1 nasa/hq april, 2009 themis artemis (a spin-off of themis) and exploration

1 NASA/HQ April, 2009

THEMIS

ARTEMIS

ARTEMIS(a spin-off of THEMIS)

and Exploration


THEMIS

ARTEMIS Overview

• Mission Concept

• Science Objectives

• Lunar Mission Phases

• Synergistic Science

• Benefits to Exploration

• Cost Benefit Analysis for Exploration


THEMIS

ARTEMIS

THEMIS: 5 satellites, Launched February 17, 2007To Solve the Mystery of what Triggers Auroral Substorms

Simulation: J. Raeder, UNH

Visualization: Tom Bridgman,GSFC/SVS


THEMIS

ARTEMIS

Dayside 12008-08-08

XGSE

YGSE

First year baseline orbit (FY08)

Dayside 22009-09-16

XGSE

YGSE

TH-B

TH-C

TH-D

TH-E

TH-A

P1

P2

P3

P4

P5 Second year baseline orbit (FY09)

Tail 12008-02-02

Tail 22009-02-18

Angelopoulos, 2008Space Sci. Rev.

THEMIS Orbits : 2008-2009


THEMIS

ARTEMIS


THEMIS

ARTEMIS THEMIS Other Media Successes

www.pbs.org/wgbh/nova/sciencenow/0304/02.html


THEMIS

ARTEMIS

• THEMIS = THEMIS baseline + ARTEMIS

Extended Phase:Mission Concept

P1, P2 will freeze in 2010, unless placed into stable orbits about the moon


THEMIS

ARTEMISARTEMIS Phases

Translunar injection phase (Oct ’09 – Oct ’10)No Science, just get there.Note: Orbit Raise Maneuvers (ORMs)start: July 2009, in parallel withTHEMIS 2nd dayside operations(THEMIS dayside requirementsmet already since 1st dayside season)

Lissajous Phase(Oct ’10 – Apr ’11)Note: First 3 months: opposite sides,Next 3 months: same side

Lunar Orbit Phase(May ’11 – Sep ’12)Note: P1 retrograde, and P2 prograde, such that orbitalseparations and separationvectors cover full parameter space


THEMIS

ARTEMIS

Heliophysics ARTEMISScience Objectives

• When moon is in the Magnetosphere:– Particle acceleration at lunar environment– Reconnection: 3D character; global effects– Turbulence: Drivers and effects

• When moon is in the Solar Wind:– Seed population for solar energetic particles– Nature of elusive low-shear reconnection– Properties of inertial range of turbulence

• Near the Moon:– Study the structure and evolution of lunar wake – Understand particle acceleration at wake– Understand formation of wake electric fields


THEMIS

ARTEMIS

ARTEMIS CapabilitiesIn Planetary Science

• Dust Levitation in Electric Fields:– Study electric field near moon with proper input – Study surface electric field with reflectometry– Provide local electric field, particles to LADEE

• LADEE dust detector detects response to input

• Lunar Exosphere– Composition, distribution of:

• exospheric ions• sputtered ions• regolith

– Exospheric variations with solar activity, cycle

• Lunar Surface and Interior– Crustal magnetic fields– Conductivity depth profile– Surface charging

P1P1P2P2

LADEELADEE

Exospheric orSputtered ions

Secondary and photo-electronsreveal regolith properties

Core?

P2P1 Conductivity


THEMIS

ARTEMIS

ARTEMIS: Synergy with other lunar missions and exploration

• Supports LRO:– ARTEMIS provides comprehensive monitoring of Lunar Space Environment– Complements LRO/CRATER radiation measurements below 200keV

• Supports NAS’s Scientific Content of Exploration of the Moon by:– Understanding the lunar atmosphere,

• as function of increasing human presence at the moon

• Monitors Lunar Radiation Environment– Over solar cycle time-scales– Provides local solar wind source to:

• Ground radiation monitors• Other missions beyond LRO


THEMIS

ARTEMIS

ARTEMIS: Additional

benefits to Exploration, #1• First operational use of Lunar Lissajous orbits (LL1 & LL2), useful for:

– Staging lunar landings– Positioning communications relay stations at the moon(Station-keeping requirements thus far unknown)

• ARTEMIS’s 6 month residence in LL1&LL2 provides:– Good estimate of station-keeping fuel requirements – Proof of operational requirements (frequency/magnitude of thrusts) needed– Rapid transition of knowledge to NASA centers for future planning

LL1 LL2

~12

0000

km

To Earth

Moon

TOP VIEW

SIDE VIEW

Moon


THEMIS

ARTEMIS

ARTEMIS: Additional

benefits to Exploration, #2

• Validate NASA G/N for Current and Future Exploration Missions– Already used with White-Sands, USN; helped certify SSC, DLR dishes– Plan to validate 3-way Doppler for LRO (Launch +/- 10 days)– Can provide “calibration standard” for 3-way Doppler for future missions

• Ref: FDF-30-NNN LRO SCN Mission Readiness Tracking Proficiency Plan.doc

Test Fly

USN Ground Stations

WS1 – Prime S/Ka GS

DSN Ground Stations

DSN 34-Meter S-BandGoldstone, California

WS1 - 18-Meter S/Ka-BandWSC, New Mexico

USN 13-Meter S-Band South Point, Hawaii

SSC 11-Meter S-BandKiruna, Sweden

DLR 15-Meter S-BandWeilheim, Germany

DSN 34-Meter S-BandMadrid, Spain

USN 13-Meter S-BandDongara, Australia

DSN 34-Meter S-BandCanberra, Australia

ARTEMISP1, P2


THEMIS

ARTEMIS

• ARTEMIS: simultaneously an extended mission AND a new mission– Benefits: low risk (spacecraft already up) and efficient (delta-cost to THEMIS)– Challenge: MO&DA as funding vehicle is insufficient

• Cost:– Development

• Reconfiguring THEMIS Ground Network for DSN use• Planning Low Thrust Orbit Design and Orbit Maintenance• Contingency Planning for Translunar Injection and Orbit Insertion• Operations in LL1, LL2 orbits and Early Lunar Orbit Phase• Transition into Heliophysics when in routine Lunar Orbit

– Routine Mission/Science Operations

• Benefit (summary):– Understand Lunar Dust and Surface Environment– Monitor Radiation Hazards over Solar Cycle variations– Pathfinder for Future Landing and Relay Methods– Synergy with LRO, LADEE and Future Lunar Missions, Including Landers– Inspirational, Efficient Use of Existing NASA Resources

ARTEMIS: Cost-Benefit AnalysisFor Exploration

1 nasa/hq april, 2009 themis artemis (a spin-off of themis) and exploration

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