Luxembourg firm enabling peek inside asteroid

ESA - Hera Mission logo / ESA - Aim Mission logo.

Nov. 18, 2019

Juventas CubeSat closing on asteroid

ESA’s Juventas is a tiny spacecraft assigned a very big goal. Small enough to fit in an aircraft carry-on bag, this nanosatellite would be carried to deep space by ESA’s proposed Hera mission, before diving down to perform the very first radar probe into the depths of an asteroid. A specialist Luxembourg-based company is developing the radar electronics to make this happen.

The Agency’s Hera mission for planetary defence is being presented to Europe’s space ministers for approval at Space19+ next week. The first mission to a binary asteroid system, Hera will carry two 6-unit ‘CubeSats’ – small spacecraft built up from standardised 10 cm boxes, making maximum use of the latest commercial technology.

APEX will survey the target asteroid’s surface, working like a mineral prospector, while Juventas will fly just 3 km away, operating a low-frequency radar to see deep into the body’s core – the first ever direct look into the mysterious interior of a space rock.

 Hera scans DART’s impact crater

Only 30x20x10 cm in size, Juventas is nevertheless as sophisticated as a full-size spacecraft, and is being planned by a Europe-wide team. Its design is being overseen for ESA by the GomSpace company in Luxembourg and Denmark with GMV in Romania.

Juventas’s radar instrument has been designed by France’s Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) at the Université Grenoble Alpes with Astronika in Poland, working on its deployable quartet of 1.5-m long radar antennas, larger in scale than the entire CubeSat.

Hera deploying CubeSats

That leaves EmTroniX in Luxembourg, working on the radar electronics and eventually their integration and testing. The 18-strong company was founded by two engineers in 2001, initially focused on automobile systems, going on to expand into other sectors including aircraft avionics and space.

“We’ve been active in the space sector for more than 10 years now,” explains co-founder Cedric Lorant, “including working with LuxSpace to pioneer Automatic Identification System (AIS) vessel tracking with the Pathfinder 2, VesselSat 1 and 2 missions.”

Hera's CubeSat companions

The internationally mandated AIS system enables port authorities and coast guards to track seagoing traffic. But the onboard transponders have a horizontal range of only around 74 km. This is sufficient for coastal tracking or ship-to-ship monitoring but means that traffic on the open ocean disappears into vast blind spots.

However AIS signals do reach much further in the vertical direction – all the way up to space. This fact is enabling a new industry of satellite-based ship tracking. The challenge is to disentangle overlapping AIS messages from highly-trafficked regions, and take account of the Doppler shifting due to satellites’ rapid motion. Achieving this has required high-performance systems and clever processing, expanding EmTroniX’s capabilities in the process.

AIS ship tracking from orbit

Mr Lorant adds: “For ESA we have developed and implemented algorithms for an autonomous software-defined radio transceiver digital signal processor – this was for the Proximity-1 UHF link, a communication standard optimised for Mars missions. We also collaborated with Thales Alenia Space on a high sensitivity ADS-B receiver for another Agency project.”

ADS-B, short for ‘Automatic Dependent Surveillance—Broadcast’, is the aircraft equivalent of AIS, requiring similarly sophisticated processing techniques to achieve accurate positioning from Earth orbit.

ADS-B aircraft tracking from orbit

“All these projects have contributed to increasing our competences,” notes the co-founder. “For example we started with our first project in the VHF frequency bands and are now working on projects in the X and soon Ka frequency bands.”

Juventas presents a new challenge, to set up a working radar system on such a small platform, in the demanding environment of deep space rather than Earth orbit.

Juventas radar CubeSat

“We have worked on several missions based on microsatellites, and currently CubeSat avionics. All the same Juventas will be one of the smallest platforms we will work on,” adds Mr Lorant. “It will not be our first mission beyond Earth orbit however, but our second. In 2015 we collaborated on the 4M Manfred Moon Memorial Mission, commemorating the founder of OHB, which flew over the Moon.”

