Mission Overview

An artist's rendering of the twin Mars Cube One (MarCO) spacecraft as they fly through deep space.
An artist's rendering of the twin Mars Cube One (MarCO) spacecraft as they fly through deep space. Image credit: NASA/JPL-Caltech

On May 5, 2018, NASA launched a stationary lander called InSight to Mars. Riding along with InSight were two CubeSats -- the first of this kind of spacecraft to fly to deep space. Both MarCO-A and MarCO-B succeeded in a flyby of Mars, relaying data to Earth from Insight as it landed on Mars.

The twin communications-relay CubeSats, built by NASA's Jet Propulsion Laboratory, Pasadena, California, constitute a technology demonstration called Mars Cube One (MarCO). CubeSats are a class of spacecraft based on a standardized small size and modular use of off-the-shelf technologies. Many have been made by university students, and dozens have been launched into Earth orbit using extra payload mass available on launches of larger spacecraft.

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).

"MarCO-A and B are our first and second interplanetary CubeSats, designed to monitor InSight for a short period around landing,” said Jim Green, director of NASA's planetary science division at the agency's headquarters in Washington. “They are a demonstration of potential future capability."

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

The two CubeSats were designed to separate from the Atlas V booster after InSight's launch and travel along their own trajectories to the Red Planet. After release from the launch vehicle, both MarCOs deployed two radio antennas and two solar panels. The high-gain, X-band antenna is a flat panel engineered to direct radio waves the way a parabolic dish antenna does. MarCO was navigated to Mars independently of the InSight spacecraft, with its own course adjustments on the way.

MarCO-B, one of the experimental Mars Cube One (MarCO) CubeSats, took this image of Mars from about 4,700 miles (7,600 kilometers) away during its flyby of the Red Planet on Nov. 26, 2018.

During InSight's entry, descent and landing (EDL) operations, the lander broadcast information in the UHF radio band to NASA's Mars Reconnaissance Orbiter (MRO) and the MarCOs. MRO cannot simultaneously receive information over one band while transmitting on another, and so confirmation of a successful Insight landing was received from the orbiter with more than an hour delay. Thanks to the MarCOs, the InSight team learned of their lander's fate in near-real-time: each CubeSat carries a softball-sized radio that provides both UHF (receive only) and X-band (receive and transmit) functions capable of immediately relaying information received over UHF.

As a bonus, MarCO-B carried an inexpensive commercial camera equipped with a fisheye lens and returned a “farewell” image of Mars immediately after the InSight relay support was completed. The grid visible on the right side of the image is the high-gain X-band antenna used to transmit InSight data to earth.

The MarCO mission successfully demonstrated a "bring-your-own" communications relay option for use by future Mars missions in the critical few minutes between Martian atmospheric entry and touchdown.

Further, by verifying CubeSats are a viable technology for interplanetary missions, and feasible on a short development timeline, this technology demonstration could lead to many other applications to explore and study our solar system.

On February 2, 2020, the MarCO mission came to an end. JPL, a division of the California Institute of Technology in Pasadena, manages MarCO, InSight and MRO for NASA's Science Mission Directorate in Washington. Technology suppliers for MarCO include: Blue Canyon Technologies of Boulder, Colorado, for the attitude-control system; VACCO Industries of South El Monte, California, for the propulsion system; AstroDev of Ann Arbor, Michigan, for electronics; MMA Design LLC, also of Boulder, for solar arrays; and Tyvak Nano-Satellite Systems Inc., a Terran Orbital Company in San Luis Obispo, California, for the CubeSat dispenser system.

For more information about MarCO, visit: go.nasa.gov/marco_launch

A MarCO media reel is available at https://vimeo.com/265040492