solar observation experiments, he became a far better solar observer when he stopped trying to become a solar scientist.

It remains a bitter disappointment to many, both inside and outside of the program that, following the glowing success of Skylab A (especially after recover­ing the station from the brink of failure), the backup OWS could not be launched as Skylab В in the second half of the 1970s. It would have been a golden opportu­nity to capitalize on the experiences of the first workshop and to correct the mistakes made first time around, as the Soviets were beginning to learn from their Salyut series of stations.