Operating beyond the protection of Earth’s magnetic field involves designing for a higher level of radiation, Mr Lorant explains: “Hopefully the payload will sleep during its travel time, helping tackle the radiation challenges. Its electronics will be well shielded, with redundancies used wherever possible, according to the size, weight and power consumption.

4M Manfred Moon Memorial Mission

“We’re making a lot of use of commercial off the shelf components, which give performance advantages, based on our previous mission experience. Our philosophy is always to improve our electronics quality by careful component selection and proper protection, using ‘derating’ – meaning operating below maximum power levels – to create a robust design.

“For the instrument itself, the big challenge is that the electronics should not perturb the operating modes of the radar in any way. There are a lot of specific requirements, for instance that we must generate an extremely low noise with stable clocks, and while working within the limits of our power and size.”

Juventas CubeSat coming in for asteroid landing

Juventas’s radar is tiny compared to the large-scale radar instruments used in planetary missions like Mars Express. But the instrument can boost its overall signal-to-noise ratio by taking advantage of its relatively slow orbit around the asteroid – around a few metres a second – to send the same signal multiple times, carefully coded to support subsequent disentangling of the reflected signals.

Hera: ESA’s planetary defence mission

“This is a really exciting and challenging mission for us,” says Mr Lorant. “And our hope it goes further than simply the Hera mission and Juventas. This radar could become an extremely useful tool for many future asteroid missions, such as ESA’s follow-up M-Argo nanosatellite, and other space resources endeavours.”

Related links:

Hera mission for planetary defence: http://www.esa.int/Safety_Security/Hera

Space19+: http://blogs.esa.int/space19plus/

APEX: https://www.esa.int/Safety_Security/Hera/Hera_s_APEX_CubeSat_will_reveal_the_stuff_that_asteroids_are_made_of

GomSpace: https://gomspace.com/home.aspx

GMV: https://www.gmv.com/en/

Université Grenoble Alpes: https://www.univ-grenoble-alpes.fr/international/international-2060.kjsp

Planétologie et d'Astrophysique de Grenoble (IPAG): https://ipag.osug.fr/english/the-institute/contact-access/

EmTroniX: https://www.emtronix.lu/

LuxSpace: https://luxspace.lu/

M-Argo nanosatellite: http://www.esa.int/ESA_Multimedia/Images/2019/11/Suitcase-sized_asteroid_explorer

Images, Video, Text, Credits: ESA/Science Office/GomSpace/LuxSpace.

Greetings, Orbiter.ch

French earthquake fault mapped

ESA - Sentinel-1 Mission logo.

Nov. 18, 2019

This week, southeast France was hit by a magnitude 5 earthquake with tremors felt between Lyon and Montélimar. The Copernicus Sentinel-1 radar mission has been used to map the way the ground shifted as a result of the quake.

Earthquakes are unusual in this part of France, but on 11 November at noon (local time) part of the Auvergne-Rhône-Alpes region was rocked by a quake leading to people having to be evacuated and buildings damaged.

Scientists are turning to satellite-based radar observations to help understand the nature of the seismic fault and map its location.

Earthquake ground shift

By combining imagery acquired before and after a quake, changes on the ground that occurred between the two acquisition dates lead to rainbow-coloured interference patterns in the combined image, known as an ‘interferogram’, which allows scientists to quantify ground movement.

An acquisition by Copernicus Sentinel-1 was made on 12 November, one day after the event, and was ready to process on ESA’s Geohazards Exploitation Platform (GEP), which is a cloud-based processing environment with on-demand terrain motion mapping services.

Several users have computed interferograms over the concerned region.

While several faults are present in the region and marked in geological maps, none were known to be seismically active. The interferogram here shows a series of fringes in the area west of the city of Le Teil and has allowed scientists to identify the fault at the origin of the earthquake. The satellite observation also measured a ground displacement that corresponds to an uplift of up to 8 cm in the southern part of the fault.

