Nasa blasts off space laser satellite to track ice loss

LOS ANGELES: Nasa´s most advanced space laser satellite blasted off Saturday on a mission to track ice loss around the world and improve forecasts of sea level rise as the climate warms.

Cloaked in pre-dawn darkness, the $1 billion, half-ton ICESat-2 launched aboard a Delta II rocket from Vandenberg Air Force base in California at 6:02 am (1302 GMT).

"Three, two one, lift off!" said a launch commentator on National Aeronautics and Space Administration. (Nasa) television. "Lifting ICESat-2 on a quest to explore the polar ice sheets of our constantly changing home planet."

The launch marks the first time in nearly a decade that Nasa has had a tool in orbit to measure ice sheet surface elevation across the globe. The preceding mission, ICESat, launched in 2003 and ended in 2009. The first ICESat revealed that sea ice was thinning, and ice cover was disappearing from coastal areas in Greenland and Antarctica.

In the intervening nine years, an aircraft mission called Operation IceBridge, has flown over the Arctic and Antarctic, taking height measurements of the changing ice.

But a view from space -- especially with the latest technology -- should be far more precise. The new laser will fire 10,000 times in one second, compared to the original ICESat which fired 40 times a second. Measurements will be taken every 2.3 feet (0.7 meters) along the satellite´s path.