NASA’s universe-mapping and asteroid-hunting satellite — assembled in Logan nearly 15 years ago — has officially been powered down, leaving a piece of Cache Valley among the stars.
Until, of course, it burns up in Earth’s atmosphere later this year.
The final command to shut off the satellite’s transmitter was sent this month, marking the end of a mission that exceeded expectations, according to a NASA news release.
On Aug. 1, Pedro Sevilla, a distinguished engineer for Utah State University’s Space Dynamics Laboratory and the project manager for the spacecraft, was among the professionals who attended the ceremony for the shutting down of the Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE.
“It’s a bittersweet moment after so many years in space and looking at the data daily,” Sevilla said. “But we’ve gotten more out of this telescope than we could have ever hoped for.”
Originally named the Wide-field Infrared Survey Explorer, or WISE, the satellite’s initial mission was to map the universe in four infrared bands. The spacecraft, assembled at Space Dynamics Laboratory in Logan, accomplished this goal within the first 13 months after its launch.
Space Dynamics Laboratory played a critical role in the assembly, integration and testing of the spacecraft, Sevilla said. After receiving components of the satellite from various subcontractors, the lab’s team conducted extensive testing to ensure the spacecraft could detect infrared light across different bands.
Infrared light, which is invisible to the naked eye, allows scientists to see objects that emit heat rather than light. Sevilla said WISE was able to take photographs to map objects in the Milky Way — such as asteroids — and objects outside of the galaxy, including brown dwarfs, supernovae, black holes and other galaxies millions of light-years away.
But the story doesn’t end with WISE’s initial mission.
After the primary assignment was completed, NASA put the spacecraft into hibernation. However, in 2013 — with two of its four detectors still operational — the satellite was awakened under a new name and mission: NEOWISE, tasked with looking for asteroids and comets, particularly those that come within a few million miles of Earth.
“We’re trying to figure out what’s out there,” Sevilla said, “what’s dangerous, what’s hazardous, what could be headed our direction.”
After taking repetitive photos of the sky from low Earth orbit, the spacecraft was able to create all-sky maps featuring 1.45 million infrared measurements of more than 44,000 solar system objects. The mission discovered 3,000-plus near-Earth objects — 215 of which were first spotted by NEOWISE — and tracked down 25 new comets, including one that streaked across the night sky in the summer of 2020.
A recent uptick in solar activity has caused the upper atmosphere to heat up and expand, creating significant drag on the spacecraft. Because of this, NEOWISE — which far exceeded its expected life span — was sent its final command to shut down its transmitter earlier this month.
The spacecraft has helped inform the development of a follow-up mission, NEO Surveyor, which is currently being developed at Space Dynamics Laboratory.
“The NEOWISE mission has provided a unique, long-duration set of the infrared sky that will be used by scientists for decades to come,” Amy Mainzer, principal investigator for both of the spacecrafts at the University of California, Los Angeles, said in the release. “But its additional legacy is that it has helped lay the groundwork for NASA’s next planetary defense infrared space telescope.”
The NEO Surveyor, set to launch no earlier than 2027, will be on the lookout for hard-to-find near-Earth objects, such as dark asteroids, comets that don’t reflect visible light and those approaching Earth from the direction of the sun.
“It’s not the end of the mission, in my opinion,” Sevilla said. “I think NEOWISE, it was sort of a pathfinder. Now we’re building this new instrument using all the lessons learned from NEOWISE.”
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