French earthquake interferogram

The intensity of the ground motion felt by the inhabitants and measured from space is unusual for this magnitude of event unless the earthquake epicentre is shallow and, indeed, seismic data put the epicentre at between 1 km and 3.5 km below the surface. Observations in the field on 13 November suggest that the rupture propagated up to the surface.

Floriane Provost, Research Fellow at ESA, said, “The rapid release to the public of up-to-date Copernicus Sentinel-1 based products visualised in a friendly fashion on the GEP geobrowser was followed by a peak of connections. It helped the scientific community better map the location of the fault and to confirm the mechanism of the earthquake.

“This example shows how the GEP environment contributes to the rapid processing and exchange of information within the geohazards community.”

Sentinel-1 radar vision

Michael Foumelis, researcher at the French Geological Survey BRGM, added, “Field investigations by BRGM experts are on-going, while interferometric synthetic aperture radar results are actually helping them to correlate the distribution of damage with the location of the activated fault and measured ground displacements.”

Read more about mapping faults on ESA’s Earth Observation Science for Society website: https://eo4society.esa.int/2019/07/30/mapping-the-faults-of-2019-california-earthquakes-with-sentinel-1-2/

Related links:

Sentinel-1: http://www.esa.int/Applications/Observing_the_Earth/Copernicus/Sentinel-1

Copernicus: http://www.esa.int/Applications/Observing_the_Earth/Copernicus

Observing the Earth: http://www.esa.int/Applications/Observing_the_Earth

Images, Text, Credits: ESA/Contains modified Copernicus Sentinel data (2019), processed by BRGM/contains modified Copernicus Sentinel data (2019), processed by ESA/ATG medialab.

Greetings, Orbiter.ch

Advanced Tech, Biology Research in Between Spacewalks

ISS - Expedition 61 Mission patch.

November 18, 2019

The Expedition 61 crew is starting the workweek in between spacewalks and running a variety advanced space investigations. A set of small satellites is also being readied for deployment outside the International Space Station by midweek.

NASA Flight Engineer Andrew Morgan and ESA (European Space Agency) Commander Luca Parmitano are gearing up for another spacewalk set to begin on Friday at 7:05 a.m. EST. Astronauts Jessica Meir and Christina Koch spent an hour reviewing robotics procedures for Friday’s spacewalk. Meir then joined Parmitano and Morgan in the afternoon to study details supporting the second Alpha Magnetic Spectrometer repair spacewalk.

Image above: This Wednesday, three small satellites will be deployed from the International Space Station. Here, a set of three CubeSats are ejected from the Japanese Small Satellite Orbital Deployer attached to a robotic arm outside the Japan Aerospace Exploration Agency’s Kibo laboratory module on June 17, 2019. Image Credit: NASA.

Morgan started his day setting up small satellites inside a deployer that will be ejected outside Japan’s Kibo laboratory module on Wednesday morning. Parmitano practiced robotic rover technology that future space crews could use to explore a planetary surface before landing humans.

Koch tested the operation of a 3D bioprinter today without using actual cells for its potential to manufacture complex human organ tissue shapes in space. She also fed lab mice being monitored for therapeutic insights into Earth-bound ailments.

International Space Station (ISS). Animation Credit: NASA

Cosmonauts Alexander Skvortsov and Oleg Skripochka collaborated Monday and researched how the human digestion system is impacted by microgravity. The duo then reviewed Soyuz MS-15 crew ship systems before working on a variety of life support maintenance.

Related links:

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

Alpha Magnetic Spectrometer (AMS): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=729

Small satellites: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8070

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

Robotic rover technology: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1863

3D bioprinter: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7599

Therapeutic insights into Earth-bound ailments: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7906

Human digestion system: https://www.energia.ru/en/iss/researches/human/09.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

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Catherine Williams.

Best regards, Orbiter.ch

NASA Scientists Confirm Water Vapor on Europa

NASA - Europa Clipper Mission patch.

