Abstract :
NASAʹs MIDEX program provides frequent flight opportunities for scientific investigations from space for missions of cost up to $140M (FY1998), including launch, spacecraft, instruments, ground systems, operations and data analysis. The launch rate is approximately one per year, with selection of two missions occurring every two years. The program covers all areas of space science, excluding interplanetary probes. Mission selections to date include MAP (microwave background), IMAGE (magnetospheric imager), Swift (gamma-ray bursts) and FAME (astrometric survey).