MarCO CubeSat Test

Engineer Joel Steinkraus uses sunlight to test the solar arrays on one of the MarCO spacecraft at NASA's Jet Propulsion Laboratory.

MarCO, short for Mars Cube One, was the first interplanetary mission to use a class of mini-spacecraft called CubeSats. The MarCOs — nicknamed EVE and WALL-E, after characters from a Pixar film — served as communications relays during InSight's landing, beaming back data at each stage of its descent to the Martian surface in near-real time, along with InSight's first image. WALL-E sent back stunning images of Mars as well, while EVE performed some simple radio science.

WALL-E was last heard from on Dec. 29; EVE, on Jan. 4. Based on trajectory calculations, WALL-E is currently more than 1 million miles (1.6 million kilometers) past Mars; EVE is farther, almost 2 million miles (3.2 million kilometers) past Mars.