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Satellite Missions Catalogue

ISS: ASIM (Atmosphere-Space Interactions Monitor)

Jun 7, 2012

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High resolution optical imagers

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Space environment

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Quick facts

Overview

Mission typeEO
AgencyESA
Mission statusOperational (nominal)
Launch date02 Apr 2018
Measurement categoryOzone, Lightning Detection
Instrument typeHigh resolution optical imagers, Space environment, Lightning sensors

ISS Utilization: ASIM (Atmosphere-Space Interactions Monitor)

ASIM Payload   Launch   Mission Status    Instrument Assemblies   Ground Segment   References

ASIM is an ESA science instrument assembly to be flown on the Columbus External Platform Facility (CEPF) of the ISS (International Space Station). The ASIM concept has been proposed by DNSC [Danish National Space Center, formerly DSRI (Danish Space Research Institute)], with the objective to observe TLEs (Transient Luminous Events) that occur in the Earth's upper atmosphere accompanied by thunderstorms in the lower atmosphere. These events are known as blue jets, sprites and elves, the phenomena were first observed in 1989. The ISS is considered a perfect platform from which to enhance our knowledge of them. 1) 2) 3) 4) 5) 6) 7)

The mission is realized through ESA. In January 2007, DNSC of Copenhagen, Denmark (formerly DSRI) became DTU-Space, an institute at the Technical University of Denmark. DTU-Space provides the scientific leadership, and the Danish company, Terma, the technical leadership. Other major partners include the University of Valencia in Spain, and the University of Bergen in Norway, who are both involved in the development of the instruments.

ASIM has a number of cameras, specially designed for the International Space Station, that will observe the Earth's atmosphere. ASIM will give new insights into climate processes that will improve climate models by quantifying the effect of electrical and chemical processes at the atmosphere/space boundary. DTU Space is responsible for delivering a package of instruments (2 cameras, 3 photometers and one X- and gamma-ray detector) which will be mounted on the International Space Station. 8) 9)

ASIM will study the Earth's atmosphere as one system, from the surface of the Earth to the edge of space. The atmosphere is the thin layer that covers the planet's crust, and protects life as we journey through space. ASIM will observe extreme thunderstorms, water vapor, clouds, aerosols and their interplay in the atmosphere.

Figure 1: The nature of electrical phenomena in the atmosphere with red sprites, blue jets and elves above thunderstorms (image credit: ESA)
Figure 1: The nature of electrical phenomena in the atmosphere with red sprites, blue jets and elves above thunderstorms (image credit: ESA)

The nature of the electrical phenomena (Figure 1) and their discharges are linked to violent storms in the tropics and inject water vapor, NOx and other greenhouse gases into the stratosphere where they become part of the climate moderators. ASIM will study these effects, as well as the electrical influence on the ionosphere and the atmospheric interactions with the particle radiation from the sun. Both of which also have a direct bearing on the Earth’s climate.

ASIM, an approved ESA project, was selected in response to a call for flight opportunity issued by the Directorate of Human Spaceflight in December 2002 for external payloads to be flown to and operated onboard Columbus external platforms. The ASIM payload is planned to be taken to the ISS in the time frame 2014.

The ASIM project has been a Danish initiative, from the very start, headed in the initial phase by the Danish National Space Centre (DNSC) with participation of the universities of Valencia (Spain) and Bergen (Norway). As of 2007, the project is in Phase B planned to complete in 2009. The ASIM development is lead by TERMA, a high-tech company of Denmark. The consortium includes DNSC, Damec Research Aps, the University of Valencia, the University of Bergen, the University of Ferrara, and the University of Bologna. The production Phase C of ASIM was started in August 2010. 10) 11) 12)

The primary research objectives of the mission require the following measurements:

• Study the physics of TLEs (Transient Luminous Events). Optical detection of TLEs with high spatial- and time resolution in selected spectral bands - a comprehensive global survey

• Study the physics of TGFs (Terrestrial Gamma-ray Flashes) and their relationship with TLEs and thunderstorms. X-ray and γ-ray detection of TGFs with high time resolution and at photon energies reaching down to 10 keV

• Simultaneous optical detection of thunderstorm- and TLE activity with TGF activity. The optical instruments must view with the X- and γ-ray detector towards the nadir

• Study the coupling to the mesosphere, thermosphere and ionosphere of thunderstorms and TLEs

• Observations from space during a minimum of one year at all local times to observe seasonal and local time variations in thunderstorm, TLE, and TGF activity.

Secondary objectives based on observations:

- Spectroscopic studies of the aurora

- Studies of greenhouse gas concentrations above thunderstorms (NOx, O3)

- Studies of meteor ablation in the mesosphere and thermosphere.

Optical and X-ray measurements are used to study aurora, differential absorption of light emissions from lightning-illuminated thunderstorm clouds measured by photometers defines ozone column densities, NOx production in TLEs is to be monitored by photometer 5, and optical imaging, and photometers will be used to study meteor ablation.

The measurements include imaging in 4 auroral bands simultaneously, coupled with high time-resolution photometer observations and X-ray and γ-ray observations. The inclination of the ISS orbit at 51.6º brings the instruments over the auroral oval during periods of high solar (geomagnetic) activity when the auroral oval expands to lower latitudes. These are also periods with high auroral activity.

Figure 2: A bright red sprite appears above a lightning flash in a photo captured from the ISS (image credit: NASA, Universe Today)
Figure 2: A bright red sprite appears above a lightning flash in a photo captured from the ISS (image credit: NASA, Universe Today)

Legend to Figure 2: The sprite was observed on April 30, 2012. Expedition 31 astronauts aboard the ISS captured this photo of a red sprite hovering above a bright flash of lightning over Myanmar. 13)

Figure 3: Illustration of a TGF. Terrestrial gamma ray flashes are high energetic discharges in the Earth atmosphere, but the origin of events is unclear. This is why ASIM aims to study the correlation between the TGF with lightning and TLE (image credit: ASIM collaboration)
Figure 3: Illustration of a TGF. Terrestrial gamma ray flashes are high energetic discharges in the Earth atmosphere, but the origin of events is unclear. This is why ASIM aims to study the correlation between the TGF with lightning and TLE (image credit: ASIM collaboration)

 

A Space Window to Electrifying Science 14)

Lightning triggers powerful electrical bursts in Earth’s atmosphere almost every second. The inner workings of these magnificent forces of nature are still unknown, but a rare observation by an ESA astronaut gave a boost to the science community. A European detector will take on the challenge of hunting for thunderstorms from space next week.

As he flew over India at 28 800 km/h on the International Space Station in 2015, astronaut Andreas Mogensen directed a high-resolution camera towards a gigantic thunderstorm. He caught a blue jet repeatedly shooting up into space towards the upper layers of the atmosphere – as high as 40 km.

Figure 4: For years, their existence has been debated: elusive electrical discharges in the upper atmosphere that sport names such as red sprites, blue jets, pixies and elves. Reported by pilots, they are difficult to study as they occur above thunderstorms. ESA astronaut Andreas Mogensen on the International Space Station in 2015 was asked to take pictures over thunderstorms with the most sensitive camera on the orbiting outpost to look for these brief features (image credit: ESA/NASA) 15)
Figure 4: For years, their existence has been debated: elusive electrical discharges in the upper atmosphere that sport names such as red sprites, blue jets, pixies and elves. Reported by pilots, they are difficult to study as they occur above thunderstorms. ESA astronaut Andreas Mogensen on the International Space Station in 2015 was asked to take pictures over thunderstorms with the most sensitive camera on the orbiting outpost to look for these brief features (image credit: ESA/NASA) 15)
Figure 5: ESA astronaut Tim Peake took this image circling Earth 400 km up in the International Space Station. He commented: “Sometimes looking down on Earth at night can be kinda spooky.” The image shows lightning strikes illuminating clouds over Western Australia during a thunderstorm (image credit: ESA/NASA) 16)
Figure 5: ESA astronaut Tim Peake took this image circling Earth 400 km up in the International Space Station. He commented: “Sometimes looking down on Earth at night can be kinda spooky.” The image shows lightning strikes illuminating clouds over Western Australia during a thunderstorm (image credit: ESA/NASA) 16)

Legend to Figure 5: Although this picture was taken in Tim’s free time, the Station is used for research into elusive phenomena in the upper atmosphere during thunderstorms – red sprites, blue jets and elves. Some of the most violent electric discharges are very difficult to capture from the ground because of the atmosphere’s blocking effect. From space, astronauts can judge for themselves where to aim the camera, where to zoom in and follow interesting regions for researchers.

Astronauts often spot thunderstorms and are impressed by how much lightning they observe.



 

ASIM Payload Elements and Accommodation

The ASIM optical instruments make up the MMIA (Miniature Multispectral Imaging Array) consisting of 3 modules, each housing 2 video-rate cameras and two photometers. Two modules view in the ram-direction towards the limb and one module towards the nadir. The MXGS (Miniature X-ray and Gamma-ray Sensor) is pointed towards nadir.

