slide1 n.
Download
Skip this Video
Download Presentation
THEMIS Extended Phase = THEMIS baseline + ARTEMIS Vassilis Angelopoulos, and the ARTEMIS team

Loading in 2 Seconds...

play fullscreen
1 / 15

THEMIS Extended Phase = THEMIS baseline + ARTEMIS Vassilis Angelopoulos, and the ARTEMIS team - PowerPoint PPT Presentation


  • 146 Views
  • Uploaded on

ARTEMIS Contributions to Planetary Exploration. THEMIS Extended Phase = THEMIS baseline + ARTEMIS Vassilis Angelopoulos, and the ARTEMIS team. Overview. THEMIS Extended Phase (FY10, FY11, FY12) Extended THEMIS Baseline (3 probes) + ARTEMIS (2 probes)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'THEMIS Extended Phase = THEMIS baseline + ARTEMIS Vassilis Angelopoulos, and the ARTEMIS team' - garth-church


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

ARTEMIS Contributions to Planetary Exploration

THEMIS Extended Phase

=

THEMIS baseline + ARTEMIS

Vassilis Angelopoulos, and the ARTEMIS team

slide2

Overview

  • THEMIS Extended Phase (FY10, FY11, FY12)
    • Extended THEMIS Baseline (3 probes) + ARTEMIS (2 probes)
    • ARTEMIS = Acceleration Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun (Heliospheric Objectives, as accepted)
      • The magnetosphere
      • The solar wind
      • The lunar wake
    • ARTEMIS Planetary Capabilities
      • Surface composition and weathering
      • Exospheric composition, structure, and dynamics
      • Electric fields and dust
      • Interior structure
      • Support for other planetary missions (LRO, LADEE, GRAIL, etc.)as solar wind monitor, provide low energy particle spectrum andcharacterize source populations of particle radiation
slide3

EFIs

EFIa

SCM

ESA

SST

Mission Ops

UCB

FGM

Tspin=3s

ARTEMIS payload, operations concept

Data volume: 100Mbits/day

Orbit periods at moon: ~1 day

Relay:

3hr daily

DSN

BGS

Products:2hr latency

Probe instruments:

ESA: ElectroStatic Analyzer (i,e: 3eV-25keV; Carlson & McFadden)SST: Solid State Telescopes (i,e: 25-1000keV; Larson)FGM: FluxGate Magnetometer (0-128Hz; Glassmeier, Auster & Baumjohann)SCM: SearchCoil Magnetometer (1Hz-4kHz; Roux & LeContel)

EFI: Electric Field Instrument (0-8kHz; Bonnell & Mozer)

slide4

ARTEMIS mission phases

Insertion: FY10; Science: FY11,12

slide5

ARTEMIS Heliophysics objectives

Insertion FY10; Science: FY11,12

FY10: Translunar injection

FY11-12: 6mo Lissajous + 18 mo Lunar

slide6

For purposes of addressing planetary objectives:Periselene of P1 can be lowered to 100km (P2 remains high)

Orbit stable for >3years; longer with little fuel

P2

P1

slide7

Issues

  • Removing 11Hz noise in magnetometerDue to internal EMI from particle sectoring
      • Not a show stopper
  • Need to change energy ranges to measure pickup ionsBest to have fine dE/E.
      • Not mission critical
slide8

Heliophysics from the Moon

  • In the Magnetosphere, study:
    • Particle acceleration
    • Reconnection: 3D character andglobal effects
    • Turbulence: Drivers and effects
  • Reveal 3D distant tail, dynamics
  • First two-point measurements;from gyroradius to RE scales
  • In the Solar Wind, study:
    • Particle acceleration at shocks
    • Nature and extent of reconnection
    • Inertial range of turbulence
  • First two-point measurements, at 1-10RE
the electrodynamic environment of the moon lunar wake
The Electrodynamic Environmentof the Moon: Lunar Wake

The Moon is an ideal plasma laboratory for studying magnetized plasmas.

