Nasa satellite launched to measure Earth’s ice changes
The mission hopes to advance knowledge of how the ice sheets of Greenland and Antarctica contribute to the rise of sea levels.
A Nasa satellite designed to precisely measure changes in Earth’s ice sheets, glaciers, sea ice and vegetation has been launched into polar orbit.
A Delta 2 rocket carrying ICESat-2 lifted off from Vandenberg Air Force Base in California at 6.02am local time and headed over the Pacific Ocean.
Nasa Earth Science Division director Michael Freilich says that the mission in particular will advance knowledge of how the ice sheets of Greenland and Antarctica contribute to sea level rise.
The melt from those ice sheets alone has raised global sea level by more than 1 millimetre a year recently, according to Nasa.
The mission is a successor to the original Ice, Cloud and Land Elevation Satellite that operated from 2003 to 2009. Measurements continued since then with airborne instruments in NASA’s Operation IceBridge.
Built by Northrop Grumman, ICESat-2 carries a single instrument, a laser altimeter that measures height by determining how long it takes photons to travel from the spacecraft to Earth and back. According to Nasa, it will collect more than 250 times as many measurements as the first ICESat.
With the #ICESat2 mission launched, it is heading to orbit. Once there, it'll time how long it takes for laser beams to travel from the satellite to Earth & back. Scientists can calculate the height of glaciers, sea ice, forests, lakes + more w/ this data https://t.co/vPDRGmrwyZ pic.twitter.com/2wdSqHcq7P— NASA (@NASA) September 15, 2018
The laser is designed to fire 10,000 times per second, divided into six beams of hundreds of trillions of photons. The round trip is timed to a billionth of a second.
In addition to ice, the satellite’s other measurements, such as the tops of trees, snow and river heights, may help with research into the amount of carbon stored in forests, flood and drought planning and wildfire behaviour, among other uses.
Today was the #DeltaII’s final launch! @ULALaunch used the last #DeltaII rocket for the 9:02 a.m. EDT liftoff of @NASA_ICE’s #ICESat2 this morning. Once on orbit, #ICESat2 will measure the thickness of Earth’s polar ice sheets. More on this rocket: https://t.co/QG4UuGbdqi pic.twitter.com/JfValD1FLl— NASA (@NASA) September 15, 2018
The launch was the last for a Delta 2 rocket, United Launch Alliance said.
The first Delta 2 lifted off on February 14 1989, and since then it has been the launch vehicle for Global Positioning System orbiters, Earth observing and commercial satellites, and interplanetary missions including the twin Mars rovers Spirit and Opportunity.