Honoring a Pioneer: Dr. George Carruthers’ Legacy Reaches Space Again

Honoring a Pioneer: Dr. George Carruthers' Legacy Reaches Space Again

By Emily Winget, U.S. Naval Research Laboratory Corporate Communications

WASHINGTON, D.C. - NASA is set to launch the Carruthers Geocorona Observatory mission in September 2025, honoring the late Dr. George R. Carruthers, whose groundbreaking work at the U.S. Naval Research Laboratory (NRL) transformed how we observe Earth and space. The observatory will launch on board a Falcon 9 rocket from NASA - Kennedy Space Center, sharing its flight with NASA's Interstellar Mapping and Acceleration Probe (IMAP) and the National Oceanic and Atmospheric Administration (NOAA), Space Weather Follow On-Lagrange 1 (SWFO-L1) satellite. Previously named the Global Lyman-alpha Imager of the Dynamic Exosphere (GLIDE), the mission was renamed to honor Carruthers' visionary science. The observatory will investigate Earth's geocorona, the delicate halo of hydrogen atoms extending far beyond the planet's visible atmosphere, to reveal how it evolves under the influence of the Sun and space weather. These insights will have direct applications for satellites, communications, navigation, and human space exploration. "Dr. George Carruthers not only expanded the frontiers of space science, he also inspired generations of scientists and engineers through mentorship and education," said former Head of NRL's Upper Atmospheric Physics Section, Robert Meier, Ph.D. "Naming this mission in his honor ensures his remarkable contributions will continue to guide discovery for decades to come." A Legacy of Space Innovation Carruthers developed a lifelong passion for space science during the height of the space race. As a youth, he designed and built telescopes and model rockets, supplementing his curiosity with extensive reading at local libraries. This early commitment to scientific exploration led him to earn degrees in Aerospace Engineering, Nuclear, Plasma and Radiological Engineering and Aerospace Engineering from the University of Illinois. In 1964, following a National Science Foundation fellowship in Rocket Astronomy, Carruthers joined NRL's Space Science Division. There, he focused on far-ultraviolet (FUV) observations of Earth's upper atmosphere and distant astronomical phenomena, producing a 1969 patent for an "Image Converter for Detecting Electromagnetic Radiation, Especially in Short Wavelengths," which expanded the ability to detect ultraviolet light. During Carruthers' 38-year-long career at NRL, he made many contributions to high-profile human space-flight missions. Carruthers' most notable achievement came in 1972, when his Far Ultraviolet Camera/Spectrograph became the first lunar-based space observatory during NASA's Apollo 16 mission. Its observations provided humanity with its first photos of Earth from the lunar surface in ultraviolet light - revealing the geocorona, the polar auroras, and what Dr. Carruthers called the "tropical airglow belt." The 50-pound, gold-plated camera enabled scientists to conduct groundbreaking studies of stars, nebulae, and other celestial objects beyond the reach of the naked eye. The instrument remains on the Moon today as a testament to his contributions. Carruthers applied his groundbreaking technologies to a range of defense initiatives, including studies of missile exhaust plumes that provided critical insights for surveillance and related systems. Throughout his distinguished career, Carruthers served as principal investigator for numerous NASA and Department of War (DoW) [formerly known as Department of Defense] missions. His momentous projects include a 1986 rocket-borne ultraviolet imaging system that captured rare images of Comet Halley, as well as an experiment aboard the DoW's Advanced Research and Global Observation Satellite (ARGOS), which produced the first far-ultraviolet image of a Leonid meteor entering Earth's atmosphere from space. In recognition of his groundbreaking research and lasting impact on space science, Carruthers received the 2012 National Medal of Technology and Innovation, the Nation's highest honor for technological achievement. During the award presentation ceremony at the White House, President Barack Obama praised the awardees. "I am proud to honor these inspiring American innovators," Obama said. "They represent the ingenuity and imagination that have long made this Nation great-and they remind us of the enormous impact a few good ideas can have when these creative qualities are unleashed in an entrepreneurial environment." The Carruthers Geocorona Observatory Mission The mission will investigate Earth's geocorona, the outermost layer of the atmosphere, composed largely of hydrogen atoms. Positioned at the Sun-Earth Lagrange Point 1, about 1.5 million kilometers from Earth, the spacecraft will have an uninterrupted view of the geocorona. From this vantage point, its ultraviolet imaging instruments will track changes in response to the solar wind and other space-weather disturbances, revealing how storms from the Sun reshape the boundary between Earth and space. Most of the hydrogen surrounding Earth is thought to originate from water vapor in the lower atmosphere, which is broken apart by sunlight and transported to extreme altitudes, however the details of this process remain limited. Carruthers' data will reveal how hydrogen migrates upward and escapes into space, offering critical insight into physics that oversees atmospheric loss on Earth. Carruthers is the first mission dedicated to continuously charting changes in Earth's geocorona and exosphere. By mapping how the region between Earth's atmosphere and the vacuum of space responds to solar energy, the observatory will advance space-weather forecasting and improve our understanding of how atmospheres evolve, from our own planet to beyond. By delivering continuous, high-resolution observations of this boundary between Earth and space, the mission will improve scientific models of how our atmosphere interacts with the solar wind. Those insights will inform efforts to safeguard satellites, communications networks, navigation systems, and human explorers operating beyond low Earth orbit. Launching as a secondary payload alongside NASA's IMAP and NOAA's SWFO-L1, the spacecraft will embark on a four-month trip to its operational orbit at L1, followed by about a month of checkout. The mission's 24-month prime science phase is set to begin in March 2026, with enough fuel onboard to continue observations for up to a decade. NRL's Compact Coronagraph-2 (CCOR-2) is the primary instrument aboard the SWFO-L1 satellite. CCOR-2 represents a major advance in coronagraph technology, providing continuous, reliable observations of the Sun's corona. Once operational, SWFO-L1 will be renamed SOLAR-1, reflecting its critical role in solar monitoring. Data from CCOR-2 will improve forecasting capabilities and advance understanding of space-weather dynamics, directly complementing Carruthers' observations of how the geocorona responds to solar activity. Continuing Carruthers' Legacy "Personally working with George Carruthers over the years was a richly rewarding experience for me," Meier said. "His approach was one of unselfish cooperation in the pursuit of scientific excellence, freely sharing his knowledge, expertise, and equipment with all. Despite his truly impressive number of accomplishments and awards, George remained a humble, quiet, and approachable person with a delightful sense of humor." The Carruthers Geocorona Observatory reflects the enduring impact of NRL's research in ultraviolet astronomy and atmospheric science. The renaming of this mission by NASA honors Carruthers' extraordinary scientific achievements and lifelong dedication to education and mentorship. About the U.S. Naval Research Laboratory NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL, located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California, and employs approximately 3,000 civilian scientists, engineers and support personnel. For more information, contact NRL Corporate Communications at (202) 480-3746 or [email protected]. ###