OVERVIEW AND STATUS OF THE INSIGHT MISSION (Invited Presentation)

The InSight spacecraft landed on Elysium Planitia in November 2018 carrying a scientific payload focused on the exploration of the deep interior of the planet. The three core experiments are SEIS, a six-sensor, broad-band seismic instrument to detect global seismic/impact activity and use it to probe planetary structure; HP³, an instrument for determining the planetary heat flow by measuring the thermal gradient and conductivity from the surface to 5 m depth, as well as the mechanical properties of the near-subsurface; and RISE, a geodetic planetary rotation investigation using sub-decimeter-scale precision tracking. These are augmented by a suite of environmental sensors comprising a pair of wind and air temperature sensors, a pressure sensor, a radiometer for measuring ground surface temperature, and a magnetometer; and an instrument deployment system, including a robotic arm (IDA), a mid-resolution color camera and a wide-angle color camera, all of which additionally support geological investigations of the lander's surroundings.

After spending the first 3 months on painstaking deployment and commissioning, the SEIS has been providing continuous seismic monitoring of Mars, with background noise levels orders of magnitude lower than any achievable on the Earth. At the time of this writing (June, 2019) the InSight marsquake catalog contains over 20 seismic events, with many fascinating and puzzling features. Only a third of the way through the primary mission, these measurements are already beginning to yield clues about the interior structure of Mars.

The HP³ mole began penetration toward its 5-m target depth in late February, but stopped making progress almost immediately at a depth of ~0.35 m. This is hypothesized to be due to a loss of wall friction due to unforeseen soil properties. At the time of this writing the project is undertaking steps using the IDA to increase the ability of the mole to resume downward progress.

The RISE experiment depends on the accumulation of 1-hour tracking arcs over the course of the mission to measure the precise direction and motion of the rotational pole. We anticipate being able to provide new constraints on Mars' moment of inertia after less than a year on the surface, and measurements of the nutation should yield the size and density of the core after about two years.