Goddard Space Flight Center, Greenbelt, Maryland 20771

ENGINEERING COLLOQUIUM

Monday, October 20, 1997 / 3:30 PM, Building 3 Auditorium

Peter Bender

The LISA Gravitational Wave Mission

ABSTRACT -- The Laser Interferometer Space Antenna (LISA) mission is being considered both by the European Space Agency and by NASA. The main objective is to search for and study gravitational wave signals from sources at cosmological distances containing massive black holes. Signals from thousands of galactic binaries also will be observed simultaneously. The interferometer operates by sending 0.5 Watt laser beams between 30 cm diameter telescopes on three spacecraft forming a triangle 5 million km on a side. Disturbance compensation (drag-free) systems are used to make the spacecraft follow freely floating test masses inside inertial sensors (accelerometers) on each spacecraft. Laser interferometry measurements are made between the test masses. The three spacecraft and the propulsion modules to put them in the proper solar orbits can be launched on a single Delta II launch vehicle.

SPEAKER: Peter L. Bender attended school at Rutgers and Princeton Universities, receiving a Ph.D. in physics from Princeton in 1956. Since then, he has been employed at the National Institute of Standards and Technology and the University of Colorado. His main areas of interest have been the applications of precision measurement techniques in atomic physics, gravitational physics, geophysics, and astronomy. With Robin T. Stebbins from the University of Colorado and William M. Folkner from JPL, he has worked on both NASA and ESA studies of the Laser Interferometer Space Antenna mission. His geophysical interests include the Moon, Mercury, and mapping the Earth's gravity field. He earlier participated in the Apollo Lunar Laser Ranging Experiment.