Solar Orbiter
Encyclopedia
Solar Orbiter is a planned Sun
-observing satellite
, under development by the European Space Agency
(ESA). The main mission scenario is a launch by an Atlas V
from the Kennedy Space Center
in Florida
in January 2017. SolO is intended to perform detailed measurements of the inner heliosphere
and nascent solar wind
, and perform close observations of the polar regions of the Sun, which is difficult to do from Earth
, both serving to answer the question 'How does the Sun create and control the heliosphere?' The Solar Orbiter will make observations of the Sun from distances as close as 60 solar radii (RS), or 0.284 astronomical unit
s (AU), placing it inside Mercury
's perihelion of 0.3075 AU.
Heliospheric in-situ instruments:
Solar remote-sensing instruments:
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
-observing satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
, under development by the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...
(ESA). The main mission scenario is a launch by an Atlas V
Atlas V
Atlas V is an active expendable launch system in the Atlas rocket family. Atlas V was formerly operated by Lockheed Martin, and is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance...
from the Kennedy Space Center
Kennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
in January 2017. SolO is intended to perform detailed measurements of the inner heliosphere
Heliosphere
The heliosphere is a bubble in space "blown" into the interstellar medium by the solar wind. Although electrically neutral atoms from interstellar volume can penetrate this bubble, virtually all of the material in the heliosphere emanates from the Sun itself...
and nascent solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
, and perform close observations of the polar regions of the Sun, which is difficult to do from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, both serving to answer the question 'How does the Sun create and control the heliosphere?' The Solar Orbiter will make observations of the Sun from distances as close as 60 solar radii (RS), or 0.284 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s (AU), placing it inside Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
's perihelion of 0.3075 AU.
Scientific objectives
- How and where do the solar wind plasma and magnetic field originate in the corona?
- How do solar transients drive heliospheric variability?
- How do solar eruptions produce energetic particle radiation that fills the heliosphere?
- How does the solar dynamo work and drive connections between the Sun and the heliosphere?
Payload
Observation packages of baseline mission definitions:Heliospheric in-situ instruments:
- Solar Wind Analyser (SWA): To measure solar windSolar windThe solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
properties and composition - Energetic Particle Detector (EPD): To measure suprathermal ions, electrons, neutral atoms, as well as energetic particles in the energy range from few keV/nuc to relativistic electrons and ions up to 100 MeV (protons) and 200 MeV/nuc (heavy ions)
- Magnetometer (MAG): will provide detailed measurements of the magnetic field
- Radio and Plasma Wave analyser (RPW): To measure magnetic and electric fields at high time resolution
Solar remote-sensing instruments:
- Polarimetric and Helioseismic Imager (PHI): To provide high-resolution and full-disk measurements of the photospheric magnetic field
- EUV full-Sun and high-resolution Imager (EUI): To image various layers of the solar atmosphere
- EUV spectral Imager (SPICE): To provide spactral imaging of solar disk and corona, characterize plasma properties at the Sun
- X-ray spectrometer/telescope (STIX): To provide imaging spectroscopy of thermal and non-thermal solar X-ray emission from 4 to 150 keV
- Coronagraph (METIS/COR): To provide broad-band, narrow-band, and polarized imaging of the corona
- Heliospheric Imager (SoloHI): To image quasi-steady and transient flows of the solar wind