In addition, there are the following subsystems:

• DHPU (Data Handling and Power Unit). The DHPU handles all electrical interfaces between ASIM and ISS. The DHPU receives two 120 V supplies, one for operational power and one for heaters. During the Dragon flight and robotic installation, a third 120 V heater supply is utilized. The DHPU converts the 120 V operational supply to 28 V instrument supplies. The 120 V heater supplies are distributed to two separate heater sets in the instruments and DHPU itself. Two sets are used since the necssary power for thermal conditioning is different in the Dragon and robotics phases compared to the mission life on Columbus.

- Apart from the 120 V supplies, the DHPU implements an ethernet connection for data link, MIL-BUS for monitored data and time synchronization with ISS, and finally a serial line which allows the ISS crew to patch the firmware of the DHPU.

Figure 6: Photo of the DHPU (image credit: ASIM collaboration)
Figure 6: Photo of the DHPU (image credit: ASIM collaboration)

• CEPA (Columbus External Payload Adapter). The CEPA is a standard structural item designed by Boeing for Columbus. It implements a standard interface to ISS called the FRAM (Flight Releasable Attachment Mechanism), which allows payloads and standard cargo like battery assemblies, to be attached on the ISS FRAM location like the Columbus External Payload Facility. The FRAM interface includes connectors which routes the electrical connections from the ISS through the FRAM system connectors on the top side of the CEPA. It is these connectors that are routed through the ASIM harness to DHPU and then distributed to the instruments.

- The CEPA provides the mechanical and electrical interface between the instrument and respectively the Columbus External Payload Facility (CEPF) and the carrier (LCC).

Figure 7: Photo of the CEPA (image credit: ASIM collaboration)
Figure 7: Photo of the CEPA (image credit: ASIM collaboration)

ASIM is designed to be accommodated on the starboard deck location of the CEPF (Columbus External Payload) platform (Figure 8).

Figure 8: Artist's view of the ASIM allocation at the Columbus External Platform Facility (image credit: ESA, DTU-Space)
Figure 8: Artist's view of the ASIM allocation at the Columbus External Platform Facility (image credit: ESA, DTU-Space)

The overall power consumption of ASIM is expected not to be 500 W (including 200W for thermal heaters). The mass of ASIM, including CEPA and the active FRAM (Flight Releasable Attachment Mechanism) is about 314 kg. The on-orbit lifetime is expected to be 2 years. ASIM has a downlink allocation of 200 kbit/s continuous data, which will be fully utilized since the instruments collect a wast amount of data, and low prioritized data cannot be fully downlinked.

 

Development Status of ASIM

• Due to a failure of the Columbus External Payload Adapter (CEPA), ASIM had to go through a complete de-integration from the failed CEPA and has started integration onto the new one sent by NASA. The ASIM schedule is still compatible with a handover to NASA at the end of November 2017, in time for launch on SpaceX CRS-14 (scheduled for early 2018). 17)


Launch

The ISS-ASIM payload was launched on 2 April 2018 (20:30 UTC) with the Falcon-9/Dragon vehicle of SpaceX CRS-14. The launch site was Cape Canaveral Air Force Station, FL. 18) 19)

This flight delivers scientific investigations looking at severe thunderstorms on Earth, the effects of microgravity on production of high-performance products from metal powders, and growing food in space. Dragon also carries cargo for research in the National Laboratory, operated by CASIS (Center for the Advancement of Science in Space), including testing the effects of the harsh space environment on materials, coatings and components; identifying potential pathogens aboard the station; and investigating an antibiotic-releasing wound patch.

Dragon is packed with 2625 kg of research, crew supplies and hardware to be delivered to the station:

ASIM (Atmosphere-Space Interactions Monitor), an ESA science instrument (314 kg) to be installed on the Columbus External Platform Facility (CEPF). ASIM surveys severe thunderstorms in Earth’s atmosphere and upper-atmospheric lightning, or transient luminous events. These include sprites, flashes caused by electrical break-down in the mesosphere; the blue jet, a discharge from cloud tops upward into the stratosphere; and ELVES, concentric rings of emissions caused by an electromagnetic pulse in the ionosphere.

RemoveDebris is an EU Framework 7 (FP7) funded research microsatellite (100 kg), low cost in-orbit demonstrator mission for future ADR (Active Debris Removal) missions. The project is a partnership of SSC (Surrey Space Center) and NanoRacks. SSC leads a consortium of partners [Airbus, Ariane Group, SSTL, ISIS (Netherlands), CSEM (Switzerland), Inria (France), Stellenbosch University (South Africa)]. This project will use the NanoRacks RemoveDEBRIS satellite platform to deploy two CubeSats as artificial debris targets to demonstrate four technologies for debris removal (net capture, harpoon capture, vision-based navigation). RemoveDebris will be deployed, via the NanoRacks Kaber system. Once in orbit the ADR experiments on board the spacecraft will be performed. 20)

MISSE-FF (Materials ISS Experiment Flight Facility) with MSCs (MISSE Sample Carriers) in the fully open position exposing samples/experiments to the harsh environment of space in LEO (Low Earth Orbit). Designed by Alpha Space and sponsored by CASIS, MISSE-FF provides a platform for testing how materials react to exposure to ultraviolet radiation, atomic oxygen, ionizing radiation, ultrahigh vacuum, charged particles, thermal cycles, electromagnetic radiation, and micro-meteoroids in the low-Earth orbit environment. MISSE-FF has a mass of ~435 kg.

The MSL SCA-GEDS-German (NASA Sample Cartridge Assembly-Gravitational Effects on Distortion in Sintering) experiment focuses on determining the underlying scientific principles to forecast density, size, shape, and properties for liquid phase sintered bodies over a broad range of compositions in Earth-gravity (1g) and microgravity (µg) conditions.

Wound Healing. NanoRacks Module 74 Wound Healing tests a patch containing an antimicrobial hydrogel that promotes healing of a wound while acting as a scaffold for regenerating tissue. Reduced fluid motion in microgravity allows more precise analysis of the hydrogel behavior and controlled release of the antibiotic from the patch.

The Canadian Space Agency’s study Bone Marrow Adipose Reaction: Red or White (MARROW) will look at the effects of microgravity on bone marrow and the blood cells it produces – an effect likened to that of long-term bed rest on Earth. The extent of this effect, and bone marrow’s ability to recover when back on Earth, are of interest to space researchers and healthcare providers alike.

Understanding how plants respond to microgravity also is important for future long-duration space missions and the crews that will need to grow their own food. The PONDS (Passive Orbital Nutrient Delivery System) arriving on Dragon uses a newly-developed passive nutrient delivery system and the Veggie plant growth facility currently aboard the space station to cultivate leafy greens. These greens will be harvested and eaten by the crew, with samples also being returned to Earth for analysis.

Orbit: Near-circular orbit of the ISS, altitude of ~400 km, inclination = 51.6º.

ASIM will be transported to ISS in the external trunk of Dragon. Once Dragon is docked to ISS Node 2, the SSRMS (Space Station Remote Manipulator System) will install ASIM in its final location on Columbus. The SSRMS will utilize the SPDM (Special Purpose Dexterous Manipulator) to grab ASIM in the Dragon trunk for extraction. The SPDM can operate the FRAM (Flight Releasable Attachment Mechanism) to detach ASIM from the trunk. The same mechanism is installed on the SPDM iteself in case ASIM needs to be fixed to the SPDM in order receive power for thermal heaters during the seven hour transfer to Columbus. On the CEPF (Columbus External Payload Facility ), ASIM will be attached to the starboard facing deck location, named EPF SDX, which also suppports the FRAM.

Figure 9: ESA's ASIM instrumentation, the center-bottom box in this image, is seen here after its installation in SpaceX Dragon’s open cargo carrier ahead of next week’s launch. On 2 April, a Falcon 9 rocket will deliver this instrument to the International Space Station to begin its mission of chasing down elusive electrical discharges in the atmosphere (image credit: 2018 Space Exploration Technologies Corp. All rights reserved) 21)
Figure 9: ESA's ASIM instrumentation, the center-bottom box in this image, is seen here after its installation in SpaceX Dragon’s open cargo carrier ahead of next week’s launch. On 2 April, a Falcon 9 rocket will deliver this instrument to the International Space Station to begin its mission of chasing down elusive electrical discharges in the atmosphere (image credit: 2018 Space Exploration Technologies Corp. All rights reserved) 21)

Additional CubeSat missions of CRS-14

Irazú, a 1U CubeSat of ACAE and ITCR (Costa Rica Institute of Technology). Irazu is a technology demonstration mission (1 kg) of ITCR.

UBAKUSAT, a joint Turkish and Japanese 3U Cubesat (4 kg) technology demonstration mission, built by ITU (Istanbul Technical University), Istanbul, Turkey in cooperation with JPF (Japan Space Forum), and KIT (Kyushu Institute of Technology).

