Twin small spacecraft in space.

This illustration depicts a moment during the lander's descent when it is transmitting data in the UHF radio band, and the twin MarCO craft are receiving those transmissions while simultaneously relaying the data to Earth in a different radio band. Credit: NASA/JPL-Caltech

Launch Date May 5, 2018 | 11:05 UTC
Launch Site Vandenberg Air Force Base, California, USA
Destination Mars
Type Flyby
Status Successful
Nation United States
Alternate Names MarCO, WALL-E, EVE

MarCO, short for Mars Cube One, demonstrated the ability of small satellites to explore deep space and provided real-time information in support of critical landing operations on a distant world.

  • The MarCO twins — nicknamed EVE and WALL-E, after characters from a Pixar film — provided an experimental communications relay to inform Earth quickly about the landing.
  • MarCO A and B successfully completed their mission as communications relay satellites for the InSight Mars landing on Nov. 26, 2018. The spacecraft will end up in orbit around the Sun. WALL-E was last heard from on Dec. 29; EVE, on Jan. 4.
  • The two briefcase-size MarCO CubeSats launched with the InSight lander on an Atlas V rocket from Vandenberg Air Force Base in California.

View of Mars from MarCO spacecraft.
MarCO-B, one of the experimental Mars Cube One (MarCO) CubeSats, took this image of Mars from about 4,700 miles (6,000 kilometers) away during its flyby of the Red Planet on Nov. 26, 2018. Credit: NASA/JPL-Caltech

Key Dates

May 5, 2018: Launch (with InSight lander)

Nov. 26, 2018: Mars Flyby / Relay Operations

Dec. 29, 2018: Final Contact with WALL-E

Jan. 4, 2019: Final Contact with EVE


Launch Vehicle: Atlas V
Spacecraft Mass: The basic CubeSat unit is a box roughly 4 inches (10 centimeters) square. Larger CubeSats are multiples of that unit. MarCO's design is a six-unit CubeSat - about the size of a briefcase -- with a stowed size of about 14.4 inches (36.6 centimeters) by 9.5 inches (24.3 centimeters) by 4.6 inches (11.8 centimeters).

Man working on small spacecraft.
Engineer Joel Steinkraus uses sunlight to test the solar arrays on one of the Mars Cube One (MarCO) spacecraft.

Spacecraft Instruments:

  1. UHF Radio Receiver

  2. X Band Radio Transmitter

Additional Resources

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