  The purpose of the MAP mission is to determine the geometry, content, and
evolution of the universe via a 13 arcmin full-width-half-max (FWHM) resolution
full sky map of the temperature anisotropy of the cosmic microwave background
radiation with uncorrelated pixel noise, minimal systematic errors,
multifrequency observations, and accurate calibration. These attributes were
key factors in the success of NASA's Cosmic Background Explorer (COBE) mission,
which made a 7 degree FWHM resolution full sky map, discovered temperature
anisotropy, and characterized the fluctuations with two parameters, a power
spectral index and a primordial amplitude. Following COBE considerable progress
has been made in higher resolution measurements of the temperature anisotropy.
With 45 times the sensitivity and 33 times the angular resolution of the COBE
mission, MAP will vastly extend our knowledge of cosmology. MAP will measure
the physics of the photon-baryon fluid at recombination. From this, MAP
measurements will constrain models of structure formation, the geometry of the
universe, and inflation. In this paper we present a pre-launch overview of the
design and characteristics of the MAP mission. This information will be
necessary for a full understanding of the MAP data and results, and will also
be of interest to scientists involved in the design of future cosmic microwave
background experiments and/or space science missions.
