The Sun Radio Interferometer Space Experiment (SunRISE)

The Sun Radio Interferometer Space Experiment (SunRISE) will provide an entirely new view on particle acceleration and transport in the inner heliosphere by creating the first dedicated low radio frequency interferometer in space to localize heliospheric radio emissions. By imaging and determining the location of decametric-hectometric (DH, 0.1 MHz–23 MHz) solar radio bursts, SunRISE will provide key information on particle acceleration mechanisms associated with coronal mass ejections (CMEs) and the magnetic field topology from active regions into interplanetary space. The SunRISE Observatory will consist of six Space Vehicles in a passive formation, in orbits designed to keep them within approximately 10 km of each other, and flying in a supersynchronous orbit, about 400 km or more above geosynchronous Earth orbit (GEO). Each Space Vehicle consists of a Science Payload and a 6U form factor Spacecraft. The SunRISE Observatory together with significant ground-based processing, will enable imaging of the Sun in a portion of the spectrum that is blocked by the ionosphere and cannot be observed from Earth. Key aspects that enable this mission are that only position knowledge of the Space Vehicles is required, not active control, and that the architecture involves a modest amount of on-board processing coupled with significant ground-based processing for navigation, position determination, and science operations. The SunRISE mission will exploit the multiple spacecraft per aperture (MSPA) capability of NASA’s Deep Space Network (DSN), for more efficient data transfers of larger data volumes. The SunRISE Space Vehicles will be carried to their target orbit as secondary payloads in conjunction with a larger host spacecraft intended for GEO. Launch is scheduled no earlier than 2024 September. This paper describes the mission and summarizes its current status, highlighting the Interferometer-Level Performance Test. With all six Space Vehicles tested simultaneously in as flight-like operations as possible, the Interferometer-Level Performance Test represented a significant milestone.