NOTE TO EDITORS: 97-154

The launch of NASA’s Tropical Rainfall Measuring Mission (TRMM) spacecraft has been postponed due to a glitch with an onboard clock during a dress rehearsal for Tuesday's planned launch. The TRMM is now scheduled for launch no earlier than Friday Nov. 21 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.

Over the next couple days engineers will continue to test and analyze the observatory and the ground support system. The onboard clock serves as "master" clock, synchronizing other onboard clocks. The unit has a backup which can take over its functions, if necessarily.

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.

The TRMM project is part of NASA’s Mission to Planet Earth enterprise, a long-term, coordinated research effort to study the total Earth system and the effects of natural and human-induced changes on the global environment. TRMM is managed by Goddard for NASA’s Office of Mission to Planet Earth, Washington, D.C.

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