ICESat-2 (Ice, Cloud, and land Elevation Satellite 2), part of NASA’s Earth Observing System, is a planned satellite mission for measuring ice sheet elevation and sea ice freeboard, as well as land topography and vegetation characteristics. ICESat-2 is a planned follow-on to the ICESat mission. It will be launched on 15 September 2018 from Vandenberg Air Force Base in California, into a near-circular, near-polar orbit with an altitude of approximately 496 km. It is being designed to operate for three years and will carry enough propellant for seven years.
The ICESat-2 mission is designed to provide elevation data needed to determine ice sheet mass balance as well as vegetation canopy information. It will provide topography measurements of cities, lakes and reservoirs, oceans and land surfaces around the globe, in addition to the polar-specific coverage.
There’s substantial evidence that Earth’s ice caps are shrinking, but we often lack the instruments to track the changes in detail. NASA already has missions in place to monitor polar ice, its ICESat satellite that has orbited the Earth since 2003, and Operation IceBridge, a research campaign that involves flyovers of polar ice to collect data on the changing landscape, but that mission ended in 2010.
In 2003, the original ICESat began seven years of laser-aided measurements of ice height, bouncing a single laser off the surface of the ice. Because ICESat-2 wasn’t ready to launch when the original mission ended, NASA designed a stopgap airplane-based mission called Operation IceBridge to track particularly crucial areas of ice.
Every second, it will blast hundreds of trillions of photons at the Earth’s surface in six seperate beams of green light. By measuring how long it takes them to return to the spacecraft, down to a billionth of a second, ICESAT-2 will be able to measure ice elevation at the poles with unprecedented precision.
For the sake of comparison, if ICESAT-2 were to scan a football field it would take 130 measurements between each end zone, whereas the original ICESat would take just two. It will travel around the Earth from pole to pole along the same path each time, measuring ice heights in the polar regions four times a year. This will allow for seasonal and annual tracking of changes in elevation down to the width of a pencil.
“ATLAS required us to develop new technologies to get the measurements needed by scientists to advance the research,” says Doug McLennan, ICESat-2 project manager at NASA’s Goddard Space Flight Center. “That meant we had to engineer a satellite instrument that not only will collect incredibly precise data, but also will collect more than 250 times as many height measurements as its predecessor.”
Meltwater from the Greenland and Antarctica ice sheets has recently raised global sea levels by more than a millimeter a year, according to NASA data. The precise measurements gathered by ICESat-2 will help researchers better predict future rates of sea level rise and how those will be influenced by drivers of climate change.
ICESat-2 will also be used to measure the height of floating sea ice, which is shrinking in the Arctic at an alarming rate. And like its predecessor, ICESat-2 capabilities will also be used to measure the height of land surface features such as forests, which can help researchers determine the amount of carbon stored within, along with risks of wildfire. Other possibilities include snow and river height measurements to help with flood planning.
“Because ICESat-2 will provide measurements of unprecedented precision with global coverage, it will yield not only new insight into the polar regions, but also unanticipated findings across the globe,” says Thorsten Markus, an ICESat-2 project scientist at Goddard. “The capacity and opportunity for true exploration is immense.”
For More Information: https://icesat-2.gsfc.nasa.gov/