Overview-1A, a 3U CubeSat (4.2 kg) of SpaceVR (Space Virtual Reality), a crowd-funded mission based on a Pumpkin platform, USA. The goal is to allow users to ‘experience space firsthand’ using any mobile, desktop, or virtual reality device.

1KUNS-PF (1st Kenyan University NanoSatellite-Precursor Flight), a 1U CubeSat developed at the University of Nairobi, Kenya in collaboration with “La Sapienza” University of Rome and ASI (Italian Space Agency). A technology demonstration mission.



 

Mission Status

• April 27, 2023: The International Space Station (ISS) partners have agreed to extend the operational period of the ISS. The United States, Japan, Canada and participant European Space Agency (ESA) countries will support operations until 2030, while Russia has committed to continuing station operations until 2028. 55)

• January 21, 2022: The first-of-its-kind complement of instruments dubbed the ‘space storm hunter’ hangs out in its new location outside the International Space Station in this image taken by on of the Station’s external cameras. 22)

- ASIM measures electric events in Earth’s upper atmosphere with cameras, photometers and X- and gamma-ray detectors.

Figure 10: Last week ASIM was switched off and moved by robotic arm to another spot outside the Columbus module to make room for an American payload. Now in its new location, the instrument is being activated and so far things are going well (image credit: ESA/NASA)
Figure 10: Last week ASIM was switched off and moved by robotic arm to another spot outside the Columbus module to make room for an American payload. Now in its new location, the instrument is being activated and so far things are going well (image credit: ESA/NASA)

- From its new vantage point, just next to its current one, ASIM is pointing in a different direction, slightly more towards the horizon instead of straight down. This will help researchers work out how much the atmosphere at different altitudes influences the processes of electrical discharges. It’s like viewing a firework display: one can enjoy the shapes more from the side than if one is just below the display!

- Though designed to look for electrical discharges born in stormy weather conditions in Earth’s upper atmosphere, ASIM recently detected a unique gamma-ray burst from outer space.

- The spurt turned out to be from an explosive giant flare from a magnetar located 10 million light-years away in a distant galaxy. Magnetars are a special type of neutron star – the collapsed core of what was once a supergiant star. This fortuitous observation was published in the December issue of Nature magazine.

- ASIM was built by Danish company Terma, the Danish Technical University, the University of Bergen in Norway and the University of Valencia in Spain for the European Space Agency.

• January 11, 2022: ASIM (Atmosphere–Space Interactions Monitor) is a first-of-its-kind complement of instruments on the International Space Station. Dubbed the ‘space storm hunter’, ASIM measures electric events in Earth’s upper atmosphere with cameras, photometers and X- and gamma-ray detectors. 23)

- Recently, ASIM unexpectedly detected a unique gamma-ray burst from outer space. This fortuitous observation was published in Nature magazine, less than a year after ASIM made a cover story. 24)

It Came from Outer Space

- Mounted outside the Columbus module (see Figure 18) and designed to look downwards for electrical discharges born in stormy weather conditions in Earth’s upper atmosphere, ASIM recently detected another peculiar phenomenon: a burst of photon radiation coming from another galaxy.

- The spurt turned out to be from an explosive flare from a magnetar located 10 million light-years away in a distant galaxy. Magnetars are a special type of neutron star – the collapsed core of what was once a supergiant star.

- Neutron stars spin very fast. The magnetic field of magnetars, however, is believed to be so powerful that it slows down the spin, tearing at the star’s crust and producing powerful bursts of radiation, x-ray and gamma-rays in particular.

- Thanks to its design and performance, ASIM was able to record this gamma-ray photon outburst at extremely high speeds.

- The measurements revealed unexpected, periodic “flickering” of the photon burst that will help to shed light on the physics of magnetars and the structure of neutron stars in general, one of the hottest topics in current research. The results were published in the December issue of Nature magazine.

Figure 11: Artist's impression of a magnetar. Magnetars are the cosmic objects with the strongest magnetic fields ever measured in the Universe. They are extremely magnetised pulsars – the hot and dense remnants of massive stars that throw off energetic radiation in impulsive bursts and longer outbursts on timescales from milliseconds to years (image credit: ESA)
Figure 11: Artist's impression of a magnetar. Magnetars are the cosmic objects with the strongest magnetic fields ever measured in the Universe. They are extremely magnetised pulsars – the hot and dense remnants of massive stars that throw off energetic radiation in impulsive bursts and longer outbursts on timescales from milliseconds to years (image credit: ESA)

Earth-Bound and Beyond

- Since its launch in 2018, ASIM has been keeping researchers busy. From its vantage point outside the International Space Station, ASIM has provided tons of data on ‘transient luminous events’ sporting names like blue jets and red sprites taking place above thunderstorms in the upper atmosphere.

- Aside from being a little-understood phenomenon and part of our world, these powerful electrical charges can reach into the stratosphere and above and change the chemical composition of the atmosphere with implications for the atmospheric radiation balance. The findings may help to make climate models more accurate.

- Researchers are investigating the relationship between terrestrial gamma-ray bursts, lightning and high-altitude electric discharges across all seasons, across our world and at different times of day and night. Learn more about ASIM’s mission in this handy infographic.

Figure 12: Animation of a terrestrial gamma-ray flash or TGF followed by an elve as observed by the Atmosphere-Space Interactions Monitor (ASIM), image credit: NASA
Figure 12: Animation of a terrestrial gamma-ray flash or TGF followed by an elve as observed by the Atmosphere-Space Interactions Monitor (ASIM), image credit: NASA

- This week ASIM was moved to another spot outside the Space Station to gracefully make place for an American technology demonstration payload. The move was carried out by the Station’s robotic arm.

- From its new vantage point, just next to its current one, ASIM is pointing in a different direction, slightly more towards the horizon instead of straight down. This will help researchers work out how much our atmosphere influences the processes of electrical discharges. It’s like viewing a firework display from the side: one can enjoy the shapes more than if one is just below the display.

- ASIM was built by Danish company Terma, Danish Technical University, University of Bergen in Norway and the University of Valencia in Spain for the European Space Agency.

Figure 13: ASIM logo (image credit: ESA)
Figure 13: ASIM logo (image credit: ESA)

• April 19, 2021: If you have been following International Space Station news, you know that hundreds of scientific experiments are performed in low-Earth orbit and the pace is only increasing. This is great news for scientists, especially those that have been preparing for years to send their experiment to the orbital outpost, but what does it mean for people on Earth? 25)

- If you are not into plasma nanoparticles, subjective time measurement in microgravity or traveling to Mars in the future, what benefit does space science have for you?

- Potentially a lot. Experiments performed on the International Space Station could in fact help save our planet. All one needs to do is look beyond the initial outcomes and ask: "How can this information be useful in other areas?"

- The ASIM (Atmosphere-Space Interactions Monitor) instrument was installed on the Space Station in 2018. The collection of optical cameras, photometers and an X- and gamma-ray detector is designed to look for electrical discharges originating from stormy weather that extends above thunderstorms into the upper atmosphere.

- The experiment has been very successful in describing elements that are associated with thunderstorms, such as ‘blue jets’, ‘elves’ and ‘sprites’ that we cannot observe and research from the Earth’s surface. It also captured the presence of short bursts of gamma rays, that are actually formed within electrical lightning flashes.

- Dissecting the anatomy of a thunderstorm is extremely interesting for those studying fundamental physics, but it can also provide valuable insights to scientists studying climate change. See Figure 22.

Thunderstorms and Climate

- Thunderstorms are formed when hot air rises and comes in contact with colder layers of air in the upper atmosphere. This airflow takes with it any particles and greenhouse gasses present in the lower regions of the Earth’s atmosphere.

- Electrical discharges in a thundercloud have a chemical effect on the gases in the air, and cause higher concentrations of ozone and nitrous oxide, greenhouse gases that at are at the root of climate change.

- Nitrous oxide is the third strongest greenhouse gas after carbon dioxide and methane, and has the strongest global warming potential. What is worse is that, the negative effects of these gases are even more pronounced at the higher altitudes of a thunderstorm.

- One type of electrical discharge that is responsible for these chemical changes is the ‘blue streamer corona’. The presence of these coronas can influence the chemical balance of the atmosphere, now and in the future. Not much was known about this phenomenon before, but through ASIM, the coronas can now be measured from low-Earth orbit and eventually applied to climate models.

- Studying thunderstorms through the ASIM will give us better insights into the progression and the effects of climate change, with strongest impact on tropical regions.

- As Francisco Gordillo-Vazquez, senior staff scientist at the Institute of Astrophysics of Andalusia (IAA-CSIC) and part of the international ASIM team says: “Fundamental understanding and knowledge can have tremendous and unsuspected practical benefits. Missions like ASIM are quite cheap when compared to commercial space programs. The knowledge learnt from this program will help create solid foundations for future space instruments to build upon.”

