selene project status -...

SELENE Project Status

H. Minamino, H. Hoshino, M. Kato, S. Sasaki and Y. Takizawa

Japan Aerospace Exploration Agency (JAXA)SELENE Project Team

Contents of the presentation

: SELENE Project Status

SELENE Project Status-Outline of project

-Development Status and Schedule etc.

SELENE Data Productsfor future lunar utilization

-Data utilization and significance

Outline of the Project (1)

Mission objective : “global survey” of the Moon- study the origin and the evolution of the Moon.- measure the lunar and solar-terrestrial environment .- research the possibility of future utilization of the Moon.

develop technology for the lunar orbit insertion and spacecraft attitude and orbit control


Launch Vehicle : H-IIA Rocket

Launch Year : 2007 (tentative)

Mission Period : 1 year (nominal)

● The Orbit : inclination 90 [deg]Main Orbiter : 100 x 100 [km]“Vstar” : 100 x 800 [km]“Rstar” : 100 x 2400 [km]

● The Total Mass : 2885[kg] (at launch)(mission payload : ~300kg)

● The Size :Main Orbiter : 2.1 x 2.1 x 4.8 [m]“Rstar” : 0.99 x 0.99 x 0.65 [m] “Vstar” : 0.99 x 0.99 x 0.65 [m]

● The Attitude Control : Main Orbiter : 3 axis controlled

(+Z direction faces to the moon center)“Rstar” : spin stabilized“Vstar” : spin stabilized


On-Orbit Configuration of SELENE(1/2)

Main orbiter↑←VRAD sat. (Vstar)

←Relay sat. (Rstar)

Mast for Lunar Magnetometer(l = 12m)

Antenna for Lunar Rader Sounder(l = 15m)

On-orbit Configuration of SELENE(2/2)

Moon

Solar array paddle

SELENE Mission Profile

SELENE Ground System Configuration

SELENESELENE Operation & Analysis Center(SOAC)(Sagamihara)Operation & Analysis Center(SOAC)(Sagamihara)

Operator

Relay Sat.Relay Sat.

VRAD Sat.VRAD Sat.

Main OrbiterMain Orbiter

UDSC

X TLM

S TLM,CMD

Level 0/1 Level 0/1 Processing Processing SystemSystem

Level2 DB Level2 DB Open SystemOpen System

Mission planning, data processing

Mission Operation SystemMission Operation System

JAXA GNTACCTACC

Tracking and Tracking and Control CenterControl Center

(Tsukuba)(Tsukuba)

NASA DSN

Data Archived Data Archived & Analysis & Analysis SystemSystemScientists

(out of SOAC)

Operation Operation Control SystemControl System--Command and Command and TelemetryTelemetry terminalterminal--Quick Look terminalQuick Look terminal

Flight Flight Dynamics Dynamics SystemSystem

USC(backup)

Tracking & Tracking & Control SystemControl System

S TLM S CMD

S TLM,CMD

SELENE Mission Instruments

VLBI Radio-source on the Relay satellite (lunar gravitational field)Relay Sat. transponder (Far-side gravity field using 4-way range rate from ground station to Orbiter via Relay Satellite)

Gravitational field distribution

Relay satellite

VLBI Radio-source on the VRAD satellite (lunar gravitational field)(VRAD = VLBI RADio source)

Gravitational field distribution

VRAD satellite

High Definition Television camera (Images of the earth and the lunar surface, for public outreach)

Imaging

Lunar Magnetometer (Magnetic field measurement, accuracy 0.5 [nT])Plasma Imager (Observation of plasmasphere of the earth, XUV to VIS)Charged Particle Spectrometer (Measurement of high-energy particles)Plasma Analyzer (Charged particle energy and composition measurement)

Surface & Space environment

Terrain Camera (High resolution stereo camera, spatial resolution 10 [m])Lunar Radar Sounder (apparent depth 5 [km], resolution 100 [m])Laser Altimeter (height resolution 5 [m], spatial resolution 1600 [m])

Surface structure

Spectral Profiler (Continuous spectral profile λ= 0.5 to 2.6 [µm], spatial resolution 500 [m])

