WASHINGTON: In a pioneering work, NASA scientists have fitted the laser-catching telescope of the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) into its place that will measure the elevation of Earth from space.

The telescope will catch individual laser photons that have travelled more than 600 miles from a satellite to Earth and back.

The findings will help scientists track changes to Earth's ice-covered poles, take stock of forests, map ocean surfaces and characterise clouds, the US space agency said in a statement.

ICESat-2’s single instrument is the Advanced Topographic Laser Altimeter System (ATLAS).

Once in orbit, ATLAS will time how long it takes for light from its green lasers to travel to Earth’s surface and back.

“By analysing those times with computer programmes and determining the distance light travels, scientists can calculate surface elevation,” said Carol Lilly, integration and testing manager for the ATLAS instrument at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland.

The telescope which will capture laser photons that have bounced off Earth and returned to the satellite is attached to the instrument’s optical bench at NASA's Goddard cleanroom.

Once all of the ATLAS components are in place and tested, the instrument will be transported to Orbital Sciences Corporation in Gilbert, Arizona, where it will be attached to the spacecraft.

ICESat-2 will then be shipped to Vandenberg Air Force Base in California for launch.