- This research will be hugely beneficial in the fight against climate change, especially as a warmer climate can also cause more thunderstorms to occur in the first place. The more we can understand, the more we will be able to avoid negative effects.

• January 20, 2021: As it turns out, there are many things left to discover, such as blue jets, elves and red sprites. These bizarre-sounding things are very difficult to observe from the surface of the Earth. As a new Nature paper reports, however, the European Atmosphere-Space Interactions Monitor (ASIM) observatory on the International Space Station is helping scientists find answers. 26)

- Looking down on Earth’s weather from the International Space Station 400 km above, ASIM’s enhanced perspective is shedding new light on weather phenomena and their characteristics.

- The collection of optical cameras, photometers and an X- and gamma-ray detector was installed on the Space Station in 2018. It is designed to look for electrical discharges originating in stormy weather conditions that extend above thunderstorms into the upper atmosphere.

- And now, for the first time for an ESA International Space Station experiment, ASIM’s findings have been published in Nature as front-page article. The paper describes a sighting of five intense blue flashes in a cloud top, one generating a ‘blue jet’ into the stratosphere. 27)

- A blue jet is a form of lightning that shoots upwards from thunderstorm clouds. They can reach as far 50 km into the stratosphere and last less than a second. The space storm-hunter measured a blue jet that was kicked off with and intense five 10-microsecond flash in a cloud near the island of Naru in the Pacific Ocean.

- The flash also generated equally fantastic-sounding ‘elves’. Elves are rapidly expanding rings of optical and UV emissions at the bottom of the ionosphere. Here, electrons, radio waves and the atmosphere interact to form these emissions.

Figure 14: Elves seen from space. Artist impression of lightning in clouds seen from space followed by a blue flash that lasts 10 micro seconds, a blue jet lasting 400 milliseconds and an elve generated by the blue flash that lasts for 30 microseconds. The International Space Station solar panels are shown in the foreground (video credit: DTU Space, Mount Visual / Daniel Schmelling)

- Capturing these phenomena using ASIM’s highly sensitive tools is vital for scientists researching weather systems on Earth. The observations hold clues to how lightning is initiated in clouds and investigators think these phenomena could even influence the concentration of greenhouse gasses in Earth’s atmosphere, underscoring once more how important it is to find out exactly what’s going on above our heads.

- Astrid Orr, ESA's Physical Sciences Coordinator for human and robotic spaceflight says, "This paper is an impressive highlight of the many new phenomena ASIM is observing above thunderstorms and shows that we still have so much to discover and learn about our Universe.

- “Congratulations to all the scientists and university teams that made this happen as well as the engineers that built the observatory and the support teams on ground operating ASIM – a true international collaboration that has led to amazing discoveries.”

• June 15, 2020: ASIM (Atmosphere-Space Interactions Monitor), mounted outside the European laboratory of the International Space Station, enters its second year of science operations. 28)

- Launched in April 2018, the payload began operating on 14 June 2018 and has been studying thunderstorms 400 km above Earth ever since.

- Specifically, ASIM is on the hunt for elusive electrical discharges in the upper atmosphere, or lightning that extends upwards into space. These discharges have alluring names like red sprites, blue jets and elves and have been reported by pilots over the years.

- Besides these phenomena ASIM is also studying terrestrial Gamma-ray flashes. These are high-energy discharges of photons that propagate out into space.

- All these light shows appear to be more common than originally thought and scientists are eager to know more about how they could influence Earth’s climate.

- ASIM is outfitted with a collection of optical cameras, photometers and an X- and gamma-ray detector designed to track and record the ‘transient luminous events’ and terrestrial gamma-ray flashes.

- Scientists knew these terrestrial Gamma-ray flashes existed because they were detected by astronomy spacecraft in the 1990s, but the ‘MXGS’ instrument on ASIM is looking down at Earth from the International Space Station and scans the globe to pinpoint where the gamma-rays are coming from, the first high-energy instrument to generate images of our planet in X-rays.

- After just one year in operation, the ASIM science team published the first image of Earth in X-rays at high spatial resolution. 29)

- As ASIM can better detect terrestrial gamma-ray flashes it is revealing more details than ever before, as well as showing where they originate. Scientists can then pool data from other spacecraft and ground-based weather stations to complete the overview.

- “ASIM is working really well for what is was built for, but it is also producing great secondary science,” says Astrid Orr, ESA’s physical sciences coordinator. “We sometimes get nice bonuses from ASIM.”

- In addition to terrestrial gamma rays, ASIM is also catching glimpses of other types of events from its vantage point on the International Space Station. The payload has clocked meteorites, for instance.

- “What really inspires me is that, besides doing fantastic experiments inside the Station, we have an external payload giving us more than what it was launched for. This illustrates what a multipurpose scientific laboratory the International Space Station is” adds Astrid.

- The data ASIM is generating are now available for download and can be consulted at the ASIM Science Data Center website upon submission of a proposal to the science team.

- ASIM was developed by TERMA for ESA for the ASIM Science Team, coordinated by the Technical University of Denmark, and is operated from the Belgian User Support and Operations Centre.

• May 14, 2019: Terrestrial gamma-ray flashes occur above some thunderstorms and propagate out into space. These high-energy discharges of photons were only discovered less than 25 years ago when a NASA spacecraft designed to observe cosmic gamma-ray bursts from outer space detected flashes that seemed to come from Earth itself. 30)

- The scientific community was intrigued, leading to the creation of an observatory to learn more that is now aboard the International Space Station. Called ASIM (Atmosphere-Space Interactions Monitor), the suite of instruments includes a gamma-ray detector mounted outside the European Columbus module that captures the whole visible part of Earth and can detect from where the gamma rays are coming.

- Since the start of operations one year ago, the storm-hunter’s MXGS (Modular X- and Gamma-ray Sensor) instrument has detected over 200 terrestrial gamma-ray flashes and, for nearly 30 of them, has pinpointed their location of origin. The image of Figure 15 shows the first-ever constructed image of a terrestrial gamma-ray flash based on data recorded on 18 June 2018.

- Thanks to these images scientists can now compare data with observations from other satellites and weather stations on the ground to piece together the sequence of events that cause the mysterious gamma-ray flashes.

- The ISS offers ASIM the perfect platform to observe our planet in this way, as it flies relatively close to Earth at 400 km altitude and often travels over areas with thunderstorms.

- We are changing our natural world faster than at any other time in history. Understanding the intricacies of how Earth works as a system and the impact that human activity is having on natural processes are huge environmental challenges. Satellites are vital for taking the pulse of our planet, delivering the information we need to understand and monitor our precious world, and for making decisions to safeguard our future. Earth observation data is also key to a myriad of practical applications to improve everyday life and to boost economies.

Figure 15: The area of interest is on the right, which corresponds to a thunderstorm occurring over Borneo at the time. The more red-white the color, the brighter the gamma-ray flux (image credit: University of Valencia, Spain)
Figure 15: The area of interest is on the right, which corresponds to a thunderstorm occurring over Borneo at the time. The more red-white the color, the brighter the gamma-ray flux (image credit: University of Valencia, Spain)

• April 9, 2019: After only one year in space, the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station has given researchers a new understanding of how lightning is created, and how thunderstorms can affect the atmosphere and the climate. 31)

- The first measurements from the facility that is flying 400 km above Earth outside Europe’s Columbus laboratory, reveal how so-called ‘terrestrial gamma-flashes’ form in the atmosphere. The flashes occur in connection with lightning and thunder storms and are short bursts of high-energy x- and gamma- rays.

- Researchers in the science team have also received unprecedented measurements showing a wealth of blue lightning above thunderclouds.

- The discoveries were published at a European Geosciences Union conference in Vienna today. In following papers this year researchers will describe in more detail how lightning creates terrestrial gamma-flashes, that were first discovered in 1993.

- “We are seeing new things and have gained so much knowledge on the internal anatomy of lightning. Besides the terrestrial gamma-flashes our recordings show lots of blue lightning that spread like fireworks above thunderclouds. It looks crazy,” says Torsten Neubert, lead scientist for the ASIM project at DTU Space working with scientists from the University of Bergen, Norway, and the University of Valencia, Spain.

Great View from Space

- Danish ESA astronaut Andreas Mogensen filmed the first blue jets from space showing the lightening firing upwards several times in quick succession.

- “The International Space Station is an ideal place to monitor these kind of phenomena as it orbits relatively low over our planet and covers areas where thunderstorms are common,” says ESA’s Astrid Orr, “the results are exciting as we are learning new things about our planet.”

