Wilkinson Microwave Anisotropy Probe Charles Mohr

The WMAP Mission Proposed to NASA in 1995 Launched on June 30, 2001 Nominal 27 month mission 3 Month trip to the L2 Sun-Earth Libration Point 24 Month Observation Period Mission extended to August 19th 2010 https://map.gsfc.nasa.gov/media/990389/index.html

Objective NASA’s Cosmic Background Explorer (COBE) found tiny fluctuations in the cosmic microwave background on the order of 100s of micro Kelvin, but it had a relatively poor angular resolution of 7 degrees WMAP was launched to Precisely, accurately, and with high angular resolution, measure the cosmic background radiation of the entire sky at several frequencies. This is achieved using dual opposed radiometers which measure the temperature difference (anisotropy) between two points in the sky instead of absolute temperatures. https://map.gsfc.nasa.gov/mission/sgoals_universe.html

Dual Radiometers - Optics Two back to back 1.4 m x 1.6 m Gregorian telescopes Each has 10 different feeds One 22 Ghz, one 30 GHz, two 40 GHz, two 60 GHz, four 90 GHz Higher frequencies have more feeds for improved sensitivity since higher frequencies tend to be noisier https://map.gsfc.nasa.gov/mission/observatory_optics.html

Dual Radiometers - Receivers https://map.gsfc.nasa.gov/mission/observatory_rec.html

Dual Radiometers - Performance https://map.gsfc.nasa.gov/mission/observatory_sens.html https://map.gsfc.nasa.gov/mission/observatory_res.html

Scientific Impact - CMB https://map.gsfc.nasa.gov/media/121238/index.html