Orbiter.ch Space News

mercredi 20 novembre 2019

Hubble Studies Gamma-Ray Burst with the Highest Energy Ever Seen

ESA - Hubble Space Telescope logo.

20 November 2019

GRB 190114C (Artist’s Impression)

New observations from the NASA/ESA Hubble Space Telescope have investigated the nature of the gamma-ray burst GRB 190114C.

Gamma-ray bursts are the most powerful explosions in the Universe. They emit most of their energy in gamma rays, light which is much more energetic than the visible light we can see with our eyes.

GRB 190114C (Artist’s Impression)

In January 2019, an extremely bright and long gamma-ray burst (GRB) was detected by a suite of telescopes, including NASA’s Swift and Fermi telescopes, as well as by the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes. Known as GRB 190114C, some of the light detected from the object had the highest energy ever observed: 1Tera electron volt (TeV) — about one trillion times as much energy per photon as visible light. Scientists have been trying to observe such very high energy emission from GRB’s for a long time, so this detection is considered a milestone in high-energy astrophysics.

Previous observations revealed that to achieve this energy, material must be emitted from a collapsing star at 99.999% the speed of light. This material is then forced through the gas that surrounds the star, causing a shock that creates the gamma-ray burst itself. For the first time, scientists have observed extremely energetic gamma rays from this particular burst.

GRB 190114C (Artist’s Impression)

Several ground- and space-based observatories have set out to study GRB 190114C. European astronomers were provided observing time with the NASA/ESA Hubble Space Telescope to observe the gamma-ray burst, to study its environment and find out how this extreme emission is produced[1].

“Hubble’s observations suggest that this particular burst was sitting in a very dense environment, right in the middle of a bright galaxy 5 billion light years away,” explained one of the lead authors, Andrew Levan of the Institute for Mathematics, Astrophysics & Particle Physics Department of Astrophysics at Radboud University in the Netherlands. “This is really unusual, and suggests that might be why it produced this exceptionally powerful light.”

Wide-field view of GRB 190114C (ground-based view)

Astronomers used the NASA/ESA Hubble Space Teleescope, together with the European Southern Observatory's Very Large Telescope and the Atacama Large Milimeter/submilimeter Array to study the host galaxy of this GRB. Hubble's Wide Field Camera 3 was instrumental in studying whether the environmental properties of the host system, which is composed of a close pair of interacting galaxies, might have contributed to the production of these very-high-energy photons. The GRB occurred within the nuclear region of a massive galaxy, a location that is rather unique. This is indicative of a denser environment than that in which GRBs are typically observed and could have been crucial for the generation of the very-high-energy photons that were observed.

Hubble Observation of the host galaxy of GRB 190114C

“Scientists have been trying to observe very-high-energy emission from gamma-ray bursts for a long time,” explained lead author Antonio de Ugarte Postigo of the Instituto de Astrofísica de Andalucía in Spain. “This new observation is a vital step forward in our understanding of gamma-ray bursts, their immediate surroundings, and just how matter behaves when it is moving at 99.999% of the speed of light.”

Animation GRB 190114C

Notes:

[1] The Hubble Space Telescope observations involved in this result were obtained from the Director's Discretionary Time programmes 15684 and 15708 (P.I.: Levan). The paper outlining these observations will appear in the journal Nature on 20 November 2019. An additional paper that details an analysis of the galaxy hosting the GRB will appear in the journal Astronomy and Astrophysics.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Hubble Space Telescope (HST)

The international team of astronomers in this study consists of A de Ugarte Postigo, C. C. Thöne, S. Martin, J. Japelj, A. J. Levan, M. J. Michalowski, J. Selsing, D. A. Kann, S. Schulze, J. T. Palmerio, S. D. Vergani, N. R. Tanvir, K. Bensch, S. Covino, V. D'Elia, M. De Pasquale, A. S. Fruchter, J. P. U. Fynbo, D. Hartmann, K. E. Heintz, A. J. van der Horst, L. Izzo, P. Jakobsson, K. C. Y. Ng, D. A. Perley, A. Rossi, B. Sbarufatti, R. Salvaterra, R. Sanchez-Ramirez, D. Watson, and D. Xu.

