Boulder, Colorado – May 5, 2025 — In a groundbreaking achievement for space science and student-driven innovation, NASA’s Miniature X-ray Solar Spectrometer (MinXSS) CubeSat missions have opened new frontiers in our understanding of the Sun’s soft X-ray emissions. These three successive CubeSat missions—MinXSS-1, MinXSS-2, and MinXSS-3 (also known as DAXSS)—have delivered unprecedented insights into the solar corona, solar flares, and their influence on Earth’s upper atmosphere.

Launched between 2016 and 2022, the MinXSS series of CubeSats demonstrated the remarkable power of small satellites to perform high-quality solar observations. The MinXSS missions were developed largely by graduate students and professionals at the University of Colorado’s Laboratory for Atmospheric and Space Physics (LASP) and were led by Principal Investigator Tom Woods, Project Manager Rick Kohnert, and James Mason who was the student class project leader initially and then lead System Engineer and Instrument Scientist.  The MinXSS missions have proved that major scientific advancements can be achieved with minimal cost and maximum ingenuity.

MinXSS-1 began this journey with a yearlong mission from the International Space Station in 2016-2017, gathering vital measurements of the Sun’s soft X-ray spectrum and validating new solar flare models. MinXSS-2 followed in a polar, sun-synchronous orbit, extending the solar observations during the solar cycle minimum period in December 2018 to January 2019, but its mission ended early with a data storage SD-card failure. MinXSS-3, flying aboard INSPIRESat-1 as the Dual-zone Aperture X-ray Solar Spectrometer (DAXSS), continues today with enhanced energy resolution and delivering over 130 solar flare observations in 2022-2023 alone.

Furthermore, the MinXSS missions have shown that the abundance of key elements like iron and silicon significantly decrease during flares by factors of two to four—a signature of the chromospheric evaporation process central to solar physics flare theories. Even more astonishing, DAXSS revealed that solar flare plasma heats up during the flare onset phase before the flare’s impulsive phase, a game-changer breakthrough with implications for solar flare nowcasting.

As a trio, these CubeSats have downlinked over 120,000 solar spectra and trained nearly 50 students, fostering the next generation of space scientists. Their success has inspired follow-on missions like SunCET CubeSat (PI James Mason, JHU/APL), CubIXSS CubeSat (PI Amir Caspi, SwRI), and rocket SSAXI (PI Chris Moore, Harvard-Smithsonian), further extending the legacy of small satellites making big science possible.

The MinXSS CubeSats have redefined how we explore the Sun—one tiny satellite at a time.

Partners for the MinXSS-1 and MinXSS-2 missions have included the CU Aerospace Engineering Science (AES) department, Blue Canyon Technologies (BCT, Boulder), Colorado Satellite Services (CSS, Parker), NASA Goddard Space Flight Center (GSFC, Greenbelt), Southwest Research Institute (SwRI, Boulder), Naval Research Laboratory (NRL, DC), NCAR High Altitude Observatory (HAO, Boulder), Harvard & Smithsonian Center for Astrophysics, University of Alaska Fairbanks (UAF), and donated launch services for MinXSS-2 provided by Google / Planet with Spaceflight and SpaceX support. Additional partners for the InspireSat-1 mission have included the Indian Institute of Space Science and Technology (IIST) in India, the Nanyang Technological University (NTU) in Singapore, the National Central University (NCU) in Taiwan, and donated launch services provided by the Indian Space Research Organization (ISRO).

For more information and MinXSS data, visit https://lasp.colorado.edu/minxss

Or contact Tom Woods at tom.woods@lasp.colorado.edu