ODIN and THOR represent two complementary advances in low frequency optomechanical inertial sensing aimed at enabling next generation mass change missions. ODIN, the Optomechanical Distributed Instrument for Inertial Sensing and Navigation, is a compact, low cost, and power efficient system currently supported by NASA’s InVEST program and planned for flight on the GRATTIS mission in February 2027. ODIN consists of an array of linear accelerometers, capable of achieving high-precision inertial measurements below 10⁻⁹ m s⁻²/√Hz and angular sensitivities better than 50 μrad/√Hz. Laboratory demonstrations have achieved noise floors below 8 pico-g above 60 mHz, positioning ODIN as a strong candidate for mass change studies, inertial navigation in GPS denied environments, and planetary seismology where size, weight, and power constraints dominate.
THOR, the Triaxial High sensitivity Optomechanical Reference, builds directly on ODIN heritage and is aimed at maturing optomechanical triaxial sensing technologies for spaceborne mass change observations. THOR targets linear acceleration sensitivities along three orthogonal axes at levels of 10⁻⁹ ms⁻²/√Hz across a measurement bandwidth of 1–100 mHz.
Together, ODIN and THOR advance optomechanical inertial sensing toward higher technology readiness, offering reduced cost, size, weight, and power as well as an innovative alternative to electrostatic systems while also supporting flexible mission architectures.