Links:

ESA Hubble Space Telescope (HST): http://www.spacetelescope.org/

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

HubbleSite release: https://hubblesite.org/contents/news-releases/2019/news-2019-56

Nature paper: https://www.nature.com/articles/s41586-019-1754-6

Astronomy and Astrophysics paper: https://arxiv.org/pdf/1911.07876.pdf

Images, Animation, Text. Credits: ESA/Hubble, M. Kornmesser/Bethany Downer/Institute for Mathematics, Astrophysics & Particle Physics, Radboud University/Andrew Levan/Digitized Sky Survey 2/Acknowledgement: Davide De Martin/NASA, ESA, A. de Ugarte Postigo and A. J. Levan/Video : ESA/NASA.

Best regards, Orbiter.ch

Research Launching on SpaceX Dragon to Enable Better Earth Images, Easier Leak Checks

SpaceX - Dragon CRS-19 Mission patch.

Nov. 20, 2019

The 19th SpaceX Commercial Resupply Services (CRS-19) contract mission for NASA carries a variety of cutting-edge scientific experiments to the International Space Station. The Dragon cargo spacecraft blasts off from Cape Canaveral Air Force Station in Florida on a Falcon 9 rocket no earlier than Dec. 4, 2019. Its payloads include investigations studying malting barley in microgravity, the spread of fire and bone and muscle loss, which will be added to the dozens of research projects already under way aboard the microgravity lab. The space station, entering its 20th year of continuous human presence, provides opportunities for research by government agencies, private industry, and academic and research institutions. Such research supports Artemis, NASA’s missions to the Moon and Mars, and leads to new technologies, medical treatments and products that improve life on Earth.

Read more about some of the scientific investigations riding on Dragon to the orbiting laboratory on CRS-19.

A Better Picture of Earth’s Surface

The Japanese Space Agency (JAXA) Hyperspectral Imager Suite (HISUI) is a next-generation, hyperspectral Earth imaging system. Hyperspectral imaging has high resolution across all colors of the light spectrum, providing more information about the characteristics and physical properties of a target. Every material on the Earth’s surface – soil, rocks, vegetation, snow, ice and human-made objects – reflects a unique spectrum of light, making it possible to identify specific materials in an image.

Image above: This image of the Chapman Glacier, located on Ellesmere Island in Canada, was taken by ASTER. Formed by the merger of several smaller glaciers, rocky debris on top of the glacier clearly marks the edge of each glacier. The JAXA Hyperspectral Imager Suite (HISUI) is a follow-on to ASTER, serving as a next-generation, space-borne hyperspectral Earth imaging system. Image Credits: NASA/METI/AIST/Japan Space Systems, and U.S./Japan ASTER Science Team.

HISUI provides in-flight performance verification of the system and its acquisition of data, as well as its usefulness for various tasks such as resource exploration and applications in agriculture, forestry and other environmental areas. This investigation is a follow-on to the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s TERRA satellite.

Malting Barley in Microgravity

Animation above: Barley germinating on the International Space Station as part of Budweiser's experiment, Barley Germination, which launched on SpaceX CRS-13. Animation Credit: Space Tango.

Barley contains antioxidants, vitamins and minerals. Malting converts starches from the raw grain into various sugars suitable for use in brewing, distilling and food production. Understanding how barley responds to microgravity could identify ways to adapt it for nutritional use on long-duration spaceflights. Malting ABI Voyager Barley Seeds in Microgravity tests an automated malting procedure and compares malt produced in space and on the ground for genetic and structural changes.

Communicating Satellite to Satellite

Image above: The AzTechSat-1, a CubeSat soon on its way to the space station to demonstrate communication with the Globalstar Constellation satellite network, during its final hardware integration. Image Credits: Andres Martinez, NASA Ames.

The AztechSat-1 investigation demonstrates communication between a CubeSat and the GlobalStar Constellation satellite network in low-Earth orbit. Such communication could reduce the need for ground stations, lowering the cost and increasing the number of data downloads possible for satellite applications. Inter-satellite communication is critical to future human space exploration. Its reduced cost and increased data capability also could improve many satellite-based services used by people on Earth. The CubeSat will be deployed from the International Space Station’s Japanese Experiment Module airlock. This is the first CubeSat built by students in Mexico that will launch from the space station.

The Spread of Fire

Image above: Preflight imagery of Confined Combustion in the MSG Ground Integration Unit. Confined Combustion examines the behavior of flame as it spreads in differently-shaped confined spaces in microgravity. Image Credit: Chris Rogers.

