[iii] The Long Duration Exposure Facility (LDEF) has been designed to take advantage of the two-way, transportation capability of the Space Shuttle Specifically, the LDEF is designed to provide a large number of economical opportunities for science and technology experiments that require modest electrical power and data processing while in space and which benefit from postflight laboratory investigations with the retrieved experiment hardware. The first LDEF mission (approximately 12 months duration) is currently scheduled for STS-13 in early April 1984. and subsequent missions are envisioned, possibly every 18 months

The editors would like to acknowledge the contributions of all the Long Duration Exposure Facility experiment investigators who furnished the descriptive material used in preparing this document. Special thanks is also due Mrs Glenna D. Martin of the LDEF Project Office staff for her invaluable assistance.

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