Multi-band Imager (UV-VIS-IR imager, λ= 0.4 to 1.6 [µm], 9 bands, spatial resolution 20 [m])

Mineralogical distribution

X-ray Spectrometer (Al, Si, Mg, Fe distribution, spatial resolution 20 [km])Gamma-ray Spectrometer (U, Th, K distribution, resolution 160 [km])

Chemical elements distribution

Main Orbiter

Instrument and CharacteristicsObservation

Environment Radio Science (Detection of the tenuous lunar ionosphere)

Mass 50Kg , Elliptical Orbit 100km×2,400kmAttitude stabilization :Spin-stabilized

Relay satellite

Mass 50Kg , Elliptical Orbit 100km×800kmAttitude stabilization :Spin-stabilized

VRAD satellite

1553B data bus systemMDR recording capacity:100Gbit

Data Handling Subsystem

1 Wing Rigid panel (with 30 deg cant)Power Generation :More than 3,200W(End of Life,β＝0deg)Un-regulated Bus voltage:52.8V～32.6VBattery : Main-Orbiter ;35Ah Ni-Cd Battely×16cells×8units

Solar Power&Electrical Power Subsystem

Number of Thrusters: 500N×1, 20N×12, 1N×8Propellant: Nitrogen Tetroxide 335Kg

Hydrazine 742Kg

Propulsion Subsystem

Attitude Control:Zero momentum systemThree-axis controlAttitude Control Accuracy :±0.1deg(three-axis)4 Skew Reaction Wheel

Attitude and Orbit Control Subsystem

Antenna/Frequency:HGA/X-band(mission),S-ant/S-band(telemetry&command)BitRate:1000bps(command),2K/40Kbps(telemetry),10Mbps(mission data)

TelemetryTracking&Command

Main Orbiter

Specification and CharacteristicsSUB System

SELENE Bus Component and RVstar

Objective : stereoscopic observations.Two cameras : for foresight and for backsight. Stereo images from two directions.Camera : monochrome, 10m resolution @100km altitude,

20 degree sight of view (35km on the moon).

Terrain Camera (TC)

Objective (1):the subsurface structure of the moon

The large amplitude RF pulse are transmitted bythe dipole antenna (30m tip to tip)Analysing the echo pulse, >> the subsurface structure.

Objective(2) : radio waves from the sun, the earth and the planets andplasma waves in the solar wind.

Lunar Radar Sounder (LRS)

Echo

Antenna(15m * 4)

LMAG (Lunar Magnetometer)

Objective : observation of the lunar and its surrounding magnetic field.>> the magnetization structure of the lunar magnetic anomalies and the lunar interior.Magnetometer : on the top of the 12m long mast (to avoid interference magnetic field caused by the main orbiter.)

magnetometer

Objective : Global gravity field measurement with two methods.(the doppler measurement / the differential VLBI)

Analysing the orbital disturbance by differential VLBI>> improve the lunar gravity model.Four way doppler measurement>> measure the farside gravitational field.

RSAT (Relay Satellite Transponder)/ VRAD (VLBI Radio source)

S/X-band dipole antenna(toward Earth)

solar arrays

Main orbiter

4-way Doppler Measurement.

Doppler Measurement

EarthRstar,Vstar

Rstar

Near-SideFar-Side

Differential VLBI

SELENE Development Status

Mission PlanMission Plan_ Transfer Orbit via Phasing loop ・Transfer orbit via 2 revolutions (350,000X 1,000km) phasing loop around the Earth

・Make an adjustment maneuver of revolution period and check system performance in this phasing loop.

