samedi 23 décembre 2017

NASA Remembers Astronaut Bruce McCandless II

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Dec. 23, 2017

Former NASA astronaut Bruce McCandless II, mission specialist on the STS-41B and STS-31 missions, passed away on Dec. 21, 2017, at the age of 80.

Image above: Official Space Shuttle portrait showing Astronaut Bruce McCandless II, attired in the Shuttle Extravehicular Activity (EVA) Suit with Manned Maneuvering Unit (MMU) attached and American flag in background. Image Credit: NASA.

Gallery: Images of Astronaut Bruce McCandless II:
Biography: Bruce McCandless II:

McCandless is perhaps best remembered as the subject of a famous NASA photograph (below right), flying alongside the space shuttle in the Manned Maneuvering Unit (MMU) -- the first astronaut to fly untethered from his spacecraft. His time as an astronaut encompassed much more than that mission, including serving as the Mission Control communicator for Neil Armstrong and Buzz Aldrin's moonwalk on the Apollo 11 mission.

"Our thoughts and prayers go out to Bruce's family," said acting NASA Administrator Robert Lightfoot. "He will always be known for his iconic photo flying the MMU."

McCandless, a retired U. S. Navy captain, was one of the 19 astronauts selected by NASA in April 1966. He was a member of the astronaut support crew for the Apollo 14 mission and was backup pilot for the first crewed Skylab mission. He flew as a mission specialist on two space shuttle missions. On STS-41B in 1984, he performed the famous spacewalk and on STS-31 in 1990 he helped deploy the Hubble Space Telescope.

Of his famous spacewalk, he wrote in 2015: "My wife [Bernice] was at mission control, and there was quite a bit of apprehension. I wanted to say something similar to Neil [Armstrong] when he landed on the moon, so I said, 'It may have been a small step for Neil, but it’s a heck of a big leap for me.' That loosened the tension a bit."

Born June 8, 1937, in Boston, McCandless graduated from Woodrow Wilson Senior High School, Long Beach, California. He received a bachelor of science degree from the United States Naval Academy in 1958, a master of science degree in Electrical Engineering from Stanford University in 1965, and a masters degree in Business Administration from the University of Houston at Clear Lake City in 1987.

Image above: Astronaut Bruce McCandless II, STS-41B mission specialist, uses his hands to control his movement above the Earth - and just few meters away from the space shuttle Challenger - during the first-ever spacewalk which didn't use restrictive tethers and umbilicals. Fellow crewmembers aboard the Challenger used a 70mm camera to expose this frame through windows on the flight deck. Image Credit: NASA.

He was a co-investigator on the M-509 astronaut maneuvering unit experiment which was flown in the Skylab Program and collaborated on the development of the MMU. He was responsible for crew inputs to the development of hardware and procedures for the Inertial Upper Stage (IUS), the Hubble Space Telescope, the Solar Maximum Repair Mission, and the Space Station Program. McCandless logged more than 312 hours in space, including four hours of flight time using the MMU.

Among the awards and honors received by McCandless are the Legion of Merit (1988); Department of Defense Distinguished Service Medal (1985); National Defense Service Medal; American Expeditionary Service Medal; NASA Exceptional Service Medal (1974); American Astronautical Society Victor A. Prather Award (1975 & 1985); NASA Space Flight Medal (1984); NASA Exceptional Engineering Achievement Medal (1985); National Aeronautic Association Collier Trophy (1985); Smithsonian Institution National Air and Space Museum Trophy (1985). He was awarded one patent for the design of a tool tethering system that was used during shuttle spacewalks.

Captain McCandless was the son of the late Rear Admiral (USN) and Mrs. Bruce McCandless. Admiral McCandless received the Congressional Medal of Honor for the naval battle of Guadalcanal, Dec. 12-13, 1942. He passed away in 1968. His paternal grandfather, Commodore (later Rear Admiral) Byron McCandless, USN, received the Navy Cross for World War I, and his maternal grandfather, Captain Willis Winter Bradley, USN, was the first recipient of the Congressional Medal of Honor in World War I.

Captain McCandless is survived by his wife, Ellen Shields McCandless of Conifer, Colorado; his son, Bruce McCandless III of Austin, Texas and his wife, Patricia; his daughter, Tracy McCandless, of Islamorada, Florida, and two granddaughters, Emma Rose and Carson Clare McCandless of Austin.  He is also survived by a brother, Douglas M. McCandless of Washington, D.C., and two sisters, Sue M. Woodridge of Texas, and Rosemary V. McCandless of Dallas, Texas.

Astronaut Bruce McCandless II Floats Free in Space

Video above: On Feb. 7, 1984, during the Space Shuttle Challenger’s STS-41B mission, NASA Astronaut Bruce McCandless II makes the first, untethered, free flight spacewalk in the Manned Maneuvering Unit. Video Credit: NASA.

Images (mentioned), Video (mentioned), Text, Credits: NASA/Sarah Loff.


Arecibo Radar Returns with Asteroid Phaethon Images

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December 23, 2017

Updated Version as of 11 am PST: corrections include close approach distance and size comparison to asteroid Bennu.

Image above: These radar images of near-Earth asteroid 3200 Phaethon were generated by astronomers at the National Science Foundation's Arecibo Observatory on Dec. 17, 2017. Observations of Phaethon were conducted at Arecibo from Dec.15 through 19, 2017. At time of closest approach on Dec. 16 at 3 p.m. PST (6 p.m. EST, 11 p.m. UTC) the asteroid was about 6.4 million miles (10.3 million kilometers) away, or about 27 times the distance from Earth to the moon. The encounter is the closest the asteroid will come to Earth until 2093. Image Credits: Arecibo Observatory/NASA/NSF.

After several months of downtime since Hurricane Maria struck the island of Puerto Rico, the Arecibo Observatory Planetary Radar has returned to normal operation, providing the highest-resolution images to date of near-Earth asteroid 3200 Phaethon during its December 2017 close approach to Earth. The radar images, which are subtle at the available resolution, reveal the asteroid is spheroidal (roughly ball-shaped) and has a large concavity, or depression, at least several hundred meters in extent near its equator, and a conspicuous dark, circular feature near one of the poles. Arecibo's radar images of Phaethon have resolutions as fine as about 250 feet (75 meters) per pixel.

"These new observations of Phaethon show it may be similar in shape to asteroid Bennu, the target of NASA's OSIRIS-REx spacecraft, but more than 1,000 Bennus could fit inside of Phaethon," said Patrick Taylor, a Universities Space Research Association (USRA), Columbia, Maryland, scientist and group leader for Planetary Radar at Arecibo Observatory. "The dark feature could be a crater or some other topographic depression that did not reflect the radar beam back to Earth."

