From: Goddard Space Flight Center
Posted: Monday, August 6, 2001
The Microwave Anisotropy Probe (MAP) successfully completed the lunar gravity assist needed for its journey to L2, the second Lagrange point of the Sun-Earth system. The lunar swing-by occurred midday on Monday, July 30.MAP, as the spacecraft is affectionately called, was placed in the proper orientation for the lunar swing-by completing a series of three phasing loops. Each phasing loop was about a week-long. MAP will reach L2 on October 1, approximately three months after launch.
MAP was launched on a Delta II rocket from Cape Canaveral, FL on June 30 at 3:46 p.m. Eastern. To date all satellite systems are functioning well.
Upon completion of the three month journey to L2, MAP will begin to chart the faint microwave glow from the Big Bang. L2 is about one million miles from Earth. MAP is the first spacecraft to use an orbit around the L2 point as its permanent observing station. It will take about 18 months to build up a full-sky picture and perform the analysis.
Scientists hope to determine the content, shape, history, and the ultimate fate of the universe, by constructing a full-sky picture of the oldest light. MAP is designed to capture the afterglow of the Big Bang, which comes to us from a time well before there were any stars, galaxies or quasars. Patterns imprinted within this afterglow carry with them the answers to cosmic mysteries such as: What happened during the first instant after the Big Bang? How did the Universe evolve into the complex patterns of galaxies that we see today? Will the Universe expand forever or will it collapse?
MAP views the infant universe by measuring the tiny temperature differences within the extraordinarily evenly dispersed microwave light, which now averages a frigid 2.73 degrees above absolute zero temperature. MAP will resolve the slight temperature fluctuations, which vary by only millionths of a degree. These temperature differences point back to density differences in the young Universe, where denser regions gave way to the vast web-like structure of galaxies that we see today.