Midcourse Space eXperiment. The MSX observatory is a BMDO sponsored mission designed to demonstrate a variety of multispectral imaging technologies to identify and track ballistic missiles during flight. In addition, it will perform scientific investigations of the composition and dynamics of the Earth's atmosphere by observing ozone, chloroflourocarbons, carbon dioxide and methane. Spacecraft cost is estimated at $325M. Spacecraft: 3-axis stabilised to 0.01 deg using reaction wheels with knowledge to 9 � rad (post-processed).108 Gbits data storage. Steerable X-band antennas with 2 kbps uplink and downlink up to 25 Mbps. Dual solar arrays (single-axis articulation) provide 1200 W BOL. NiH2 batteries. Payload: The instruments consist of 11 optical sensors making observations at a wide range of infrared, visible and ultraviolet wavelengths from 110 nm to 28 � m. Primary instruments: SPIRIT III (Space Infrared Imaging Telescope), UVISI (Ultraviolet and Visible Imagers and Spectrographic Imagers), SBV (Space-Based Visible instrument), OSDP (On-board Signal and Data Processor), and reference objects (2 cm spheres to be deployed from MSX).
Financial/Operational:
Initial project $ 800 million; reduced to $ 350 million. Started 1988. Utah State University built SPIRIT III, Hughes the OSDP.

Design Life: 4 years (with 18-20 months of coolant for IR senso. Total Length: 5.1 m. Maximum Diameter: 1.5 m. Total Mass: 2,700 kg.

LEO. Midcourse Space eXperiment; missile detection technology tests; also used for auroral and atmospheric studies

• 4 - McDowell, Jonathan, Jonathan's Space Report (Internet Newsletter), Harvard University, Weekly, 1989 to Present. HTML when accessed: ftp://sao-ftp.harvard.edu/pub/jcm/space/news
• 6 - JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. HTML when accessed: http://msl.jpl.nasa.gov/home.html