Nov. 18, 2019

Forty years ago, a Voyager spacecraft snapped the first closeup images of Europa, one of Jupiter’s 79 moons. These revealed brownish cracks slicing the moon’s icy surface, which give Europa the look of a veiny eyeball. Missions to the outer solar system in the decades since have amassed enough additional information about Europa to make it a high-priority target of investigation in NASA’s search for life.

What makes this moon so alluring is the possibility that it may possess all of the ingredients necessary for life. Scientists have evidence that one of these ingredients, liquid water, is present under the icy surface and may sometimes erupt into space in huge geysers. But no one has been able to confirm the presence of water in these plumes by directly measuring the water molecule itself. Now, an international research team led out of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, has detected the water vapor for the first time above Europa’s surface. The team measured the vapor by peering at Europa through one of the world’s biggest telescopes in Hawaii.

Image above: On the left is a view of Europa taken from 2.9 million kilometers (1.8 million miles) away on March 2, 1979 by the Voyager 1 spacecraft. Next is a color image of Europa taken by the Voyager 2 spacecraft during its close encounter on July 9, 1979. On the right is a view of Europa made from images taken by the Galileo spacecraft in the late 1990s. Image Credits: NASA/JPL.

Confirming that water vapor is present above Europa helps scientists better understand the inner workings of the moon. For example, it helps support an idea, of which scientists are confident, that there’s a liquid water ocean, possibly twice as big as Earth’s, sloshing beneath this moon’s miles-thick ice shell. Another source of water for the plumes, some scientists suspect, could be shallow reservoirs of melted water ice not far below Europa’s surface. It’s also possible that Jupiter’s strong radiation field is stripping water particles from Europa’s ice shell, though the recent investigation argued against this mechanism as the source of the observed water.

“Essential chemical elements (carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur) and sources of energy, two of three requirements for life, are found all over the solar system. But the third — liquid water — is somewhat hard to find beyond Earth,” said Lucas Paganini, a NASA planetary scientist who led the water detection investigation. “While scientists have not yet detected liquid water directly, we’ve found the next best thing: water in vapor form.”

Paganini and his team reported in the journal Nature Astronomy on November 18 that they detected enough water releasing from Europa (5,202 pounds, or 2,360 kilograms, per second) to fill an Olympic-size swimming pool within minutes. Yet, the scientists also found that the water appears infrequently, at least in amounts large enough to detect from Earth, said Paganini: “For me, the interesting thing about this work is not only the first direct detection of water above Europa, but also the lack thereof within the limits of our detection method.”

Animation above: Water molecules emit specific frequencies of infrared light as they interact with solar radiation. Animation Credits: Michael Lentz/NASA Goddard.

Indeed, Paganini’s team detected the faint yet distinct signal of water vapor just once throughout 17 nights of observations between 2016 and 2017. Looking at the moon from the W. M. Keck Observatory atop the dormant Mauna Kea volcano in Hawaii, the scientists saw water molecules at Europa’s leading hemisphere, or the side of the moon that’s always facing in the direction of the moon’s orbit around Jupiter. (Europa, like Earth’s moon, is gravitationally locked to its host planet, so the leading hemisphere always faces the direction of the orbit, while the trailing hemisphere always faces in the opposite direction.)

They used a spectrograph at the Keck Observatory that measures the chemical composition of planetary atmospheres through the infrared light they emit or absorb. Molecules such as water emit specific frequencies of infrared light as they interact with solar radiation.

Mounting Evidence for Water

Before the recent water vapor detection, there have been many tantalizing findings on Europa. The first came from NASA’s Galileo spacecraft, which measured perturbations in Jupiter’s magnetic field near Europa while orbiting the gas giant planet between 1995 and 2003. The measurements suggested to scientists that electrically conductive fluid, likely a salty ocean beneath Europa’s ice layer, was causing the magnetic disturbances. When researchers analyzed the magnetic disturbances more closely in 2018, they found evidence of possible plumes.

