SMILE SXI
Soft X-ray Imager
SXI is the X-rax instrument on the Chinese-European Mission SMILE
(Solar wind Magnetosphere Ionosphere Link Explorer)
ROLE OF THE INSTITUTE FOR DATA SCIENCE
> Thermal design of SXI
> Imaging software
> Data analysis and interpretation
Project lead at FHNW: Säm Krucker
Partners: University of Leicester (PI Steven Sembay) , Koegl Space, Space Acoustics, FHNW IPP, ZHAW
Funding: Swiss Prodex
Start: December 2018
Launched: May 19, 2026
Keywords: space sciences, heliophysics, space weather, Smile mission
SUMMARY
The space mission SMILE orbits the Earth in an elliptical pathway from 5000 km above the Earth to one third of the distance to the moon. While previous studies used observations from within or around Earth’s magnetic field, SMILE takes images and movies from outside of Earth’s protective magnetic shield. We see the region where the solar wind slams into the Earth’s magnetic field. With these global and time dependent images, SMILE will revolutionize our understanding of the influences of space weather on our planet.
Space weather
Space Weather triggers
beautiful polar lights.
But it can also cause
damage on Earth.
Tiny charged particles are constantly streaming away from the Sun – the solar wind. It travels through the solar system at a speed of about 400 km per second.
When the Sun’s magnetic fields build up too much tension, they release the energy in spectacular explosions. Millions of tons of matter are hurled into space and collide with planets or space probes that happen to be in the way.
With such explosions, the solar wind becomes a solar storm with speeds of up to 800 km per second. The high-energy particles (X-rays and gamma rays) even reach the speed of light. On Earth, we don’t feel the solar wind because it bounces off the magnetic bubble surrounding our planet. However, a solar storm can disrupt the Earth’s Earth’s magnetic field. This results in beautiful auroras. The particles from the Sun collide with the gases in the Earth’s atmosphere, causing them to glow.
Auroras have also been observed on Venus, Mars, Jupiter, and Saturn, but not on Mercury, because it has no atmosphere.
Are solar storms dangerous?
Here on Earth, we are safe. In space, however, it’s a different story. When scientists detect the light from an X-ray burst on the Sun, they know that astronauts have only 20 minutes to take shelter in the space station to protect themselves from the high-energy, deadly particles.
Airplanes must be rerouted to avoid high radiation levels over the poles.
Satellites can be damaged or knocked out of orbit. This affects us, as we are becoming increasingly dependent on satellite technology: telecommunications, broadcasting, weather services, navigation…
Space weather effects on the ground can include damage and disruption to power distribution networks, increased pipeline corrosion, and degradation of radio communications.
Predicting Space Weather
Currently, this is only possible to a limited extent. Precise predictions would be necessary to take timely and targeted precautions to protect exposed technology from a solar storm. Some pressing questions regarding space weather are:
- When do solar storms occur?
- How does a solar storm move through the solar system?
- Why does it accelerate instead of slowing down?
- Can we calculate whether a solar storm will hit Earth or pass it by?
- How do the particles interact with the Earth’s atmosphere?
The fact that everything in the solar system moves at different speeds and that the Sun rotates on its own axis doesn’t make things any easier.
What happens to other planets that are struck by a solar storm? We know that not all of them have a magnetic shield. Why, and how do they differ from Earth?
PEOPLE @FHNW WHO WORK ON SXI
PEOPLE @FHNW WHO WORKED ON SXI BEFORE
- Oliver Studer, until 2024
- Florian Wirz, until 2024
- Anya Liebendörfer, until 2021
- Manela Dreier, until 2021
- Nico Gradwohl, until 2020
- Matthias Fankhauser, until 2019
OPEN RESOURCES AND RESULTS
Presentation SMILE SXI at Transfer Transparent
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
Initial Presentation SMILE SXI
EARLY MORNING LAUNCH PARTY @HSI
SMILE SXI was successfully launched from Kourou on May 19, 2026, 5.52 CET. SXI scientists, an impressive crew of professionals from diverse media, including Keystone, SRF, AZ and a Tele M1, and a few others made it to Windisch by 5.30, some walking long distances where public transportation was not running, yet.
VISUALS AND AUDIO
GENERAL INFORMATION
Every day, Earth faces a relentless attack from the Sun. A usually steady rain of tiny but fierce particles known as the solar wind can sometimes be interrupted by much bigger blasts, just like the one shown at the beginning of this video.
Luckily, we have a defence: Earth’s magnetic field. This shield that Earth holds up against the solar wind and coronal mass ejections is all that prevents our thriving planet from turning into a barren wasteland.
And finally, we’ve reached a moment in history where our scientific tools and technologies are advanced enough to get to the bottom of how exactly this magnetic shield works.
Our latest investigator is a special space mission called Smile. Smile is equipped with a unique toolkit to give us our first complete look at the interaction between the solar wind and Earth.
It will be the first-ever mission to look at the edge of Earth’s magnetic field with X-ray vision, to uncover where and how our shield is hit.
At the same time, it will use ultraviolet vision to record the northern lights for 44 hours at a time, helping us understand how exactly Earth responds to solar storms.
Smile will send the data it collects back down to Earth, mainly to a ground station in O’Higgins, Antarctica. Scientists will dig deep into this data to find out more.
