Post on 15-Jan-2016
1 NASA/HQ April, 2009
THEMIS
ARTEMIS
ARTEMIS(a spin-off of THEMIS)
and Exploration
2 NASA/HQ April, 2009
THEMIS
ARTEMIS Overview
• Mission Concept
• Science Objectives
• Lunar Mission Phases
• Synergistic Science
• Benefits to Exploration
• Cost Benefit Analysis for Exploration
3 NASA/HQ April, 2009
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
4 NASA/HQ April, 2009
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
5 NASA/HQ April, 2009
THEMIS
ARTEMIS
6 NASA/HQ April, 2009
THEMIS
ARTEMIS THEMIS Other Media Successes
www.pbs.org/wgbh/nova/sciencenow/0304/02.html
7 NASA/HQ April, 2009
THEMIS
ARTEMIS
• THEMIS = THEMIS baseline + ARTEMIS
Extended Phase:Mission Concept
P1, P2 will freeze in 2010, unless placed into stable orbits about the moon
8 NASA/HQ April, 2009
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
9 NASA/HQ April, 2009
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
10 NASA/HQ April, 2009
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
11 NASA/HQ April, 2009
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
12 NASA/HQ April, 2009
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
13 NASA/HQ April, 2009
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
14 NASA/HQ April, 2009
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