NASA’s internship programs offer opportunities year-round for students to undertake meaningful and challenging projects that truly make an impact on humanity. Selected students are provided with training, mentoring, and career development throughout their session with some of the best minds in the world.
With over 100 applicants to the mission’s internship program, the Stratospheric Aerosol and Gas Experiment (SAGE) III on the International Space Station (ISS) team at NASA’s Langley Research Center in Hampton, VA selected three undergraduate student interns to work on a team science and engineering project during the 10-week summer session.
Matilda Damon, Linnea Johansson, and Riley Runyon worked together on developing the SAGE III limb scattering science processing code. Experimental SAGE III measurements of atmospheric limb scattered sunlight provide an innovative way to collect atmospheric data such as stratospheric ozone and aerosol. If successfully implemented, SAGE III atmospheric observations would cover a much larger range of times and Earth locations, providing even more atmospheric data to the public.
Currently, the SAGE III instrument uses solar and lunar occultation to capture these data products for the public. Such measurements only occur when the orbiting ISS experiences a sunrise, sunset, moonrise, or moonset. SAGE observes the light from the Sun or the Moon that passes through the atmosphere during both rise and set events to measure gases and particles in that region of the atmosphere. Occultation is a measurement of transmitted light, not scattered light. Adding limb scattering products to the SAGE inventory would add considerable value.
The intern team worked on coding a software Multiplicative Extended Kalman Filter (MEKF) that provides SAGE with an absolute attitude reference during limb scattering measurements. By combining solar edge detection with attitude rate data from the Disturbance Monitoring Package (DMP) subsystem aboard the SAGE III payload, the MEKF-derived attitude will supply high-accuracy telescope pointing information, which is important for ensuring the accuracy of the limb scattering atmospheric retrievals. The DMP is a three-axis ring laser gyroscope that the students used for attitude dead reckoning. Pointing error slowly accumulates as an angle random walk while dead reckoning in the absence of an occasional absolute attitude correction. Their filter will work to reduce the effects of this random walk between absolute measurements. To show how the filter impacts the attitude estimation, they also compared DMP dead reckoning directly with the filter results. To accomplish this, they relied heavily on quaternion mathematics. Quaternions are hypercomplex 4-D numbers that can represent rotations in 3-D space and are used for more than just aerospace applications. Your phone likely uses quaternion math to determine whether you’re holding it in portrait or landscape mode!
In addition to their limb scatter remote sensing project, the interns attended weekly SAGE III science and mission operations team meetings, weekly mentor check-ins, and several presentations on other missions, projects, and facilities at Langley. They particularly enjoyed learning about the history of NASA Langley’s Gantry.
Matilda Damon is a rising sophomore at Brown University studying astrophysics, engineering, and planetary science. At Brown, she rows for the Varsity Women’s Crew team, which helped prepare her for productive teamwork during her internship at NASA. She flies planes and studies astronomy in her free time at Brown.
“Knowing that code we wrote will help produce the gold standard of atmospheric data for the world is incredibly exciting. I am grateful to my mentors and peers for the opportunity to contribute to the SAGE III mission and for all the wisdom they imparted to me. Our mentors not only taught us coding, math, and science relevant to the mission, but also life skills such as collaboration, coding resource management, overcoming setbacks, and critical thinking,” said Damon.
Linnea Johansson is a rising junior at Washington and Jefferson College studying physics and mathematics. At school, she is a member of the varsity soccer team. She is also a leader of the Special Olympics Club and the Society for Physics Students. In her free time, she enjoys being outside and reading.
“This has been an incredible experience to help contribute to SAGE III. Working alongside my mentors has been rewarding and has taught me many valuable skills such as coding, version control, and working in a professional environment. I have also enjoyed the bonds that I have formed with the other interns,” said Johansson.
Riley Runyon is a rising junior at Washington and Jefferson College majoring in physics and mathematics. He is the leader of his school’s Climbing and Outdoors Club. He spends his free time running and playing his guitar.
“I loved every second of it. My mentors and coworkers are the coolest, most eclectic bunch of people I’ve ever had the privilege of knowing. Because of them and the work they assigned to me, I feel like I’ve learned how to think and work like an engineer and a scientist—systematically, precisely, and cautiously,” said Runyon.
The innovation, hard work, and dedication of the SAGE III summer internship team will continue to support and benefit the Langley mission team for the foreseeable future.
To apply for the next session of NASA internships, please visit intern.nasa.gov.