Figure 16: The search for the magic lightning. The Danish astronaut Andreas Mogensen (in connection with his mission Thor on the ISS) was in 2015 able to capture some of the magic lightning with his hand-held camera. This project has shed more light on the lightning phenomena and a vast crowd of international scientists have high hopes for the results of the ASIM observations. The hope is to get jet another important piece for a better understanding of the Earth's climate and climate development (video credit: DTUdk, Published on 3 April 2019)

Legend to Figure 16: The film, as the title suggests, takes as a starting point in the quest for magic lightning, which already began many years ago. From the porch one could see mysterious light over the thunderstorm, and pilots told about seeing glimmer of lightning above the clouds. There were many stories, but no one believed them before in 1989. In Minnesota students accidentally took a picture of a so-called ‘red fairy’ at night on the prairie. They thought there was something wrong with the camera, but when NASA looked at the pictures and compared them with pictures taken from the spacecraft, they discovered several giant red lightning stretches 50 km along the horizon, filling 10,000 km3 of the atmosphere.

Since 2000, lightning has been studied from mountain tops and several different types of lightning have been discovered. At the beginning of the 2000, Danish space research began, working for a mission to the space station ISS to study the magic lightning. Since then, ASIM instrument was launched to space 2. April, 2018. The project has been created in close collaboration between Terma, DTU Space, ESA and a large number of international partners. Including University of Bergen (N), University of Valencia (E), Polish Space Research Center - SRC and OHB in Italy. To date, ASIM is the largest, most expensive, most complicated and advanced space instrument we have ever created in Denmark.

Figure 17: Thunderstorm seen from Space Station. For years, their existence has been debated: elusive electrical discharges in the upper atmosphere that sport names such as red sprites, blue jets, pixies and elves. Reported by pilots, they are difficult to study as they occur above thunderstorms. ESA astronaut Andreas Mogensen on the International Space Station in 2015 was asked to take pictures over thunderstorms with the most sensitive camera on the orbiting outpost to look for these brief features (image credit: ESA/NASA, released on 8 February 2017)
Figure 17: Thunderstorm seen from Space Station. For years, their existence has been debated: elusive electrical discharges in the upper atmosphere that sport names such as red sprites, blue jets, pixies and elves. Reported by pilots, they are difficult to study as they occur above thunderstorms. ESA astronaut Andreas Mogensen on the International Space Station in 2015 was asked to take pictures over thunderstorms with the most sensitive camera on the orbiting outpost to look for these brief features (image credit: ESA/NASA, released on 8 February 2017)

Software Update for More Accuracy – and More

For the past six months, the Danish company Terma, who heads the technical part of the project, has completed an upgrade of the software that controls ASIM’s two main instruments. The MXGS (Modular X- and Gamma-ray Sensor) is complemented by the MMIA (Modular Multispectral Imaging Array) that consists of two cameras and three photometers that detect flashes of light at different wavelengths.

“The updates will offer the researchers better measurements, because the instruments have become more sensitive in relation to capturing gamma radiation and gigantic lightning above the clouds. It will also improve the time accuracy between the two instruments to better than ten millionths of a second, which again will improve the analysis of the signals from the many sensors,” says project manager Ole Hartnack from Terma.

Figure 18: ASIM in action. ASIM is performing well outside the European Columbus laboratory module on the International Space Station (image credit: NASA)
Figure 18: ASIM in action. ASIM is performing well outside the European Columbus laboratory module on the International Space Station (image credit: NASA)

Now months into regular operations, ASIM is performing well. Using data continuously collected by ASIM, researchers are investigating the relationship between terrestrial gamma-ray bursts, lightning and high-altitude electric discharges across all seasons, different latitudes and different times of day and night.

Aside from being a little-understood phenomenon and part of our world, these powerful electrical charges can reach high above the stratosphere and have implications for how our atmosphere protects us from radiation from space.

ASIM is keeping researchers busy. Data collected so far have prompted over eight presentations so far at the December meeting of the American Geophysical Union, the largest international gathering of Earth and space scientists.

• January 8, 2019: ASIM (Atmosphere-Space Interactions Monitor) is performing well outside the European Columbus laboratory module on the International Space Station. 32)

Launched in April 2018, the storm-hunter is a collection of optical cameras, photometers and an X- and gamma-ray detector designed to look for electrical discharges born in stormy weather conditions that extend above thunderstorms into the upper atmosphere. These ‘transient luminous events’ sport names such as red sprites, blue jets and elves.

Satellites have probed them and observations have even been made from mountain tops but because they occur above thunderstorms they are difficult to study in greater detail from Earth. In contrast, the International Space Station’s low orbit covers a large part of Earth along the equator and is ideally placed to capture the sprites and jets.

ESA astronaut Andreas Mogensen managed to catch the elves and sprites in action with the help of a camera during his 2015 mission on board the International Space Station.

Figure 19: Red sprites and blue jets: ESA astronaut Andreas Mogensen explains the phenomena he filmed over India from the International Space Station’s Cupola observatory in September 2015 during his postflight tour at ESA’s technical heart ESTEC in The Netherlands (video credit: ESA)

Now months into regular operations, ASIM is performing well. Using data continuously collected by ASIM, researchers are investigating the relationship between terrestrial gamma-ray bursts, lightning and high-altitude electric discharges across all seasons, different latitudes and different times of day and night.

Aside from being a little-understood phenomenon and part of our world, these powerful electrical charges can reach high above the stratosphere and have implications for how our atmosphere protects us from radiation from space.

ASIM is keeping researchers busy. Data collected so far have prompted over eight presentations so far at the December meeting of the American Geophysical Union, the largest international gathering of Earth and space scientists.

Figure 20: Photo of the ASIM instrument on the Columbus module (image credit: NASA)
Figure 20: Photo of the ASIM instrument on the Columbus module (image credit: NASA)

• May 23, 2018: As the International Space Station flew over the Indonesian coast of Sumatra on an April night, lightning from a thunderstorm reached the upper layers of the atmosphere and its light show was captured by ESA’s latest observatory in space. 33)

ASIM (Atmosphere-Space Interactions Monitor), also known as the Space Storm Hunter, is completing its initial tests a month after it was installed outside Europe’s Columbus laboratory. “We collected 100,000 measurements per second of this amazing force of nature,” explains Torsten Neubert, science team coordinator at the Technical University of Denmark, “this is a fantastic example of how powerful our photometers are”.

Figure 21: Eyes on the storm. The two cameras of ASIM captured the strong signature of lightning with unprecedented accuracy 400 kilometers above Earth. As the International Space Station flew over the Indonesian coast of Sumatra on an April night, lightning bursts from a thunderstorm reached the upper layers of the atmosphere. Even with the clouds partly blocking the lightning, the instruments show powerful electrical discharges high in the atmosphere. Scientists believe it is an elve. Elves are the highest of all the ‘transient luminous events’ known to date. In the blink of an eye concentric rings appear as a dim, expanding glow hundreds of kilometers wide formed by electrons colliding and excited nitrogen molecules (image credit: DTU)
Figure 21: Eyes on the storm. The two cameras of ASIM captured the strong signature of lightning with unprecedented accuracy 400 kilometers above Earth. As the International Space Station flew over the Indonesian coast of Sumatra on an April night, lightning bursts from a thunderstorm reached the upper layers of the atmosphere. Even with the clouds partly blocking the lightning, the instruments show powerful electrical discharges high in the atmosphere. Scientists believe it is an elve. Elves are the highest of all the ‘transient luminous events’ known to date. In the blink of an eye concentric rings appear as a dim, expanding glow hundreds of kilometers wide formed by electrons colliding and excited nitrogen molecules (image credit: DTU)

• April 13, 2018: The ASIM (Atmosphere-Space Interactions Monitor) instrumentation, also known as the Space Storm Hunter, was installed today outside the European space laboratory Columbus. Operators in Canada commanded the International Space Station’s 16 m long robotic arm (Canadarm2) to move ASIM from a Dragon spacecraft’s cargo hold to its place of operation on Columbus. 34)

Pointing straight down at Earth, the storm hunter will observe lightning and powerful electrical bursts in the atmosphere that occur above thunderstorms, the so-called transient luminous events. The inner workings of these magnificent forces of nature are still unknown. The ISS offers a great vantage point to gather information about such events – it circles 400 km above Earth and covers the areas where most thunderstorms appear.

Setting up: The first part to getting data is checking the communication channels. The storm hunter will send data over the International Space Station network beamed via communication satellites to a ground station in White Sands, USA, then on to the Space Station mission control in Houston, under the Atlantic Ocean to the Columbus Control Center in Oberpfaffenhofen, Germany, and finally to the Belgian user operations and support center in Brussels.

The observatory has two suites of instruments to capture optical images in infrared and ultraviolet, and X-ray and gamma-ray detectors. The sensors will measure light levels to determine if an image should be taken and the data sent back to Earth.

Setting the levels will be a matter of trial and error – setting the trigger too low will flood the network with images that are of no use, too high and some thunderstorms will not be recorded. The operators will collaborate with scientists at the Technical Institute of Denmark who are eagerly awaiting readings from the observatory, in order to find the best solution.

