PHOBOS - GRUNT

Phobos Sample Return Mission

1. Basis for choice, goals and methods of study

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Content

• Choice of the mission: The main criterias

• Selected Mission

• Phobos: Basis of the choice

• Phobos: Main steps of investigation

• Phobos & Deimos: Likeness and Difference

• Phobos: Current understanding

• PHOBOS-GRUNT mission: Scientific objections

• Phobos: Methods of investigation

• PHOBOS-GRUNT: Strawman Payload

• PHOBOS-GRUNT project: Current status

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Choice of the mission: the main criteria

• determination of the topical significant scientific task in planetary exploration;

• taking into account of results, heritage and available experience in planetary exploration in the country;

• taking into account of interests of wide circle of scientists in the country and drawing in the project young scientists;

• keeping of international cooperation in preparation and implementation of the project;

• necessity of creation of new space platform for planetary exploration, based on new technology;

• taking into account of limited funding of the Russian space program;

• necessity of realization of the project during the next 3-5 years;

• realizeness (technical and financial reability).

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Selected mission

Phobos Sample Return Mission -

“PHOBOS - GRUNT”

• delivery of samples of the regolith,

• study of Phobos from sc during orbiting and landing on the Phobos surface,

• monitoring of Mars.

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Phobos: Basis of the choice

• Delivery to the Earth a sample of relict matter and its investigation in the laboratories is one of the most important task of current Solar system exploration;

• scientific and technical solutions of a mission to Phobos have heritage and choosing a mission to Phobos continues the strategy of planetary exploration in our country;

• Phobos and Deimos are the most accessible small bodies for space research from the technical point of view;

• preparation and realization of a Phobos mission reflects interests of many institutes of the Russian academy of sciences - IKI, Vernadsky Institute, Apply Mathematics Institute, Institute of Radioelectronic, Institute of Earth Physic and others;

• besides Phobos investigation a mission to Phobos allows to study several important problems of Mars, its environment, some interesting problems of fundamental physics;

• a mission for Phobos investigation is independent on any current foreign space mission and from other side supplement the current American and European program on Mars exploration and exploration of Solar system small bodies what can be a base for international cooperation.

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Phobos: Main steps of investigation

1610 - Johannes Kepler was one of the first who suggested the existence two Martian moons,

1877 - Asaph Hall, American astronomer discovered two satellite of Mars Phobos and Deimos;

1896 -1909 - S. Kostinsky (Pulkovo observatory) made the first pictures of these satellites;

1911 - G.V. Struve suggested a theory of moving of Martian satellites;

1945 - B.Shurpless came to the conclusion on the existence of century acceleration of Phobos;

1958 - J. Koiper made the first photometric measurements (albedo - 0,06-0,07; carbonaceous chondrites),

1971 - 1972 - «Mariner-9» (TV-camera, IR-radiometer, UF-spectrometer);

1976 - 1977 - «Viking-Orbiter» (TV-camera, orbital measurements).

1989 - «PHOBOS-2» (TV-camera, radiometers and spectral measurements of regolith)

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Phobos & Deimos: Likeness and Difference

Phobos Deimos

Dimensions

Mean density

26,6 22,2 18,6 km

1,9 0,1 g/cm3

15,0 12,4 10,8 km

1,8 0,3 g/cm3

Norm. Reflect. (0,54 m)

Taxonomy

0,071 0,012

Т (?)

0,068 0,007

D (?)

Geologic features

Acceleration in a free fall

Global grooves

0,54 cm/с 2

No grooves

0,31 cm/s2

Circular orbit R = 9378 km (2,76 RM),

T = 7h 39min, i = 240

R = 23459 km (6,9 RM),

T = 30h 21min, i = 240

Proper motion Synchronous rotation

Libration: period 10 h

amplitude 70

Synchronous rotation

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Phobos: Current understanding

• In overall the data acquired on Phobos and Deimos have shown their unique features:

– dramatic different appearance,– low density,– the failure to establish a direct «class relatives» among the family of asteroids

(«brotherly» relation to D-type is currently suspended),– peculiarity of orbital and proper motion.

