The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission was a robotic lander designed to study the deep interior of the planet Mars. It was manufactured by Lockheed Martin Space, was managed by NASA's Jet Propulsion Laboratory (JPL), and two of its three scientific instruments were built by European agencies. The mission launched on 5 May 2018 at 11:05:01 UTC aboard an Atlas V-401 launch vehicle and successfully landed at Elysium Planitia on Mars on 26 November 2018 at 19:52:59 UTC. InSight was active on Mars for 1440 sols.

A lander is a spacecraft that descends towards, then comes to rest on the surface of an astronomical body other than Earth. In contrast to an impact probe, which makes a hard landing that damages or destroys the probe upon reaching the surface, a lander makes a soft landing after which the probe remains functional.