Understanding how fire spreads and behaves in space is crucial for the safety of future astronauts and for understanding and controlling fire here on Earth. The Confined Combustion investigation examines the behavior of flame as it spreads in differently-shaped confined spaces in microgravity. More specifically, it will look at the interactions between spreading flames and surrounding walls. The spread of flames in confined spaces (such as buildings and vehicles) may pose a more serious fire hazard than flame spread in open spaces because of acceleration caused by heat radiating back from the surrounding walls. Studying flames in microgravity gives researchers a better look at the underlying physics and basic principles of combustion by removing gravity from the equation.

Keeping Bones and Muscles Strong

The goal of Rodent Research-19 (RR-19) is to investigate a proposed method of preventing bone and muscle loss. The human body evolved within the constant pull of Earth’s gravity. Astronauts have to exercise for multiple hours every day to prevent bone and muscle atrophy during their stays in space. Bone and muscle atrophy also occurs during normal aging, due to a sedentary lifestyle and during illnesses. RR-19 investigates myostatin (MSTN) and activin, molecular signaling pathways that influence muscle degradation, as possible targets for preventing muscle and bone loss during spaceflight and enhancing recovery following return to Earth. This study also could support the development of therapies for a wide range of conditions that cause muscle and bone loss on Earth.

Checking for Leaks

Image above: The Robotics Tool Stowage (RiTS) undergoes testing in the Neutral Buoyancy Lab at the Johnson Space Center. The RiTS will allow for the Robotic External Leak Locator to be stored outside the space station, eliminating crew time needed to transport it into space. Image Credit: NASA.

Nobody wants a spacecraft to spring a leak – but if it happens, the best thing you can do is locate and fix it, fast. That is why NASA launched the Robotic External Leak Locator (RELL) in 2015, and a second RELL in April 2019. Operators can use these tools with the Dextre robot to quickly detect leaks outside of station and help engineers formulate a plan to resolve an issue. On CRS-19, NASA is now launching the Robotic Tool Stowage (RiTS), a docking station that allows the RELL units to be stored on the outside of space station, making it quicker and simpler to deploy the instruments. Outside storage eliminates the need to rely on crew member and airlock availability to move a unit to the outside. These capabilities can be applied to any place that humans live in space, including Gateway and eventually habitats on the Moon, Mars and beyond.

Measuring Gravity From Space

CRS-19 carries upgrades for the Cold Atom Laboratory (CAL), a multi-use facility that produces clouds of atoms chilled to temperatures much colder than deep space. Atoms have almost no motion at such low temperatures, making it possible to study fundamental behaviors and quantum characteristics that are difficult or impossible to probe at higher temperatures. Microgravity may allow for cooling to even colder temperatures than on the ground, and also allows researchers to observe atom clouds for longer periods of time. The new package launching on CRS-19 will include hardware that will allow scientists to make subtle measurements of gravity. This could enable scientists to probe fundamental theories of gravity and lead to the development of improved sensors that can be used for spacecraft navigation and to study Earth's climate.

Science Launching On SpaceX CRS 19

mardi 19 novembre 2019

Agriculture and Disease Studies Ahead of Next Spacewalk

ISS - Expedition 61 Mission patch.

November 19, 2019

Today’s biology research aboard the International Space Station is helping scientists improve the health of astronauts in space and people on Earth. The Expedition 61 crew is also deploying a set of tiny satellites on Wednesday while getting ready for another spacewalk on Friday.

Flight Engineer Jessica Meir of NASA fed mice and watered plants today supporting a pair of long-running life science experiments. The rodent research study aims for cellular-level insights into diseases like cancer and diabetes to provide advanced therapies. The botany investigation explores the nutritional and morale-boosting benefits of growing fresh food in space.

Image above: NASA astronauts (from left ) Jessica Meir and Christina Koch are at the robotics workstation controlling the Canadarm2 robotic arm to support the first spacewalk to repair the Alpha Magnetic Spectrometer. Imge Credit: NASA.

NASA astronauts Christina Koch and Andrew Morgan recorded themselves with a 3-D video camera setting up gear that will deploy three small satellites outside Japan’s Kibo laboratory module. The deployer will eject the CubeSats in Earth orbit Wednesday morning to demonstrate technologies developed by several Asian nations.

