The secondary reflectors transmit the signals to the corrugated feedhorns that sit on a focal plane array box beneath the primary reflectors.
The WMAP mission succeeded the COBE space mission and was the second medium-class (MIDEX) spacecraft in the NASA Explorers program.
In 2003, MAP was renamed WMAP in honor of cosmologist David Todd Wilkinson (1935–2002), who had been a member of the mission's science team.
In the Lambda-CDM model of the universe, the age of the universe is Less than 1% of the current contents of the universe is in neutrinos, but WMAP's measurements have found, for the first time in 2008, that the data prefers the existence of a cosmic neutrino background.
The WMAP measurements also support the cosmic inflation paradigm in several ways, including the flatness measurement.
40 minutes daily – to minimize radio frequency interference.
The telescope's position is maintained, in its three axes, with three reaction wheels, gyroscopes, two star trackers and sun sensors, and is steered with eight hydrazine thrusters.
The telescope's primary reflecting mirrors are a pair of Gregorian 1.4m × 1.6m dishes (facing opposite directions), that focus the signal onto a pair of 0.9m × 1.0m secondary reflecting mirrors.
They are shaped for optimal performance: a carbon fibre shell upon a Korex core, thinly-coated with aluminium and silicon oxide.
The map required the fewest systematic errors, no correlated pixel noise, and accurate calibration, to ensure angular-scale accuracy greater than its resolution.
The WMAP was preceded by two missions to observe the CMB; (i) the Soviet RELIKT-1 that reported the upper-limit measurements of CMB anisotropies, and (ii) the U. COBE satellite that first reported large-scale CMB fluctuations.
Upon the array sit a bottom deck (supporting the warm components) and a top deck.