Comparison of analytical predictions and verification flight test results for the performance of the Spacelab environmental control and life support subsystem as obtained during the 1st mission.

The environmental control and life support subsystem (ECLS) of the Spacelab module provides various functions which can be assigned to its various branches as follows: Thermal insulation from the external environment is achieved by the passive thermal control subsystem (PTCS). Rejection of the heat produced by the Spacelab subsystem equipment and by the various experiments is the task of the active thermal control subsystem (ATCS). Life support in the form of cabin air ventilation, oxygen/carbon dioxide partial pressure control; total pressure and air temperature/humidity control is achieved by the life support subsystem (LSS). In the first part of the paper a brief description of the various elements and loops forming the Spacelab ECLS will be given by discussing the PTCS, ATCS and LSS in some detail. Objective of the verification flight test program--as implied in the title already--is the verification of major requirements the ECLS has to comply with. Those requirements will then be comprehensively discussed in the second part of the paper. A description of the analytical approach is given in the third part of the paper. However, only those areas will be addressed which were included in the verification flight test program. A brief description of the flight instrumentation, the data transmission and collection follows then in the fourth part of the paper. In the fifth part of the paper the approach to select and compile flight test data obtained during the first mission (Shuttle flight STS 9) from November 28 till December 8, 1983 is illustrated. Flight test data are compared with the analytical predictions in form of examples. In the sixth and last portion of the paper the actual/measured performance is compared with the requirements, and conclusions are drawn with respect to comprehensiveness/accuracy of the flight test verification and the compliance of the Spacelab actual performance with the requirements.