The Laser Interferometer Space Antenna (LISA), once a joint mission between the European Space Agency and NASA, as a part of NASA's Beyond Einstein Program, represents the next stage in scientific observations of the universe in the effort to understand it's underlying structre and evolution.

LISA's goal is to detect gravitational waves generated by highly accelerated masses. Expected signals range from galactic neutron star binaries to merging super massive black holes in colliding galaxies.

LISA will consist of 3 spacecraft flying in a triangular formation with a 5 million km baseline. Each spacecraft will house two freely falling proof masses. Laser interferometer will monitor the distances between the proof masses on different spacecraft with 10pm/rtHz accuracy.

The two main technological challenges in LISA are the disturbance reduction system (DRS) and the laser interferometry measurement system (IMS). The disturbance reduction system will to measure the position of the proof mass with respect to the spacecraft, steer the spacecraft around the proof mass, and reduce all external forces on the proof mass to below fN/rtHz. The laser interferometry system will monitor the distance between the proof masses with signals highly dominated by laser frequency noise, Doppler shifts, spacecraft motion, and clock noise.

Our group has developed an experimental testbed to study the interferometry, the data acquisition, the noise cancellation algorithms, and to verify data analysis techniques.

Currently, NASA and ESA are independently considering modifications to the design by weighing the sensitivity and scientific value of the detector against the cost and risks associated with each mission concept. Despite these design and oribtal modifications, the essential parts of any LISA-like design, including the IMS and DRS systems, will likely remain the same.

LISA Image

For more information about the LISA program you can visit http://lisa.nasa.gov.