BurstCube
BurstCube is a 6U CubeSat project that is designed to automatically detect gamma-ray transients onboard (astrophysical, solar, and terrestrial) while sending rapid alerts to the ground to enable follow-up observations. BurstCube also increases the sky coverage for short, less than 2 second gamma-ray bursts (GRBs) which in recent years have been proven to be produced by binary neutron star mergers.
This satellite is also designed to detect solar flares, magnetar flares, and other hard X-ray transients and can provide all-sky coverage at a small fraction of the cost needed for an Explorer. Since BurstCube also provides localizations, follow-up observations can be made in afterglow detection and redshift measurement to provide insight into cosmological parameter estimation, onstraints on the neutron star equation of state, and an inventory of r-process elements in the Universe constrained by the faint short GRB kilonova signature.