Mars Cube One

Mars Cube One, usually shortened to MarCO, was a pair of small spacecraft built at the NASA Jet Propulsion Laboratory to accompany the InSight Mars lander and relay data back to Earth in real time during its landing, a phase in which the Mars Reconnaissance Orbiter, MAVEN and Mars Odyssey would not be in a position to listen. The two craft, nicknamed Wall-E and Eva, were MarCO A and MarCO B. Each used the 6U CubeSat form factor, with two deployable solar arrays, a deployable X-band antenna and a UHF antenna, giving an 8 kbps UHF link from InSight to the relay and an 8 kbps X-band link onward to the Deep Space Network. Each weighed 13.5 kilograms and carried a wide-field engineering camera, a narrow-field color camera and a cold-gas propulsion system with eight 25 millinewton thrusters. Both were launched on 5 May 2018 from Vandenberg on an Atlas V 401 together with InSight, then flew to Mars on their own, making trajectory correction maneuvers on the way.