・Phasing loop contributes reduction of mission risk

・System analysis (orbit, fuel, maneuver plan etc.) : In Progress

SELENE Development StatusTransfer Orbit via Phasing loopTransfer Orbit via Phasing loop


Mission Profile


Main OrbiterMain Orbiter_ First Assembly Test: Finished (2004/03)

_ Qualification Tests of component: Finished

_ PFM proto-flight Test :In Progress

・Electrical Performance Test (before panel assembly):In Progress・refurbishment of component: planned・ Electrical Performance Test (after panel assembly):Planned・Vibration Test/ Thermal vacuum test:planned・Final electrical performance test:planned

_ Launch Site acceptance test:In Tanegashima Space Center(Planned)


SELENE PFM ProtoSELENE PFM Proto--flight test flow flight test flow

Main OrbiterCarry-In TKSC

Equipment install onthe Panel

Electrical Peformancetest(before panel assmbly)

System Integration(withoutSAP,HGA,RVS)

First Electrical Peformance test(after panel assmbly)Compatibility test with Ground Equipment

Lower ModuleCarry-in TKSC

UPS leak check/mass flowperformance test

LM magneticmeasurement test

System magneticmeasurement test

SystemElectro-magneticcompatibility Test

System Integration(Full configuration)

Alignmentmeasurement test

Mass property test

Vibration test Acoustic testPyro Explosion Shocktest

Thamalvalance/vaccum test

Final Electrical Peformance test

Visual Inspection Transpaort to TNSC


SELENE Rvstar ProtoSELENE Rvstar Proto--flight test flow flight test flow

Rstar/VstarCarry-InNEC/TOSHIBA KEIHINFactrory

Equipment installon the Panel

First ElectricalPeformance test

Mass propertymesurement

Acoustic test

Vibration test(Sine,Random)

ThemalBalance/Vaccumtest

Final ElectricalPeformance test

Visual InspectionIntegrate toSELENE system


Rstar/Vstar MASS property test Rstar/Vstar MASS property test


Rstar/Vstar Acoustic Test Rstar/Vstar Acoustic Test

Summary SELENE Project Status

Configuration of SELENE Configuration of SELENE (without Solar Array Paddle and (without Solar Array Paddle and Rstar/Vstar)Rstar/Vstar)

--SELENE is the Japanese large-scale lunar orbiting mission.

-SELENE measures the lunar surface and solar-terrestrial environment .

-SELENE project team adopts Transfer orbit via Phasing loop

-JAXA is now conducting Proto-flight test of SELENE PFM towards launch in 2007 .

-These data are used for studying the Lunar origin and evolution, and future utilization of the Moon.

SELENE Data Products for future lunar utilization

H. Hoshino, H. Minamino, M. Kato and Y. Takizawa

Japan Aerospace Exploration Agency (JAXA)SELENE Project Team

SELENE Data Products for future lunar utilization

•One of the objectives of SELENE scientific mission is to “research the possibility of future utilization of the Moon”.

•The following maps which may be used for especially future lunarIn-situ Resource Utilization (ISRU) can be produced from SELENE Data Products.

(1) Maps of water ice

(2) Maps of permanent polar shadow/sunshine areas, polar DEM

(3) Maps of surface composition (ex. ilmenite-rich region)

Expected GRS (Gamma-Ray Spectrometer) spectrum

•For example, Berezhnoy et al. (2003) said that “At 80 hours of accumulation time it is possible to detect hydrogen if H content is higher than 0.03 [wt %]”.

Direct evidence of hydrogen

1: H (2223.3[keV]), 0.05[wt %]Al (2210.4[keV])

2: S, O

Si (2235.4[keV])GRS

A. A. Berezhnoy et al., LPS XXXIV, #1210, 2003.


•GRS (Gamma-Ray Spectrometer) is capable of measuring the amount of gamma ray emitted by hydrogen in response to excitation by cosmic rays if water ice exists in ~30 [cm] subsurface. The distribution and the abundance of water ice in the permanent shadow areas around the polar regions will be determined. *GRS is a high-purity Ge detector and will measure gamma rays with energies from 100 to 10,000 [keV].

