PRINCIPALS OF VOLATILE COMPONENTS MEASUREMENTS IN THE GAP EXPERIMENT ONBORD THE PHOBOS-GRUNT MISSION AND BEYOND.

M.V.Gerasimov and the GAP team

IKI RAS, Moscow, 11.10.2011

Kaidun

Phobos

Origin of Phobos?

Trapped asteroid or in orbit formation?

How much it was differentiated?

Which type of meteorites simulates its material?

What can we learn from investigation of volatiles of Phobos?

Chemical composition of some carbonaceous chondrites

Carbonaceous chondrites names

Concentration of volatiles in different petrographic types of meteorites (Wood, 1968)

petrographic types 1 2 3 4 5 6

Sulfides - >0.5% <0.5%

Carbon ~ 2.8% 0.6 – 2.8% 0.2 – 1.0% <0.2%

Water ~20% 4 – 18% <2%

Insoluble organics in meteorites

Van Krevelen diagram of thermal evolution of kerogen

Carbonaceous chondrites

Moon

Earth

SNC meteorites(Mars)

Ordinary chondritesPrimitive water

δ1

7 O, ‰

δ18O, ‰0 5 10 15

-6

-4

-2

0

6

4

2

8CI

CO

CV

CRCH

CM

Oxygen isotopes in the Solar System

Hydrogen isotopes in the Solar System

- to investigate the origin of Martian satellites on example of Phobos;

- to investigate properties of small planetary objects in space environment;

- to study possible differentiation of early planetary materials;

- to study volatiles inventory;

- to study organic materials;

- to study the influence of Phobos on the near Martian environment (dust torus, gas, plasma and magnetic field perturbations);

- to investigate the detailed structure of the Martian atmosphere including vertical profiles of temperature, aerosol, and trace atmospheric components (water vapor, CO, CH

4, etc);

- to investigate diurnal variations of surface temperature of Mars.

Scientific objectives of the “PhSR” mission

Phobos Sample Return mission (2011)

Three main questions to characterize volatiles:

1. Concentration of volatile elements?

Concentration = Total mass of the volatile element in the sample

Mass of the sample

water

organics

trapped hydrogen

other

hydrogen

Three main questions to characterize volatiles:

1. Concentration of volatile elements?

2. Form of incorporation of volatiles in the soil?

carbonates

carbides

organics

other

carbon

3. Isotopic composition of volatile elements?

Three main questions to characterize volatiles:

1. Concentration of volatile elements?

2. Form of incorporation of volatiles in the soil?

Gas Analytic Package (GAP) for the “Phobos Sample Return Mission”

Scientific objectives of the GAP1. Investigation of chemical composition and inventory

of volatiles (water, СО2, N2, SO2, organics, noble gases, etc.) in situ in the soil at the landing place;

2. Investigation of volatile-containing phases in the soil of the Phobos;

3. Investigation of organic components in the soil of the Phobos;

4. Measurement of isotopic composition of CHON elements (13С/12С, D/H, 17O/16O, 18O/16O, 15N/14N) and noble gases;

5. To constrain the mineralogical composition of the Pobos soil (with emphasis on the volatile-bearing minerals) on the basis of thermal and gas evolving experiments with the use of data from other experiments.

The structure of the GAP

Soil preparationand loading

system

ThermalDifferentialAnalyzer

ChromatographMass-

spectrometer

TDA

MS

GC

Objectives of the TDA

1. To measure exo- and endothermal reactions in the sample of soil to determine minerals with phase transitions at temperatures <1000C;

Thermal Differential Analyzer (TDA)

2. To perform the release of volatile components into the gas phase and provide their transfer into GC and MS;

3. To perform pyrolysis of heavy organics (kerogens?) for their analysis in GC and MS;

SOil Preparation SYStem = SOPSYS

Tasks of the device

1. To take a portion of soil from the manipulator.

2. To mill large pieces of rocks and sieve the soil to extract the necessary fraction for loading into pyrolytic cells.

3. To extract the dose of the sample for loading into the pyrolytic cell.

4. To clean itself for the next cycle.

Pyrolytic cell

Cell parameters:

Т mах - 1000С (1350С) W max - 22 WMass - 20 g

He He + газы

10

9

1

2

3

4

7

6

8

11

5

Sample volume - 4 mm 5 mm

PC cross-section

Tasks of the chromatograph

1. Accumulation of gases which are released from the sample during pyrolysis.

2. Redistribution of gases of different types (permanent gases, organics, etc.) between respective columns.

3. Separation of different gases by time of retention.

4. Measurement of abundance of separate gas component.

5. Measurement of isotopic ratios of D/H, 13C/12C, 17O/16O, 18O/16O in CO2 and H2O using TDLAS.

Gas Chromatograph

HDOH2

17OH2

18O

H216O

HDO

H216O

H216O

Laser = 2.64 m

Name* Target molecule

Sigma (cm-1) Lambda (nm)

C2H2 C2H2 6523.8794 cm-1 1533 nm

CO2iso 18OC16O 4898.7822 cm-1 2041 nm

18OC16O 4899.5653 cm-1

13CO2 4899.6133 cm-1

H2Oiso HDO 3788.3366 cm-1 2640 nm

H2 17O 3788.7852 cm-1

H2 18O 3788.9125 cm-1

H2O-CO2 H2O 3727.7376 cm-1 2682 nm

CO2 3728.4101 cm-1

TDLAS scheme

Assemblage of the GC block

Carrier gas tanks (Не) 2250 см3 40 bar.

Pressure sensor

Calibration gas tankPressure regulators

TDLAS tube Injection traps

GC modules

ON/OFF valvesmanifolds

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hexaneС6Н14

4,410-8 g benzeneС6Н6

4,010-8 g

A piece of test chromatogram

signal/noise ~ 600

The mass-spectrometerL.P. Moskaleva (PI) Vernadsky Institute of Geochemistry and Analytical Chemistry (GEOKHI)Ryazan University (contractor)

Block of electronics (BE)

Mass analyzer (MA)

Main parameters of the MS

1. Mass - 3,5 кг2. Power consumption - 32 Вт3. Dimentions: МА - 256х78х73 (mm)

BE - 256х110х120 (mm)4. Mass range - (2÷400) amu/q5. Sensitivity for Ar - (3÷5)х10-12 hPa6. Dynamic range - 104

7. Mass resolution - 400(?)

A test mass-spectrum of CO2 in GC+MS mode

Mass number (amu/q)0 10 20 30 40 50 60 70 80 90 100

Sig

nal (

a.u.

)

0

200

400

600

800

1000

1200

ÑÎ 2+

m/z=44

ÑÎ +

m/z=28

H2Î+

m/z=18

Î 2+

m/z=32

Î +

m/z=16

C+

m/z=12 He+

m/z=4

- background spectrum

Main partners of the Phobos-GruntGas Analytic Package team

IKI RAS (Russia) TDA+GCGEOKHI RAS (Russia) MS

LATMOS (France) GCLISA University of Paris (France) GCGSMA (France) TDLAS

MPS (Germany) GC

Polytechnic University of Hong Kong (China) SOPSYS (TDA)

Gas Analytic Package for Lunar-Resource (2014) and Lunar-Globe (2015) Russian missions

Preliminary positioning of the GAP on the instruments panel