Lockheed Martin Selected for Negotiations With Jet Propulsion Laboratory to Build NASA's First Space-Based Science Interferometer.

SUNNYVALE, Calif.--(BUSINESS WIRE)--Sept. 11, 1998--Lockheed Martin Missiles & Space has been selected by the Jet Propulsion Laboratory (JPL) in Pasadena to enter negotiations to become the instrument industry team member that will design and build the interferometer for NASA's Space Interferometry Mission (SIM).

The Missiles & Space Advanced Technology Center in Palo Alto, Calif., provided the design and associated technology for the SIM interferometer as proposed. TRW Inc., Space and Electronics Group was selected for negotiations to become the spacecraft industry team member.

SIM, a major observatory in NASA's Origins Program, will be the agency's first space interferometer designed specifically for measuring the positions of stars. The Origins Program follows the 15-billion-year-long chain of events that began with the birth of the Universe at the Big Bang. It seeks to understand the entire process of cosmic evolution from the formation of chemical elements, galaxies, stars and planets, through the mixing of chemicals and energy that cradles life on Earth, to the earliest self-replicating organisms and the profusion of life. In short, Origins hopes to answer the fundamental question: Are we alone in the Universe?

"We're enormously pleased to have been chosen by JPL as a partner in the development of the instrument for this important mission," said Mike Coats, Missiles & Space Vice President of Civil Space Programs. "Our long heritage of space observatories, including Hubble and SIRTF, and extensive experience with interferometers, precision pointing, and highly advanced optical systems will serve us well in charting a course for SIM that will ensure mission success."

NASA's Space Interferometry Mission is the first space mission with an optical interferometer as its primary instrument. The technique of interferometry, as used on SIM, will combine the light waves from two sets of four one-foot diameter telescopes arrayed across a 33-foot boom. The combined light waves will "interfere" or blend together. The effective resolution of the multiple telescopes should approach that of a 33-foot diameter mirror.

The small telescopes will, however, gather less than one percent as much light as a 33-foot diameter mirror. But the SIM mission is not about taking pictures of extended objects, but rather measuring precisely the positions of stars -- which is the science of astrometry.

SIM's precision astrometry will allow scientists to look at the 100 or so nearest stars and determine, by inference, whether planets accompany those distant suns. Just as the Moon exerts tidal forces on the Earth, and the planets in our solar system cause the Sun to wobble slightly from side to side, a planet circling another star will cause it to jiggle in its orbit.

SIM will not have the sensitivity to detect directly a planet orbiting a nearby star, because its reflected light would be far too faint. Instead, using precise positional measurements, SIM will be able to measure a star's wobble -- a telltale perturbation that would herald the presence of one or more planets orbiting the star. Using SIM's precision optics, planets that range in size from Uranus to Jupiter will be easily detectable, and even a small planet the size of Earth could be inferred around a star up to 30 light years away.

SIM will also be determining the angular positions and intrinsic luminosities of stars in the Milky Way galaxy, and the distances to nearby galaxies using rotational parallax. The dynamics of open and globular clusters and spiral arms will be revealed to SIM scientists. The mission will revolutionize the field of astrometry. It will achieve accuracy, over the whole sky, of four microarcseconds, more than 250 times more precise than the best available star catalogs.

Through a process called synthesis imaging, SIM will be able to generate images. The SIM images will have higher angular resolution than those achieved by the Hubble Space Telescope (HST) and Earth-based telescopes, but only of very small objects or selected regions of large objects. Many of its targets will be selected from the incredibly detailed images of star-forming regions imaged by HST. SIM will produce images with more detail, but over a narrow field less than 1 arcsecond across. Ideal candidates for this mode of operation include dust disks around young stars, and black-hole masses at the centers of galaxies.

SIM is a key mission in NASA's Origins Program. Many of its science objectives are related to Origins goals including planet detection, and the study of other solar systems in formation. SIM's other goals cover important areas of astrophysics, including the study of star and star cluster dynamics in our Galaxy, the calibration of distance and age indicators used for the cosmic distance scale, and research into the dynamics and evolution of active galaxies.

The Space Interferometry Mission development phase is capped at $480 million. The spacecraft will be launched in 2005 on an Evolved Expendable Launch Vehicle, like one under development at Lockheed Martin Astronautics in Denver. SIM will operate from a Sun-centered Earth-trailing orbit. Mission duration is seven years.

Lockheed Martin Missiles & Space, based in Sunnyvale, is a leading supplier of satellites and space systems to military, civil government and commercial communications organizations around the world. These spacecraft and systems have enhanced military and commercial communications; provided new and timely remote-sensing information; and furnished new data for thousands of scientists studying our planet and the universe.

Note to Editors: A dramatic artist's concept of the SIM mission is available at the following Web address: http://www.lmsw.external.lmco.com/photos/civil_space/sim/sim.html

CONTACT: Lockheed Martin Missiles & Space

Buddy Nelson, 510/797-0349 (Pager: 888/916-1797)

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