Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Solar Orbiter A
high-resolution mission to the Sun and inner heliosphere Slide 2
Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Study team E. Marsch
Max-Planck-Institut fr Aeronomie, Germany E. Antonucci Osservatorio
Astronomico di Torino, Italy P. Bochsler University of Bern,
Switzerland J.-L. Bougeret Observatoire de Paris, France R.
Harrison Rutherford Appleton Laboratory, UK R. Schwenn
Max-Planck-Institut fr Aeronomie, Germany J.-C. Vial Institut
dAstrophysique Spatiale, France ESA: Study Scientists: B. Fleck,
ESA/GSFC and R. Marsden, ESA/ESTEC Study Manager: O. Pace,
ESA/ESTEC Solar System Mission Coordinator: M. Coradini, ESA/HQ
Slide 3 Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Solar
Orbiter rationale The Sun's atmosphere and heliosphere are -
uniquely accessible domains of space, - excellent laboratories for
studying in detail fundamental processes common to astrophysics,
solar and plasma physics Remote sensing and in-situ measurements, -
much closer to the Sun than ever before, - combined with an
out-of-ecliptic perspective, promise to bring about major
breakthroughs in solar and heliospheric physics Slide 4 Solar
Orbiter F2/F3 Presentations, 12 Sep 2000 Close-up observations of
the Sun Imaging and spectroscopy, due to proximity, with an order
of magnitude improvement over past missions SOHO/EIT TRACE Solar
Orbiter 1850 km pixels 350 km pixels 35 km pixels Slide 5 Solar
Orbiter F2/F3 Presentations, 12 Sep 2000 Sources of solar wind and
magnetic network Solar wind emanates from supergranular cell
boundaries in coronal hole. The Solar Orbiter line- of-sight allows
detailed analysis of the polar outflows Co-rotation will enable
steady magnetic linkage Linking corona and heliosphere Slide 6
Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Basic questions Why
does the Sun vary and how does the solar dynamo work? What are the
fundamental processes at work in the solar atmosphere and
heliosphere? What are the links between the magnetic field
dominated regime in the solar corona and the particle dominated
regime in the heliosphere? These questions are basic to
astrophysics in general Slide 7 Solar Orbiter F2/F3 Presentations,
12 Sep 2000 Solar Orbiter firsts explore the uncharted innermost
regions of our solar system study the Sun from close-up (45 solar
radii or 0.21 AU) fly by the Sun tuned to its rotation and examine
the solar surface and the space above from a co-rotating vantage
point provide images of the Suns polar regions from heliographic
latitudes as high as 38 Slide 8 Solar Orbiter F2/F3 Presentations,
12 Sep 2000 Novel orbital design Projected trajectory - closer to
the Sun - out of the ecliptic Slide 9 Solar Orbiter F2/F3
Presentations, 12 Sep 2000 Scientific goals determine in-situ the
properties and dynamics of plasma, fields and particles in the
near-Sun heliosphere investigate the fine-scale structure and
dynamics of the Suns magnetised atmosphere, using close-up,
high-resolution remote sensing identify the links between activity
on the Suns surface and the resulting evolution of the corona and
inner heliosphere, using solar co-rotating passes observe and fully
characterise the Suns polar regions and equatorial corona from high
latitudes Slide 10 Solar Orbiter F2/F3 Presentations, 12 Sep 2000
New perspectives Co-rotation remote-sensing observations In-situ
diagnostics of the innermost heliosphere Close-up high-resolution
imaging and spectroscopy Observations from out of the ecliptic
plane These unique scientific perspectives form the basis for our
scientific case Slide 11 Solar Orbiter F2/F3 Presentations, 12 Sep
2000 Co-rotation observations: linking corona and heliosphere q
Global solar corona and solar wind SOHO Ulysses Solar Orbiter will
discriminate spatial from temporal variations Slide 12 Solar
Orbiter F2/F3 Presentations, 12 Sep 2000 Co-rotation observations:
linking corona and heliosphere Boundaries and fine structures Solar
Orbiter will determine relationships between coronal and solar wind
structures on all scales correlate in-situ particle characteristics
with coronal sources identify ion compositional boundaries Slide 13
Solar Orbiter F2/F3 Presentations, 12 Sep 2000 In-situ measurements
of the inner heliosphere Plasma microstate Temperature anisotropies
Ion beams Plasma instabilities Interplanetary heating Solar Orbiter
will make high-resolution plasma measurements (10 ms) Proton
velocity distributions (Helios) Slide 14 Solar Orbiter F2/F3
Presentations, 12 Sep 2000 In-situ measurements of the inner
heliosphere Magnetohydrodynamic waves and turbulence Spectrum of