Radar images obtained by Arecibo indicate Phaethon has a diameter of about 3.6 miles (6 kilometers) -- roughly 0.6 miles (1 kilometer) larger than previous estimates. Phaethon is the second largest near-Earth asteroid classified as "Potentially Hazardous." Near-Earth objects are classified as potentially hazardous asteroids (PHAs), based on their size and how closely they can approach Earth's orbit.

Animation above: Near-Earth asteroid 3200 Phaethon. Animation Credits: Arecibo Observatory/NASA/NSF.

Tracking and characterizing PHAs is a primary mission of NASA's Planetary Defense Coordination Office. Radar is a powerful technique for studying asteroid sizes, shapes, rotation, surface features and roughness, and for more precise determination of their orbital path, when they pass relatively close to Earth.

"Arecibo is an important global asset, crucial for planetary defense work because of its unique capabilities," said Joan Schmelz of USRA and deputy director of Arecibo Observatory. "We have been working diligently to get it back up and running since Hurricane Maria devastated Puerto Rico."

The Arecibo Observatory has the most powerful astronomical radar system on Earth. On Sept. 20, the telescope suffered minor structural damage when Maria, the strongest hurricane to hit the island since 1928, made landfall. Some days after the storm, the observatory resumed radio astronomy observations, while also serving as a base for relief efforts to surrounding communities. Radar observations, which require high power and diesel fuel for generators at the site, resumed operations in early December after commercial power returned to the observatory and the generators could then be used exclusively for the radar.

Asteroid 3200 Phaethon was discovered on Oct. 11, 1983, by NASA's Infrared Astronomical Satellite (IRAS), and the planetary dust that produces the annual Geminid meteor shower originates from this asteroid. Observations of Phaethon were conducted at Arecibo from Dec. 15 through 19, 2017, using the NASA-funded planetary radar system. At time of closest approach on Dec. 16 at 3 p.m. PST (6 p.m. EST, 11 p.m. UTC) the asteroid was about 6.4 million miles (10.3 million kilometers) away, or about 27 times the distance from Earth to the moon. The encounter is the closest the asteroid will come to Earth until 2093, but it came a little closer in 1974 and about half this distance back in 1931 before its existence was known.

The Arecibo Planetary Radar Program is funded by NASA's Near-Earth Object Observations Program through a grant to Universities Space Research Association (USRA), from the Near-Earth Object Observations program. The Arecibo Observatory is a facility of the National Science Foundation operated under cooperative agreement by SRI International, USRA, and Universidad Metropolitana.

NASA's Planetary Defense Coordination Office is responsible for finding, tracking and characterizing potentially hazardous asteroids and comets coming near Earth, issuing warnings about possible impacts, and assisting coordination of U.S. government response planning, should there be an actual impact threat.

More information about the National Science Foundation's Arecibo Observatory can be found at:

More information about asteroids and near-Earth objects can be found at:

For more information about NASA's Planetary Defense Coordination Office, visit:

For asteroid and comet news and updates, follow AsteroidWatch on Twitter:

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Dwayne Brown/JPL/DC Agle/Universities Space Research Association/Suraiya Farukhi .


CASC Long March 2D lofts LKW-2

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Dec. 23, 2017

Long March 2D launches LKW-2

The Chinese have launched the Yaogan Weixing remote sensing satellite – also known as the Land Surveying Satellite -2 (LKW-2) – via a Long March-2D (Chang Zheng-2D) on Saturday. The launch – from the Jiuquan Satellite Launch Center (JSLC) – took place at 04:14 UTC from the 603 Launch Platform at the LC43 Launch Complex.

China Launches Land Exploration Satellite

As per usual for the Chinese media, this spacecraft is once again classed as a new remote sensing bird that will be used for scientific experiments, land survey, crop yield assessment, and disaster monitoring.

As was the case in previous launches of the Yaogan Weixing series, analysts believe this class of satellites is used for military purposes.

As was the case with the former Soviet Union (and in a smaller scale with Russia) with the ‘Cosmos’ designation, the ‘Yaogan’ designation is used to hide the true military nature of the vehicles orbited.

LKW-2 satellite

The satellite is probably an electro-optical observation satellite, with the previous launch gaining the public name Land Surveying Satellite -1 (LKW-1).

For more information: China Aerospace Science and Technology Corporation (CASC):

Images, Video, Text, Credit: CASC/NASA Graham/CCTV+.


JAXA H-IIA rocket launches GCOM-C mission

JAXA - GCOM-C Mission patch.

Dec. 23, 2017

H-IIA rocket carrying GCOM-C Mission launch

Japan launched the second satellite of its Global Change Observation Mission Saturday. The GCOM-C satellite lifted off from the Tanegashima Space Centre atop an H-IIA rocket at the start of a 22-minute window that opened at 10:26:22 local time (01:26 UTC).

Saturday’s launch, also lofting the Super-Low Altitude Test Satellite (SLATS), was Japan’s seventh of the year. It came two and a half months after the rocket’s previous mission delivered the fourth QZSS navigation satellite into orbit.

Video above: JAXA H-2A Launching GCOM-C And SLATS Satellites Into Low Earth Orbit From Tanegashima Space Center. Video Credit: JAXA.

The Global Change Observation Mission (GCOM) is a project that is being undertaken by the Japan Aerospace Exploration Agency (JAXA) to study long-term changes in Earth’s climate and water cycle. The project’s first satellite – Shizuku, or GCOM-W – was launched in May 2012 with an expected five-year operational lifespan, and remains in service. Shizuku is dedicated to monitoring Earth’s water cycle, while the GCOM-C satellite that is being launched on Saturday will focus on climate change. Once in orbit, the satellite will be renamed Shikisai.

GCOM-C, which is also known as GCOM-C1, is a 2,093-kilogram (4,614 lb) spacecraft that is expected to operate for at least five years. The satellite carries an imaging payload that will allow it to monitor aspects of Earth’s climate. Its images will be used to study distributions of aerosols, water vapor and clouds in the atmosphere, to monitor the color and temperature of the oceans, snow and ice cover on land and to monitor vegetation and land usage.

The Super-Low Altitude Test Satellite, or SLATS, is an approximately-400-kilogram (880 lb) miniature satellite that was deployed into a lower orbit after GCOM-C separates from the carrier rocket. SLATS, which will be renamed Tsubame – meaning Swallow – after deployment, is a technology demonstration mission that will test the use an ion engine to allow the satellite to operate in a very low orbit without re-entering the atmosphere.

