Solar orbiter

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Solar orbiter

A 1: 1 model of the Solar Orbiter used for testing, the heat shield in black
Mission goal Investigation of the solar wind
Client European space agencyESA ESA
Launcher Atlas V (411)
construction
Takeoff mass approx. 1800 kg
Instruments

STIX, PHI, EUI, C-METIS, SoloHI, SPICE, EPD ( SIS, STEIN, EPT-HET, LET ), SWA, MAG, RPW

Course of the mission
Start date February 10, 2020, 04:03 ( UTC )
launch pad Cape Canaveral , SLC-41
 
 Feb 2020 begin
 
 Dec. 2020 Swing-by on Venus
 
 Aug 2021 Swing-by on Venus
 
 Nov 2021 Swing-by on earth
 
 Sep 2022Template: future / in 2 years Swing-by on Venus
 
 Feb 2025Template: future / in 4 years Swing-by on Venus
 
 Dec. 2026Template: future / in 5 years Swing-by on Venus
 
 March 2028Template: future / in 5 years Swing-by on Venus
 
 Jun. 2029Template: future / in 5 years Swing-by on Venus
 
 Sep 2030Template: future / in 5 years Swing-by on Venus
 

The Solar Orbiter ( SolO ) is a space probe of the European Space Agency (ESA), which was realized in cooperation with NASA . It is the first mid-range mission of ESA's Cosmic Vision 2015-2025 science program.

The main objective of the mission is to study the solar wind . The Solar Orbiter will be able to record structures in the solar corona from a size of 35 kilometers. The mission is initially funded for seven years and can be extended by at least two to three years if it is successful.

The start date originally planned for July 2017 has been postponed several times. The probe was completed in October 2019; the launch took place on February 10, 2020 (American local time on February 9) with an American Atlas V rocket from Cape Canaveral Air Force Station .

Construction of the probe

ESA hired Astrium UK as prime contractor to build the probe for EUR 300 million. ESA calculated that the solar orbiter mission would cost 500 million euros, plus a further 400 million US dollars from NASA for the rocket and the part of the payload provided by NASA: an instrument and a sensor on the probe.

Structure and functionality

Due to the proximity to the sun, the side of the probe designed as a heat shield must be oriented towards the sun. For the heat shield, which also contains components made from animal charcoal , temperatures of around 500 ° C are expected at the minimum distance from the sun. There are openings for the instruments in the heat shield, the protective caps of which are only opened when necessary to collect images and measurement data. The two solar generators, each with three solar panels, are turned out of the sun near the sun. This reduces the projected area that interacts with the solar radiation in order to keep the temperature of the solar cells and the panels within acceptable ranges. A Li-ion battery provides additional energy at various points on the mission, such as B. at darkening during planetary flyby. The space probe requires a maximum of approx. 1100 W electrical power to operate. The takeoff mass should be approx. 1800 kg. The probe has a chemical drive, the originally planned ion drives , which were developed for BepiColombo , have been canceled.

Remote sensing instruments on board

The remote sensing instruments examine the surface and atmosphere of the sun:

Flight model of the imager & detector electronics module of the "Spectrometer / Telescope for Imaging X-rays (STIX)"
  • Spectrometer / Telescope for Imaging X-rays (STIX)
    STIX is a spectrometer / telescope designed for the observation of X-rays. The observed energy range should be around 4 to 150  keV with an angular resolution of 7  arc seconds . The remote sensing instrument STIX is supposed to observe the intensity, spectrum, time and origin of X-ray sources in order to e.g. B. to draw conclusions about electrons that are accelerated to high energies in the solar atmosphere. STIX works with an image technology that measures and stores individual Fourier components . This data should later be sent to earth and reassembled into an image.
    STIX consists of three parts: the X-ray windows (not shown in the picture on the right), the imager with two sets of 32     collimators built into tungsten , and the corresponding 32 CdTe X-ray detectors, which are located in the cuboid detector electronics module behind the Imager are located. The transmission through the pair of tungsten grids containing the collimators is very sensitive to the direction of incidence of the X-rays . The measured relative counting rates of the detectors behind the grids therefore allow conclusions to be drawn about the position and energies of the X-ray source .
Properties of STIX
Energy range: 4 - 150 keV
Energy resolution: 1 - 15 keV (depending
on the photon energy)
Max. Angular resolution: 7 arc seconds
Field of view: 2 °
Time resolution: ≥ 0.1 s
  • Polarimetric and Helioseismic Imager (PHI)
    PHI is designed to provide images of the sun's surface (photosphere) in visible light. In addition, the instrument should determine the strength and direction of the magnetic fields as well as the flow velocity of the plasma on the sun's surface. From this information one expects, among other things, conclusions about the plasma movements inside the sun. The instrument consists of two telescopes: the Full Disc Telescope will have the entire solar disk in view if the mission progresses as planned, while the High Resolution Telescope will focus on a small section. When the sun is as close as possible, the High Resolution Telescope can display structures with a size of 150 kilometers.
  • Extreme-Ultraviolet Imager (EUI)
    EUI is supposed to provide images of the solar corona in extremely short-wave UV light. The recordings are made every second so that the instrument can make highly dynamic processes visible. EUI consists of three reflecting telescopes. While one of them keeps the entire solar disk in view, the other two should offer high-resolution images of individual regions.
  • The Coronagraph METIS
    Metis is a coronograph that covers the sun and part of the solar corona. It should enable a view of the transition region between the hot corona and the innermost heliosphere.
  • The Heliospheric Imager (SoloHI) is supposed to observe the disturbances of visible light by the electrons of the solar wind. Thereby one would like to determine the mass movements in the corona.
  • Spectral Imaging of the Coronal Environment (SPICE)
    SPICE is a spectrograph that splits the UV radiation from the solar corona into its various wavelengths. In this way, the instrument is intended to obtain information about the temperatures and speeds of the solar plasma in the corona. It should also be possible to determine the frequency of some elements.

