NASA sends a laser to space to measure ice on Earth

NASA is preparing to launch its most advanced space laser on Saturday, the ICESat-2, a $ 1 billion mission to discover the depths of the planet's ice, which melts as the weather heats up.

The satellite, about the size of a small car and weighing half a ton, will be launched - as planned - aboard a Delta II rocket from Vandenberg Air Base in California.

The 40 minute launch window opens at 05:46 local (12h46 GMT). The mission is "exceptionally significant for science," NASA's ICESat-2 program executive Richard Slonaker told reporters ahead of the launch.