Solar Orbiter (SolO) 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 an eccentric orbit moving as close as 45 solar radii (RS), or 0.21 astronomical units (AU), placing it inside Mercury's perihelion of 0.3075 AU.
A Comparison of the size of the Sun as seen from Earth (left, 1 AU) and the Solar Orbiter Spacecraft (0.284 AU,right)
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?
Observation packages of baseline mission definitions:
- Heliospheric in-situ instruments
- Solar Wind Analyser (SWA): To measure solar wind 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): To provide simultaneous UV (121.6 nm), and polarized visible light imaging of the corona
- Heliospheric Imager (SoloHI): To image quasi-steady and transient flows of the solar wind
See also 
External links