For more information about the mission, visit:

Images, Video, Text, Credits: JAXA/NASA Graham.

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SpaceX - Iridium-4 Mission Success

SpaceX - Iridium NEXT IV Mission patch.

Dec. 23, 2017

Image above: A SpaceX Falcon 9 rocket lifts off from Space Launch Complex 4E at Vandenberg Air Force Base. Image Credit: SpaceX.

The Falcon 9 mission, launched from Vandenberg Air Force Base in California at 8:27 p.m. Eastern in an instantaneous launch window, was the fourth of eight missions for Iridium, carrying the McLean, Virginia-based operator’s second generation satellites, called Iridium Next.

SpaceX - Iridium-4 Webcast

In what now is considered a rarity, SpaceX opted not to recover the rocket’s first stage, instead letting the booster fall into the Pacific Ocean. SpaceX has recovered 20 out of 42 first stage Falcon 9 boosters to date, with the first success following the launch of 11 Orbcomm satellites to low Earth orbit (LEO) in December 2015. Today’s launch was SpaceX’s fifth with a previously flown Falcon 9, using a first stage that had launched the second batch of 10 Iridium Next satellites back in June.

Iridium NEXT

This was the fourth set of 10 satellites in a series of 75 total satellites that SpaceX will launch for Iridium’s next generation global satellite constellation, Iridium® NEXT.

Related links:

Iridium NEXT:


Images, Video, Text, Credits: SpaceX/Iridium/ Aerospace.


vendredi 22 décembre 2017

Hubble's Holiday Nebula “Ornament”

NASA - Hubble Space Telescope patch.

Dec. 22, 2017

The Hubble Space Telescope captured what looks like a colorful holiday ornament in space. It's actually an image of NGC 6326, a planetary nebula with glowing wisps of outpouring gas that are lit up by a central star nearing the end of its life.

When a star ages and the red giant phase of its life comes to an end, it starts to eject layers of gas from its surface leaving behind a hot and compact white dwarf. Sometimes this ejection results in elegantly symmetric patterns of glowing gas, but NGC 6326 is much less structured. This object is located in the constellation of Ara, the Altar, about 11,000 light-years from Earth.
Planetary nebulae are one of the main ways in which elements heavier than hydrogen and helium are dispersed into space after their creation in the hearts of stars. Eventually some of this out-flung material may form new stars and planets.

This picture was created from images taken using the Hubble Space Telescope’s Wide Field Planetary Camera 2.  The vivid blue and red hues come from material including ionized oxygen and hydrogen glowing under the action of the fierce ultraviolet radiation from the still hot central star.

Hubble Space Telescope

For images and more information about Hubble, visit:

Image, Animation, Credits: ESA/Hubble & NASA/Text Credits: European Space Agency/NASA/Karl Hille.

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jeudi 21 décembre 2017

Crew Heads into Holidays with Bone and Muscle Research

ISS - Expedition 54 Mission patch.

Dec. 21, 2017

International Space Station (ISS). Animation Credit: NASA

Three veteran International Space Station crew members and three first-time astronauts will spend Christmas and New Year’s Eve orbiting Earth. They are continuing to research how living in space affects the human body and maintaining the orbital laboratory.

Veteran cosmonaut Anton Shkaplerov is spending his third holiday season in space having served on two previous Expeditions. He recently arrived Dec. 19 with NASA astronaut Scott Tingle and JAXA astronaut Norishige Kanai. Greeting the new crew were Expedition 54 Commander Alexander Misurkin and NASA astronauts Joe Acaba and Mark Vande Hei. Misurkin and Acaba are in the middle of their second station mission and this is Vande Hei’s first mission.

Today, the station residents explored why bone and muscle atrophy occur in space and ways to prevent that loss to keep astronauts healthy.

Image above: Expedition 54-55 Flight Engineer Norishige Kanai of the Japan Aerospace Exploration Agency is inside the International Space Station’s seven-windowed cupola as the Earth passes 250 miles below. Image Credit: NASA.

Kanai collected and stored his breath and blood samples for the Marrow study to understand what is happening to his bone marrow and blood cells during spaceflight. Kanai later joined Acaba peering at synthetic bone cells through a microscope. The synthetic material is being incubated and then integrated with real bone cells potentially benefitting bone health on Earth and in space.

Vande Hei studied zebrafish today observing how their muscles adapt to the microgravity environment. The experiment seeks to identify chemical, protein and cellular activity taking place during muscle atrophy that may lead to new drugs and treatments.

Related links:

Marrow study:

Synthetic bone cells:

Zebrafish study:

Expedition 54:

International Space Station (ISS):

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

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NASA Invests in Concept Development for Missions to Comet, Saturn Moon Titan

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Dec. 21, 2017

Image Credit: NASA

NASA has selected two finalist concepts for a robotic mission planned to launch in the mid-2020s: a comet sample return mission and a drone-like rotorcraft that would explore potential landing sites on Saturn’s largest moon, Titan.

The agency announced the concepts Wednesday, following an extensive and competitive peer review process. The concepts were chosen from 12 proposals submitted in April under a New Frontiers program announcement of opportunity.

“This is a giant leap forward in developing our next bold mission of science discovery,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “These are tantalizing investigations that seek to answer some of the biggest questions in our solar system today.”

The finalists are:

Comet Astrobiology Exploration Sample Return (CAESAR)

Image above: The CAESAR (Comet Astrobiology Exploration SAmple Return) mission will acquire a sample from the nucleus of comet Churyumov-Gerasimenko, returning it safely to Earth. Comets are made up of materials from ancient stars, interstellar clouds, and the birth of our solar system. The CAESAR sample will reveal how these materials contributed to the early Earth, including the origins of the Earth's oceans, and of life. Image Credit: NASA.

The CAESAR mission seeks to return a sample from 67P/Churyumov-Gerasimenko, a comet that was successfully explored by the European Space Agency’s Rosetta spacecraft, to determine its origin and history. Led by Steve Squyres of Cornell University in Ithaca, New York, CAESAR would be managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland.


Dragonfly is a drone-like rotorcraft that would explore the prebiotic chemistry and habitability of dozens of sites on Saturn’s moon Titan, an ocean world in our solar system. Elizabeth Turtle from the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, is the lead investigator, with APL providing project management.

