StarBurst

StarBurst [NASA]

The StarBurst observatory is a astrophysics SmallSat mission developed the NASA Marshall Space Flight Center to detect high-energy gamma rays from events such as the mergers of dense stellar remnants called neutron stars. The mission is part of NASA’s Astrophysics Pioneer program and is focused on time-domain and multimessenger astrophysics. Its primary objective is the detection of gamma-ray counterparts to neutron star mergers, providing rapid electromagnetic observations in support of gravitational-wave detections.

StarBurst is optimized to operate as a partner to the global gravitational-wave detector network. By continuously monitoring the unocculted sky with high sensitivity, the observatory is intended to improve the detection rate and localization accuracy of short gamma-ray bursts associated with neutron star mergers. These measurements support follow-up observations across the electromagnetic spectrum and contribute to the understanding of compact object physics.

The spacecraft and instrument are based on mature scintillation detector technology adapted to a SmallSat platform. The payload consists of a single gamma-ray instrument developed using cesium iodide scintillation crystals coupled with modern solid-state photon sensors. Advances in detector electronics and timing systems enable performance significantly exceeding earlier missions of comparable scope.

The StarBurst instrument comprises twelve CsI(Tl) scintillation detectors sensitive to gamma rays in the 30 to 1,000 keV energy range. The detectors are arranged to provide full coverage of the unocculted sky. Incoming gamma rays interact within the scintillation crystals, producing ultraviolet and visible photons that are detected by silicon photomultipliers. These signals are converted into voltage pulses and digitized by onboard electronics to determine photon energies.

Precise timing is provided by an onboard clock synchronized to the Global Positioning System, allowing accurate measurement of gamma-ray arrival times. Source localization is achieved through comparison of relative signal strengths across the detector array. The effective detection area exceeds that of the Fermi (GLAST) Gamma-ray Burst Monitor by more than a factor of five.

StarBurst is designed for deployment to low Earth orbit as a secondary payload. The spacecraft uses the ESPA Grande interface. Launch is planned for 2027, with a nominal mission duration of one year.