Alfvnic fluctuations: Steepening and dissipation! Solar Orbiter
will show how MHD turbulence varies and evolves spatially, what
generates Alfvn waves in the corona, how the turbulence is
dissipated. Slide 15 Solar Orbiter F2/F3 Presentations, 12 Sep 2000
In-situ measurements of the inner heliosphere Solar energetic
particles Solar Orbiter will provide novel information on shock,
flare and CME related particle acceleration, by virtue of proximity
to the Sun co-rotating orbit (long- term magnetic linkage) Slide 16
Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Close-up
observations of the solar atmosphere Solar Orbiter will resolve the
highly structured solar atmosphere an order of magnitude better
than presently possible (both images and spectra) Slide 17 Solar
Orbiter F2/F3 Presentations, 12 Sep 2000 Close-up observations of
the solar atmosphere An illustration of the multi-thermal nature of
the solar atmosphere Solar Orbiter will observe loops and resolve
their fine structure and map plasma flows Slide 18 Solar Orbiter
F2/F3 Presentations, 12 Sep 2000 The Suns polar regions and
equatorial corona The polar magnetic fields and the dynamo What are
the detailed flow patterns in the polar regions? What is the
magnetic field structure in the polar regions? Slide 19 Solar
Orbiter F2/F3 Presentations, 12 Sep 2000 The Suns polar regions and
equatorial corona Coronal mass ejection longitudinal extent and
global distribution Viewing from out of the ecliptic plane allows
the Solar Orbiter to study - CME longitudinal spreads - CME
directions - the global distribution of CMEs Slide 20 Solar Orbiter
F2/F3 Presentations, 12 Sep 2000 The Suns polar regions and
equatorial corona Solar luminosity variations Solar Orbiter will
address questions such as: Does luminosity vary globally, or is
brightening at the equator balanced by polar darkening? What is the
angular distribution of radiance from active regions? The Sun is
the only star for which we can determine the 3-D luminosity
contribution. Slide 21 Solar Orbiter F2/F3 Presentations, 12 Sep
2000 Solar Orbiter payload The science goals require a
sophisticated suite of remote sensing and in-situ instruments. The
mission profile demands that the instruments be low-mass,
autonomous and thermally robust. The thermal aspects have demanded
quite mature instrument concepts at this early stage. Slide 22
Solar Orbiter F2/F3 Presentations, 12 Sep 2000 Heliospheric in-situ
package Slide 23 Solar Orbiter F2/F3 Presentations, 12 Sep 2000
Heliospheric in-situ package First in-situ detection of neutral
(hydrogen) atoms from the Sun First measurement of near-Sun dust
(e.g., from grazing comets) First detection of low-energy solar
neutrons from flares Slide 24 Solar Orbiter F2/F3 Presentations, 12
Sep 2000 Remote-sensing instruments Slide 25 Solar Orbiter F2/F3
Presentations, 12 Sep 2000 Visible-light Imager and Magnetograph
(VIM) Vector magnetograph consisting of: - 25 cm diameter Gregorian
telescope - 5 cm diameter full disc telescope (refractor) -
Filtergraph optics (two 50 mm Fabry- Perot etalons) High-resolution
images (35 km pixels), Dopplergrams (helioseismology) and
magnetograms of the photosphere Slide 26 Solar Orbiter F2/F3
Presentations, 12 Sep 2000 Extreme UV Spectrometer (EUS) - 120 mm
Ritchey- Chretien feeding spectrometer - light-weight carbon fibre
structure with SiC optics - thermal control includes radiators,
light rejection and shield High-resolution plasma diagnostics (75
km pixels) Slide 27 Solar Orbiter F2/F3 Presentations, 12 Sep 2000
Extreme UV Imager (EUI) High-resolution imaging (35 km pixels) of
the corona - EUV imaging, simultaneously in 3 part-Sun and and one
full- Sun Gregorian 20 mm telescopes - long baffle system for
thermal control of each telescope - common pointing mechanism Slide
28 Solar Orbiter F2/F3 Presentations, 12 Sep 2000 UV and Visible
Light Coronagraph (UVC) Imaging of the visible and UV emission line
corona - imaging of visible, H I and He II corona using off-axis
Gregorian with external occulter - resolving element down to 1200
km. Stray light Solar Orbiter F2/F3 Presentations, 12 Sep 2000
Conclusions: Solar Orbiter... q will explore unknown territory near
the Sun q will deliver the first images of the solar poles q will
provide unprecedented high-resolution observations of the Sun (>
35 km) q will correlate in-situ & remote-sensing measurements
at 45 Rs from a co-rotational vantage point q is technically
feasible (using electric propulsion) q will maintain ESAs position
at the forefront of solar and heliospheric physics...is the next
logical step towards understanding our star, the Sun.
