NOTE TO EDITORS/NEWS DIRECTORS:

NASA engineers announced late Tuesday that all is ready for the Thursday launch of the Tropical Rainfall Measuring Mission (TRMM) satellite aboard a Japanese H-II rocket. The launch window extends from 3:40 p.m. EST for approximately two-hours. The liftoff will be from the Japanese Space Center, Tanegashima, Japan.

The launch of TRMM was postponed last week to allow engineers a few days to verify the spacecraft data subsystem and a possible software solution to an observed anomaly.

During a pre-launch rehearsal earlier last 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.

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Although engineers were not able to recreate the anomaly, they believe any reoccurrence could be handled by modifying onboard software on orbit. Subsequently, a decision was made to launch tomorrow afternoon.

Launch coverage on NASA TV will begin at approximately 3:30 p.m. EST and continues through liftoff. A replay of the launch is scheduled for 6:30 p.m. EST. The post launch news conference from Japan will not be carried on NASA TV.

NASA TV is available on GE-2, transponder 9C (C-Band), located at 85 degrees west longitude, vertical polarization with a frequency of 3880 MHz and audio of 6.8 MHz.

TRMM is the first Earth science observatory dedicated to studying the properties of tropical and subtropical rainfall. 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 primary objective of this joint NASA/Japanese Space Program mission 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 improve satellite rainfall measurement techniques.

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

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