In the meantime, scientists announced in 2013 that they had used NASA’s Hubble Space Telescope to detect the chemical elements hydrogen (H) and oxygen (O) — components of water (H2O) — in plume-like configurations in Europa’s atmosphere. And a few years later, other scientists used Hubble to gather more evidence of possible plume eruptions when they snapped photos of finger-like projections that appeared in silhouette as the moon passed in front of Jupiter.

“This first direct identification of water vapor on Europa is a critical confirmation of our original detections of atomic species, and it highlights the apparent sparsity of large plumes on this icy world” said Lorenz Roth, an astronomer and physicist from KTH Royal Institute of Technology in Stockholm who led the 2013 Hubble study and was a co-author of this recent investigation.

Roth’s research, along with other previous Europa findings, have only measured components of water above the surface. The trouble is that detecting water vapor at other worlds is challenging. Existing spacecraft have limited capabilities to detect it, and scientists using ground-based telescopes to look for water in deep space have to account for the distorting effect of water in Earth’s atmosphere. To minimize this effect, Paganini’s team used complex mathematical and computer modeling to simulate the conditions of Earth’s atmosphere so they could differentiate Earth’s atmospheric water from Europa’s in data returned by the Keck spectrograph.

Water Vapor Plumes on Europa. Video Credits: NASA Goddard

“We performed diligent safety checks to remove possible contaminants in ground-based observations,” said Avi Mandell, a Goddard planetary scientist on Paganini’s team. “But, eventually, we’ll have to get closer to Europa to see what’s really going on.”

Scientists will soon be able get close enough to Europa to settle their lingering questions about the inner and outer workings of this possibly habitable world. The forthcoming Europa Clipper mission, expected to launch in the mid-2020s, will round out half a century of scientific discovery that started with a modest photo of a mysterious, veiny eyeball.

When it arrives at Europa, the Clipper orbiter will conduct a detailed survey of Europa’s surface, deep interior, thin atmosphere, subsurface ocean, and potentially even smaller active vents. Clipper will try to take images of any plumes and sample the molecules it finds in the atmosphere with its mass spectrometers. It will also seek out a fruitful site from which a future Europa lander could collect a sample. These efforts should further unlock the secrets of Europa and its potential for life.

Other Goddard researchers on Paganini’s team included Geronimo Villanueva, Michael Mumma, and Terry Hurford. Kurt Retherford, from Southwest Research Institute, also contributed to the research.

Related links:

Nature Astronomy: https://www.nature.com/articles/s41550-019-0933-6

Europa Clipper: http://www.nasa.gov/europa

Goddard Space Flight Center (GSFC): https://www.nasa.gov/centers/goddard/home/index.html

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Svetlana Shekhtman/GSFC/Nancy Neal Jones, by Lonnie Shekhtman.

Greetings, Orbiter.ch

The First Global Geologic Map of Titan Completed

NASA & ESA - Cassini International logo.

November 18, 2019

The first map showing the global geology of Saturn's largest moon, Titan, has been completed and fully reveals a dynamic world of dunes, lakes, plains, craters and other terrains.

Titan is the only planetary body in our solar system other than Earth known to have stable liquid on its surface. But instead of water raining down from clouds and filling lakes and seas as on Earth, on Titan what rains down is methane and ethane - hydrocarbons that we think of as gases but that behave as liquids in Titan's frigid climate.

Image above: The first global geologic map of Titan is based on radar and visible-light images from NASA's Cassini mission, which orbited Saturn from 2004 to 2017. Labels point to several of the named surface features. Image Credits: NASA/JPL-Caltech/ASU.

"Titan has an active methane-based hydrologic cycle that has shaped a complex geologic landscape, making its surface one of most geologically diverse in the solar system," said Rosaly Lopes, a planetary geologist at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of new research used to develop the map.

"Despite the different materials, temperatures and gravity fields between Earth and Titan, many surface features are similar between the two worlds and can be interpreted as being products of the same geologic processes. The map shows that the different geologic terrains have a clear distribution with latitude, globally, and that some terrains cover far more area than others."

