GeMini: A High-Resolution, Low-Resource, Gamma-Ray Spectrometer for Planetary Science Applications

• Published in: Space science reviews 2020-10, Vol.216 (7), Article 115
• Main Authors: Burks, Morgan T., Drury, Owen B., Goldsten, John O., Hagler, Lisle B., Heffern, Lena E., Hines, Nathan R., Kim, Geon-Bo, Lawrence, David J., Nelson, Karl E., Peplowski, Patrick N., Yokley, Zach W.
• Format: Article
• Language: English
• Subjects: Aerospace Technology and Astronautics; Asteroid missions; Asteroids; ASTRONOMY AND ASTROPHYSICS; Astrophysics and Astroparticles; Chemical composition; Design; Environmental conditions; Gamma ray spectrometers; Gamma rays; Gamma-ray spectroscopy; Germanium; High resolution; High-purity germanium detectors; Japanese space program; Mars; Mars missions; Mars satellites; Measuring instruments; Mechanical cooling; Moon; Physics; Physics and Astronomy; Planetary composition; Planetary nuclear spectroscopy; Planetology; Radiation; Radiation damage; Sample return missions; Space Exploration and Astronautics; Space missions; Space Sciences (including Extraterrestrial Physics; Special Communication; Spectroscopy; Titan
• ISSN: 0038-6308; 1572-9672
• DOI: 10.1007/s11214-020-00746-y

GeMini is a high-resolution gamma-ray spectrometer designed for planetary-science exploration. GeMini serves as the basis for instruments being flown on three upcoming deep-space missions: NASA’s mission to the M-class asteroid (16) Psyche, the Japan Aerospace Exploration Agency sample-return mission to the moons of Mars, and NASA’s Dragonfly mission that will land on Saturn’s largest moon, Titan. These science missions require high-resolution spectroscopy in a low-power, low-mass, rugged design that can survive in a variety of environments. GeMini addresses these needs by providing a cryogenically cooled crystal of high-purity germanium that can operate with as little as 10 to 20 watts, depending on the implementation and mission, and has a mass of less than 2 kg. GeMini helps determine the elemental composition of planetary bodies by measuring gamma rays emitted from the surface. This paper describes the mechanical, thermal, and electrical design of GeMini as well as its performance. It also describes testing that was performed to validate the design with respect to launch loads and radiation damage. Although the basic design of GeMini is common to all three missions, each planetary body has unique environmental conditions and mission specifications. This paper concludes by describing these upcoming missions and how GeMini is customized for each.