Image above: Dragonfly is a dual-quadcopter lander that would take advantage of the environment on Titan to fly to multiple locations, some hundreds of miles apart, to sample materials and determine surface composition to investigate Titan's organic chemistry and habitability, monitor atmospheric and surface conditions, image landforms to investigate geological processes, and perform seismic studies. Image Credit: NASA.

The CAESAR and Dragonfly missions will receive funding through the end of 2018 to further develop and mature their concepts. NASA plans to select one of these investigations in the spring of 2019 to continue on to subsequent mission phases. 

The selected mission will be the fourth in NASA’s New Frontiers portfolio, a series of principal investigator-led planetary science investigations that fall under a development cost cap of approximately $850 million. Its predecessors are the New Horizons mission to Pluto and a Kuiper Belt object known as 2014 MU69, the Juno mission to Jupiter, and OSIRIS-REx, which will rendezvous with and return a sample of the asteroid Bennu.

NASA also announced the selection of two mission concepts that will receive technology development funds to prepare them for future mission competitions.

The concepts selected for technology development are:

Enceladus Life Signatures and Habitability (ELSAH)

The ELSAH mission concept will receive funds to develop cost-effective techniques that limit spacecraft contamination and thereby enable life detection measurements on cost-capped missions. The principal investigator is Chris McKay of NASA’s Ames Research Center in California’s Silicon Valley, and the managing NASA center is Goddard.

Venus In situ Composition Investigations (VICI)

Led by Lori Glaze at Goddard, the VICI mission concept will further develop the Venus Element and Mineralogy Camera to operate under the harsh conditions on Venus. The instrument uses lasers on a lander to measure the mineralogy and elemental composition of rocks on the surface of Venus.

The call for concepts was limited to six mission themes: comet surface sample return, lunar south pole-Aitken Basin sample return, ocean worlds (Titan and/or Enceladus), Saturn probe, Trojan asteroid tour and rendezvous, and Venus in situ explorer.

New Frontiers Program investigations address NASA’s planetary science objectives as described in the 2014 NASA Strategic Plan and the 2014 NASA Science Plan. The program is managed by the Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Planetary Science Division in Washington.

Related links:

2014 NASA Strategic Plan and the 2014 NASA Science Plan:

ESA's Rosetta:

New Horizons:



Read more about NASA’s New Frontiers Program and missions at:

Images (mentioned), Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/Karen Northon/Marshall Space Flight Center/Molly Porter.


Bridging the Gap: NASA Studies the Human Body in Space for One Year to Extrapolate for Missions to Mars

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Dec. 21, 2017

Before we can run or jump, we walk. Before sending humans to Mars, NASA must understand how the human body is affected by living and working in space. Typical missions to the International Space Station last six months. A round-trip mission to Mars could last three years.  Do the effects of being in space change over time? NASA is asking the scientific community to propose research that will help bridge the gap in our knowledge regarding long-term experiences in space.

Call for Proposals to Address Physiological and Psychological Effects of Spaceflight

NASA’s Human Research Program is now soliciting proposals for research that, when combined with ongoing NASA studies, could enable safer and more effective travel to destinations beyond low-Earth orbit. NASA is seeking research proposals in seven topic areas.   Such research will help NASA establish a baseline for proposed deep space missions up to 400 days in length as well as understand, prevent, diagnose, treat, mitigate, and cure the potential health effects of prolonged spaceflight. Interested scientists and researchers will find a detailed description of the research emphases, as well as the proposal process and awards, on the NSPIRES website.

“To draw any conclusions about the cumulative effects of exposure to space, we need to observe more astronauts spending larger amounts of time in the space environment,” said John Charles, Ph.D., associate director for Exploration Research Planning of the Human Research Program at NASA’s Johnson Space Center.  “Scientists can use the information to predict physical and behavioral health trends.”

Image above: NASA is taking the first steps on its Journey to Mars. Artist’s concept, looking toward Mars. Image Credit: NASA.

Research from the selected proposals is expected to build upon data collected during the first one-year mission when Scott Kelly and Mikhail Kornienko spent nearly a year in space. Additional space station studies, supplemented with research conducted at analogs on Earth, will allow NASA to accumulate a more comprehensive biomedical, behavioral, and performance health dataset.  NASA plans to use the findings to support long-term missions that will reach new milestones in human achievement as astronauts forge a path to Mars. The findings may also support innovative diagnostic and behavioral approaches on Earth; for example, research in team problem-solving skills has the potential to be applied to all personnel involved in any long-duration mission (operational and mission control team members as well as spaceflight crew members) and to any team involved in critical decision-making processes.

Proposals are due January 4, 2018, and NASA expects in late summer 2018 to select 15 to 18 proposals for grants with a maximum duration of seven years.

Connecting the Dots via Multiple Studies in Multiple Missions

Soliciting research for future one-year missions lays the groundwork for exploration missions and will enable NASA to begin planning and preparation for a proposed program of multiple concurrent missions. Researchers and scientists submitting proposals should consider a robust program that could include as many as 30 astronauts: 10 to conduct shorter missions of up to two months, 10 as part of standard six-month missions, and 10 one-year missions in space. An additional 18 research subjects are proposed for Earth-based analog studies (at planned lengths of four months, eight months, and one year).

With information gained from the selected studies, NASA aims to address five hazards of human space travel: space radiation, isolation and confinement, distance from Earth, gravity fields (or lack thereof), and hostile/closed environments that pose great risks to the human mind and body in space.  Analyzing the experiences of multiple astronauts at varying durations could potentially close critical gaps in current scientific understanding.  As NASA moves into a proving ground of missions near the Moon, the agency would continue to test capabilities. NASA could then extrapolate trends from six months out to two or three years, the expected duration of a typical mission to Mars.  Ultimately, such studies could enable NASA to develop and test technologies and countermeasures to protect the health and safety of crew members making history on interplanetary expeditions.

When the day comes for humans to launch on a journey to Mars, humanity will take another giant leap.  The knowledge gained from this research could give NASA a running start.

NASA's Human Research Program (HRP) is dedicated to discovering the best methods and technologies to support safe, productive human space travel. HRP enables space exploration by reducing the risks to astronaut health and performance using ground research facilities, the International Space Station, and analog environments. This leads to the development and delivery of an exploration biomedical program focused on: informing human health, performance, and habitability standards; the development of countermeasures and risk mitigation solutions; and advanced habitability and medical support technologies. HRP supports innovative, scientific human research by funding more than 300 research grants to respected universities, hospitals, and NASA centers to over 200 researchers in more than 30 states.

Related links:

NSPIRES website:!

