Sami K. SolankiSami K. Solanki

Max Planck Institute forMax Planck Institute forSolar System ResearchSolar System Research

with thanks to Richard Marsden and Eckart Marschwith thanks to Richard Marsden and Eckart Marsch

Solar Orbiter

Introduction to the Solar Orbiter

Mission in ESA’s science program with a strong NASA contribution (launch plus instruments)

It will orbit close to the Sun & will leave the ecliptic

It will carry a strong suite of in-situ and optical instruments.

Strong interaction with NASA’s Inner Heliosphere Sentinals mission Solar Orbiter + Sentinals = HELEX

Currently scheduled launch of Solar Orbiter in 2015, Sentinals to follow in 2017

Solar Orbiter Top-level Science Goals

Determine the properties, dynamics and interactions Determine the properties, dynamics and interactions of plasma, fields and particles in the near-Sun of plasma, fields and particles in the near-Sun HeliosphereHeliosphere

Investigate the Links Between the Solar Surface, Investigate the Links Between the Solar Surface, Corona, and Inner HeliosphereCorona, and Inner Heliosphere

Explore, at all Latitudes, the Energetics, Dynamics, Explore, at all Latitudes, the Energetics, Dynamics, and Fine-scale Structure of the Sun's Magnetized and Fine-scale Structure of the Sun's Magnetized AtmosphereAtmosphere

Probe the Solar Dynamo by Observing the Sun's Probe the Solar Dynamo by Observing the Sun's High-Latitude Field, Flows, and Seismic WavesHigh-Latitude Field, Flows, and Seismic Waves

Localize Sources of Energetic Particles

Problem: Multiple SEP events easily separated close to the Sun as demonstrated by Helios, but are all mixed together by the time the SEPs reach Earth orbit

Wibberenz & Cane, ApJ, 650, 1100, 2006

0.3AU

1 AU

Linking Corona and Heliosphere

Solar Orbiter will enable us to link specific sources to their in-Solar Orbiter will enable us to link specific sources to their in-situ manifestations and to discriminate between spatial and situ manifestations and to discriminate between spatial and

temporal variations, especially through temporal variations, especially through quasi-quasi-heloisynchronous observationsheloisynchronous observations

Global solar corona and solar wind

SOHO

Ulysses

High Resolution & Coupling Science

SOHO

SOHO/EIT TRACE Solar Orbiter

1850 km pixels 350 km pixels 80 km pixels

Owing to proximity, Solar Orbiter will resolve scales ~150 km in the photosphere, the chromosphere and the corona

highest resolution ever reached in the EUV ideal for studying the coupling between these layers

Polar Convection and Dynamo

SOHO

Solar Orbiter will allow us to study the:

• magnetic structure and evolution of the polar regions

• detailed surface and subsurface flow patterns in the polar regions

• the workings of the polar dynamo through these investigations

Mission & System Requirements

Orbit: Reach orbit with perihelion between 0.2 and 0.25 AU Increase inclination with respect to solar equator to:

30º minimum for nominal mission 35º minimum for extended mission

Launcher: 2 options studied (2015 with 2017 back-up):

Soyuz-Fregat 2-1b from Kourou NASA-provided launch

Payload:Mass: 140 kg max. incl. maturity marginsPower: 180 W incl. maturity margin

Trajectory for 2015 launch

Trajectory for 2015 launch

Science Payload

Instruments selected via a competetive process (AO was open to the international scientific community)

Philosophy: Resource-efficient instrumentation (e.g., remote-

sensing instruments to be "1 metre, 1 arcsec resolution" class)

Constrained resource envelope

Successful proposals have been selected by ESA and NASA, but not yet publicly announced

Baseline Mission (PDD)

Instruments Mass

kg

Power

W

Rate

kbps

Plasma Package (SWA) 17.5 15 14

Fields Package (MAG +RPW + CRS) 15 9.5 5.8

Particles Package (incl. neutrons, γ-rays, and dust)

16 15.5 3.6

Visible Light Imager & Magnetograph (VIM)

30 35 20

EUV Imager (3 telescopes incl. FSI) 15.5 25 20

EUV Spectrometer 16 25 17

Spectrometer/Telescope Imaging X-rays (STIX)

4.5 4 0.2

Coronagraph (COR) 21 25 5

Total 135.5 154 85.6

VIM: Visible-light Imager and Magnetograph

2 telescopes that provide:

• High resolution & full-disk magnetic vector and intensity.

• Local helioseismology data

Hinode images: same resolution as VIM

Extreme UV Imager (EUI)High-resolution coronal &

chromospheric imaging (75 km pixels) vs. 350 km pixels of TRACE & AIA

Full-Sun (174Å & 304Å) and high-resolution telescopes (Lyα & 174Å)

EUV Spectrometer (EUS)

High-resolution plasma diagnostics (150 km pixels)

5 times higher resolution than SUMER

Diagnostics cover broad temp. range

Off-limb capabilities out to 3 R

Global strategy - Goals

Out of Sun-Earth line/multi-point observations [3-D star,

Earth-directed ejecta]

High latitude [polar processes and dynamo,

3-D star/CMEs]

Close up/co-rotation [link Sun and inner heliosphere]

High resolution, Earth Orbit

[fundamental processes]

Global strategy - Missions

NASA STEREO [2006]

Solar Orbiter

Solar Orbiter

Sentinels

Hinode [2006]

SDO [2009]

NASA STEREO

[2006]