TRW Delivers Two CERES Instruments to NASA; CERES to Study Role of Clouds and Radiation.

REDONDO BEACH, Calif.--(BUSINESS WIRE)--March 13, 1997--TRW Inc. is delivering next week to NASA Langley Research Center, Hampton, Va., two instruments that will be used to study the role of clouds and radiation on the environment.

The Clouds and the Earth's Radiant Energy System (CERES) instruments will measure reflected solar and emitted thermal radiation from the Earth's surface to determine the influence of clouds on the Earth's temperature. CERES will be integrated onto the Earth Observing System AM-1 (EOS AM-1) satellite, which is set for launch in June 1998.

The CERES instruments are part of NASA's Mission to Planet Earth (MTPE), an ambitious, long-term program that includes the development of instruments and spacecraft to monitor natural and human-induced changes to Earth's climate and environment.

As part of the CERES contract, TRW is also providing two instruments for the EOS PM-1 spacecraft -- which will be built by TRW. These instruments are currently beginning fabrication and assembly.

``Clouds are still a mystery to scientists,'' said Steve Carman, CERES program manager at TRW's Space & Electronics Group in Redondo Beach. ``We know that clouds act as an umbrella to shield the Earth against the sun's radiation and as a blanket to warm the Earth, but clouds remain the single largest area of uncertainty in climate models today.''

``CERES will gather data to help scientists build more accurate models to forecast long-range climatic trends, and to better understand the effects of clouds on the climate,'' he said.

These instruments represent two of six units that TRW is under contract to build and deliver by 2001. The first instrument, set for launch on the Tropical Rainfall Measuring Mission satellite, was delivered to NASA Langley in October 1995. The remaining three instruments will be delivered for integration on the EOS PM-1 satellite and the EOS AM-2 mission.

CERES is a scanning broadband radiometer that measures reflected sunlight and emitted thermal energy from the surface of the Earth and the atmosphere. The radiometer is made up of three sensors, each with its own telescope mounted on a gimbaled platform that continuously scans across the Earth in a 6.6-second cycle.

The two CERES instruments will operate in different scan modes (one, cross-track scanning and the other, biaxial scanning), allowing scientists to view the Earth's surface and atmosphere from different angles simultaneously. The additional data will enable scientists to build better models of the Earth and make more accurate predictions.

CERES radiometric measurement accuracy requirements are at the state-of-the-art level of greater than 99 percent. To meet this requirement, CERES sensors have been precisely calibrated using standards from the National Institute of Standards and Technology at TRW's absolute radiometric calibration facility.

In recent tests, the instruments have demonstrated accuracy better than specifications.

CERES data will be combined with data from supporting imaging instruments that identify cloud conditions. NASA Langley is responsible for CERES data reduction. The CERES science investigation will be conducted by an international team of scientists, led by Co-Principal Investigators Bruce Barkstrom and Bruce Wielicki of NASA Langley Research Center.

TRW Space & Electronics Group has built more than 190 communications, scientific and defense spacecraft; produced, integrated and tested more than 130 payloads; developed more than 200 advanced space instruments; and integrated some 550 experiments into spacecraft.

It is an operating unit of TRW Inc., which provides advanced technology products and services for the automotive, space and defense, and civil systems markets worldwide. TRW's 1996 sales totaled $9.86 billion.

CONTACT: TRW Inc., Redondo Beach

Sally Koris, 310/812-4721