Spacelab was a cylindrically shaped reusable laboratory carried aboard the space shuttle that was designed to allow scientists to perform experiments in microgravity conditions while orbiting Earth. It was designed and developed by the European Space Agency (ESA) in cooperation with the National Aeronautics and Space Administration's (NASA) George C. Marshall Space Flight Center. Cradled in the shuttle's spacious cargo bay, Spacelab was used on numerous shuttle missions between 1983 and 1997. In addition to the United States, countries like Germany and Japan also conducted dedicated Spacelab missions.
Spacelab was developed as a modular structure with several components that could be connected and installed to meet specific mission requirements. For each mission, Spacelab components were assembled and placed into the shuttle's cargo bay at Kennedy Space Center (KSC) in Florida. Its four principal components consisted of the pressurized module, which contained a laboratory with a shirt-sleeve working environment; one or more open pallets that exposed materials and equipment to space; a tunnel to gain access to the module from the shuttle; and an instrument pointing subsystem.
The pressurized module, or laboratory, provided a habitable environment for the crew. It was available in several configurations that included either one segment (core) or two segments (core and experiment) that could be reused for up to fifty missions. The core segment contained supporting systems, such as data processing equipment and utilities for the pressurized module and pallets. Inside the module, laboratory equipment was mounted in racks and other areas. The laboratory also had fixtures, such as floor-mounted racks and a workbench. The so-called "experiment segment," provided more working laboratory space and contained only floor-mounted racks.
Together, the core and experiment segments were approximately 7 meters long. Added to this assembly were U-shaped pallets located outside the pressurized module. The pallets were often used on Spacelab missions for mounting instrumentation, large instruments, experiments needing exposure to space, and instruments requiring a large field of view, such as telescopes.
Conducting Experiments on Spacelab
Scientists onboard Spacelab included mission specialists and payload specialists , who were primarily scientists, not career astronauts. To make working in space easier, handrails were mounted on the racks and overhead. Foot restraints were also provided on the floor and on rack platforms. During some missions, the crew split into two twelve-hour shifts, allowing research to continue around the clock.
Each Spacelab mission required years of planning. Before each mission, support personnel developed a timeline for conducting experiments, and worked closely with the principal investigators to make sure the resources for each experiment were available. In addition, scientists on the ground could follow the progress of experiments aboard Spacelab using television and computer displays from orbit. Earth-bound scientists also could command experiments, and talk with the crew.
Research into many fields of science was performed aboard Spacelab. Experiments on Earth's atmosphere included research into atmospheric chemistry, energy, and dynamics. In addition, Spacelab was used to correlate atmospheric data from satellites. The space-based laboratory also provided an ideal platform to conduct experiments on space plasma. From orbit, scientists could closely observe the electrified gases in the ionosphere layer of the atmosphere.
Studies of the Sun were a major focus of Spacelab activities. Crews on-board Spacelab were able to observe all of the Sun's radiant energy. Using the instruments on Spacelab missions, astronomers obtained some of the best images of the Sun in both still photographs and videos. Additionally, sensitive spectrometers collected information on the chemistry and the physics of our nearest star. The images and spectral analysis contributed to the modeling of the Sun's dynamics and structure.
Spacelab also allowed scientists to look farther into space and conduct sophisticated astronomical research. While in orbit, scientists had the opportunity to select targets, fine-tune their instruments based on the current conditions, and look at interesting events, just like an astronomer at a ground-based observatory. In addition, astronomers were able to view the universe at various wavelengths , including cosmic rays, X rays , ultraviolet , and infrared . Increasingly complex astronomical instruments were deployed with succeeding Spacelab missions, allowing scientists to increase the quality and quantity of data collected.
Progress in materials science on Earth has been limited in some areas due to the effects of gravity. However, the microgravity condition on Space-lab provided scientists an opportunity to study how materials behave outside of the influence of Earth's gravity. Experiments conducted on Spacelab significantly advanced the science of material processing by providing a sustained microgravity environment for melting, combining or separating raw materials into useful products, and creating defect-free crystals.
In addition, the microgravity environment in the Spacelab module allowed scientists to test basic theories and to develop new processing techniques. This research advanced the study of new metals and alloys, as well as protein crystals for drug research, electronics and semiconductors , and fluid physics. Improvements in processing developed on Spacelab might lead to the development of valuable drugs; high-strength, temperature resistant ceramics and alloys; and other improved materials.
Many life sciences experiments were also conducted aboard Spacelab. Scientists were able to study life from the simplest, one-celled forms such as bacteria, to larger, more complex systems such as animals and humans. The Spacelab module provided habitats for plants and animals, and most importantly, the trained scientists to perform experiments. Basic biology questions were investigated, as well as practical questions related human adaptation to space and the phenomena of "space sickness." Commercial and pharmacologic products were also produced in purer forms than ever before onboard Spacelab. At the same time, biological materials could be studied with great precision because crystals could be grown both larger and purer.
Spacelab's Contribution to Space Exploration
Over a 15-year period, Spacelab served as an orbiting laboratory that allowed scientists to study the universe, the Sun and Earth, and conduct materials and biologic experiments. During that time, Spacelab served as both a laboratory and an observatory as scientists could both stimulate the environment with active experiments and observe the effects. Work on Space-lab also provided a "dress rehearsal" into the types of activities that are currently performed on the International Space Station.
see also Crystal Growth (volume 3); International Space Station (volumes 1 and 3); Made in Space (volume 1); Microgravity (volume 2); Space Shuttle (volume 3).
John F. Kross
Yenne, Bill. The Encyclopedia of US Spacecraft. New York: Exeter Books, 1988.
"Spacelab Science." Kennedy Space Center. <http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/spacelab.html#spacelab>. "Spacelab." Manned Spaceflight Center. <http://liftoff.msfc.nasa.gov/Shuttle/spacelab>.
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