Lead scientist Frank Eparvier retires after more than three decades at LASP
As LASP’s lead scientist, Frank guided LASP’s science priorities and managed the institute’s more than 100 scientists and extensive portfolio of research programs. Frank served as LASP’s interim director from January through August 2025, and prior to that worked as a LASP researcher for more than 25 years. He’s an expert in measuring the Sun’s output of light energy and has served as the principal investigator for the four EXIS instruments aboard the NOAA GOES constellation of weather satellites. He earned a Ph.D. from CU Boulder in 1991 and is the author or co-author of more than 125 publications. Credit: LASP
Frank Eparvier, who has been a scientific and programmatic leader within the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP) since the late 1980s, retired this week. In his own words, Frank sought a career “focused on making better measurements of things that matter for science and society,” and in that he succeeded immensely.
Frank first came to the University of Colorado Boulder as a graduate student after earning a bachelor’s degree in physics and mathematics from the University of Wisconsin in 1985. He began working with Dr. Charles Barth, then director of LASP, using rocket measurements to study the Earth’s upper atmosphere and earning his doctorate from the Department of Astrophysical, Planetary, and Atmospheric Sciences in 1991. With his subsequent research as a LASP post-doc doing photochemical modeling of the Earth’s thermosphere and ionosphere, he realized that the largest uncertainty in the models was knowing the solar irradiance.
He then spent several years at the NOAA Space Environment Lab, NCAR, and the CIRES/NOAA Space Environment Center prior to returning to LASP in 1997 and has been focusing on instrumentation to observe the solar Extreme Ultraviolet (EUV) input into the Earth’s upper atmosphere since then. His goal was to improve the accuracy of EUV solar measurements and to produce data products that are vital to understanding both the processes in our heliosphere and how they affect everyday life on Earth.
In his career, he was the instrument scientist on the TIMED-SEE instrument; instrument scientist and project scientist on SDO-EVE; instrument lead on the MAVEN EUVM (at Mars); principal investigator on the GOES-R EXIS instruments; and was involved in a dozen or more rocket flights to observe the Sun. The series of four GOES EXIS instruments was, at the time, the largest single contract for funds that have come through LASP.
Frank was a key figure in the development of the Extreme ultraviolet Variability Experiment (EVE), which is an instrument aboard NASA’s Solar Dynamics Observatory (SDO). EVE measures EUV radiation from the Sun, providing crucial data on solar variability and its impacts on space weather. EVE observations led to the reduction of uncertainty in the important EUV and soft X-ray irradiances from a factor of four at some wavelengths down to less than 10%. These instruments also led to the discovery of the EUV late phase of some solar flares, allowing a giant leap forward in the accuracy of modeling the EUV irradiance. By studying these fluctuations, scientists can better understand how the Sun’s energy output affects Earth’s atmosphere, satellites, and communications systems.
Frank’s work on solar irradiance variability has been foundational in understanding how the Sun’s energy output changes over time. This includes studying how solar flares, sunspots, and other solar phenomena contribute to these variations and how they influence space weather events, which can impact technology on Earth. His work provided the world with the next generation of real-time EUV and soft X-ray solar irradiances for GOES-16, 17, 18, and 19, measurements that will be used for space weather operations and scientific research for at least the next decade.
The MAVEN EUV monitor for which he led the development has been central to understanding the influence of the solar EUV input to the Martian upper atmosphere and its role in affecting and controlling the escape of atmospheric gases to space and changing the Mars climate over billions of years.
When asked, Frank identified two moments that made him especially proud. One was when he was in the control room for the high-bay cleanroom in LSTB and realized that there were half a dozen instruments in the cleanroom and that he was involved in building or leading all of them. Another proud moment was when he saw the GOES soft X-ray irradiance data go live on the NOAA SWPC website, providing the primary, operational, real-time solar flare data for the entire world.
On top of his scientific achievements, Frank has played key roles in management at LASP. He served for several years as the solar-group assistant director for science. The assistant directors and the associate director for science provided leadership to the science division, including helping to define the scientific directions for the lab. From there, he stepped into the role of associate director for science, which he held for several years. His leadership in that role was instrumental in keeping LASP science moving forward during the difficult post-covid times.
When Dan Baker stepped down as lab director at the end of 2024, Frank stepped up once again in service to the lab— despite his burgeoning retirement plans—to fill the position as interim director while LASP conducted a national search for a new director. His tenure as interim director came at a very difficult time, as federal funding for science, including NASA, has been in a state of uncertainty. Frank threw himself into the job and showed his abilities as a true leader during challenging times. He clearly was the right choice for the job of interim director.
Throughout his entire career, Frank has exemplified what a scientist can contribute to LASP, to NASA, to the scientific community, and to the world. And as a leader of LASP during a very difficult transition, he played a key role in continuity within LASP and in setting us up for future success. We wish him the best on his retirement and will miss him greatly!
-By Bruce Jakosky, LASP Senior Research Scientist and CU Boulder Professor Emeritus of Geological Sciences
Founded a decade before NASA, the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder (LASP) is revolutionizing human understanding of the cosmos. LASP is deeply committed to inspiring and educating the next generation of space explorers. From the first exploratory rocket measurements of Earth’s upper atmosphere to trailblazing observations of every planet in the solar system, LASP continues to build on its remarkable history with a nearly $1 billion portfolio of new research and engineering programs.