The simple geometry of the Moon and its absorbing boundary produces a system that can be readily modeled with computers.

This allows the codes to be tested and the physics to be understood.

ARTEMIS measurements are particularly useful for such tests.

9

dust levitation in electric fields
Dust Levitation in Electric Fields

Apollo observers saw dust elevated above the lunar surface to possibly high altitudes.

LADEE will probably have a dust detector, but has no capability of measuring the solar wind electric and magnetic fields.

ARTEMIS measures the solar wind velocity, the interplanetary magnetic field and hence the solar wind electric field. It also can measure surface potentials with electron reflectometry.

ARTEMIS plus LADEE will enable us to determine the response of charged lunar dust to the lunar and solar wind electric fields.

LADEE

ARTEMIS-1

ARTEMIS-2

10

slide11

Lunar Exosphere

ARTEMIS mass spectrometryof pickup ions assumed “protons”

  • Apollo’s ALSEP package contained a suprathermal ion detector (SIDE) that detected ions accelerated by electric field toward lunar surface.WIND observations confirmed presence of heavy ions around moon.
  • Temporal history of ion fluxes on SIDE suggested that the moon might be episodically outgassing. Alpha particle observations of localized concentrations of radon also support this viewpoint.
  • This observation needs confirmation. If true, there may be a source of lunar volatiles at low latitudes, not just at the poles.
  • ARTEMIS has an ion detector and measures the solar wind electric field so it can test the SIDE hypothesis of an outgassing moon.

V,y

H+

V,x

He+

H2O+

S+

Solar Wind

ARTEMIS-2

Exospheric

Pickup

Ion

ARTEMIS-1

Hartle et al., 2005

slide12

ARTEMIS and Lunar Surface

  • Lunar Surface:
    • Study composition and distribution of sputtered ions
    • Understand crustal magnetic fields, surface charging
    • Remotely sense surface properties of lunar regolith
  • Result:
    • Advance our understanding of fundamental plasma interactions with planetary surfaces.
  • Using first of kind:
    • …two point measurementsof ions and electrons near the Moon, with unprecedented energy coverage and resolution; beyond LP electron reflectometry capability

Secondary electrons

measured by Lunar

Prospector [Halekas et al. 2008]

Trace sputtered ions

back to lunar surface

ARTEMIS

Secondary and photo-electrons

accelerated from charged lunar surface

reveal regolith surface properties

interior structure of the moon
Interior Structure of the Moon

Apollo orbital measurements provided evidence of an iron core of about 400 km radius.

Lunar Prospector made similar (single instrument) measurements and confirmed the Apollo subsatellite result.

Two-point measurements are needed to go beyond the current two-layer model of the interior electrical conductivity.

ARTEMIS will provide measurements of both the “exciting” field and the resulting induced magnetic field at about 100 km over a range of frequencies and sound the electrical conductivity profile above the core.

P1

P2

Core?

13

slide14

ARTEMIS and Planetary

  • In support of LRO:
    • ARTEMIS can provide comprehensive monitoring of Lunar Space Environment
    • Complements LRO/CRATER providing measurements below 6MeV
    • Note: ARTEMIS has been already supporting LRO via White Sands G/N testing
  • Supports NAS’s Scientific Content of Exploration of the Moon to:
    • Understand the lunar atmosphere
  • In support of all missions
    • ARTEMIS provides comprehensive monitoring of plasma conditions and lunar surface electric fields
    • Allows study of the response of the lunar exosphere and dust to external drivers
    • ARTEMIS provides solar wind monitoring
summary
Summary

ARTEMIS consists of two well-instrumented spacecraft measuring the Moon’s plasma and magnetic environment.

ARTEMIS can determine

How dust is levitated

The interior electrical conductivity of the Moon

Whether the Moon has significant outgassing episodes

The effect of the exploration program on the lunar exosphere

The fundamental physical processes at work in a magnetized plasma

ARTEMIS is effectively a new mission with high science return at low cost

Can provide high value science return to the community

15