The
Wilkinson Microwave Anisotropy Probe (
WMAP), originally known as the
Microwave Anisotropy Probe (
MAP) was a
spacecraft operating from 2001 to 2010 which measured differences across the sky in the temperature of the
cosmic microwave background (CMB) – the radiant heat remaining from the
Big Bang. Headed by Professor
Charles L. Bennett of
Johns Hopkins University, the mission was developed in a joint partnership between the NASA
Goddard Space Flight Center and
Princeton University. The WMAP spacecraft was launched on June 30, 2001 from Florida. 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. After 9 years of operations, WMAP was switched off in 2010, following the launch of the more advanced
Planck spacecraft by ESA in 2009.