International Space Station (ISS):

Journey to Mars:

NASA’s Human Research Program:

Image (mentioned), Text, Credits: NASA Human Research Strategic Communications/Laurie Abadie/Amanda vonDeak/Timothy Gushanas.


mercredi 20 décembre 2017

Giant Bubbles on Red Giant Star’s Surface

ESO - European Southern Observatory logo.

20 December 2017

The surface of the red giant star π1 Gruis from PIONIER on the VLT

Astronomers using ESO’s Very Large Telescope have for the first time directly observed granulation patterns on the surface of a star outside the Solar System — the ageing red giant π1 Gruis. This remarkable new image from the PIONIER instrument reveals the convective cells that make up the surface of this huge star, which has 350 times the diameter of the Sun. Each cell covers more than a quarter of the star’s diameter and measures about 120 million kilometres across. These new results are being published this week in the journal Nature.

Located 530 light-years from Earth in the constellation of Grus (The Crane), π1 Gruis is a cool red giant. It has about the same mass as our Sun, but is 350 times larger and several thousand times as bright [1]. Our Sun will swell to become a similar red giant star in about five billion years.

Widefield image of the sky around π1 Gruis

An international team of astronomers led by Claudia Paladini (ESO) used the PIONIER instrument on ESO’s Very Large Telescope to observe π1 Gruis in greater detail than ever before. They found that the surface of this red giant has just a few convective cells, or granules, that are each about 120 million kilometres across — about a quarter of the star’s diameter [2]. Just one of these granules would extend from the Sun to beyond Venus. The surfaces  — known as photospheres —  of many giant stars are obscured by dust, which hinders observations. However, in the case of π1 Gruis, although dust is present far from the star, it does not have a significant effect on the new infrared observations [3].

When π1 Gruis ran out of hydrogen to burn long ago, this ancient star ceased the first stage of its nuclear fusion programme. It shrank as it ran out of energy, causing it to heat up to over 100 million degrees. These extreme temperatures fueled the star’s next phase as it began to fuse helium into heavier atoms such as carbon and oxygen. This intensely hot core then expelled the star’s outer layers, causing it to balloon to hundreds of times larger than its original size. The star we see today is a variable red giant. Until now, the surface of one of these stars has never before been imaged in detail.

The red giant star π1 Gruis in the constellation of Grus

By comparison, the Sun’s photosphere contains about two million convective cells, with typical diameters of just 1500 kilometres. The vast size differences in the convective cells of these two stars can be explained in part by their varying surface gravities. π1 Gruis is just 1.5 times the mass of the Sun but much larger, resulting in a much lower surface gravity and just a few, extremely large, granules.

While stars more massive than eight solar masses end their lives in dramatic supernovae explosions, less massive stars like this one gradually expel their outer layers, resulting in beautiful planetary nebulae. Previous studies of π1 Gruis found a shell of material 0.9 light-years away from the central star, thought to have been ejected around 20 000 years ago. This relatively short period in a star's life lasts just a few tens of thousands of years – compared to the overall lifetime of several billion – and these observations reveal a new method for probing this fleeting red giant phase.

Zooming in on the red giant star π1 Gruis


[1] π1 Gruis is named following the Bayer designation system. In 1603 the German astronomer Johann Bayer classified 1564 stars, naming them by a Greek letter followed by the name of their parent constellation. Generally, stars were assigned Greek letters in rough order of how bright they appeared from Earth, with the brightest designated Alpha (α). The brightest star of the Grus constellation is therefore Alpha Gruis.

π1 Gruis is one of an attractive pair of stars of contrasting colours that appear close together in the sky, the other one naturally being named π2 Gruis. They are bright enough to be well seen in a pair of binoculars. Thomas Brisbane realised in the 1830s that π1 Gruis was itself also a much closer binary star system. Annie Jump Cannon, credited with the creation of the Harvard Classification Scheme, was the first to report the unusual spectrum of π1 Gruis in 1895.

[2] Granules are patterns of convection currents in the plasma of a star. As plasma heats up at the centre of the star it expands and rises to the surface, then cools at the outer edges, becoming darker and more dense, and descends back to the centre. This process continues for billions of years and plays a major role in many astrophysical processes including energy transport, pulsation, stellar wind and dust clouds on brown dwarfs.

[3] π1 Gruis is one of the brightest members of the rare S class of stars that was first defined by the American astronomer Paul W. Merrill to group together stars with similarly unusual spectra. π1 Gruis, R Andromedae and R Cygni became prototypes of this type. Their unusual spectra is now known to be the result of the “s-process” or “slow neutron capture process” — responsible for the creation of half the elements heavier than iron.

More information:

This research was presented in a paper “Large granulation cells on the surface of the giant star π1 Gruis”, by C. Paladini et al., published in the journal Nature on 21 December 2017.

The team is composed of C. Paladini (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium; ESO, Santiago, Chile), F. Baron (Georgia State University, Atlanta, Georgia, USA), A. Jorissen (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), J.-B. Le Bouquin (Université Grenoble Alpes, CNRS, IPAG, Grenoble, France), B. Freytag (Uppsala University, Uppsala, Sweden), S. Van Eck (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), M. Wittkowski (ESO, Garching, Germany), J. Hron (University of Vienna, Vienna, Austria), A. Chiavassa (Laboratoire Lagrange, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, Nice, France), J.-P. Berger (Université Grenoble Alpes, CNRS, IPAG, Grenoble, France), C. Siopis (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), A. Mayer (University of Vienna, Vienna, Austria), G. Sadowski (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), K. Kravchenko (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), S. Shetye (Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles, Brussels, Belgium), F. Kerschbaum (University of Vienna, Vienna, Austria), J. Kluska (University of Exeter, Exeter, UK) and S. Ramstedt (Uppsala University, Uppsala, Sweden).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and by Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.


ESOcast 144 Light: Giant Bubbles on Red Giant Star’s Surface:

Research paper in Nature:

Photos of the VLT:

Further information about the VLTI:

SIMBAD entry for π1 Gruis:

PIONIER instrument:

ESO’s Very Large Telescope (VLT):

Images, Text, Credits: ESO/Richard Hook/Claudia Paladini/Institut d’Astronomie et d’Astrophysique, Université libre de Bruxelles/Alain Jorissen/Georgia State University/Fabien Baron/ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/Video: ESO/Digitized Sky Survey 2/N. Risinger ( Astral Electronic.

Best regards,

mardi 19 décembre 2017

Genes in Space-3 Successfully Identifies Unknown Microbes in Space

ISS - International Space Station logo.

