ARTEMIS Independent Integrated Review 1 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Science Vassilis Angelopoulos ESS/IGPP UCLA and SSL/UCB

ARTEMIS Independent Integrated Review 2 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS Overview Science Background Mission Concept Science Objectives L1 Requirements Lunar Mission Phases Science Instrument Utilization

ARTEMIS Independent Integrated Review 3 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS THEMIS: 5 satellites, Launched February 27, 2009 To Solve the Mystery of what Triggers Auroral Substorms Simulation: J. Raeder, UNH Visualization: Tom Bridgman, GSFC/SVS

ARTEMIS Independent Integrated Review 4 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS THEMIS Mission elements Five probe conjunctions along Sun-Earth line recur once per 4 days over North America. Ground based observatories completely cover North American sector; determine auroral breakup within 1-3s … … while THEMIS’s space-based probes determine onset of Current Disruption and Reconnection each within <10s. : Ground Based Observatory

ARTEMIS Independent Integrated Review 5 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS Mission overview Instrument I&T UCB Mission I&T UCB Encapsulation & launch BGS Operations UCB Probe instruments: ESA: ElectroStatic Analyzer (coIs: Carlson and McFadden) SST: Solid State Telescopes (coI: Larson) FGM: FluxGate Magnetometer (coIs: Glassmeier, Auster & Baumjohann) SCM: SearchCoil Magnetometer (coI: Roux) EFI: Electric Field Instrument (coI: Bonnell) Ground SST ESA EFIa EFIs FGM SCM T spin =3s Release CCAS

ARTEMIS Independent Integrated Review 6 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS Launch= X GSE Y GSE TH-B TH-C TH-D TH-E TH-A P1 P2 P3 P4 P5 First 10 months: Commissioning and Coast Phase Observations Angelopoulos, 2008 Space Sci. Rev.

ARTEMIS Independent Integrated Review 7 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS Dayside X GSE Y GSE First year baseline orbit (FY08) Dayside X GSE Y GSE TH-B TH-C TH-D TH-E TH-A P1 P2 P3 P4 P5 First year baseline orbit (FY08) Tail Tail Angelopoulos, 2008 Space Sci. Rev.

ARTEMIS Independent Integrated Review 8 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS

ARTEMIS Independent Integrated Review 9 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS All instruments functioning nominally –Cross calibration, inter-calibration performed during coast-phase Team discoveries in the news –Data collected per plan, widely disseminated –Science discoveries piling up 100 science papers during the last year Space Science Reviews volume in print (>20 papers) >20 GRL papers in special issue on THEMIS >20 JGR papers in special issue on THEMIS THEMIS in the news every AGU meeting –First tail season showed thinner tail than expected –Adjusted 2 nd tail season orbit to account for it –Second tail season results are a resounding success A dozen substorms collected: unique features Provide further insight into last years’ observations Anticipate mission completion on time, on budget by September 2009 Constellation available in good health for extended mission: FY10-12 Extended Phase Approved in Senior Review (Jun 09) thru Sep 2012 –THEMIS and ARTEMIS comprise the THEMIS Extended Phase –Extended Phase Contract expected to be signed March 09 –Two ARTEMIS peer reviews conducted already –Instruments checked out especially for low field conditions –ARTEMIS implementation is a “go” pending results from this review THEMIS Status

ARTEMIS Independent Integrated Review 10 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS THEMIS = THEMIS baseline + ARTEMIS Extended Phase Proposal: Mission Concept

ARTEMIS Independent Integrated Review 11 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS (P1,P2) in FY10,11,12: Mission Concept FY10: Translunar injection FY11-12: 6mo in Lissajous orbits + 17 mo in Lunar orbits

ARTEMIS Independent Integrated Review 12 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Science Objectives, #1 In the Magnetosphere, study: –Particle acceleration: X-line or O-line? –Reconnection: 3D character; global effects –Turbulence: Drivers and effects Result: –Reveal 3D distant tail, dynamics In conjunction with: –Solar wind monitors: ACE, WIND, STEREO –Inner magnetosphere monitors: Cluster, Geotail, FAST Using the first: –Two point: dX, dY measurements –…at scales from ion gyroradius to several R E –Even single point measurements are critical in this region

ARTEMIS Independent Integrated Review 13 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS Using first of a kind: –…two point measurements at scales 1-10 R E, ideal for study of particle evolution in shocks, at foreshock and inertial range of turbulence –WIND can replace one of two probes in this study In the Solar Wind, study: –Particle acceleration at shocks –Nature and extent of elusive low-shear reconnection –Properties of inertial range of turbulence Result: –Advance our understanding of particle acceleration and turbulence in Heliosphere In conjunction with: –Other solar wind monitors: ACE, WIND, STEREO ARTEMIS is: –High-fidelity solar wind monitor –In beacon mode if requested ARTEMIS Science Objectives, #2

ARTEMIS Independent Integrated Review 14 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS At the Moon/Wake: –Study 3D structure and evolution of wake –Understand particle acceleration at wake –Understand wake refilling under various SW conditions Result: –Advance our understanding of wakes at planetary moons, plasma void refilling around large objects (Shuttle, ISS, Hubble) Using first of a kind: –…two point measurements at scales R E, ideal for two- point correlations within wake and between wake and solar wind –Comprehensively instrumented satellites have never studied wake from various vantage points, thus even single point measurements are critical. ARTEMIS Science Objectives, #3