Morgan and ESA (European Space Agency) commander Luca Parmitano are reviewing the tasks they will perform during this Friday’s spacewalk. They are continuing the intricate thermal control system repairs of the Alpha Magnetic Spectrometer, the station’s cosmic particle detector. Meir joined the duo at the end of the day and practiced the Canadarm2 robotics maneuvers to necessary support the spacewalkers.

Image above: Flying over Austral Ocean, seen by EarthCam on ISS, speed: 27'558 Km/h, altitude: 430,34 Km, image captured by Roland Berga (on Earth in Spain) from International Space Station (ISS) using ISS-HD Live Now application with EarthCam's from ISS on November 19, 2019 at 19:44 UTC. Image Credits: NASA/Orbiter.ch Aerospace.

Cosmonauts Alexander Skvortsov and Oleg Skripochka set up communications gear ahead of next month’s arrival of a Russian resupply ship. The duo also worked on station plumbing tasks before setting atmospheric observation gear.

Related article:

A very good start
https://orbiterchspacenews.blogspot.com/2019/11/a-very-good-start.html

Related links:

Expedition 61: https://www.nasa.gov/mission_pages/station/expeditions/expedition61/index.html

Rodent research study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7906

3-D video camera: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7877

Kibo laboratory module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory

Canadarm2: https://www.nasa.gov/mission_pages/station/structure/elements/mobile-servicing-system.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

First Detection of Sugars in Meteorites Gives Clues to Origin of Life

NASA - OSIRIS-REx Mission patch.

Nov. 19, 2019

An international team has found sugars essential to life in meteorites. The new discovery adds to the growing list of biologically important compounds that have been found in meteorites, supporting the hypothesis that chemical reactions in asteroids – the parent bodies of many meteorites – can make some of life’s ingredients. If correct, meteorite bombardment on ancient Earth may have assisted the origin of life with a supply of life’s building blocks.

Image above: This is a mosaic image of asteroid Bennu, from NASA’s OSIRIS-REx spacecraft. The discovery of sugars in meteorites supports the hypothesis that chemical reactions in asteroids – the parent bodies of many meteorites – can make some of life’s ingredients. Image Credits: NASA/Goddard/University of Arizona.

The team discovered ribose and other bio-essential sugars including arabinose and xylose in two different meteorites that are rich in carbon, NWA 801 (type CR2) and Murchison (type CM2). Ribose is a crucial component of RNA (ribonucleic acid). In much of modern life, RNA serves as a messenger molecule, copying genetic instructions from the DNA molecule (deoxyribonucleic acid) and delivering them to molecular factories within the cell called ribosomes that read the RNA to build specific proteins needed to carry out life processes.

“Other important building blocks of life have been found in meteorites previously, including amino acids (components of proteins) and nucleobases (components of DNA and RNA), but sugars have been a missing piece among the major building blocks of life,” said Yoshihiro Furukawa of Tohoku University, Japan, lead author of the study published in the Proceedings of the National Academy of Sciences November 18. “The research provides the first direct evidence of ribose in space and the delivery of the sugar to Earth. The extraterrestrial sugar might have contributed to the formation of RNA on the prebiotic Earth which possibly led to the origin of life.”

Image above: Artist’s concept of meteors impacting ancient Earth. Some scientists think such impacts may have delivered water and other molecules useful to emerging life on Earth. Image Credits: NASA's Goddard Space Flight Center Conceptual Image Lab.

“It is remarkable that a molecule as fragile as ribose could be detected in such ancient material,” said Jason Dworkin, a co-author of the study at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “These results will help guide our analyses of pristine samples from primitive asteroids Ryugu and Bennu, to be returned by the Japan Aerospace Exploration Agency’s Hayabusa2 and NASA’s OSIRIS-REx spacecraft.”

Image above: This is a model of the molecular structure of ribose and an image of the Murchison meteorite. Ribose and other sugars were found in this meteorite. Image Credits: Yoshihiro Furukawa.

An enduring mystery regarding the origin of life is how biology could have arisen from non-biological chemical processes. DNA is the template for life, carrying the instructions for how to build and operate a living organism. However, RNA also carries information, and many researchers think it evolved first and was later replaced by DNA. This is because RNA molecules have capabilities that DNA lacks. RNA can make copies of itself without “help” from other molecules, and it can also initiate or speed up chemical reactions as a catalyst. The new work gives some evidence to support the possibility that RNA coordinated the machinery of life before DNA.