Dec. 19, 2017

International Space Station (ISS). Image Credit: NASA

Being able to identify microbes in real time aboard the International Space Station, without having to send them back to Earth for identification first, would be revolutionary for the world of microbiology and space exploration. The Genes in Space-3 team turned that possibility into a reality this year, when it completed the first-ever sample-to-sequence process entirely aboard the space station.

The ability to identify microbes in space could aid in the ability to diagnose and treat astronaut ailments in real time, as well as assisting in the identification of DNA-based life on other planets. It could also benefit other experiments aboard the orbiting laboratory. Identifying microbes involves isolating the DNA of samples, and then amplifying – or making many copies - of that DNA that can then be sequenced, or identified.

Image above: NASA astronaut Peggy Whitson performed the Genes in Space-3 investigation aboard the space station using the miniPCR and MinION, developed for previously flown investigations. Image Credit: NASA.

The investigation was broken into two parts: the collection of the microbial samples and amplification by Polymerase Chain Reaction (PCR), then sequencing and identification of the microbes. NASA astronaut Peggy Whitson conducted the experiment aboard the orbiting laboratory, with NASA microbiologist and the project’s Principal Investigator Sarah Wallace and her team watching and guiding her from Houston.

As part of regular microbial monitoring, petri plates were touched to various surfaces of the space station. Working within the Microgravity Science Glovebox (MSG) about a week later, Whitson transferred cells from growing bacterial colonies on those plates into miniature test tubes, something that had never been done before in space.

Image above: Sarah Wallace (L), NASA microbiologist and Genes in Space-3 principal investigator, and Sarah Stahl (R), microbiologist, are seen in their Johnson Space Center lab with the in-flight sample from the Genes in Space-3 investigation. Image Credit: Rachel Barry.

Once the cells were successfully collected, it was time to isolate the DNA and prepare it for sequencing, enabling the identification of the unknown organisms – another first for space microbiology. An historic weather event, though, threatened the ground team’s ability to guide the progress of the experiment.

“We started hearing the reports of Hurricane Harvey the week in between Peggy performing the first part of collecting the sample and gearing up for the actual sequencing,” said Wallace.

When JSC became inaccessible due to dangerous road conditions and rising flood waters, the team at Marshall Space Flight Center’s Payload Operations Integration Center in Huntsville, Alabama, who serve as “Mission Control” for all station research, worked to connect Wallace to Whitson using Wallace’s personal cell phone.

Image above: The Genes in Space-3 team worked throughout Hurricane Harvey to ensure operations continued on the space station. Pictured are Aaron Burton, Kristen John, Sarah Stahl and Sarah Wallace as they watch NASA astronaut Peggy Whitson work within the Microgravity Science Glovebox (MSG) during part one of the investigation. Image Credit: Sarah Wallace.

With a hurricane wreaking havoc outside, Wallace and Whitson set out to make history. Wallace offered support to Whitson, a biochemist, as she used the MinION device to sequence the amplified DNA. The data were downlinked to the team in Houston for analysis and identification.

“Once we actually got the data on the ground we were able to turn it around and start analyzing it,” said Aaron Burton, NASA biochemist and the project’s co-investigator. “You get all these squiggle plots and you have to turn that into As, Gs, Cs and Ts.”

Those As, Gs, Cs and Ts are Adenine, Guanine, Cytosine and Thymine – the four bases that make up each strand of DNA and can tell you what organism the strand of DNA came from.

“Right away, we saw one microorganism pop up, and then a second one, and they were things that we find all the time on the space station,” said Wallace. “The validation of these results would be when we got the sample back to test on Earth.”

Soon after, the samples returned to Earth, along with Whitson, aboard the Soyuz spacecraft. Biochemical and sequencing tests were completed in ground labs to confirm the findings from the space station. They ran tests multiple times to confirm accuracy. Each time, the results were exactly the same on the ground as in orbit.

“We did it. Everything worked perfectly,” said Sarah Stahl, microbiologist.

Animation above: Working within the Microgravity Science Glovebox, Whitson transferred cells from growing bacterial colonies on petri dishes into miniature test tubes, something that had never been done before in space. Animation Credit: NASA.

Developed in partnership by NASA’s Johnson Space Center and Boeing, this National Lab sponsored investigation is managed by the Center for the Advancement of Science in Space.

Genes in Space-1 marked the first time the PCR was used in space to amplify DNA with the miniPCR thermal cycler, followed shortly after by Biomolecule Sequencer, which used the MinION device to sequence DNA. Genes in Space-3 married these two investigations to create a full microbial identification process in microgravity.

“It was a natural collaboration to put these two pieces of technology together because individually, they’re both great, but together they enable extremely powerful molecular biology applications,” said Wallace.

Sequencing the Unknown

Video above: Being able to identify microbes in real time aboard the International Space Station, without having to send them back to Earth for identification first, would be revolutionary for the world of microbiology and space exploration, and the Genes in Space-3 team turned that possibility into a reality this year when it completed the first-ever sample-to-sequence process entirely aboard the space station. This advance could aid in the ability to diagnose and treat astronaut ailments in real time, as well as assisting in the identification of DNA-based life on other planets. It could also benefit other experiments aboard the orbiting laboratory. Image Credit: NASA.

For more information about the investigations happening every day aboard the orbiting laboratory, follow

Related links:

Genes in Space-3:

Microgravity Science Glovebox (MSG):

MinION device:

Genes in Space-1:

Biomolecule Sequencer:

National Lab:

Center for the Advancement of Science in Space:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Animation (mentioned) Video (mentioned), Text, Credits: NASA/Michael Johnson/JSC/International Space Station Program Science Office/Jenny Howard.

Best regards,

A New Twist in the Dark Matter Tale

NASA - Chandra X-ray Observatory patch.

Dec. 19, 2017

Image above: Composite image of the Perseus galaxy cluster using data from NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and Hitomi, a Japanese-led X-ray telescope. Image Credits: X-ray: NASA/CXO/Fabian et al.; Radio: Gendron-Marsolais et al.; NRAO/AUI/NSF Optical: NASA, SDSS.

An innovative interpretation of X-ray data from a cluster of galaxies could help scientists fulfill a quest they have been on for decades: determining the nature of dark matter.

The finding involves a new explanation for a set of results made with NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton and Hitomi, a Japanese-led X-ray telescope. If confirmed with future observations, this may represent a major step forward in understanding the nature of the mysterious, invisible substance that makes up about 85% of matter in the universe.

“We expect that this result will either be hugely important or a total dud,” said Joseph Conlon of Oxford University who led the new study. “I don't think there is a halfway point when you are looking for answers to one of the biggest questions in science.”

