impacts on Mars, which could provide knowledge about such processes on Earth. Measurements of crust thickness, mantle viscosity, core radius and density, and seismic activity should result in a three- to tenfold increase in accuracy compared to current data. This is the first time a robotic lander dug this deep into the martian crust. In terms of fundamental processes shaping planetary formation, it is thought that Mars contains the most in-depth and accurate historical record, because it is big enough to have undergone the earliest accretion and internal heating processes that shaped the terrestrial planets, but is small enough to have retained signs of those processes. The science phase is expected to last for two years. In March 2021, NASA reported, based on measurements of over 500 Marsquakes by the InSight lander on the planet Mars, that the core of Mars is between , about half the size of the core of Earth, and significantly smaller than thought earlier, suggesting a core of lighter elements. Design The mission further develops a design based on the 2008 Phoenix Mars lander. Because InSight is powered by solar panels, it landed near the equator to enable maximum power for a projected lifetime of two years (1 Martian year). The mission includes two relay microsatellites called Mars Cube One (MarCO) that launched with InSight but were flying in formation with InSight to Mars. Three major aspects to the InSight spacecraft are the cruise stage, the entry, descent, and landing system, and the lander. Overall specifications Mass Total mass during cruise: Lander: Aeroshell: Aeroshell Diameter (backshell and heat shield) : 2.64 meters (8.67 ft) Cruise stage: Propellant and pressurant: Relay probes flew separately but they weighed each (there were 2) Lander specifications Lander mass: including about 50 kg of science payload. Mars weight (0.376 of Earth's): About wide with solar panels deployed. The science deck is about wide and between high (depending on leg compression after landing). The length of the robotic arm is Tilt of lander at landing on Mars: 4° Power Power is generated by two round solar panels, each in diameter when unfurled, and consisting of SolAero ZTJ triple-junction solar cells made of InGaP/InGaAs/Ge arranged on Orbital ATK UltraFlex arrays. After touchdown on the Martian surface, the arrays are deployed by opening like a folding fan. Rechargeable batteries Solar panels yielded 4.6 kilowatt-hours on Sol 1 Payload InSight lander payload had a