Visual cameras will pinpoint areas of interest while photomultiplier tubes record the details of the lightning and transient luminous events. Other sensors are included to learn more about terrestrial gamma-ray flashes, for high and low energy X-ray and gamma-ray bursts.

Each element of the storm hunter will be activated in turn and tested to ensure they are working as expected. This is expected to take up to six weeks, during which the user control center will be run continuously.

Anuschka Helderweirt, operations engineer at the Belgian operations center, says: “We are thrilled to start operating these instruments in space, this is what the hours spent training, developing procedures and preparing for anomalies was for. We are ready to deliver some fascinating new scientific data.”

Figure 22: Atmospheric zoo of light and energy: ASIM observes a wide variety of phenomena in Earth's upper atmosphere. The inner working of these magnificent forces of nature are still unknown, but lightning affects the concentration of atmospheric gases that are important for the climate. New data will improve our understanding of the effect of thunderstorms on the atmosphere and contribute to more accurate climate models (image credit: ESA)
Figure 22: Atmospheric zoo of light and energy: ASIM observes a wide variety of phenomena in Earth's upper atmosphere. The inner working of these magnificent forces of nature are still unknown, but lightning affects the concentration of atmospheric gases that are important for the climate. New data will improve our understanding of the effect of thunderstorms on the atmosphere and contribute to more accurate climate models (image credit: ESA)

• On April 4, 2018, the SpaceX Dragon CRS-14 arrived at the International Space Station to deliver more than 2630 kg of research investigations, cargo and supplies, including NASA's Materials International Space Station Experiment (MISSE). This is the ninth MISSE mission in the program's long history of testing material samples in space. 35)

Figure 23: The MISSE Flight Facility is shown here, as manufactured by Alpha Space Test and Research Alliance. The new configuration offers multiple sides, allowing material specimens to be exposed to the space environment from all four orientations (ram, wake, zenith, and nadir), image credit: Alpha Space Test & Research Alliance
Figure 23: The MISSE Flight Facility is shown here, as manufactured by Alpha Space Test and Research Alliance. The new configuration offers multiple sides, allowing material specimens to be exposed to the space environment from all four orientations (ram, wake, zenith, and nadir), image credit: Alpha Space Test & Research Alliance

• April 4, 2018: The SpaceX Dragon capsule has arrived at the International Space Station (ISS) after a two-day orbital chase. Astronauts aboard the ISS snagged the uncrewed Dragon at 10:40 GMT using the orbiting lab's huge Canadarm2 robotic arm. The cargo vehicle had launched Monday afternoon (April 2) aboard a SpaceX Falcon 9 rocket, on a contracted mission for NASA. 36)

Figure 24: Astronauts aboard the ISS snagged the uncrewed Dragon today (April 4) at 10:40 GMT using the orbiting lab's huge Canadarm2 robotic arm (image credit: NASA TV)
Figure 24: Astronauts aboard the ISS snagged the uncrewed Dragon today (April 4) at 10:40 GMT using the orbiting lab's huge Canadarm2 robotic arm (image credit: NASA TV)

ISS crewmembers will soon start unloading the 2,630 kg of cargo Dragon, which includes a number of scientific experiments. Among them is a study designed to help optimize plant growth in space, and an investigation into how bone marrow produces red blood cells in a microgravity environment.

Also aboard Dragon is an experimental spacecraft called RemoveDebris, which will be deployed from the ISS in the near future to test ways to clean up space junk. Once it's flying freely, the RemoveDebris mothership will practice hitting an onboard target with a harpoon, and it will also jettison a small piggyback satellite and then try to bag it up with a net.

The Dragon will remain at the ISS until next month, when crewmembers will load it up with about 1,800 kg of cargo from the station, SpaceX representatives have said. The capsule will depart and maneuver its way to a splashdown in the Pacific Ocean off Baja California, where SpaceX personnel will retrieve it by boat.



 

Sensor Complement

SIM consists of two optical cameras, 3 photometers, and one large X- and Gamma ray detector. The instruments will be installed on the Columbus External Pallet to be mounted on the exterior of the Columbus module, housing ESA's laboratory on the ISS. 37) 38) 39) 40) 41) 42) 43) 44)

The optical assembly, referred to as MMIA (Modular Multispectral Imaging Array), comprises two optical narrow band cameras and three photometers with related optical and signal processing capabilities, including autonomous event detection algorithms to identify and prioritize events for download to Earth.

The MMIA instrument will be combined with the MXGS (Modular X- and Gamma-ray Sensor) into the Nadir Viewing Assembly looking directly down on top of thunderstorms according above the Earth.

MXGS is designed to detect radiation from TGF (Terrestrial Gamma Flashes) and from lightning induced electron precipitation. The detector is built around a BiGe (Bismuth Germanium) as well as a CZT (Cadmium Zinc Telluride) semiconductor detection plane of 32 cm x 32 cm with possible imaging capabilities.

Fast electronic circuitry used in the MXGS will provide time history and spectra over the course of the expected lifetime of 1-5 ms for each TGF. Also, a TGF burst trigger signal is passed to the adjacent MMIA module (and visa versa) for synchronization of the two types of observation.

X- and gamma-rays are strongly absorbed in the atmosphere. This is why the detector points directly downwards, such that a minimum of atmosphere is between the detector and the thunderstorms within its field of view. Most of the atmosphere is below the altitude where giant lightning and terrestrial gamma-ray flashes are generated. Therefore, space is particularly well suited to observe these phenomena in the band reaching from gamma-rays to UV, which is difficult to observe from the ground. ASIM is measuring in these bands (colors).

The ASIM mission will address a variety of important scientific and technological aspects which will include:

• Understanding of the processes involved in thunderstorm initiated electrical discharges

• Understand their impact on atmospheric processes and possible links to climate determining factors

• Development of new technologies with spin-off into terrestrial applications for advanced process control and optical instrumentation

• Demonstration of the fruitful utilization of the collaborative investments in the International Space Station.

In view of the unique observation point, the advanced instrumentation set, and the long duration of the mission, it is expected that ASIM will produce scientific data of high quality which will give an unprecedented contribution to the understanding of interaction mechanisms between the atmosphere and space.

Figure 25: Layout of the ASIM instrument assembly (image credit: ASIM collaboration)
Figure 25: Layout of the ASIM instrument assembly (image credit: ASIM collaboration)

 

MMIA (Modular Multispectral Imaging Array)

ASIM uses optical observiations in carefully selected bands in order to filter out data with TLEs from the lightning data. Since the data downlink is limited, the algorithms are implemented in the on-board software. The ASIM MMIA instrument is capable of observing 12 frames/s continuously in the 777.4 nm and 337 nm bands, both only 5 nm wide. Combined with the 100 kHz photometer data from the same two bands in addition to a 180-230 nm band, data is filtered in realtime to optimize the available downlink capability allocated to ASIM on ISS.

Figure 26: Illustration of the MMIA assembly (image credit: ASIM collaboration)
Figure 26: Illustration of the MMIA assembly (image credit: ASIM collaboration)

The optical instruments are grouped into two) groups, each composed of two optical narrow band cameras and 2 photometers with related optical and signal processing capabilities including autonomous event detection algorithms to identify and prioritize events for download.

• 4 cameras and 4 photometers look forward towards the limb

• 2 cameras and 2 photometers look downwards towards the nadir

The cameras and photometers are equipped with baffles for stray light protection. The camera sampling is 12 bit 1024 x 1024 pixel frames at a maximum of 25 Hz.

Parameter

Cameras

Photometers

FOV (Field of View)

20º x 20º (limb or ram direction)
80º x 80º (nadir direction)

20º x 20º (limb or ram direction)
80º x 80º (nadir direction)

Detector

1024 x 1024 pixels, frame type CCD

 

Spatial resolution

300-600 m (limb or ram direction)
300-400 m (nadir direction)

 

Data quantization

12 bit

12 bit

Time resolution

65 ms

100 kHz (temporal sampling)

Table 1: Parameters of the MMIA optical instruments

The photometers are used to measure rapid time variations, which cannot be done by the imaging cameras. They view the exact same region but measure only the total photon flux from the region - but with high time resolution. The photometer FOVs are identical to those of the cameras: 20º x 20º (limb or ram direction) and 80º x 80º (nadir direction).

Band

Cameras

Band

Photometers

Spectral band (nm)

Bandwidth (nm)

Spectral band (nm)

Bandwidth (nm)

LC1 (limb)

336.2

5.0

LP1

337.0

5.0

LC2

391.4

5.0

LP2

391.4

5.0

LC3

650-740

90

LP3

650-740

90

LC4

762.4

5.0

LP4

236.6

5.0

NC1 (nadir)

337.0

5.0

NP1

337.0

5.0

NC2

777.4

5.0 (1 nm*)

NP2

145-250

broadband

Table 2: Optical parameters of the MMIA instruments

Legend: *extension under consideration – will allow also day time observations of lightning

Figure 27: Block diagram of the MMIA photometers (TNO Science and Industry)
Figure 27: Block diagram of the MMIA photometers (TNO Science and Industry)
Figure 28: View of the MMIA limb assembly with 4 cameras and 4 photometers (image credit: DNSC)
Figure 28: View of the MMIA limb assembly with 4 cameras and 4 photometers (image credit: DNSC)

Data handling subsystem: Time synchronizing of instrument measurements with a relative time accuracy < 10 µs and with an accuracy of 100 µs compared to GPS/UTC.