Lopes and her team, including JPL's Michael Malaska, worked with fellow planetary geologist David Williams of the School of Earth and Space Exploration at Arizona State University in Tempe. Their findings, which include the relative age of Titan's geologic terrains, were recently published in the journal Nature Astronomy.

Image above: The colorful globe of Titan passes in front of Saturn and its rings in this true-color snapshot from NASA's Cassini spacecraft in 2011. Image credits: NASA/JPL-Caltech/Space Science Institute.

Lopes' team used data from NASA's Cassini mission, which operated between 2004 and 2017 and did more than 120 flybys of the Mercury-size moon. Specifically, they used data from Cassini's radar imager to penetrate Titan's opaque atmosphere of nitrogen and methane. In addition, the team used data from Cassini's visible and infrared instruments, which were able to capture some of Titan's larger geologic features through the methane haze.

"This study is an example of using combined datasets and instruments," Lopes said. "Although we did not have global coverage with synthetic aperture radar [SAR], we used data from other instruments and other modes from radar to correlate characteristics of the different terrain units so we could infer what the terrains are even in areas where we don't have SAR coverage."

Williams worked with the JPL team to identify what geologic units on Titan could be determined using first the radar images and then to extrapolate those units to the non-radar-covered regions. To do so, he built on his experience working with radar images on NASA's Magellan Venus orbiter and from a previous regional geologic map of Titan that he developed.

 Cassini Titan flyby. Image Credits: NASA/ESA

"The Cassini mission revealed that Titan is a geologically active world, where hydrocarbons like methane and ethane take the role that water has on Earth," Williams said. "These hydrocarbons rain down on the surface, flow in streams and rivers, accumulate in lakes and seas, and evaporate into the atmosphere. It's quite an astounding world!"

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency (ESA) and the Italian Space Agency. NASA's JPL, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and several European countries.

More information about Cassini can be found here: https://solarsystem.nasa.gov/cassini

Nature Astronomy: https://www.nature.com/articles/s41550-019-0917-6

School of Earth and Space Exploration: https://sese.asu.edu/

Images (mentioned), Text, Credits: NASA/Alana Johnson/JPL/Gretchen McCartney/School of Earth and Space Exploration/Karin Valentine.

Best regards, Orbiter.ch

Hibernating astronauts would need smaller

ESA - European Space Agency patch / HIbernation and torpor study logo.

Nov. 18, 2019

If a sci-fi spaceship does not come with hyperdrive then it is usually fitted with hibernation capsules instead. In movies from 2001: A Space Odyssey to Event Horizon, Alien to Passengers, fictional astronauts get put into ‘suspended animation’ to cross the vastness of space. Now ESA has investigated how real life crew hibernation would impact space mission design.

Hibernation pods in Alien movie

Human hibernation has been the subject of initial research within the Discovery element of ESA’s Basic Activities, then recommended as a key ‘enabling technology’ for space by the Agency’s Future Technology Advisory Panel, resulting in a dedicated ‘Topical Team’ on hibernation.

Now the Agency’s SciSpacE team has called in ESA’s Concurrent Design Facility – a multimedia facility enabling expert teams to perform initial evaluations of proposed future missions – to assess the advantages of human hibernation for a trip to a neighbouring planet, such as Mars.

Concurrent Design Facility

Beginning with an assessment on the current state of the art in human hibernation, with the help of ESA Topical Team scientists from Ludwig Maximilian University of Munich and the University of Goethe, Frankfurt, the CDF team went to investigate for the first time the potential impact of hibernation on system-level mission design. They took as their reference an existing mission study to send six humans to Mars and back in a five year timescale.

“We worked on adjusting the architecture of the spacecraft, its logistics, protection against radiation, power consumption and overall mission design,” comments Robin Biesbroek of the CDF.

“We looked at how an astronaut team could be best put into hibernation, what to do in case of emergencies, how to handle human safety and even what impact hibernation would have on the psychology of the team. Finally we created an initial sketch of the habitat architecture and created a roadmap to achieve a validated approach to hibernate humans to Mars within 20 years.”

