Gaia
Description
Gaia is a European Space Agency astronomy mission whose primary goals are to: (1) measure the positions and velocity of approximately one billion stars; (2) determine the brightness, temperature, composition, and motion through space of those stars; and, (3) create a three-dimensional map of the Milky Way galaxy. (NASA - National Space Science Data Center) Gaia will be placed in an orbit around the Sun, at the second Lagrange point L2, which is named after its discoverer, Joseph Louis Lagrange (1736-1813). For the Sun-Earth system, the L2 point lies at a distance of 1.5 million kilometres from the Earth in the anti-Sun direction and co-rotates with the Earth in it's 1-year orbit around the Sun. One of the principal advantages of an L2 orbit is that it offers uninterrupted eclipse-free observations. From L2 the entire celestial sphere can be observed during the course of one year. To ensure Gaia stays at L2, the spacecraft must perform small manoeuvres every month. Gaia will not be the only ESA mission going to L2. Herschel and Planck have operated from there and currents plans call for JWST to be placed there, too. (http://sci.esa.int/gaia/28820-summary/) |
Links
http://sci.esa.int/gaia/ Facts Spectrum Studied: Visible Launch Date: 2013-12-19 Status: Still Operational Orbital Location: Sun-Earth L2 Lagrange point Launch Vehicle: Soyuz-Fregat Launch Site: Guiana Space Centre, French Guiana Mass: 2,030 kg Funding Agency European Space Agency |