The InSight mission (formerly called GEMS), would place a lander on Mars that would be designed to drill beneath the surface and investigate the planet's deep interior to better understand Mars' evolution as a rocky planet. As part of its investigation, InSight would use a seismometer and a heat-flow probe to study the interior structure of the Red Planet.

InSight was provisionally selected for funding through NASA's Discovery Program for launch in 2016 and the spacecraft design would be based on NASA's successful Phoenix Mars lander mission.