Figure 29: Overview of system data and signal interfaces (image credit: DNSC)
Figure 29: Overview of system data and signal interfaces (image credit: DNSC)
Figure 30: The nadir-viewing assembly (MMIA) of 2 cameras + 2 photometers + MXGS, (image credit: DNSC)
Figure 30: The nadir-viewing assembly (MMIA) of 2 cameras + 2 photometers + MXGS, (image credit: DNSC)

 

MXGS (Modular X-ray and Gamma-ray Sensor)

The MXGS instrument carries two set of detectors for TGFs (Terrestrial Gamma-ray Flashes). The low energy detector is senstive in the spectral band from 15 keV to 400 keV and the high energy detector is sensitive from 200 keV to 40 MeV. The low energy detector is pixellated in 128 by 128 channels, which, in combination with a high mass density coded mask in front of the detector, allows advanced post-processing algorithms to pin point the direction to the TGF source. Overlaying the TGF direction with the optical imaging by the MMIA instrument, the correllation with lightning and TLE is possible. 45) 46) 47) 48) 49) 50) 51) 52) 53)

Parameter

Low-E

High-E
(extension under consideration)

Energy range

10 – 500 keV

0.2 – 10 MeV

Effective area of detector

1032 cm2

900 cm2

Energy resolution of detector

< 10% @ 60 keV

18% @ 662 keV

Efficiency

> 90% @ 100 keV

> 60%

Imaging (extension under consideration)

< 2º

 

Table 3: Technical parameters of MXGS 54)

The MXGS detector plane consists of a 1024 cm2 array of CZT detector crystals. It is protected against the background radiation by a passive graded shield surrounding the detector housing. A hopper shaped collimator defines the 80º x 80º field of view for MXGS and shields the detector plane against the Cosmic X-ray Background. The DFEE (Detector Front End Electronics) is mounted in the housing below the detectors. The electronics contains also the HVPS (High Voltage Power Supply) and LVPS (Low Voltage Power Supply) as well as the DPU (Data Processing Unit).

The DFEE design consists of 4 DAUs (Detector Assembly Units), and each DAU consists of 16 DM (Detector Modules) and one DAB (Detector Assembly Board). The DAB holds the read-out electronics and the RCU (Readout Control Unit). The RCUs interface to the DPU. The purpose of the DAU is to read out the events and transfer the data to the DPU.

The DM consists of two separable units, a CZT sensor and an ASIC. The sensor comprises four 20 mm x 20 mm x 5 mm CZT detectors tiled together on a PCB. Each detector is pixelated into 64 pixels (2.5 mm pixel pitch), making a 16 x 16 pixel array in total. The detector unit is stacked onto the ASIC unit via three connectors (Figure 33).

The MXGS uses fast ASICs to provide the time history and spectra over the course of the expected TGFs lifetime of 1-5 ms and a TGF burst trigger signal is passed to the companion MMIA module (and visa versa). The observation plane is protected from background radiation by a passive shield and the field of view is defined by a hopper shaped collimator.

Figure 31: Illustration of the MXGS instrument (image credit: University of Bergen)
Figure 31: Illustration of the MXGS instrument (image credit: University of Bergen)
Figure 32: Schematic view of the MXGS instrument elements (image credit: MAPRAD)
Figure 32: Schematic view of the MXGS instrument elements (image credit: MAPRAD)
Figure 33: Photo of the detector module (image credit: DNSC, University of Bergen)
Figure 33: Photo of the detector module (image credit: DNSC, University of Bergen)

ISS-ASIM_Auto1

Figure 34: Illustration of the MXGS instrument (image credit: ASIM collaboration)



 

Ground Segment

ASIM is controlled from a ground USOC (User Operator Center) connected to the ISS ground stations. When USOC sends a command to ASIM, it is routed to theCOL-CC ( Columbus Control Center), then to the ISS ground station in Houston responsbile for uplinking the command to ISS, which eventually reaches ASIM through Columbus. The DHPU will process all commands and it also supports a command schedule for autonomous observation timelines. The ASIM science and housekeeping data follow the same route in reverse back to the USOC.

Figure 35: Overview of the ground segment elements for ASIM operations (image credit: ESA)
Figure 35: Overview of the ground segment elements for ASIM operations (image credit: ESA)

Ground Observations

Ground observations are important parts of the ASIM and TARANIS missions (observe from space what is best observed from space and from ground what is best observed from ground).



References

1) G. G. Reibaldi, R. Nasca, T. Neubert, O. Hartnack, “The Atmosphere-Space Interactions Monitor (ASIM) Payload Facility on the ISS,” 58th IAC (International Astronautical Congress), International Space Expo, Hyderabad, India, Sept. 24-28, 2007, IAC-07- B1.1.09

2) ASIM Topical Team Meeting, June 26-27, 2006, URL: http://www.dsri.dk/atmosphere/asim/tt1/tt1.html

3) P. L. Thomsen, “ASIM Payload System Overview,” ASIM Topical Team Meeting-1, ESA/ESTEC, June 26-27, 2006

4) T. Neubert, I. Kuvvetli, C. Budtz-Jørgensen, N. Ostgaard, V. Reglero, N. Arnold, “The Atmosphere-Space Interactions Monitor (ASIM) for the International Space Station,” ILWS (International Living With a Star) Workshop 2006, Goa, India, Feb. 19-20, 2006, URL: http://cdaw.gsfc.nasa.gov/publications/ilws_goa2006/448_Neubert.pdf

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6) Torsten Neubert, “The Atmosphere-Space Interactions Monitor (ASIM) for the International Space Station,” Workshop on Coupling of Thunderstorms and Lightning Discharges to Near-Earth Space, June 23-27, 2008, University of Corsica, Corte, France

7) V. Pilipenko, “New physical phenomena in the atmospheric lightning discharges: observations from microsatellites and ground,” FP7-SPACE-2010-1, URL: http://www.kpk.gov.pl/pliki/
10346/Pilipenko_New_physical_phenomena_in_the_atmospheric_lightning_discharges.pdf

8) ”ASIM: Climate and giant lightning discharges to be studied from the International Space Station,” URL: http://www.space.dtu.dk/English/Research/Projects/ASIM.aspx

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Space/forskning/missioner/ASIM/asim_neubert_3.ashx?la=da

10) Torsten Neubert, Lundgaard Rasmussen, “Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station,” URL: http://www.iapg.bv.tum.de/mediadb/15094/15095/05_080526-asim.pdf

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12) “Terma To Head ASIM Observatory For ISS,” Space Travel, Aug. 27, 2010, URL: http://www.space-travel.com/reports/Terma_To_Head_ASIM_Observatory_For_ISS_999.html

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/publications/ESA-Bulletin-171/offline/download.pdf

18) ”Dragon lifts off,” ESA, 3 April 2018, URL: http://m.esa.int/spaceinimages/Images/2018/04/Dragon_lifts_off

19) Stephen Clark, Spaceflight Now, URL: https://spaceflightnow.com/launch-schedule/

20) ”Double News ... SpaceX to Launch Experiments for ISS National Laboratory and Cleaning Up Space with a Harpoon,” Satnews Daily, 29 March 2018, URL: http://www.satnews.com
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21) ”In the Dragon's den,” ESA Human Spaceflight and exploration image of the week: Atmosphere monitor awaits launch to the International Space Station inside a Dragon supply vehicle,” 27 March 2018, URL: http://m.esa.int/spaceinimages/Images/2018/03/ASIM_in_Dragon

22) ”New location, same ASIM,” ESA Science & Exploration, 21 January 2022, URL: https://www.esa.int/ESA_Multimedia/Images/2022/01/New_location_same_ASIM

23) ”The Incredible ASIM: Distant galaxy edition,” ESA Science & Exploration, 11 January 2022, URL: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/
International_Space_Station/The_Incredible_ASIM_Distant_galaxy_edition