The story of this work started in 2014 when a team of astronomers led by Esra Bulbul (Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.) found a spike of intensity at a very specific energy in Chandra and XMM-Newton observations of the hot gas in the Perseus galaxy cluster.

This spike, or emission line, is at an energy of 3.5 kiloelectron volts (keV).  The intensity of the 3.5 keV emission line is very difficult if not impossible to explain in terms of previously observed or predicted features from astronomical objects, and therefore a dark matter origin was suggested. Bulbul and colleagues also reported the existence of the 3.5 keV line in a study of 73 other galaxy clusters using XMM-Newton.

The plot of this dark matter tale thickened when only a week after Bulbul’s team submitted their paper a different group, led by Alexey Boyarsky of Leiden University in the Netherlands, reported evidence for an emission line at 3.5 keV in XMM-Newton observations of the galaxy M31 and the outskirts of the Perseus cluster, confirming the Bulbul et al. result.

However, these two results were controversial, with other astronomers later detecting the 3.5 keV line when observing other objects, and some failing to detect it.

The debate seemed to be resolved in 2016 when Hitomi especially designed to observe detailed features such as line emission in the X-ray spectra of cosmic sources, failed to detect the 3.5 keV line in the Perseus cluster.

“One might think that when Hitomi didn’t see the 3.5 keV line that we would have just thrown in the towel for this line of investigation,” said co-author Francesca Day, also from Oxford. “On the contrary, this is where, like in any good story, an interesting plot twist occurred.”

Conlon and colleagues noted that the Hitomi telescope had much fuzzier images than Chandra, so its data on the Perseus cluster are actually comprised of a mixture of the X-ray signals from two sources: a diffuse component of hot gas enveloping the large galaxy in the center of the cluster and X-ray emission from near the supermassive black hole in this galaxy. The sharper vision of Chandra can separate the contribution from the two regions. Capitalizing on this, Bulbul et al. isolated the X-ray signal from the hot gas by removing point sources from their analysis, including X-rays from material near the supermassive black hole

In order to test whether this difference mattered, the Oxford team re-analyzed Chandra data from close to the black hole at the center of the Perseus cluster taken in 2009. They found something surprising: evidence for a deficit rather than a surplus of X-rays at 3.5 keV. This suggests that something in Perseus is absorbing X-rays at this exact energy. When the researchers simulated the Hitomi spectrum by adding this absorption line to the hot gas’ emission line seen with Chandra and XMM-Newton, they found no evidence in the summed spectrum for either absorption or emission of X-rays at 3.5 keV, consistent with the Hitomi observations.

Chandra X-ray Observatory. Image Credit: NASA/CXC

The challenge is to explain this behavior: detecting absorption of X-ray light when observing the black hole and emission of X-ray light at the same energy when looking at the hot gas at larger angles away from the black hole.

In fact, such behavior is well known to astronomers who study stars and clouds of gas with optical telescopes. Light from a star surrounded by a cloud of gas often shows absorption lines produced when starlight of a specific energy is absorbed by atoms in the gas cloud. The absorption kicks the atoms from a low to a high energy state. The atom quickly drops back to the low energy state with the emission of light of a specific energy, but the light is re-emitted in all directions, producing a net loss of light at the specific energy – an absorption line – in the observed spectrum of the star. In contrast, an observation of a cloud in a direction away from the star would detect only the re-emitted, or fluorescent light at a specific energy, which would show up as an emission line.

The Oxford team suggests in their report that dark matter particles may be like atoms in having two energy states separated by 3.5 keV. If so, it could be possible to observe an absorption line at 3.5 keV when observing at angles close to the direction of the black hole, and an emission line when looking at the cluster hot gas at large angles away from the black hole. 

“This is not a simple picture to paint, but it’s possible that we’ve found a way to both explain the unusual X-ray signals coming from Perseus and uncover a hint about what dark matter actually is,” said co-author Nicholas Jennings, also of Oxford.

To write the next chapter of this story, astronomers will need further observations of the Perseus cluster and others like it. For example, more data is needed to confirm the reality of the dip and to exclude a more mundane possibility, namely that we have a combination of an unexpected instrumental effect and a statistically unlikely dip in X-rays at an energy of 3.5 keV. Chandra, XMM-Newton and future X-ray missions will continue to observe clusters to address the dark matter mystery.

A paper describing these results was published in Physical Review D on December 19, 2017 and a preprint is available online. The other co-authors of the paper are Sven Krippendorf and Markus Rummel, both from Oxford. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Physical Review:

Read More from NASA's Chandra X-ray Observatory:

For more Chandra images, multimedia and related materials, visit:

Images (mentioned), Text, Credits: NASA/Lee Mohon/Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke.


CERN hosts ESA for high-energy radiation experiments

ESA - European Space Agency patch / CERN - European Organization for Nuclear Research logo.

19 December 2017

An ESA-led group subjected components and space equipment to the most intense beam of ultra-high energy heavy ions available – short of travelling into space – during a week-long visit to CERN, the European Organization for Nuclear Research.

Test items were placed in a path of an experimental beamline fed by the Super Proton Synchrotron (SPS) particle accelerator. Located in a circular tunnel nearly 7 km in circumference, the SPS is CERN’s second largest accelerator after the Large Hadron Collider (LHC), which the SPS feeds into in turn.

Super Proton Synchrotron

ESA was invited to make use of the Geneva-based centre’s beamline as part of an ESA–CERN cooperation agreement signed by their respective Director Generals.

The team donned hard hats and ventured into a ground floor ‘cave’ surrounded by protective concrete blocks to place items in the beam path, retreating upstairs before the beam was fired.

ESA team at beamline

“It was a very exciting experience – we were exploring,” said Véronique Ferlet-Cavrois, heading ESA’s Power Systems, EMC and Space Environments division. “This ion beam is equivalent to the ultra-high energy part of the galactic cosmic ray spectrum – above 10 GeV/nucleon – whose effects have never been experimentally measured on the ground before.”

Space is a vacuum, but it is far from empty. It is awash in charged particles, including protons from the Sun as well as cosmic rays from the wider Universe, highly charged nuclei originating from violent cosmic regions such as exploding stars or black holes, then accelerated by magnetic fields during their galactic journeys.

360 degree view of SPS

The challenge for ESA electronics and space environment specialists is to ensure that components needed for space missions can go on performing in these high-radiation conditions.

Microprocessors, for instance, are growing ever more powerful as the number of transistors placed on a single chip doubles every two years or less – the famous ‘Moore’s Law’ – but this leaves them ever more vulnerable to ‘single event events’ as the transit of charged particles flip memory bits, or even trigger destructive short circuit ‘latch-ups’.