Standard habitat module compared to a hibernation module

The study found the spacecraft mass could be reduced by a third by removing the crew quarters with a similar reduction in consumables, equivalent to several tons of saved mass. Hibernation would take place in small individual pods that would double as cabins while the crew are awake.

The assumption was that a drug would be administered to induce ‘torpor’ – the term for the hibernating state. Like hibernating animals, the astronauts would be expected to acquire extra body fat in advance of torpor. Their soft-shell pods would be darkened and their temperature greatly reduced to cool their occupants during their projected 180-day Earth-Mars cruise.

Hibernation module

The hibernating cruise phase would end with a 21 day recuperation period – although based on the experience of animal hibernation, the expectation would be that the crew would not experience bone or muscle wastage.

Radiation exposure from high-energy particles is a key hazard of deep space travel, but because the hibernating crew will be spending so much time in their hibernation pods, then shielding – such as water containers – could be concentrated around them. And existing research into hibernation shows it gives enhanced radiation protection in its own right.

Hibernation pods

But with all the crew incapacitated for extended periods of time, the mission would have to be designed for largely autonomous operations, with optimum use of artificial intelligence and ‘fault detection, isolation and recovery’ to maintain a minimum level of system performance until the crew could be revived.

“For a while now hibernation has been proposed as a game-changing tool for human space travel,” explains SciSpacE Team Leader Jennifer Ngo-Anh. ‘If we were able to reduce an astronaut’s basic metabolic rate by 75% – similar to what we can observe in nature with large hibernating animals such as certain bears – we could end up with substantial mass and cost savings, making long-duration exploration missions more feasible.

HIbernation and torpor study logo

“And the basic idea of putting astronauts into long-duration hibernation is actually not so crazy: a broadly comparable method has been tested and applied as therapy in critical care trauma patients and those due to undergo major surgeries for more than two decades. Most major medical centres have protocols for inducing hypothermia in patients to reduce their metabolism to basically gain time, keeping patients in a better shape than they otherwise would be.

“We aim to build on this in future, by researching the brain pathways that are activated or blocked during initiation of hibernation, starting with animals and proceeding to people.”

Related links:

Enabling & Support: http://www.esa.int/Enabling_Support

Space Engineering & Technology: http://www.esa.int/Enabling_Support/Space_Engineering_Technology

European Space Agency (ESA): http://www.esa.int/

Images, Text, Credits: ESA/G. Porter/NASA/20th Century Fox.

Greetings, Orbiter.ch

Earth’s magnetic song recorded for the first time during a solar storm

ESA - Cluster Mission patch.

Nov. 18, 2019

Data from ESA’s Cluster mission has provided a recording of the eerie ‘song’ that Earth sings when it is hit by a solar storm.

The song comes from waves that are generated in the Earth’s magnetic field by the collision of the storm. The storm itself is the eruption of electrically charged particles from the Sun’s atmosphere.

The foreshock in Earth’s magnetic environment

A team led by Lucile Turc, a former ESA research fellow who is now based at the University of Helsinki, Finland, made the discovery after analysing data from the Cluster Science Archive. The archive provides access to all data obtained during Cluster’s ongoing mission over almost two decades.

Cluster consists of four spacecraft that orbit Earth in formation, investigating our planet’s magnetic environment and its interaction with the solar wind – a constant flow of particles released by the Sun into the Solar System.

As part of their orbits, the Cluster spacecraft repeatedly fly through the foreshock, which is the first region that particles encounter when a solar storm hits our planet. The team found that in the early part of the mission, from 2001 to 2005, the spacecraft flew through six such collisions, recording the waves that were generated.

The new analysis shows that, during the collision, the foreshock is driven to release magnetic waves that are much more complex than first thought.

“Our study reveals that solar storms profoundly modify the foreshock region,” says Lucile.

