SSL STAFF LOGIN

Carruthers has reached target orbit between Earth and the Sun

NASA’s Carruthers Geocorona Observatory (Carruthers) has reached its target orbit at Lagrange Point 1 (L1) between the Earth and the Sun. The mission, which will study Earth’s exosphere, is led by University of Illinois Urbana-Champaign professor Lara Waldrop and operated by UC Berkeley’s Space Sciences Laboratory (SSL). This successful achievement of L1 orbit is the result of an insertion burn performed by the SSL mission operations center on January 8.

“Our operations team of some 15 people can now proudly say that we operate spacecraft in low-Earth orbit, around the Moon, the Sun and on the way to Mars,” says Abhishek Tripathi, SSL’s director of mission operations.

Video credit: Bryan Mendez and Kathryn Chong Quigley

Carruthers is the first mission specifically designed to study the exosphere—the outermost layer of Earth’s atmosphere. It launched from Kennedy Space Center in Florida on September 24, 2025, and several months of spacecraft and instrument commissioning activities followed. A test of the ultraviolet imaging instrument resulted in “first light” images of the Earth, Moon and the geocorona—the glow emitted by the atomic hydrogen that largely constitutes the exosphere.

 “The imagers are producing exactly the data we wanted to collect. The scene is amazing,” says Thomas Immel, project scientist on Carruthers and senior space fellow at SSL.

  • These four images constitute the “first light” for the Carruthers Geocorona Observatory mission. The images were taken on Nov. 17, 2025, from a location near the Sun-Earth Lagrange point 1 by the spacecraft’s Wide Field Imager (left column) and Narrow Field Imager (right column) in far ultraviolet light (top row) and the specific wavelength of light emitted by atomic hydrogen known as Lyman-alpha (bottom row). Earth is the larger, bright circle near the middle of each image; the Moon is the smaller circle below and to the left of it. The fuzzy “halo” around Earth in the images in the bottom row is the geocorona: the ultraviolet light emitted by Earth’s exosphere, or outermost atmospheric layer. The lunar surface still shines in Lyman-alpha because its rocky surface reflects all wavelengths of sunlight — one reason it is important to compare Lyman-alpha images with the broad ultraviolet filter. The far ultraviolet light imagery from the Narrow Field Imagery also captured two background stars, whose surface temperatures must be approximately twice as hot as the our Sun’s to be so bright in this wavelength of light. (Credit: NASA/Carruthers Geocorona Observatory)
    “First light” images for the Carruthers Geocorona Observatory mission. The images were taken on Nov. 17, 2025, from a location near the Sun-Earth Lagrange point 1 by the spacecraft’s Wide Field Imager. (Credit: NASA/Carruthers Geocorona Observatory)
  • Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)
    Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)
  • Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)
    Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)
  • Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)
    Flight operators and technicians sit at workstations at the UC Berkeley Space Sciences Lab mission operations center. Photo from September 24th, 2026 launch. (Credit: Robert Lettieri)

Now that Carruthers has reached L1, the team can begin preparing for the science mission, which is expected to begin in March. Carruthers will then begin imaging the exosphere three times every hour for two years, which will allow the science team to observe how the exosphere changes with the seasons and in response to solar activity. Only a handful of images exist of the exosphere, so Carruthers is poised to redefine our understanding of this vast region of our local space.

“The Berkeley community, NASA, and the nation should feel proud that a university team pulled this off,” says Tripathi.