They will tackle big questions like: What happens where the solar wind meets Earth’s magnetic shield? What causes magnetic glitches on the dark side of Earth? And how can we predict the most dangerous threats in advance? Credit: CAS/ESA
The SMILE spacecraft will carry two imaging instruments – the wide field of view soft X-ray imager (SXI) and an auroral ultraviolet imager (UVI) – and an in situ measurement package that will work in conjunction with the imagers to explore the properties of the solar wind. Image credit: CAS/ESA
The Soft X-ray Imager SXI is one of four instuments onboard the SMILE spacecraft. It is a wide-field lobster-eye telescope with two X-ray-sensitive CCD detectors observing emissions from charged particles hitting the Earth’s magnetospheric boundaries. The FHNW astro-helio group will build the radiator for cooling the X-ray detectors and develop the imaging software. The four CAD-images above show the SXI instrument and the radiator. Image credit: U. Leicester, UK
Official video of the ESA-Chinese Academy of Sciences SMILE mission presented by NSSC. View video on YouTube
SMILE is a joint China – ESA mission to study the impact of the solar wind on the Earth’s magnetosphere. Artist’s conception by ESA/ATG medialab
Auroras (polar lights) are one example of solar wind impacting the Earth. However, charged particles from the sun may affect our planet in many ways. Technology in space, e.g. satellites, is particularly at risk. Image: ESA/NASA
AFTER THE DELIVERY
Our hardware was delivered to ESA at the end of 2020, but that’s not the end of the story. Following some reports and images of the subsequent tests, some at FHNW and others at premises of the ESA, the University of Leicester and in Shanghai.
Tests and images by Stefan Koegl, Koegl Space
December 7, 2023: Another door closed! … This time it is the door of the thermal vacuum chamber at FHNW with the VenSpec-H Filter Wheel Mechanism Breadboard inside.
After successful vibration tests in November, the thermal vacuum tests on the Filter Wheel Mechanism Breadboard have been started this week and are well on the way. Due to its high technical maturity also a lifetime test will be carried out after the thermal vacuum testing.
On the picture: the Filter Wheel Mechanism Breadboard in the thermal chamber at FHNW. It was developed by HSLU, FHNW and KOEGL Space which are members of the Swiss Consortium for VenSpec-H Instrument on ESA’s EnVision mission.
November 27, 2023: Door closed! … the door of the Thermal Vaccum Chamber at RAL was closed last Friday with the flight model of the SMILE SXI instrument inside. After successful vibration tests in October, the Thermal Vacuum test campaign of the SMILE SXI flight model has started this week, conducted by the instrument lead University of Leicester (UK) supported by Space Acoustics from the Swiss team in charge of the thermal engineering. On the picture in the front row: the cryogenic radiator developed by our Swiss team, comprising FHNW, ZHAW, Space Acoustics and KOEGL Space.
February 7, 2023: The flight model of our cryogenic radiator was accepted. At the University of Leicester, the radiator is now to be ttached to the soft X-ray imager SXI. SXI is the largest instrument that will be launched into space in 2025 on board the Chinese-European solar mission SMILE.
As every step in the development of such an instrument has to be meticulously documented, we have images of it in very good quality.
April 21, 2022: The SMILE payload module ready for the thermal- and the vibration tests, featuring the X-ray telescope SXS. The Swiss contribution is the radiator assembly behind the red protective device. See our logos from FHNW, ZHAW, Space Acoustics and KOEGL Space.
Video with the highlights from the test campaign of the Smile payload module at Airbus Madrid and the European Space Research and Technology Centre (ESTEC) in Noordwijk, October 2021 – March 2022. For some tests, the red protective device has been removed, and you can see the white radiator assemby produced at FHNW, for example at minute 3:08.
Video: ESA/Airbus/Lightcurve Films
November 26, 2020: After assembling the Structure and Thermal Model (STM) of our Radiator Assembly (RadA) in the summer, we were able to successfully carry out the shock and vibration test at the FHNW in October / November. Despite the corona-related restrictions, everything went very well.
After various other tests, the RadA STM was cleaned and packed.
Today we sent the associated data package with more than 30 documents for acceptance on 01.12.20 by the University of Leicester (UoL) and ESA / Prodex. Delivery is planned for 07.12.2020.
The MLI (Multi Layer Insulation) for the SXI STM, which is part of the SXI Thermal Subsystem under our technical leadership, was accepted on 10.11.20 and will be delivered to UoL in the next few days.
This will complete all hardware deliveries for the SMILE SXI STM under our responsibility. At the beginning of 2021, we expect to start Phase C Extension, which is currently under discussion with Prodex / SSO.
June 4, 2025: The gold-cloaked Smile spacecraft in the Maxwell Test Chamber at Europe’s largest satellite test facility, ESTEC as part of its ‘space environment testing’ phase.
The Maxwell chamber’s 9 m-high walls, lined with foam spikes, absorb signals and sound, mimicking the void of space. Once its main door is sealed, Maxwell’s metal walls form a ‘Faraday Cage’, screening out all external electromagnetic signals.
In this image, we see engineers from ESA, the Chinese Academy of Sciences, and European Test Services preparing Smile for electromagnetic compatibility testing.
Like most spacecraft, Smile is very sensitive. It is designed to pick up very weak magnetic field signals, whilst transmitting a lot of data down to Earth with high-power antennas. Engineers use electromagnetic compatibility tests to check that the spacecraft works well when all its electronics are switched on, making sure that there is no ‘crosstalk’ between them.
Another important part of the electromagnetic compatibility tests is to make sure that Smile is safe to launch inside the Vega-C rocket that will take it to space. The rocket and its associated ground systems also carry lots of electronics; we need to be sure that they are not disturbed by Smile, and vice versa.
During the space environment testing phase, engineers are taking Smile through tough checks, needing it to pass with flying colours before being allowed out on its own. Other tests include making sure that the entire system can operate properly in the vacuum of space, that its solar arrays will unfold correctly after launch, and that the violent launch won’t shake the spacecraft apart. Credit: ESA – M. Roos