Final Delta 2 rocket launch puts NASA’s ICESat-2 satellite in orbit to monitor ice

ICESAT-2 launch
A United Launch Alliance Delta 2 rocket rises from its launch pad at Vandenberg Air Force Base in California, carrying NASA’s ICESAT-2 satellite into orbit. (NASA via YouTube)

NASA kicked off its ICESat-2 mission to monitor our planet’s ice sheets from space using a laser-scanning satellite this morning, with a launch that marked the end of a nearly 30-year run for United Launch Alliance’s Delta 2 rocket.

Liftoff came at 6:02 a.m. PT from Vandenberg Air Force Base in California, after a slight delay in the countdown due to concerns about the chilldown of the rocket’s helium bottles. The two-stage rocket made a trouble-free ascent to orbit.

ICESat-2 follows up on an earlier NASA mission that used laser-ranging data to measure ice sheet balance and sea level. This time around, the laser-scanning instrument will be capable of measuring Earth’s elevation every 30 inches (70 centimeters) across a 30-foot-wide track as it circles the planet.

The data will help scientists determine how climate change is affecting global ice levels, and how changes in the ice affect the height of Earth’s oceans.

“ICESat2 is designed to answer a simple glaciology question very, very well: It will tell us where, and how fast, the ice sheets are thickening and thinning,” Benjamin Smith, a glaciologist at the University of Washington’s Applied Physics Laboratory who’s a member of the mission’s science definition team, said in a news release. “When these data start coming in, we will immediately get a big-picture map of how Antarctica and Greenland have changed over the past decade.”

As a side benefit, the satellite will measure the height of the planet’s forests and deserts as well. The mission’s tortured acronym stands for “Ice, Cloud and land Elevation Satellte.”

ICESat-2 deputy project scientist Tom Neumann said the satellite measurements would serve as a reality check for the computer models that predict future impacts of climate change. “When they’re predicting out 100 years, or 200 years, if you’re getting the modern changes right, it gives you confidence looking ahead,” he explained.

After ICESat-2’s deployment, four student-built satellites were released into orbit from the rocket’s second stage. CalPoly’s DAVE satellite will try out a technology to dampen vibrations on spacecraft, two ELFIN satellites built at UCLA will study space weather, and the University of Central Florida’s SurfSat will test materials designed to protect spacecraft from electrical discharges.

Today’s pre-dawn liftoff served as a swan song for the Delta 2, a class of rockets that made its debut in 1989 and has been launched 155 times. It’s been built over the years by McDonnell Douglas, Boeing and United Launch Alliance, which is a Boeing-Lockheed Martin joint venture. Thanks to ICESat-2, the rocket went out with a streak of 100 successful launches in a row.

The more advanced Delta 4 is still in use. Just last month, a Delta 4 Heavy rocket sent NASA’s Parker Solar Probe on the first leg of its journey to a blazingly close orbit around the sun. United Launch Alliance also offers the Atlas 5 rocket, the heir of a rocket family that goes back to the 1950s.

The last Delta 2 launch sparked a wave of tributes on Twitter. Here’s a selection, starting with a thank-you note from NASA Administrator Jim Bridenstine:

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