[vii] Skylab will be the first manned project in the space program of the United States with the specific purpose of developing the utility of space flight in order to expand and enhance man's wellbeing on Earth. Experiments and observations will be carried out on Skylab in a number of different areas, among them observations of the Earth, solar astronomy, stellar astronomy, space physics, geophysics, biomedical studies, zero-gravity biological studies, zero-gravity technology studies, and spacecraft environment.
In all these areas, exciting observations and discoveries already have been made during the brief history of space flight. However, Skylab will offer decisive improvements over earlier space projects. It is an experimental space station that will provide a comfortable shirtsleeve environment for its three-man astronaut-scientist crew. Three crews will occupy Skylab in three shifts for periods of 28, 56, and 56 days. During Skylab's eight-month operational lifetime, some instruments will work in automated modes, transmitting their data directly to Earth or storing them on tapes or film. Other instruments will be operated or monitored by the astronauts. In these observations, man will contribute his unique capabilities for on-the-spot judgment, decision-making, analyzing and interpreting unusual situations, recognizing unexpected developments, changing the course of an experiment, selecting a new target of study, adjusting and reorienting instruments, learning quickly from experience, adapting readily to new conditions, and discussing his observations with specialists on the ground. These qualities, so valuable to the scientist on Earth, will give the scientist in space the power to advance research far beyond the limits set by the earthly environment. The Skylab mission will utilize man as an engineer and as a research scientist, and it will give him the opportunity of assessing his potential capabilities for future space missions.
Skylab will have several distinct goals: to enrich our scientific knowledge of the Earth, the Sun, the stars, and cosmic space; to study the effects of weightlessness on living organisms, including man; to develop methods for the processing and manufacturing of materials utilizing the absence of gravity; and, in perhaps its most important objective, to develop means of observing and monitoring the Earth's surface in support of earthly needs. In addition, a program of student projects will be carried out on Skylab, designed to stimulate interest in science and technology among high school students. More than 3,400 boys and girls in secondary schools submitted proposals for space experiments and demonstrations on Skylab; 19 of these proposed experiments were selected to be carried out during the Skylab missions.
[viii] With a total length of about 35 meters (117 ft.),1 Skylab has the size of an average house. Its launch weight is 90,606 kilograms (199,750 lbs.).2 Skylab's orbital altitude will be 432 km (268 statute miles or 234 nautical miles); 3 it will orbit the Earth once every 93 minutes. With its relatively steep orbital inclination of 50 degrees, it will be visible from the earth under lighting conditions which prevail during several hours after sundown and before sunrise, in all regions other than the Arctic and Antarctic. The orbital trajectories of Skylab will sweep out an area which covers 75 percent of the Earth's surface, 80 percent of its food-producing regions, and 90 percent of its population.
Skylab will represent a milestone of paramount importance in the American space program. It may turn out to be the beginning of man's permanent foothold and settlement in space. This booklet will give a brief overview of Skylab, its history, its design, its operation, and its program of experiments and observations.
Skylab is the most diversified and most complex orbiting spacecraft of the U.S. space program so far; its potential returns in experience and knowledge will be of decisive value to science, and they will help us in our effort to cope with many of the problems which beset man's life on Earth.