NASA Will Measure Polar Ice Cover Down to the Centimeter with Lasers From Space

Shooting lasers at Earth sounds like a sketchy idea on paper, but it’s actually one of the best possible methods of studying our planet from space. Many satellites carry LIDAR systems that bounce harmless laser pulses toff Earth’s surface, and pick up valuable information about the contours and dynamics of target regions from the returning photons.

Now, NASA is upping the ante on space-based lasers with a new mission called Ice, Cloud, and land Elevation Satellite-2 (ICESat-2). Scheduled for launch on September 15 from Vandenberg Air Force Base in California, ICESat-2 will monitor ice sheet elevation, land topography, and vegetation cover with an unprecedented LIDAR component called the Advanced Topographic Laser Altimeter System (ATLAS).

ATLAS is far more sensitive and active compared to the LIDAR system onboard this mission’s predecessor, ICESat, which retired in 2010. Once it safely reaches its polar orbit and becomes operational, the satellite will fire 10,000 pulses every second, which will result in ground elevation measurements accurate to within a centimeter. Every pulse unleashes about 20 trillion photons, and only around a dozen return to be recorded by the satellite’s telescope.

“ATLAS required us to develop new technologies to get the measurements needed by scientists to advance the research,” Doug McLennan, ICESat-2 project manager at NASA’s Goddard Space Flight Center, said in a statement. “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.”

The ICESat program required this major upgrade because accurate measurements of polar land and sea ice are a crucial dataset for anticipating the impacts of climate change. Ice cover at the poles has been progressively receding as Earth warms, which is a partial driver of rising sea levels.

To prepare for the catastrophes that will result from these changes—and perhaps even predict them—scientists need the absolute best measurements possible. If all goes well with ICESat-2’s launch and deployment, it will be contributing to that effort for years to come.

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