spin axis direction, precession, and nutation amplitudes are better understood, it should be possible to calculate the size and density of the Martian core and mantle. This should increase the understanding of the formation of terrestrial planets (e.g. Earth) and rocky exoplanets. Temperature and Winds for InSight (TWINS), fabricated by the Spanish Astrobiology Center, monitors weather at the landing site. Laser RetroReflector for InSight (LaRRI) is a corner cube retroreflector provided by the Italian Space Agency and mounted on InSight top deck. It enables passive laser range-finding by orbiters after the lander is retired, and will function as a node in a proposed Mars geophysical network. This device previously flew on the Schiaparelli lander as the Instrument for Landing-Roving Laser Retroreflector Investigations (INRRI), and is an aluminum dome in diameter and in mass featuring eight fused silica reflectors. Instrument Deployment Arm (IDA) is a robotic arm that deployed the SEIS, wind and thermal shield, and HP3 instruments to Mars' surface. It is a 4 DOF motorized manipulator, constructed from carbon-fiber composite tubes. Originally intended for the canceled Mars Surveyor mission, the IDA features a scoop, wax actuated grappling claw, and the IDC camera. The Instrument Deployment Camera (IDC) is a color camera based on the Mars Exploration Rover and Mars Science Laboratory navcam design. It is mounted on the Instrument Deployment Arm and images the instruments on the lander's deck and provides stereoscopic views of the terrain surrounding the landing site. It features a 45° field of view and uses a 1024 × 1024 pixel CCD detector. The IDC sensor was originally black and white for best resolution; a program was enacted that tested with a standard Hazcam and, since development deadlines and budgets were met, it was replaced with a color sensor. The Instrument Context Camera (ICC) is a color camera based on the MER/MSL Hazcam design. It is mounted below the lander's deck, and with its wide-angle 120° panoramic field of view provides a complementary view of the instrument deployment area. Like the IDC, it uses a 1024 × 1024 pixel CCD detector. The two relay 6U cubesats were part of the overall InSight program, and were launched at the same time as the lander but they were attached to the centaur upper stage (InSight's second stage in the launch). They were ejected from the stage after launch and coasted to Mars independent of the main InSight cruise