Big Bang Observer

The Big Bang Observer (BBO) is a proposed successor to the Laser Interferometer Space Antenna (LISA). The primary scientific goal will be the observation of gravitational waves from the time shortly after the Big Bang, but it will also be able to detect younger sources of gravitational radiation, like binary inspirals. BBO will likely be sensitive to all LIGO and LISA sources, and others. Its extreme sensitivity comes from the higher-power lasers, and correlation of signals from several different interferometers located around the Sun.

The proposed instrument is a collection of four instruments like LISA, each composed of three spacecraft flown in a triangular pattern. Two of the triangles will be on top of each other, in a hexagram formation. The other two triangles will be located at distant places along Earth's orbit.

The individual satellites will differ from those in LISA by having far more powerful lasers. In addition each triangle will be much smaller than the triangles in LISA's pattern. Because of this smaller size, the test masses will experience smaller tidal deviations, and thus can be locked on a particular fringe of the interferometer — much as in LIGO. By contrast, LISA's test masses will fly in an essentially free orbit, with the spacecraft flying around them, and interferometer fringes will simply be counted, in a technique called "time-delay interferometry".

The BBO instruments present massive technological challenges. Funding has not been allocated for development, and even optimistic estimates place the instrument's launch date many decades away.

See also

Further reading