ARTEMIS Independent Integrated Review 15 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Science Objectives Summary A cceleration, R econnection and T urbulence and E lectrodynamics of M oon’s I nteraction with the S un (ARTEMIS) will be the first Heliophysics mission to study with comprehensive instrumentation: Particle acceleration, reconnection and turbulence –In the solar wind –In the magnetosphere Wake formation and refilling –In the solar wind (supersonic) –In the magnetosheath (subsonic) ARTEMIS requires one probe (minimum) plus a solar wind monitor (ACE, WIND), but will reach full mission potential with both probes, as baselined. ARTEMIS will benefit concurrent lunar missions LADEE and LRO. ARTEMIS will also advance our understanding of planetary processes and is in-line with as well

ARTEMIS Independent Integrated Review 16 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Level 1 Requirements … 4. Baseline Mission Full success requires: collection of a 50% aggregate interval from a 24 month period of particles and fields observations on two probes; select fast rate data captures from key intervals (10% time); and a total of 10 wake crossings by one ARTEMIS probe with simultaneous observations by the other ARTEMIS probe at separation distances ranging from 0.1 to 20 R E. Adherence: Data collection will be adjusted to match nominal downlink capability by reducing cadence. Data collection will include continuous, low resolution (~ once per 3 spins) Slow Survey data, 2hrs per orbit of Fast Survey data with one burst each. Wake crossings will be part of Fast Survey schedules. This volume can be accommodated in the memory and downlinked once per 2 days. This can be accomplished in 24 months with a factor of 2 margin. 5. Minimum Success Minimum success requires collection of a 50% aggregate interval from a 6 month period of particles and fields observations on one probe, including at least 5 wake crossings by one ARTEMIS probe with simultaneous observations of the solar wind by one or more Heliophysics missions (e.g. ACE, the other ARTEMIS spacecraft, Geotail, or Cluster). Adherence: Same as above, but for one ARTEMIS probe plus another Heliophysics mission during a 6 month period. This can be accomplished in 6 months with a factor of 2 margin.

ARTEMIS Independent Integrated Review 17 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Phases Translunar injection phase (Oct ’09 – Oct ’10) No Science, just get there. Note: Orbit Raise Maneuvers (ORMs) start: July 2009, in parallel with THEMIS 2 nd dayside operations (THEMIS dayside requirements met already since 1 st 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 orbital separations and separation vectors cover full parameter space

ARTEMIS Independent Integrated Review 18 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Science Analysis Wake, Solar Wind, and Tail R1 alpha R2 delta R delta R - inter s/c distance in RL alpha - angle between the inter s/c vector and the sun-moon line hours - number of hours within region. number bins - alpha = 36, delta R = 50 (5 degrees for alpha, total hours - orbits propagated for 12,000 hours (500 days)

ARTEMIS Independent Integrated Review 19 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS Science Analysis Wake only D1 D2 D1 - the distance between s/c and moon, along the sun line D2 - the distance from the s/c to the sun moon line bin size - D1/D2 = 0.25 (one quarter rl) hours - number of hours within region. total hours - orbits propagated for 12,000 hours (500 days)

ARTEMIS Independent Integrated Review 20 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS: Science Instrument Utilization All instruments will be utilized in their standard Survey and Burst Modes –Magnetometer will observe lower fields than at Earth, used in most sensitive range –Search coil will be sensitive as is, in nominal operation –ESA will be in solar wind mode, designed to resolve the SW beam –SST will be in its nominal mode If Planetary decides to fund ARTEMIS to study Planetary objectives then: –SST energy bins will be adjusted to provide better dE/E in a smaller E-range Instrument operations will be similar (if not identical) to present because: –The near-equatorial, 26hr period orbits during lunar phase and the planned downlink schedule of once per 2 days provides the same shadow, power, data through-put and thermal environment as at Earth –Instrument have already operated and tuned in the solar wind environment, the magnetosheath and magnetotail environment and are known to perform nominally Science operations (modes) will be similar (if not identical) to now since: –Slow Survey will accomplishing science requirements at low cadence –Fast Survey can accomplish pre-planned, time-based “conjunction” science peri-selene, wake crossings, or 2-probe wake crossings Opportunity science, when in SW –Bursts can accomplish high cadence science in interesting times Current triggers (Bz, Ni) expected to work to capture reconnection, wake events Sufficient flexibility exists in triggers to capture other event types if necessary (shocks, CMEs).

ARTEMIS Independent Integrated Review 21 NASA/GSFC – Feb. 24, 2009 THEMIS ARTEMIS ARTEMIS: Summary ARTEMIS is a robust mission, extending P1, P2’s life in a familiar environment ARTEMIS orbits are benign and science optimization has already been done –Current L1 minimum requirements drive minimally mission design and operations –Current L1 baseline requirements benefit from 3 years of mission optimization, and have been built into a “natural” baseline design that is also operationally optimal ARTEMIS instruments can do the job –Have been studying the same environment successfully for just over 2 years –Can be commanded to perform Survey and Burst captures in familiar methods ARTEMIS rates and volumes are commensurate with proposed science –Expecting 1/4 of data volume per data downlink capability and a Survey cadence that can fit continuous coverage, there is a factor of 2 margin that can be used to benefit low cost operations.