“The sugar in DNA (2-deoxyribose) was not detected in any of the meteorites analyzed in this study,” said Danny Glavin, a co-author of the study at NASA Goddard. “This is important since there could have been a delivery bias of extraterrestrial ribose to the early Earth which is consistent with the hypothesis that RNA evolved first.”

The team discovered the sugars by analyzing powdered samples of the meteorites using gas chromatography mass spectrometry, which sorts and identifies molecules by their mass and electric charge. They found that the abundances of ribose and the other sugars ranged from 2.3 to 11 parts per billion in NWA 801 and from 6.7 to 180 parts per billion in Murchison.

Since Earth is awash with life, the team had to consider the possibility that the sugars in the meteorites simply came from contamination by terrestrial life. Multiple lines of evidence indicate contamination is unlikely, including isotope analysis. Isotopes are versions of an element with different mass due to the number of neutrons in the atomic nucleus. For example, life on Earth prefers to use the lighter variety of carbon (¹²C) over the heavier version (¹³C). However, the carbon in the meteorite sugars was significantly enriched in the heavy ¹³C, beyond the amount seen in terrestrial biology, supporting the conclusion that it came from space.

OSIRIS-REx artist's concept. Image Credit: NASA

The team plans to analyze more meteorites to get a better idea of the abundance of the extraterrestrial sugars. They also plan to see if the extraterrestrial sugar molecules have a left-handed or right-handed bias. Some molecules come in two varieties that are mirror images of each other, like your hands. On Earth, life uses left-handed amino acids and right-handed sugars. Since it’s possible that the opposite would work fine – right-handed amino acids and left-handed sugars – scientists want to know where this preference came from. If some process in asteroids favors the production of one variety over the other, then maybe the supply from space via meteorite impacts made that variety more abundant on ancient Earth, which made it more likely that life would end up using it.

The research was funded by a Japan Society for the Promotion of Science KAKENHI (science grant), the National Institutes of Natural Sciences Astrobiology Center, Japan, the Institute of Low Temperature Science, Hokkaido University, the Simons Foundation, and the NASA Astrobiology Institute, Goddard Center for Astrobiology. Jason Dworkin and Danny Glavin are members of the Goddard Center for Astrobiology team.

Related links:

Hayabusa2: http://www.hayabusa2.jaxa.jp/en/

OSIRIS-REx: https://www.nasa.gov/osiris-rex and

OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer): http://www.nasa.gov/mission_pages/osiris-rex/index.html

Goddard Center for Astrobiology: https://astrobiology.gsfc.nasa.gov/

Proceedings of the National Academy of Sciences: https://www.pnas.org/content/early/2019/11/12/1907169116

Images (mentioned), Text, Credits: NASA/GSFC/Bill Steigerwald/Nancy Jones.

Greetings, Orbiter.ch

A very good start

ESA - Beyond Mission patch / EVA - Extra Vehicular Activities patch.

Nov. 19, 2019

The first spacewalk to service the Alpha Magnetic Spectrometer (AMS) could not have gone better. Lead spacewalker ESA astronaut Luca Parmitano is imaged here hitching a ride on the International Space Station’s 16-metre long robotic arm to kick off the first of four ventures to service the particle physics detector on 15 November.

While all spacewalks are a carefully planned and detailed affair, the four spacewalks for AMS are exceptionally difficult as the bus-sized dark matter detector was never designed to be maintained in space. But after three successful years of delivering ground breaking science, the decision was made to extend its lifetime.

The cooling pumps for AMS-02 need maintenance and without them it will no longer be able to collect data on the cosmic rays that are bombarding our planet. The first question spacewalk designers had to answer whether this was even possible.

The first spacewalk proved it was not only possible, but thanks to the planning and trained that began as early as 2017, Luca and his spacewalking partner Andrew Morgan could achieve more than scheduled – setting them in good stead for the next phase.

The spacewalk began, as they all do, with “prebreathing” for up to two hours. Similar to scuba divers, astronauts can suffer from the ‘bends’: quickly changing pressure can turn the nitrogen in human bodies into bubbles with serious symptoms. To avoid this, astronauts breathe pure oxygen to purge their bodies of nitrogen.

