TOMS-EP was boosted into a 740 km sun-synchronous orbit from its 500 km orbit through a series of thruster burns over nine days by a TRW/NASA team earlier this month. The higher altitude will widen the coverage of the TOMS instrument and exert less atmospheric drag on the TRW-built satellite, enabling it to provide measurements for several years beyond its two-year design life.

NASA decided to boost TOMS-EP following the failure of the Japanese-built ADEOS satellite, which carried two NASA ozone tracking instruments. While some smaller scale aerosol and ozone research performed by TOMS-EP will not be gathered, scientists will receive continuous ozone data until the next Total Ozone Mapping Spectrometer instrument is launched in the year 2000 on a Russian Meteor-3M spacecraft.

``Providing data on ozone is critical to helping scientists understand, predict and develop plans to mitigate the effects of global ozone depletion,'' said Tim Hannemann, executive vice president and general manager, TRW Space & Electronics Group. ``We're pleased the TOMS satellite was in the right place, at the right time, to help NASA continue to perform this important mission.''

TOMS-EP is part of NASA's Mission to Planet Earth (MTPE) initiative to gather data on the global environment. Scientists use TOMS-EP data in conjunction with atmospheric chemistry measurements from other satellites to understand the processes that drive the global creation, destruction and distribution of the Earth's ozone layer.

Since TOMS-EP's launch in July 1996, the lightweight satellite has been providing scientists with daily, space-based mapping of the global distribution of the Earth's ozone layer, a process critical to monitoring the Earth's environmental health. In addition, TOMS has been used to provide high-resolution imagery of urban pollution, biomass burning, forest fires, desert dust and small volcanic eruptions.

NASA has been tracking ozone measurements since 1978.

TRW built the 650-pound satellite and integrated the TOMS-EP instrument for NASA Goddard Space Flight Center. TOMS-EP initially took over the ozone monitoring role from Russian Meteor-3 satellite, which completed its mission in December 1994.

TRW also is building two Earth Observing Satellites (EOS) for NASA based on a standardized bus design that accommodates a variety of instruments. The EOS PM-1 spacecraft, scheduled for launch in 2000, will focus on climate-related measurements of the Earth's atmosphere, cloud cover, precipitation, terrestrial snow cover and sea ice. The second, EOS Chemistry-1, scheduled for a launch in 2002, will measure a variety of chemicals in the Earth's atmosphere.