The fully fitted-out space laboratory Spacelab is designed to be carried into orbit in the space shuttle's payload bay. It remains in the bay for the whole time. Spacelab is built by the European Space Agency (ESA), and manned by US and European astronauts. It made its space debut in November 1983 on the STS-9/Spacelab 1 mission. On that mission, the German astronaut Ulf Merbold became the first European to fly on a US spacecraft. Spacelab can be flown in a variety of configurations. Usually the so-called long module is flown. This consists of a pressurized laboratory about 7 metres long and 4 metres across. It is fitted out with laboratory equipment, instruments and computers in standard-sized racks. Often the laboratory module is flown with additional instruments mounted on pallets, which fit behind it in the payload bay. The pallets are open to space. Sometimes Spacelab flies in a pallet-only configuration, with a so-called 'igloo', which is a command and control unit. On Spacelab flights investigators carry out experiments in a wide range of disciplines: Earth-resources, space medicine, the effects of weightlessness on biological and physical processes, materials processing, astronomy, and so on. Experimental results may be processed on the spot or transmitted to Earth for analysis. A typical Spacelab mission lasts for up to 10 days.