•SP (Spectral Profiler) may detect the secondary scattered light whose infrared spectrum will be absorbed at the surface frost area. *SP is capable of measuring the light intensity reflected at the lunar surface in continuous wavelength ranging 500-1,000 [nm] (VIS), 900-1,700 [nm] (NIR1) and 1,700-2,600 [nm] (NIR2).

radiance/refrectance ratio map (NIR) [future study, observation is only proposed.]SP

global map of gamma ray intensity for HydrogenGRS

global map of the relative abundance for HydrogenGRS

Contents of products

secondary scattered light

crater in the polar regionsurface frost area

(2) Maps of permanent polar shadow/sunshine areas

100km

Spacecraft orbit

TC Swath 35km(FOV 20°）

MI Swath 19.3km(FOV 11°）

SP Foot print 500m X 500m（FOV 0.29°）

SP VIS : 500 - 1000 nmSP NIR1: 900 - 1700 nmSP NIR2:1700 - 2600 nm(Resolution 6 - 8 nm)

Line profiling

Operation with MI or TC

Swath 35km (FOV 20°）Overlap betweensequential strips

100km

60km

10m/pixel＠100km430 – 850 nm

B/H = 0.6

Spacecraft orbit

Two slant telescopes

Push-broom imagery

19.3km/swath (FOV 11°）

100km

Spacecraft orbitTwo nadir telescopes

Push-broom imagery

MI-NIR: 62m/pixel@100km

•1050 ±15nm•1000 ±15nm•1550 ±25nm•1250 ±15nm

MI-VIS: 20m/pixel@100km

• 415 ±10nm• 750 ± 5nm•1000 ±20nm• 950±15nm• 900±10nm

TC MI

SP

(2) Maps of permanent polar shadow/sunshine areas

•TC (Terrain Camera) and MI (Multi-band Imager) will identify the permanent shadow/sunshine areas around the polar region by monitoring the seasonal illuminated variation of the lunar surface. *MI is a UV-VIS-NIR imager (VIS: 415, 750, 900, 950 and 1000 [nm] (Si-CCD detector), NIR: 1000,1050,1250 and 1550 [nm] (InGaAs detector)).

VIS Reflectance mapMI

MI Reflectance mapMI

TC (morning, evening) reflectance map

at the low solar elevation angle (single-eyed observation)

TC

Contents of products

TC

MI

(inside part)

(2) Polar DEM (Digital Elevation Model)

•Polar DEM will be produced by processing TC stereoscopic data.

•LALT (Laser ALTimeter) has a function of slant ranging in one side direction of 40 degrees aside from nadir on both polar regions to achieve altimetry near 90 degrees in latitude. *LALT measures accurately the topographical undulations and altitudes on the lunar surface by transmitting laser beam and measuring the time of reflection.

•LRS (Lunar Rader Sounder) data with synthetic aperture technique will also be used for making polar region surface topography image.

Topographic Image of the Lunar North/South Pole

(5 degrees in radius)

LALT

TC stereoscopic vision dataTC

Grid Topographic Data of the Lunar North/South Pole

(5 degrees in radius)

LALT

Polar region surface topography imageLRS

Contents of ProductsLALT

(3) Maps of surface composition (ilmenite-rich region)

•The search of oxygen-rich soil is also important. FeTiO3 is one of the candidates for oxygen production using H2, F2, CH4, etc. The map of ilmenite-rich region will be produced from the data set of Fe and Ti. *XRS (X-Ray Spectrometer) examines the fluorescent X ray (0.7-8[keV]) emitted from the substances on the lunar surface and detects the amounts of the elements (Mg, Al, Si, Fe, etc.) constituting the substances on the surface.

Fe map (except polar regions) [wt %]XRS

Fe/Si ratioXRS

global map of gamma ray intensity for Fe, TiGRS

global map of the relative abundance for Fe, TiGRS

MI Reflectance mapMI

VIS Reflectance mapMI

NIR Reflectance mapMI

Contents of Products

Ilmenite map will be produced by integrating these MI products. XRS

Summary

•SELENE data are used for studying the lunar origin and evolution, and future utilization of the Moon.

•The following maps which may be used for especially future lunar In-situ Resource Utilization (ISRU) can be produced from SELENE Data Products.


(2) Maps of permanent polar shadow/sunshine areas, polar DEM

(3) Maps of surface composition (ex. ilmenite-rich region)

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