The Delta II rocket carrying a new 1.4 billion euro weather satellite has blasted off from the Vandenberg Air Force Base on the Californian coast.
The Joint Polar Satellite System 1, a collaboration between NASA and the National Oceanic and Atmospheric Administration (NOAA), will be the first of four satellites to orbit around the Earth’s poles.
The NOAA says the JPSS will cross the equator 14 times a day, providing data on hurricanes, tornadoes and blizzards.
They will also monitor droughts, fires, poor air quality and harmful coastal waters.
The data will then be downloaded to stations in the Arctic and Antarctic.
The polar orbiters will work with the more familiar Geostationary Operational Environmental Satellites — GOES — weather stations that provide hemispheric views from their 36000km above the equator.
But it is the polar orbiters that provide 85 percent of the data needed by the computer models to generate the forecasts.
JPSS 1 will share its orbit with Suomi NPP, a satellite launched in 2011 to serve as a test bed for the sophisticated instruments featured in the Joint Polar Satellite System spacecraft.
While it was launched as a research satellite, Suomi NPP is now considered operational.
But the spacecraft is aging and JPSS 1 will ensure uninterrupted, more accurate forecasting in the event of problems with the older satellite.
JPSS 1 is expected to begin routine observations after about three months of tests and checkout.