In-situ instruments on board

The in-situ instruments examine the immediate vicinity of the spacecraft:

  • The Energetic Particle Detector (EPD) examines suprathermal ions , electrons , neutral atoms and energetic particles in the range from a few keV to relativistic electrons and ions up to 100 MeV (protons) and 200 MeV / nucleon (heavy ions). EPD consists of the instruments Suprathermal Ion Spectrograph (SIS), Suprathermal Electrons, Ions and Neutrals Telescope (STEIN) and Electron and Proton Telescope-High Energy Telescope (EPT-HET).
  • The Solar Wind Plasma Analyzer (SWA) measures the composition and properties of the solar wind .
  • The magnetometer (MAG) measures the magnetic field .
  • Radio and Plasma Waves (RPW) measures magnetic and electric fields with a high temporal resolution.

Participating research institutions

Among others responsible for the development and construction of the individual instruments are:

Mission flow

The Solar Orbiter was launched into an elliptical orbit around the Sun. By means of a ground and eight Venus - Swing-bys he should initially gradual approach and then swung into an increasingly poleward inclined orbit by 2030 the sun. At the end of the primary mission about seven years after the start, it should have an orbit inclined by 24 ° and at the end of the extended mission a 33 ° to the ecliptic , in which it approaches the sun to within 42 million kilometers.

The probe should descend on an orbit with a 168-day orbit and, thanks to the inclination of the orbit, can observe the poles of the sun from an angle of up to 33 °, compared to a maximum of 7 ° when observing from Earth and 80 ° for the Ulysses space probe (1990– 2009). The closest distance to the Sun should be 60 R S ( solar radii ) or 0.28 AU .

See also

Web links

Commons : Solar Orbiter  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b Chris Gebhardt: ESA Solar Orbiter mission rides on ULA Atlas V to study the Sun . Nasaspaceflight.com, 9./10. February 2020.
  2. ↑ Solar Orbiter: Mission to the sun and inner heliosphere to investigate the relationships between sun-heliosphere and sun-earth through high-resolution observations. In: Max Planck Institute for Solar System Research. Max Planck Institute, accessed on December 13, 2019 .
  3. ↑ a b c d e f Satellite Missions - Solar Orbiter Mission. In: Earth Observation Portal. ESA - eoPortal, accessed on December 13, 2019 .
  4. ↑ a b Summary. In: ESA - Science & Technology - Solar Orbiter. ESA, accessed December 13, 2019 .
  5. ↑ a b ESA contracts Astrium UK to build Solar Orbiter, Date: April 26, 2012, Accessed: April 27, 2012
  6. ↑ a b Stephen Clark: Astrium UK picked to build Solar Orbiter spacecraft. Spaceflight Now, April 26, 2014, accessed April 27, 2014 .
  7. ↑ Jonathan Amos: Solar Orbiter: Sun mission blasts off. In: BBC News. February 10, 2020, accessed February 10, 2020 : "We've had to develop lots of new technologies in order to make sure that the spacecraft can survive temperatures of up to 600C," said Dr Michelle Sprake, a systems engineer with European aerospace manufacturer Airbus. "One of the coatings that makes sure the spacecraft doesn't get too hot is actually made out of baked animal bones," she told BBC News. "
  8. ↑ a b The Solar Orbiter built by Airbus will initially set course for the Florida sun. In: Airbus Home - Media. Retrieved December 13, 2019 .
  9. ↑ Polarimetric and Helioseismic Imager (PHI) . Max Planck Institute for Solar System Research, accessed on May 10, 2020.
  10. ↑ Extreme-Ultraviolet Imager (EUI) . Max Planck Institute for Solar System Research, accessed on May 10, 2020.
  11. ↑ SPICE on Solar Orbiter |. Retrieved November 12, 2019 .
  12. ↑ Solar Orbiter: Mission to the sun and inner heliosphere. Max Planck Institute for Sun Systems Research, accessed on May 12, 2020 .
  13. ^ Leibniz Institute for Astrophysics Potsdam: Solar Orbiter (SolO). In: website. Retrieved January 18, 2020 .
  14. ^ Solar Orbiter. In: ESA . Retrieved February 12, 2020 .