While the Red Planet, Mars, has been well-studied by a flotilla of orbiting spacecraft and a handful of rovers and landers, its two natural satellites, Phobos and Deimos, are relatively mysterious and their origins and evolution remain uncertain.

Image of Phobos obtained with Mars Express. Credit: ESA/DLR/FU Berlin (G. Neukum)

The Phobos-Soil (Phobos-Grunt) mission, dedicated to the extensive study of the moon Phobos - with investigations of the environment, in situ measurements and a sample return - would fill this gap in our knowledge. The mission builds on Russia’s long heritage in space science and robotic exploration.

Mission objectives and planned observations

The study of Phobos is expected to provide insight into its own origins and evolution as well as on the history of Mars. Although Mars has been studied extensively, its moon holds secrets that may help us better understand the Red Planet.

The main objective of this mission is to return Phobos regolith samples back to Earth for comprehensive studies in terrestrial laboratories. The mission is also equipped for comprehensive in situ measurements of the physical and chemical properties of the regolith at the landing site and to measure the bulk characteristics of Phobos from orbit. It will also study the near-Mars environment from its position in a quasi synchronous orbit with Phobos.

Spacecraft

Phobos-Soil (Phobos-Grunt) will deploy a spacecraft in an orbit around Mars that is quasi synchronous with Phobos. The spacecraft will also carry a lander that will perform in situ investigations of the Phobos regolith and a return capsule that will bring pristine samples of the regolith back to Earth.

In its launch configuration, the spacecraft will be composed of four key elements:

• Orbiter and lander system
• A Phobos descent module
• A return module
• A return capsule

A Chinese orbiter, Yinghuo-1 (YH-1), will piggyback with the mission to be delivered in orbit around Mars.

Mission architecture

The mission will have several distinct phases after launch (on 8 November 2011), before it settles into a quasi synchronous orbit (QSO) with Phobos. The landing is planned for 14 February 2013, although detailed observations from QSO will ascertain the exact day and time of landing.

Phobos-Soil (Phobos-Grunt) is a Russian Federal Space Agency mission with ESA participation. The mission was originally proposed by the Council on Space of the Russian Academy of Science and is being implemented by the Russian Federal Space Agency (ROSCOSMOS). The Lavochkin Association is the prime contractor for the space segment. The Space Research Institute of the Russian Academy of Sciences (IKI RAS) is leading science investigations.

ESA provides ground station support under an agreement between ESA and the Russian Federal Space Agency on the ExoMars and Phobos-Soil (Phobos-Grunt) missions.

The Mission Control Centre is located at the Lavochkin Association which has connections with satellite communication antennas at Bear Lakes, Ussuriysk and Baikonur. The Space Research Institute of the Russian Academy of Sciences (IKI RAS) is responsible for the Ground Science Complex, which takes care of the processing, distribution and archiving of science data. The programme of analysis of the Phobos soil samples is prepared by the Vernadski Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences (GEOHI RAS).