Luca and NASA astronaut Drew Morgan left the depressurised Quest airlock at 13:10 CET (12:10 GMT), with Luca grabbing the ride to AMS on the robotic arm controlled by NASA astronaut Jessica Meir while Drew ferried handrails and equipment by hand to the worksite.

The main task of this spacewalk was to remove the debris shield covering AMS, with an estimated three hours portioned for this task. Luca and Drew managed to jettison the debris shield to burn up safely in Earth’s atmosphere well ahead of schedule.

Luca and Drew also installed three handrails in the vicinity of AMS to prepare for the next spacewalks and removed zip ties on the AMS’ vertical support strut.

Amazingly, the duo were still well ahead of the six hours planned for the main task of removing the debris shield.

When time permits, mission control give spacewalkers some “get ahead” tasks. Although there were no get-ahead tasks planned for this spacewalk the duo was so far ahead of schedule that mission control agreed they continue work originally planned for the second AMS spacewalk. Luca removed the screws from a carbon-fibre cover under the insulation and passed the cover to Drew to jettison once again.

The pair cleaned up, took some photos of their killer views, gathered tools, and made their way back to the airlock, clocking in 6 hours and 39 minutes for this promising start to AMS maintenance.

The next spacewalk is scheduled for 22 November. Watch the spacewalk via ESA Web TV:
https://www.esa.int/ESA_Multimedia/ESA_Web_TV

Related articles & links:

Spacewalkers Complete First Excursion to Repair Cosmic Particle Detector
https://orbiterchspacenews.blogspot.com/2019/11/spacewalkers-complete-first-excursion.html

Leading the way
https://orbiterchspacenews.blogspot.com/2019/11/leading-way.html

Alpha Magnetic Spectrometer (AMS): https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station/AMS_ready_to_discover_the_particle_universe

Human Spaceflight: http://www.esa.int/ESA_Multimedia/Directorates/Human_Spaceflight/

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images, Text, Credits: ESA/NASA.

Best regards, Orbiter.ch

CASC - Kuaizhou-1A launches KL-α-A and KL-α-B satellites

CASC - China Aerospace Science and Technology Corporation logo / KZ-1A Y8 - Centispace-1-S1 patch.

Nov. 19, 2019

Kuaizhou-1A launches KL-α-A and KL-α-B satellites

A Kuaizhou-1A (KZ-1A) launch vehicle launched two satellites, KL-α-A and KL-α-B, from the Jiuquan Satellite Launch Center, Gansu Province, northwest China, on 17 November 2019, at 10:00 UTC (18:00 local time).

Kuaizhou-1A launches KL-α-A and KL-α-B satellites

KL-a-A and KL-a-B were developed by the Innovation Academy for Microsatellites of the Chinese Academy of Sciences and will be mainly used for Ka-band communication technology tests.

KL-a satellite

KZ-1A (快舟一号) is a type of low-cost solid-fuelled carrier rocket with high reliability, short preparation period and designed to launch low-orbit satellites weighing under 300 kg each. Kuaizhou-1A is developed by ExPace Technology Corporation, a subsidiary of China Aerospace Science and Industry Corporation (CASIC).

China Aerospace Science and Technology Corporation (CASC): http://english.spacechina.com/n16421/index.html

Images, Video, Text, Credits: China Central Television (CCTV)/SciNews/Günter Space Page/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Using AI to predict Earth’s future

ESA - European Space Agency logo.

Nov. 19, 2019

A recent ‘deep learning’ algorithm – despite having no innate knowledge of solar physics – could provide more accurate predictions of how the Sun affects our planet than current models based on scientific understanding.

Fresh from Earth

For decades, people have tried to predict the impact of the Sun on our planet’s atmosphere. Up until now, algorithms based on solar physics have been used to predict the shifting density of Earth’s atmosphere.

But with so many variables affecting the complex and dynamic layers of gases around Earth, Artificial Intelligence (AI) could provide real improvements in this area because of its ability to handle vastly more complex data, with important implications for how we fly missions in Earth orbit.

The Sun’s a real drag

The conditions in space vary depending on the mood swings of the Sun, known as ‘space weather’. The Sun spews out radiation in a constant stream, but it sometimes also sends out violent bursts of high energy particles that can directly hit our planet. These particles cause geomagnetic storms - temporary disturbances in Earth’s protective magnetic field.