24) A. J. Castro-Tirado, N. Østgaard, E. Gögüs, C. Sánchez-Gil, J. Pascual-Granado, V. Reglero, A. Mezentsev, M. Gabler, M. Marisaldi, T. Neubert, C. Budtz-Jørgensen, A. Lindanger, D. Sarria, I. Kuvvetli, P. Cerdá-Durán, J. Navarro-González, J. A. Font, B.-B. Zhang, N. Lund, C. A. Oxborrow, S. Brandt, M. D. Caballero-García, I. M. Carrasco-García, A. Castellón, M. A. Castro Tirado, F. Christiansen, C. J. Eyles, E. Fernández-García, G. Genov, S. Guziy, Y.-D. Hu, A. Nicuesa Guelbenzu, S. B. Pandey, Z.-K. Peng, C. Pérez del Pulgar, A. J. Reina Terol, E. Rodríguez, R. Sánchez-Ramírez, T. Sun, K. Ullaland & S. Yang, ”Very-high-frequency oscillations in the main peak of a magnetar giant flare,” Nature, Volume 600, pp:621-624, Published: 22 December 2021, https://doi.org/10.1038/s41586-021-04101-1

25) ”How space science is combating climate change,” ESA Science & Exploration, 19 April 2021, URL: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration
/How_space_science_is_combating_climate_change

26) ”Genesis of blue lightning into the stratosphere detected from the International Space Station,” ESA Science & Exploration, 20 January 2021, URL: https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/
Genesis_of_blue_lightning_into_the_stratosphere_detected_from_the_International_Space_Station

27) Torsten Neubert, Olivier Chanrion, Matthias Heumesser, Krystallia Dimitriadou, Lasse Husbjerg, Ib Lundgaard Rasmussen, Nikolai Østgaard & Victor Reglero, ”Observation of the onset of a blue jet into the stratosphere,” Nature, Volume 589, pp: 371-375, Published: 20 January 2021, https://www.nature.com/articles/s41586-020-03122-6

28) ”Storm hunter turns two,” ESA Science & Exploration, 15 June 2020, URL: http://www.esa.int/ESA_Multimedia/Images/2020/06/Storm_hunter_turns_two

29) Torsten Neubert, Nikolai Østgaard, Victor Reglero, Olivier Chanrion, Matthias Heumesser, Krystallia Dimitriadou, Freddy Christiansen, Carl Budtz-Jørgensen, Irfan Kuvvetli, Lundgaard Rasmussen, Andrey Mezentsev, Martino Marisaldi, Kjetil Ullaland, Georgi Genov, Shiming Yang, Pavlo Kochkin, Javier Navarro-Gonzalez, Paul H. Connell, Chris J. Eyles, ”A terrestrial gamma-ray flash and ionospheric ultraviolet emissions powered by lightning,” Science, Vol. 367, Issue 6474, pp. 183-186, 10 January 2020, https://science.sciencemag.org/content/367/6474/183

30) ”Terrestrial gamma-ray flash,” ESA, 14 May 2019, URL: http://www.esa.int/spaceinimages/Images/2019/05/Terrestrial_gamma-ray_flash

31) ”Fireworks of blue lightning and gamma rays above thunderclouds,” ESA, 9 April 2019, URL: http://m.esa.int/Our_Activities/Human_and_Robotic_Exploration/
Research/Fireworks_of_blue_lightning_and_gamma_rays_above_thunderclouds

32) ”Storm hunter in action,” ESA, Human and robotic exploration image of the week: A typical day for electrical thunderstorm observer, 8 January 2019, URL: http://m.esa.int/spaceinimages/Images/2019/01/ASIM_in_action

33) ”First light for the Storm Hunter,” ESA, 23 May 2018, URL: http://www.esa.int/Our_Activities
/Human_Spaceflight/International_Space_Station/First_light_for_the_storm_hunter

34) ”Storm Hunter in Position,” ESA, 13 April, 2018, URL: https://www.esa.int/Our_Activities/Human_Spaceflight/Storm_hunter_in_position

35) ”SpaceX Dragon Arrives at Space Station with Material Samples and New Facility for Testing Them,” NASA, 4 April 2018, URL: https://www.nasa.gov/centers/armstrong
/features/SpaceX_Dragon_Brings_Material_Samples_to_ISS.html

36) Mike Wall, ”SpaceX Cargo Capsule Arrives at Space Station with Tons of Supplies,” SpaceX.com, 4 April 2018, URL: https://www.space.com/40193-spacex-dragon-cargo-capsule-arrives-iss.html

37) “ASIM Instruments Development,” Terma, January 2012, URL: http://www.terma.com/media/101689/asim_instruments_development.pdf

38) C. Budtz-Jørgensen, I. Kuvvetli, I. L. Rasmussen, T. Neubert, N. Ostgaard, A. Spilde, J. Stadsness, G. A. Johansen, V. Reglero, A. R. Berlanga, P. H. Connell, C. Eyles, J. M. Rodrigo, “The Miniature X- and Gamma-Ray Sensor (MXGS) on ASIM,” EDCE Workshop, Rome, Italy, Dec. 21, 2006, URL: http://projects.iasf-roma.inaf.it/EdgeGMPresentations/52_Budz_ASIM_ROME.ppt

39) http://www.spacecentre.dk/research/solarphysics/asim

40) http://www.terma.com/multimedia/ASIM_flyer_v2__2_.pdf

41) P. J. Espy, T. Neubert, N. Ostgaard, “A Nitric Oxide Photometer for ASIM,” Workshop on Coupling of Thunderstorms and Lightning Discharges to Near-Earth Space, June 23-27, 2008, University of Corsica, Corte, France

42) Andy J. Court, “Fast Photometer Design for the ASIM ISS >Mission,” Proceedings of the 60th IAC (International Astronautical Congress), Daejeon, Korea, Oct. 12-16, 2009, IAC-07-B1.3.06

43) Torsten Neubert and the ASIM Team, “Status of the Atmosphere-Space Interactions Monitor (ASIM) for the International Space Station and plans for Ground Campaigns in 2009 and beyond,” URL: http://www.costp18-lightning.org/Publications/Symposium2009/Release/S4/02_Neubert.pdf

44) Ole Hartnack, “The ASIM Observatory,” Terma, 2011, URL: http://www.termanorthamerica.com
/print/?id=1764

45) http://asim.dk/payload.php#

46) M. Marisaldi, “A High Energy gamma-ray detector for the ASIM mission,” AAE Workshop, Jan. 21, 2009, Rome, Italy, URL: http://projects.iasf-roma.inaf.it/aae/Meeting20-21Jan09/13-Marisaldi_ASIM_AAE2009.pdf

47) Francesca Renzi, “Background estimation in MXGS apparatus on ISS,” 6th Geant 4 (GEometry ANd Tracking) Space Users' Workshop,Madrid, Spain, May 19-22, 2009, URL: http://www.inta.es/g4suw2009/docs/Presentations/20_Wed_May_2009
/G4SUWS_2009_Renzi_BackgroundEstimationInMXGS.pdf

48) C. Budtz-Jørgensen, I Kuvvetli, Y. Skogseide, K. Ullaland, N. Ostgaard, “Characterization of CZT Detectors for the ASIM Mission,” 2008, URL: http://ipy-icestar.uib.no/~nikost/papers/R04-5_MIC08.pdf

49) Irfan Kuvvetli, “X- and Gamma Ray Detector Development at DNSC,” First International Workshop of the Astrophysics of Neutron Stars Project (ASTRONS), July 2-6, 2007, Istanbul, Turkey, URL: http://astrons.sabanciuniv.edu/workshop2007/PDFs/Kuvvetli.pdf

50) http://www.uib.no/rg/space/projects/asim/instruments

51) Carl Budtz-Jørgensen, Irfan Kuvvetli, Ib Lundgård Rasmussen, Torsten Neubert, Nikolai Ostgaard, Asbjørn Spilde, Johann Stadsness, Geir Anton Johansen, Victor Reglero, Andrés R. Berlanga, Paul H. Connell, Chris Eyles, Juana M. Rodrigo, “The Miniature X- and Gamma-Ray Sensor (MXGS) on ASIM,” Toledo, Sain, June 29, 2006, URL: http://projects.iasf-roma.inaf.it
/EdgeGMPresentations/52_Budz_ASIM_ROME.ppt

52) C. Budtz-Jorgensen, I. Kuvvetli, Y. Skogseide, K. Ullaland, N. Ostgaard, “Characterization of CZT Detectors for the ASIM Mission,” IEEE Transaction on Nuclear Science, Vol. 56, Issue 4, Aug. 2009, pp. 1842-1847

53) http://web.ift.uib.no/Romfysikk/RESEARCH/PROJECTS/ASIM/

54) Mark R. Drinkwater, “Remote Sensing Observations of the Mesosphere-Lower Thermosphere Region by Earth Observation Satellites,” QB50 Workshop, Nov. 17, 2009, URL: http://www.vki.ac.be/QB50/download/workshop/papers_17nov/drinkwater.pdf

55)Garcia, Mark. “Partners Extend International Space Station for Benefit of Humanity – Space Station.” NASA Blogs, 27 April 2023, https://blogs.nasa.gov/spacestation/2023/04/27/partners-extend-international-space-station-for-benefit-of-humanity/


The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (eoportal@symbios.space).

ASIM Payload   Launch   Mission Status    Instrument Assemblies   Ground Segment   References