When the frequencies of these magnetic waves are transformed into audible signals, they give rise to an uncanny song that might recall more the sound effects of a science fiction movie than a natural phenomenon.

Earth’s magnetic song during calm space weather conditions

In quiet times, when no solar storm is striking the Earth, the song is lower in pitch and less complex, with one single frequency dominating the oscillation. When a solar storm hits, the frequency of the wave is roughly doubled, with the precise frequency of the resulting waves being dependent on the strength of the magnetic field in the storm.

“It’s like the storm is changing the tuning of the foreshock,” explains Lucile.

Earth’s magnetic song during a solar storm

And it doesn’t stop there because not only does the frequency of the wave change but it also becomes much more complicated than the single frequency present in quiet times. Once the storm hits the foreshock, the wave breaks into a complex network of different, higher frequencies.

Computer simulations of the foreshock, performed using a model called Vlasiator, which is being developed at the University of Helsinki, demonstrate the intricate wave pattern that appears during solar storms.

The changes in the foreshock have the power to affect the way the solar storm is propagated down to the Earth’s surface. Although it is still an open question exactly how this process works, it is clear that the energy generated by waves in the foreshock cannot escape back into space, as the waves are pushed towards Earth by the incoming solar storm.

Simulation of Earth’s foreshock during calm space weather conditions

Before they reach our atmosphere, however, the waves encounter another barrier, the bow shock, which is the magnetic region of space that slows down solar wind particles before they collide with Earth's magnetic field. The collision of the magnetic waves modifies the behaviour of the bow shock, possibly changing the way it processes the energy of the incoming solar storm.

Behind the bow shock, the magnetic fields of Earth start to resonate at the frequency of the waves and this contributes to transmit the magnetic disturbance all the way to the ground. It is a fast process, taking around ten minutes from the wave being generated at the foreshock to its energy reaching the ground.

Lucile and colleagues are now working to understand exactly how these complex waves are generated.

“We always expected a change in frequency but not the level of complexity in the wave,” she adds.

Simulation of Earth’s foreshock during a solar storm

Solar storms are a part of space weather. While the solar wind is always blowing, explosive releases of energy close to the Sun’s surface generate turbulence and gusts that eventually give rise to solar storms.

Understanding space weather has become increasingly important to society because of the damaging effects solar storms can have on sensitive electronics and technology on ground and in space. It is now more important than ever that we understand how space weather disturbances such as solar storms propagate through the Solar System and down to Earth, and ESA’s upcoming Solar Orbiter mission, scheduled for launch in February 2020, will greatly contribute to these investigations.

Cluster Constellation

This new scientific study based on the long-lived Cluster mission provides another detail in that knowledge but it also has a larger role to play in our understanding of the Universe. Magnetic fields are ubiquitous and so the kind of complex interaction seen in Earth’s foreshock may take place in a variety of cosmic environments, including exoplanets orbiting close to their parent star, as they would be immersed in intense magnetic fields.

“This is an excellent example of how Cluster continues to extend our knowledge of the Sun-Earth connection, even years after the original data was obtained,” says Philippe Escoubet, ESA Project Scientist for Cluster.

“The results take us deeper into the details of fundamental magnetic interactions that take place across the Universe.”

Notes for editors:

First observations of the disruption of the Earth’s foreshock wave field during magnetic clouds by L. Turc et al is published in Geophysical Research Letters:

https://doi.org/10.1029/2019GL084437

The audio files with the sonification of the Cluster measurements are available on ESA’s Soundcloud page: https://soundcloud.com/esa

Related links:

ESA Cluster: https://sci.esa.int/web/cluster/

Space weather: http://www.esa.int/Safety_Security/This_week_we_re_under_the_space_weather

ESA Solar Orbiter: http://www.esa.int/Science_Exploration/Space_Science/Solar_Orbiter

Images, Videos, Text, Credits: ESA/Philippe Escoubet/University of Helsinki, Department of Physics/Lucile Turc/Vlasiator team, University of Helsinki.

Best regards, Orbiter.ch