Orbiting the Sun

Solar Orbiter

Following the launch of POLAR in 2016, Art of Technology is back in space on-board Solar Orbiter that was launched from the Kennedy Space Center in Cape Canaveral on 10th February 2020, and is now making its way towards the sun… yes, towards the sun.

Solar Orbiter is an ESA space probe and part of the Cosmic Vision programme that will study the Sun at close quarters. Flying to within 42 million kilometres (26 million miles) of the Sun’s surface. Solar Orbiter will come closer to the Sun than any other probe before… a mere quarter of the distance between the earth and the Sun. Solar Orbiter will make numerous gravity assisted flybys of Venus (and one of Earth) over the course of its mission to adjust its orbit, bringing it closer to the Sun and also out of the plane of the Solar System to observe the Sun from progressively higher inclinations. This will enable the spacecraft to take the first ever images of the Sun’s unchartered polar regions from high-latitudes, crucial for understanding how our Sun works.

During its closest approaches to the Sun, which bring Solar Orbiter within the orbit of Mercury and just 42 million kilometres from the Sun, the spacecraft will also be travelling fast enough to study how magnetically active regions evolve for up to four weeks at a time. Solar Orbiter surfaces facing the Sun will have to withstand temperatures above +500°C while the shaded areas will undergo the temperature of the interstellar vacuum of -180°C.

With its suite of complementary instruments, Solar Orbiter will study the plasma environment locally around the spacecraft (in-situ data collected by 4 instruments) and collect remote data from the Sun (remote sensing by 6 instruments including STIX and SPICE), linking the activity of the Sun with the space environment of the inner solar system. This extremely important mission will also investigate the Sun-Earth connection, helping us to better understand and predict periods of stormy space weather.

Solar Orbiter was launched from NASA’s Kennedy Space Center in Cape Canaveral, Florida on 10 February 2020
Photo: ESA – S. Corvaja

Solar Orbiter accommodates a set of in-situ and remote-sensing instruments, with a total payload mass of 180 kg.

  • STIX-Telescope-Exploded-View

The Spectrometer Teclescope for Imaging X-rays (STIX) includes an Imager (left) and Detector Module (right) (Photo: FHNW)

The STIX Instrument

Spectrometer Telescope for Imaging X-rays (STIX)

Art of Technology was awarded a contract by the European Space Agency (ESA) for the design, development, production and supply of the Detector Electronics Module (DEM) used in the STIX instrument, a Swiss experiment, funded by the Swiss Space Office and one of ten instruments on-board the Solar Orbiter.

Developed and built under the leadership of the University of Applied Sciences Northwestern (FHNW), the STIX instrument will provide observations of the sun with unprecedented sharpness and direct measurements of solar winds and charged particles close to their point of origin. The new orbit will allow study of the far side of the Sun that cannot be seen from Earth… and for the first time, the polar regions.

STIX will contribute to understanding the mechanisms behind the acceleration of electrons at the Sun and their transport into the interplanetary space. STIX will also play a key role in linking remote-sensing and in-situ observations on Solar Orbiter with imaging spectroscopy of solar thermal and non-thermal X-ray emissions providing quantitative information on the timing, location, intensity and spectra of accelerated electrons as well as of high temperature thermal plasmas, which are mostly associated with flares or micro-flares in the solar corona and chromosphere.

The STIX instrument is divided into three subsystems operating in two different thermal environments: Feedthrough with two X-ray windows, Grids with aspect system and the Detector Electronics Module (DEM). The Grids and DEM are located inside the spacecraft, while the feedthrough is surrounded by the heat-shield and one of the windows is directly exposed to the Sun. The spacecraft interior temperature is kept at +50°C and -20°C in hot and cold operational modes respectively, while the CdTe detectors located inside the DEM are kept at around -20°C by a cold element provided by the spacecraft.

  • STIX - Telescope Exploded

Detector Electronics Module (DEM)

  • STiX-DEM - DeE Alignment

Optical Alignment of the Detector Electronics (DeE-Q1)

Detector Electronics Module (DEM)

The Detector Electronics Module includes cold electronics with 32 detectors (aligned behind each collimator of the imager to perform photon-counting and spectroscopy in the hard X-ray range, as well as analogue buffers, filters and temperature sensors) connected to a cold element at −20°C, and warm front-end electronics (including analogue-to-digital converters, voltage regulators, test pulse generator, filters) possibly at +50°C.

The Instrument Data Processing Unit (IDPU) includes Power Supply Units (PSU), FPGAs to control the Detectors (configuration and event readout) and all ADC (for aspect system photodiode, temperature and photon energy signal encoding) as well as flight application software for scientific data processing and Space-wire communication with the spacecraft.

Our Contribution

Design, development, production, integration and test ofSystem design support
  • Detector Electronics (DeE)
  • High Voltage Electronics (HVE)
  • Back-End Electronics (BEE)
  • Support and review of flight design layout (PSU)
  • Interface to Power Supply Unit (PSU)
  • Interface to Instrument Data Processing Unit (IDPU)
Support instrument integration and testingElectronic Ground Support Equipment (EGSE)
  • Power Supply Unit (PSU)
  • Instrument Data Processing Unit (IDPU)
  • Supervision of functional testing during production
  • Supervision of functional testing during integration
  • Supervision of EMC testing,
  • Supervision of Qualification & Acceptance testing
  • Production and test of electronics and test adaptors

The SPICE Instrument

Stratospheric Particle Injection for Climate Engineering

SPICE is a high resolution imaging spectrometer operating at extreme ultraviolet wavelengths that will address the key science goals of Solar Orbiter by providing quantitative knowledge of the physical state and composition of the plasmas in the solar atmosphere, in particular investigating the source regions of outflows and ejection processes which link the solar surface and corona to the heliosphere.

SPICE is designed to study the structure, dynamics and composition of the transition region and corona by observing key emission lines on the solar disk on timescales from seconds to tens of minutes. A key aspect of the SPICE observing capability is the ability to quantify the spatial and temporal signatures of temperature and density tracers to unravel the inter-relationship between the chromosphere, coronal structures, coronal mass ejections, the solar wind and the low corona.

Observing the intensities of selected spectral lines and line profiles of two extreme ultraviolet (EUV) wavelength bands (70.4 – 79.0 nm / 97.3 – 104.9 nm), SPICE will derive temperature, density, flow and composition information of a wide range of plasmas (ionised atoms) formed in the Sun’s atmosphere at temperatures from 10’000 to 10’000’000 Kelvin.

SPICE Slit Change Mechanism (Photo: Almatech SA)

The Slit Change Mechanism (SCM)

The Slit Change Mechanism located at the heart of the SPICE instrument provides four interchangeable slits of different widths that are necessary for the dispersion of the light from the Sun. The image of the sun formed by the off-axis parabolic mirror is sent to the four slits. Each of the slits selects a portion of the solar image and passes it onto two detector arrays and can be individually selected into the active slit position depending upon the science activities to be conducted.

Our Contribution

  • Review functional design, schematics and layout of electronics
  • Production and test of electronics
  • EMC safety check and testing

Acknowledgement

Art of Technology is proud to be one of the industrial partners to the scientists for the STIX and SPICE instruments and would like to extend our thanks to Prof. Dr. Samuel Krucker (STIX Instrument Principal Investigator), Almatech SA  and the Swiss Space Office for their trust, support and the opportunity to participate and contribute to these exciting and extremely important experiments.