Juno’s main body is made of an advanced carbon composite material in a honeycomb structure. The spacecraft has a hexagonal shape, with three large solar arrays symmetrically placed around the hexagon. Most of the science instruments are between the solar arrays, with their sensors attached to Juno’s main deck. The instruments’ electronics are housed inside Juno’s titanium vault, atop the main deck, which provides the base for Juno’s main antenna. Beneath the main deck reside the propellant tanks and Juno’s rocket engine that’s used for maneuvers and orbit insertion.