[1][2] The spacecraft would have arrived in a high orbit above Mars in 2010 and relayed data packets to Earth from a variety of Mars landers, rovers and orbiters for as long as ten years, at an extremely high data rate.

Such a dedicated communications satellite was thought to be necessary due to the vast quantity of scientific information to be sent to Earth by landers such as the Mars Science Laboratory.

[1] After the cancellation, a broader mission was proposed as the Mars Science and Telecommunications Orbiter.

The two newest science orbiters are the MAVEN, which arrived at Mars on September 21, 2014 with an Electra transceiver; and the 2016 European ExoMars Trace Gas Orbiter, that also carries an Electra UHF band transceiver.

[15] It is anticipated to employ a laser communication subsystem, that was successfully tested aboard the Lunar Atmosphere and Dust Environment Explorer mission in 2013.