“CERN has to deal with comparable issues,” adds Véronique. “The particle collisions they trigger to study the nature of matter can emit radiation which may affect the detectors, electromagnets and other electronics around their accelerators. 

“For instance, in 2007 CERN created their R2E task force – Radiation to Electronics – evaluating the risk of failures due to radiation in the control electronics of the LHC. So we have a long history of collaboration, long before our formal cooperation agreement was signed in 2014.”

Space radiation

ESA maintains a network of external facilities equipped with particle accelerators, such as the Louvain Cyclotron Resource Centre in Belgium, the Accelerator Laboratory at the University of Jyväskylä, Finland, and Paul Scherrer Institute in Switzerland, but these offer access only to the lower energy segments of the cosmic ray spectrum.

“Our external facilities are suitable and used largely for testing individual components, but we typically have to remove them from their packaging so that heavy ions can reach them,” comments Véronique. “Testing at CERN, the beam was energetic enough to easily penetrate packaging, a fact which also allowed us to test entire items of equipment.”

View down onto beamline

Items under test included a complete Raspberry Pi computer, a new type of power component – a schottky diode made in silicon carbide – and novel ‘field effect transistors’ offering improved control of electron flows, as well as multiprocessor system-on-chip (MPSoC) ‘field programmable gate arrays’ (FPGAs) – standardised programmable chips that can be customised to perform a wide variety of different tasks.

Also under test was a Standard Radiation Environment Monitor (SREM), a highly-sensitive radiation detector already flown on multiple ESA missions. The results should enhance calibration of the SREMs in space.

Space radiation coverage from ground facilities

The ESA team was accompanied to CERN during the last week of November by representatives of a number of companies and institutions partnering with the Agency on various projects: Germany’s Fraunhofer Institute for Technological Trend Analysis, France’s iRoC Technologies, Poltecnico di Torino, the National Technical University of Athens and French space agency CNES.

“We will now study our results and use them to fine-tune our simulations,” concludes Véronique. “We will have a second CERN test campaign this time next year, while also planning to employ the similarly high-energy GSI-FAIR facility in Darmstadt, Germany.”

Related links:

European Organization for Nuclear Research (CERN):

CERN's Super Proton Synchrotron:

ESA and CERN sign cooperation agreement:

Standard Radiation Environment Monitor:

Electromagnetics and Space Environment:

Newly-launched missions extend ESA's radiation map of space:

New radiation research programme for human spaceflight:

Images, Text, Credits: ESA/CERN.

Best regards from neighbor of CERN,

State-of-the-art solar reference spectrum

ESA - Columbus Laboratory patch.

19 December 2017

For almost a decade, the International Space Station tracked the Sun to measure our star’s energy. Now, years of work have delivered the most accurate-ever data on the Sun’s power – but the journey to achieve this feat was almost abandoned before the experiment ended.

SWAP sees the Sun

Computer models can calculate and predict large-scale events such as our planet’s weather and climate but they need hard numbers to work on. Processing power can simulate our planet, but the researchers need the numbers to key into the computer models and, with so many numbers flowing, inaccuracies quickly add up.

This is where the Solspec instrument comes in. Part of the Solar package on the International Space Station, it was launched with the European Columbus space laboratory in 2008 and tracked the Sun until it was shut down this year. It measured the energy of each wavelength in absolute terms and its variability – a feat that requires a higher order of precision than relative measurements. As an analogy, it is easy to feel a change in temperature, but nobody on Earth can sense the exact temperature without a thermometer.

Solar on Columbus

The teams behind the facility, the Belgian BIRA-IASB institute and France’s Latmos, improved the accuracy of the reference data across the Sun’s spectrum down to 1.26% and, more importantly, an estimation of how accurate this variation is – meaning the team not only knows how much energy per square metre is emitted per wavelength, but also the margin of error. This number might seem insignificant, but the more accurate it is, the better researchers can understand how our climate has changed and is changing.

Solar power plants also use the reference data to predict how much electricity they will generate, to work out how many solar panels should be installed and to fine-tune their facilities.

Painstaking measurements

The Solar facility achieved these measurements by repeatedly rotating to point at the Sun as the Space Station flew around Earth every 90 minutes. As it measured each wavelength in the Sun’s spectrum, the rays had to be separated into separate wavelengths. Gratings with extremely small nanometre-sized grooves – up to 3600 per mm – spread sunlight like a prism on to receivers.

On Earth these measurements are made in a laboratory with a constant temperature to avoid any disturbances and ensure accurate measurements. The Space Station offered far from ideal conditions, aside from the general vibrations that come with an orbital outpost, the Station passes from light to darkness and back again every 45 minutes – almost 12 000 times in the instrument’s lifetime. Each pass caused the temperature to fluctuate by 30°C – straining the instruments as well as expanding and contracting the instrument’s components resulting in skewed measurements.

Sunrise seen from Space Station

Of course, these conditions were well known before the instrument was built and launched, so engineers designed Solar and Solspec to cope with the harsh climate outside the Space Station. Despite this, initial readings when it was turned on in 2008 were not as accurate as expected

The teams despaired, but did not give up as they realised they could analyse the data at a higher level to understand the readings over time. Towards the end of its mission, Solspec was stressed to its limits to test how it was affected by external thermal factors and to calibrate the machine better. The operators left Solar working throughout the night and even moved the whole Space Station to keep it pointing at the Sun for as long as possible.

“Metrology is the science of measurement and it requires painstaking work to achieve the hair-splitting accuracy we now have for the Sun’s output,” says ESA’s Astrid Orr, ESA’s project scientist for Solar.

Solar spectrum

“The team put the instrument and themselves through extremes to understand and calibrate the readings, spending years meticulously going over the numbers.

“One of the original scientific goals set in 1996 for Solar was to obtain the most precise possible absolute measurement of the solar irradiance: objective achieved.”

With the Solar facility now powered off, researchers still have over nine years of data to analyse and interpret the variability in the Sun’s spectrum. Results are still coming in. The quest for more accuracy continues next year with NASA’s TSIS-1 on the Space Station.

Related link:

Columbus laboratory:

Research partners:

Belgian Institute for Space Aeronomy BIRA-IASB:


Belgian User Support and Operations Centre:

Centre national de la recherche scientifique:

Fraunhofer Institute for Physical Measurement Techniques:

Images, Text, Credits: ESA/SWAP PROBA2 science centre/NASA/CNRS.