Spacelab, in its many possible configurations, represents a major ESA development effort tailor-made for integration into the USSTS program (Section 3.1). With a mass of up to 14.5 metric tons, Spacelab is actually a modular system which can be assembled in a variety of forms using a Pressurized Module (short or long) and payload pallets. The long Pressurized Module, in which crew-tended materials science experiments can be performed is approximately 4 m in diameter with a length of 7m and a total mass in excess of 8 metric tons. The Pressurized Module is connected to the Orbiter crew cabin via a 1.3 m diameter tunnel. One to five 2.9 m long equipment pallets can also be part of a Spacelab configuration depending upon flight needs and the presence of a short or long Pressurized Module. A "typical" Spacelab mission includes a long Pressurized Module and one or two pallets. Principal contractors for Spacelab included Matra Marconi (France) for command and data management, Dornier (Germany) for environmental control and life support systems, AEG-Telefunken (Germany) for electrical power distribution, Aeritalia (Italy) for the Pressurized Module, Fokker (The Netherlands) for the airlock, and British Aerospace (UK, now part of Matra Marconi) for the pallets (References 745-746). Together, France, Germany, Italy, and the UK contributed more than 85% of the funding for Spacelab.
Although Spacelab (Figure 4.100) has flown on numerous STS missions, only a few have supported major ESA materials science research: Spacelab 1 (1983), Spacelab D1(1985), IML-1 [International Microgravity Laboratory] (1992), Spacelab D2 (1993), and IML-2(1994). The STS-55 mission (April-May, 1993) carried the German-sponsored Spacelab D2 along with ESA's Advanced Fluid Physics facility. The following US Space Shuttle mission, STS-57 (June-July, 1993) not only retrieved ESA's EURECA satellite (below) but also supported protein crystallization experiments in the Spacelab module. The July, 1993 flight of IML-2 permitted a variety of ESA materials science devices to be operated, including the Bubble Drop and Particle Unit, the Critical-Point Facility, and the Advanced Protein Crystalization Facility (References 743, 747-749).
743. Annual Report '93, ESA, May 1994, pp. 67-68.
744. European Space - On Course for the 21st Century, ESA BR-39, ESA, 1987.
745. Spacelab Data Book, ESA BR-14, ESA, 1983.
746. D. J. Shapland, "Spacelab and the Space Shuttles", The Cambridge Encyclopedia of Space, 1990, p. 278-283.
747. Annual Report '94, ESA, 1995, pp. 69-70.
748. J.T. McKenna, "Shuttle Flight To Aid Materials, Life Studies", Aviation Week and Space Technology, 1994, pp. 28-29.
749. Experiments in Space. The Second German Spacelab Mission D-2, DLR, March 1992.