What is space weather?

Earth’s atmosphere is also affected by these outbursts, as geomagnetic storms and increased ultraviolet light heat the upper atmosphere, causing it to expand. As heated air rises, its density at orbits of up to 1000 km increases, and satellites in the vicinity experience more resistance, or ‘drag’, causing them to slow down and shift orbit.

Without intervention, such as firing the thrusters to keep them aloft, satellites would slowly fall to Earth and burn up in the atmosphere. At mission control, we are routinely lifting the orbit of our fleet of Earth explorers.

Measuring cyclones

Improving these predictions would allow operators to plan longer and more accurate cycles of correction manoeuvres, meaning less thruster firings would be needed, increasing the amount of time satellites can spend gathering scientific data.

Vitally, our knowledge of the future position of spacecraft would also increase, so we could predict more accurately the chances of collisions in space, helping us to protect our spacecraft in the current space debris environment.

Atmospheric predictions

Two important factors are needed to make atmospheric predictions: the solar index and the geomagnetic index. Both measurements are taken from Earth, and collected in several places across the globe.

The solar index comes from what is called the ‘10.7cm Solar Radio Flux' – the amount of light emitted by the Sun with a wavelength of 10.7cm. ‘F10.7’, as it is also known, is an excellent proxy for solar activity, and because it can be observed in all weather conditions, measurements can be taken every day, come rain or shine.

Solar flare seen by ESA/NASA SOHO satellite 23 January

The geomagnetic index is used to characterise the size of storms in Earth’s magnetic field, caused by activity at the Sun. Such storms can severely disrupt electrical power grids, spacecraft operations, radio signals and of course the beautiful aurora borealis at the poles.

“We observe the past, but we can only predict the future” says Pere Ramos Bosch, Flight Dynamics Engineer at ESA's ESOC operations centre.

Space weather effects

“We currently use an algorithm developed long ago, that takes the evolution of the values of the F10.7 and geomagnetic indices from previous years, as well as knowledge of solar and atmospheric physics, to make predictions for the next 27 days.”

However, current predictions are in general pretty inaccurate. Although we haven’t lost a mission yet, our lack of understanding of how atmospheric density changes is the largest source of error when it comes to flying satellites in low-Earth orbit, such as the Aeolus wind mission and Sentinel series of Earth explorers.

Could AI make a difference?

ESA is now testing an entirely different algorithm that uses the same measured data from the Sun and Earth, but ignores physics altogether and instead employs ‘deep learning’. Teams are hoping it will use its ‘Long Short Term Memory’ to recognise complex relationships and patterns that we humans just cannot detect.

“We are about to start getting results, but it looks like AI is proving to make the best use of data available,” says David Remili, a Luxembourg National Trainee in ESA’s Artificial Intelligence and Operations Innovation Group who has been tasked with developing the AI prediction tool.

Predicting an unpredictable star

“It's a privilege to be given the resources to combine AI and astrophysics, and ultimately to positively impact how space missions are flown.”

So far the AI tool seems promising, but stay tuned to find out which algorithm better predicts the future, and whether we can use these new computing abilities to better understand the interactions between the Solar System and our home.

Solar warning

ESA's future Lagrange mission to monitor the Sun

ESA's future Lagrange mission will keep constant watch on the Sun. The satellite, located at the fifth Lagrange point, will send early warning of potentially harmful solar activity before it affects satellites in orbit or power grids on the ground, giving operators the time to act to protect vital infrastructure.

Related links:

ESOC Mission control: http://www.esa.int/About_Us/ESOC

Space debris: http://www.esa.int/Safety_Security/Space_Debris/About_space_debris

Aeolus: http://www.esa.int/Applications/Observing_the_Earth/Aeolus/Introducing_Aeolus

SOHO: http://soho.esac.esa.int/

Sentinel series: http://www.esa.int/Applications/Observing_the_Earth/Copernicus/Overview4

Solar Orbiter: http://www.esa.int/Safety_Security/Lagrange_mission2

Safety & Security: http://www.esa.int/Safety_Security

Images, Videos, Text, Credits: European Space Agency (ESA)/ATG medialab/NASA/Science Office, CC BY-SA 3.0 IGO.

Best regards, Orbiter.ch