• Composition (including presence of water ice) remain poorly defined.• Interior structure is unknown.• The matter and dynamics of dust tori associated with Phobos and Deimos

warrants investigation.• Origin of the Martian satellites remains the mystery; its unveiling may

contribute to the understanding of the origin of satellite systems of other planets.

• Their characteristics demonstrate our inability to model some important solid body and surface processes on small bodies.

• Phobos and Deimos study continues to be important in the context of Mars exploration.

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PHOBOS-GRUNT mission: Scientific objections

• study physical and chemical characteristics of Phobos regolith and subsurface layers in situ and under laboratory conditions - these data can provide information on properties of primordial matter of the Solar system;

• study of the role played by asteroidal impacts in the formation of terrestrial planets, in the evolution of their atmospheres, crusts, and inventories of volotiles;

• study of the origin of the Martian satellites and their relation to Mars - these data can help in our understanding of their evolution and the origin of satellite systems near other planets;

• search of organic matter, possible life or paleolife;• study of peculiarities of orbital and proper motion of Phobos, what is important for

understanding their origin, internal structure, celestial mechanics applications; • study physical conditions of the Martian environment (dust, gas, plasma

components) what is important to study of treatment processes of small body regolith under influence of external conditions and creation of engineering model of the Martian environment for future Martian missions;

• Monitoring of dynamic of the Martian atmosphere and seasons climate changing.

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Phobos: Methods of investigation

1. Delivery of sample of the matter at the Earth. With a returned sample it would be possible to address the following topics:

–absolute dating, the length of formatting interval and the subsequent evolution; –precise identification of primitive material, its chemical composition;–origin of Phobos / Deimos and their relation to Mars;–search of organic material.

2. In-situ study. Measurements on Phobos`s surface will provide the opportunity to establish a ground truth data need for validation and interpretation of remote sensing and to do a detailed, in situ study of regolith samples, specifically their:

–elemental and mineral composition, volatile content;–microscopic structure, physical and mechanical properties of the regolith; –celestial mechanic and fundamental physics experiments;–long duration monitoring of Mars.

3. Remote sensing: Remote sensing of Phobos from co-orbiting spacecraft will provide global coverage of data related to both the surface and internal structure of the satellite, will provide an opportunity to relate data returned from the landing site to the all Phobos`s surface:

–global geologic mapping,–size, shape, mass, bulk density,–color, albedo, photometric scattering and thermal properties,–mapping of global elemental and mineral composition,–internal structure,–landing site certification and selection,–The Martian environment (dust tori, solar wind - Phobos`s surface interaction).

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PHOBOS-GRUNT: Strawman Payload

Instrument TV-system Gamma-spectrometer Neutron spectrometer Alpha-X spectrometer Mass-spectrometer Seismometer Long-waves radar Visual-near IR spectrometer Dust counter Ion comp. spectrometer Solar sensor Precise transmitter

In situ

++++++++++++

Rem. Sen.

+++---++++--

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PHOBOS-GRUNT project: Current status

The PHOBOS-GRUNT project is the only national planetary project in the current decade and Rosaviacosmos and the Academy of sciences take the special attention to this project.

Two versions of the spacecraft are under the development now. During the current year we are holding a tender between these versions to choose the most effective and more realistic one in our conditions.

Space Research Institute has a contract with Rosaviacosmos for development of a set of scientific instruments for the mission. The main subcontractor is Vernadsky Institute. Several other Institutes of the Russian academy of sciences participate in this contract.

More then 20 proposals for scientific experiments have been received for the mission. The main purpose of the work during the current year is to select instruments for the mission from scientific and technical point of view.

We would be very interested in participation of foreign scientists in this mission, in particular we would like to invite American and European scientists to participate in proposal and selection processes of science instruments.

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