Our understanding of the universe may be completely transformed when the Laser Interferometer Space Antenna (LISA) is launched in 2011. It's five year mission: to detect gravitational waves generated by black holes, stars, and neutron stars that orbit each other (binaries).
LISA will travel an Earth's orbit away from the Sun, but follow behind our planet by 30 million miles. It will consist of three freely flying spacecraft 'connected' to one another by laser beams, forming a gigantic triangle of light about three million miles on each side. When a gravity wave hits the triangle, distortions in the laser light will be picked up by the antenna's instruments.
The observatory will be able to detect and measure gravitational waves that have been around since the birth of the universe, and perhaps answer one of mankind's greatest mysteries: how did the universe begin? Read more at JPL's LISA site(1).