12:00 noon EST

After nearly five days of the observatory being on-orbit, NASA controllers report the Tropical Rainfall Measuring Mission (TRMM) operations are going according to plan and no problems are reported.

"The observatory has been operating extremely well," said Tom LaVigna, TRMM project manager at NASA’s Goddard Space Flight Center, Greenbelt, Md. "All data indicate we have a very healthy spacecraft. We already have received our initial TRMM Microwave Imager (TMI) instrument data and it looks good."

During the past few days, controllers began normal operations using the Tracking and Data Relay Satellite System (TDRSS), and turned on all instruments but one, the Clouds and Earth Radiant Energy System (CERES) instrument which will be turned on tomorrow.

On Wednesday, controllers will begin performing several decent maneuvers lasting for five days and culminating with the satellite arriving at a circular orbit of 217 miles (350 kilometers), ranging between 35 degrees north and 35 degrees south of the equator. This orbit will allow TRMM to fly over each position of the Earth’s surface at a different local time each day.

The first space mission dedicated to studying tropical and subtropical rainfall launched Thanksgiving day from the Japanese Space Center, Tanegashima, Japan. TRMM lifted off at 4:27 p.m. EST on a Japanese H-II rocket and just fourteen minutes later, TRMM separated from the rocket’s second stage. The automatic sequencer on TRMM successfully deployed the solar arrays, and the high gain antenna after a short time-out period initiated at separation.

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The TRMM satellite was built as an in-house project at NASA Goddard and launched by the National Space Development Agency of Japan. NASDA provided one of the five instruments - the Precipitation Radar. NASA’s Marshall Space Flight Center provided the Lightning Imaging Sensor and the Langley Research Center provided the CERES instrument while Goddard provided the remaining two instruments - TMI and the Visible Infrared Scanner.

The primary objective of the TRMM program is to obtain and study multi-year science data sets of tropical and subtropical rainfall measurements; to understand how interactions between the sea, air and land masses produce changes in global rainfall and climate; to improve modeling of tropical rainfall processes and its influence on global circulation in order to predict rainfall and variability at various periods of time; and to test, evaluate and to test, evaluate and improve satellite rainfall measurement techniques.

For additional information on the TRMM program, call the Goddard Newsroom at (301) 286-8955. The next TRMM status report will be issued on or about Dec. 4, 1997.