Hera

Hera is a European Space Agency planetary defense mission to study the aftermath of NASA's DART impact on the Didymos binary asteroid system. Where DART delivered a kinetic impulse to the moonlet Dimorphos, Hera's task is to characterize the result: mapping the impact crater, measuring momentum transfer efficiency, and refining deflection models that could guide future planetary defense planning.

The mission launched during a Falcon 9 stand-down following the Crew-9 second-stage deorbit anomaly. The FAA granted a specific exemption because the trajectory to heliocentric orbit required no second-stage reentry over populated areas - the central concern under investigation. The first stage was expended, as the energy requirements of the heliocentric trajectory left no margin for a recovery burn.