NASA recently launched an ice-measuring satellite that scientists say will define the next decade of Antarctic research. The Ice, Cloud, and land Elevation Satellite 2, or ICESat-2, is the most advanced laser instrument of its kind and will measure changes in the heights of Earth’s polar regions, helping scientists calculate future impacts on global sea level and climate.
The satellite was successfully launched into space on Sept. 15 at 6:02 a.m. from Vandenberg Air Force Base in California via United Launch Alliance’s last Delta II rocket. [View the launch here.]
A team of scientists from Scripps Institution of Oceanography at the University of California San Diego attended the pre-dawn launch, gathering with a crowd of onlookers at a viewing site overlooking the launch pad. Several Scripps Oceanography scientists have contributed to the ICESat-2 mission, notably glaciologist Helen Fricker who has served as a member of NASA’s Science Definition Team for more than a decade. She described the experience of seeing the launch as “incredibly exciting and actually rather overwhelming.”
“The launch was splendid to see, and the fact it was dark made it even more striking. The flash and then the sound of the rocket blasting off, and then seeing it being propelled upwards through the marine layer and then out again for a second glimpse, was thrilling,” said Fricker, a professor at the Institute of Geophysics and Planetary Physics at Scripps.
Fricker’s research focuses on ice sheets in Antarctica and Greenland and their role in the climate system. As these areas are vast and extremely difficult to monitor at ground level, she and other scientists rely on satellite radar and laser altimetry and other remote-sensing data to understand ice sheet processes.
Data collected by ICESat-2 will be instrumental to her research. The Smart car-sized satellite will measure the average annual elevation change of polar ice down to the width of a pencil, providing a precise and unprecedented view of Earth’s icy surfaces.
Fricker was joined at the launch by her current graduate student Susheel Adusumilli, former PhD students Matt Siegfried and Fernando Paulo (both Scripps alumni), and Scripps geophysicist Adrian Borsa. [View photo gallery.]
“It was amazing to be able to see the launch, especially knowing that it was a mission that could define the next decade of my field,” said Adusumilli, a fourth-year PhD student whose research is focused on monitoring Antarctica's ice sheets. “It was crazy to think that all the previous work done by NASA and other groups toward ICESat-2, and the future trajectories of so many scientists, was in the balance for a two-hour period.”
ICESat-2 is a follow-on project to the original ICESat mission, which launched in January 2003 and operated for seven years before being retired and decommissioned in 2010. The original satellite was the benchmark mission for measuring the height of ice sheets, but it also experienced some technical difficulties that limited its operations. NASA’s Operation IceBridge, the largest airborne survey of Earth's polar ice, helped scientists close the gap between the two ICESat missions.
The new ICESat-2 spacecraft has been redesigned and represents the latest in cutting-edge technology to study Earth’s frozen regions, known as the cryosphere. The satellite has an Advanced Topographic Laser Altimeter System (ATLAS) which will send 10,000 laser pulses a second to Earth’s surface and measure the height of ice sheets, glaciers, sea ice, and vegetation by calculating the time it takes the pulses to return to the spacecraft.
ICESat-2 is currently orbiting the Earth from an average altitude of 290 miles. The door to the ATLAS instrument was successfully opened on Sept. 29, and on the following day the laser was turned on and began firing its first photons. The first returns from Antarctica came in overnight on Oct. 3.
Borsa, an assistant professor at Scripps, will be involved with the calibration and validation of the ICESat-2 laser system. He is currently serving as a liaison between the ICESat-2 science team and NASA’s Goddard Space Flight Center. The task of calibrating and validating the instrument’s measurements is a critical component to the overall success of the mission.
The entire science team now awaits the trove of data that is bound to begin pouring in.
“We just got the first photons from the ground, so we know that the instrument is working as designed,” said Fricker, noting there is still much work to be done as a member of the science team. “In about two weeks’ time it will be all hands on deck to look at the data.”
Fricker originally came to Scripps from Tasmania in 1999 to work as a postdoctoral scholar with geophysicist Jean-Bernard Minster, a member of the original ICESat science team who helped contribute to the mission’s scientific goals. She said that Minster involved her in many of the ICESat Science Team meetings that he attended at the Goddard Space Flight Center in Maryland.
Now that she serves as an ICESat-2 team member in a similar role, Fricker realizes she has come full circle.
“At the team meeting the day before launch, it struck me how significant these two missions and the people involved in them have been to my career, and as a result to my life and family here in the United States,” she said.
Echoing the sentiments of many in the science community, Fricker and Adusumilli said they are hopeful that the ICESat-2 data will lead to new discoveries about ice sheets and sea ice.
“I was at a scientific conference on the West Antarctic Ice Sheet—the part of Antarctica that is changing rapidly—just two days after launch, said Adusumilli, “and nearly every time someone mentioned an unanswered question, we knew that ICESat-2 could play a crucial role in answering it.”
– Brittany Hook