Planck (spacecraft)

Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013. The project aimed to map the anisotropies of the cosmic microwave background (CMB) at microwave and infrared frequencies, with high sensitivity and angular resolution. The mission provided data that substantially improved upon previous observations made by the NASA Wilkinson Microwave Anisotropy Probe (WMAP). The Planck observatory was a major source of information relevant to several cosmological and astrophysical issues. One of its key objectives was to test cosmological theories about the early Universe, its composition and evolution, and the origin of cosmic structure. Planck was initially called COBRAS/SAMBA, which stands for the Cosmic Background Radiation Anisotropy Satellite/Satellite for Measurement of Background Anisotropies. The project started in 1996, and it was later renamed in honor of the German physicist Max Planck (1858–1947), who is widely regarded as the originator of quantum theory by deriving the formula for black-body radiation. Built at the Cannes Mandelieu Space Center by Thales Alenia Space, Planck was created as a medium-sized mission for ESA's Horizon 2000 long-term scientific program. The observatory was launched in May 2009 and reached the Earth/Sun L2 point by July 2009. By February 2010, it had successfully started a second all-sky survey. On 21 March 2013, the Planck team released its first all-sky map of the cosmic microwave background. The map allowed researchers to measure temperature variations in the CMB with the highest accuracy then available. In February 2015, an expanded release was published, which included polarization data. The final papers by the Planck team were released in July 2018, marking the end of the mission. At the end of its mission, Planck was put into a heliocentric graveyard orbit and passivated to prevent it from endangering any future missions. The final deactivation command was sent...