RELEASE NO. 97-157

The launch of NASA’s Tropical Rainfall Measuring Mission (TRMM) spacecraft has been postponed to Nov. 27 to allow engineers a few days to verify the spacecraft data subsystem and a possible software solution to an observed anomaly. Project managers are now working toward a launch no earlier than Thursday, Nov. 27, at 3:40 p.m. EST, aboard a Japanese H-II rocket from the Tanegashima Space Center in Japan. The launch window extends for approximately two-hours.

During a pre-launch rehearsal earlier this week, engineers went to internal spacecraft power. At that time, they experienced an anomaly or "interrupt" with the clock, which is part of the command and data handling system. Engineers are currently completing a series of tests of the observatory and the ground support system to gain an understanding this anomaly. Although the spacecraft has a backup system, engineers want to have a clear understanding of this anomaly before launch.

TRMM is the first Earth science observatory dedicated to studying the properties of tropical and subtropical rainfall. This joint NASA/Japanese Space Program mission will 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. Another important science goal of TRMM is to study how El Niño-related rainfall anomalies correlate with other oceanic and atmospheric processes. Tropical rainfall comprises more than two-thirds of global rainfall. More precise information about this rainfall and its variability is crucial to understanding and predicting global climate change.

More information on TRMM is available via the Internet at http://trmm.gsfc.nasa.gov .