REUTERS/NASA
The H-IIA rocket will blast off from a southern Japanese island at 3:37 am on Friday, (1837 GMT Thursday) with the Global Precipitation Measurement (GPM) core observatory aboard, the Japan Aerospace Exploration Agency (JAXA) said.
The satellite, jointly developed by Japan and the United States, is designed to collect data from several other satellites in orbit and add that to its own measurements to build up a detailed picture of precipitation around the planet.
Weather forecasters say that with a more detailed and complete map of rain they will be better able to predict extreme events such as typhoons and floods.
Japanese astronaut Koichi Wakata, who is now aboard the International Space Station along with NASA astronaut Rick Mastracchio and Russia's Mikhail Tyurin, told his 74,000 Twitter followers he was hoping for a smooth launch.
"From the ISS, I wish for the success of the launch," he wrote.
