samedi 26 octobre 2019

Hubble Sees a Familiar Sight












NASA - Hubble Space Telescope patch.

Oct. 26, 2019


This image from the NASA/ESA Hubble Space Telescope shows IC 4653, a galaxy just over 80 million light-years from Earth. That may sound like quite a distance, but it’s not that far on a cosmic scale. At these kinds of distances, the types and structures of the objects we see are similar to those in our local area.

The galaxy's whirling arms tell us a story about what’s happening inside this galaxy. Bright blue patches mark sites of active star formation. Studying the structures of other galaxies is a key way to learn about the structure of our own, given that humans can’t leave the Milky Way to look back and see what it looks like from the outside. It helps to compare our observations of our home galaxy with those of nearby galaxies we can see in their entirety.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: European Space Agency (ESA)/NASA/Lynn Jenner/Image, Animation, Credits: ESA/Hubble & NASA, D. Rosario (CEA, Durham University).

Greetings, Orbiter.ch

vendredi 25 octobre 2019

Astronauts Explore How Space Impacts Brain and Muscles













ISS - Expedition 61 Mission patch.

October 25, 2019

Brain and muscle research were on today’s schedule of human research aboard the International Space Station. The Expedition 61 crew also ensured the plumbing and air conditioning systems stay in tip-top shape.

The brain is able to optimize its blood flow even if the cardiovascular system cannot maintain an ideal blood pressure. Flight Engineer Jessica Meir explored the brain’s capacity to regulate that blood flow in space today. She used Doppler gear to measure her blood pressure in her finger artery and blood flow velocity in her cerebral artery. Scientists may use the data to help astronauts adjust to microgravity and ease the return to Earth after months or years in space.


Image above: Portions of the International Space Station are pictured as the orbiting complex was flying into an orbital sunset. Image Credit: NASA.

NASA astronauts Christina Koch and Andrew Morgan collaborated on the Myotones muscle tone in space study. The duo took turns measuring their arms and legs before scanning them with an ultrasound device. Observations may help doctors improve rehabilitation techniques for astronauts on long-duration missions and sedentary patients on Earth.

Commander Luca Parmitano of ESA (European Space Agency) put on his plumber’s hat today and replaced hydraulic components in the station’s bathroom located in the Tranquility module. He also deactivated science hardware that was tracking ocean-going vessels.

International Space Station (ISS). Image Credit: NASA

Cosmonauts Alexander Skvortsov and Oleg Skripochka stayed focused on the upkeep of the Russian segment of the orbiting lab. The duo charged Soyuz spacecraft batteries and cleaned fans and filters in the air conditioning system in their portion of the space station.

Related links:

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

Regulate that blood flow: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1938

Myotones: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7573

Tranquility module: https://www.nasa.gov/mission_pages/station/structure/elements/tranquility/

Tracking ocean-going vessels: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/search.html?#q=maritime&i=&p=&c=&g=&s=

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

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

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

Greetings, Orbiter.ch

A Mega-Cluster of Galaxies in the Making













NASA - Chandra X-ray Observatory patch.

Oct. 25, 2019


Astronomers using data from the Chandra X-ray Observatory and other telescopes have put together a detailed map of a rare collision between four galaxy clusters. Eventually, all four clusters – each with a mass of at least several hundred trillion times that of the Sun – will merge to form one of the most massive objects in the universe.

Galaxy clusters are the largest structures in the cosmos that are held together by gravity. Clusters consist of hundreds or even thousands of galaxies embedded in hot gas, and contain an even larger amount of invisible dark matter. Sometimes two galaxy clusters collide, as in the case of the Bullet Cluster, and occasionally more than two will collide at the same time.

The new observations show a mega-structure being assembled in a system called Abell 1758, located about 3 billion light-years from Earth. It contains two pairs of colliding galaxy clusters that are heading toward one another. Scientists first recognized Abell 1758 as a quadruple galaxy cluster system in 2004 using data from Chandra and XMM-Newton, a satellite operated by the European Space Agency (ESA). 

 Chandra X-ray Observatory

X-rays from Chandra are shown as blue and white, depicting fainter and brighter diffuse emission, respectively. This new composite image also includes an optical image from the Sloan Digital Sky Survey. The Chandra data revealed for the first time a shock wave -- similar to the sonic boom from a supersonic aircraft -- in hot gas visible with Chandra in the northern pair's collision. From this shock wave, researchers estimate two clusters are moving about 2 million to 3 million miles per hour (3 million to 5 million kilometers per hour), relative to each other.

The team also used radio data from the Giant Metrewave Radio Telescope (GMRT), and X-ray data from the European Space Agency’s XMM-Newton mission.

Chandra X-ray Observatory: https://www.nasa.gov/mission_pages/chandra/main/index.html

Image, Animation, Credits: X-ray: NASA/CXC/SAO/G.Schellenberger et al.; Optical:SDSS/Text Credits: Yvette Smith.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of October 21, 2019













ISS - Expedition 61 Mission patch.

Oct. 25, 2019

Following the first all-woman space walk on Friday, Oct. 18, the crew of the International Space Station spent the week of Oct. 21 conducting scientific studies on amyloid fiber formation, the human gut biota and more. The space station provides a platform for long-duration research on the human body in microgravity and makes important contributions to Artemis, NASA’s program to go forward to the Moon and on to Mars.

International Space Station (ISS). Animation Credit: NASA

Here are details on some of the science conducted on the orbiting laboratory during the week:

Creating a virtual reality space experience

The ISS Experience creates virtual reality videos from footage covering different aspects of crew life, execution of science and the international partnerships involved on the space station. Crew members record footage using a Z-CAM V1 Pro Cinematic Virtual Reality (VR) 360-degree camera with nine 190° fisheye lenses. Events recorded this week included NASA astronaut Jessica Meir’s thoughts following the historic, all-female spacewalk.

Examining amyloid formation in microgravity

The Ring Sheared Drop investigation takes advantage of the fact that fluids float in microgravity, which allows researchers to examine formation of amyloid fibrils in liquids held together by surface tension rather than a container. Abnormal fibrous deposits found in organs and tissues, amyloids are associated with neurodegenerative conditions such as Alzheimer’s disease. Results could contribute to better understanding of and treatments for these diseases. Data on the flow of liquids without the complications associated with solid walls also could contribute to development of advanced materials. The crew reviewed procedures and conducted tests in preparation for investigation operations.

Building a better gut biota


Image above: NASA astronaut Christina Koch conducts the Ring Sheared Drop investigation in the Microgravity Sciences Glovebox. The investigation uses microgravity to examine the formation and flow of amyloids in microgravity, which may contribute to a better understanding of neurodegenerative diseases caused by these fibers. Image Credit: NASA.

Crew members collected saliva samples and completed questionnaires for the Probiotics investigation.The human immune system is weaker in space and some species of harmful bacteria become stronger and more virulent in microgravity. This combination poses an increased risk to crew member health. The investigation studies whether beneficial bacteria or probiotics can improve the intestinal microbiota and immune function and help protect astronaut health on long-duration space missions.

On the trail of dark matter

Stars, planets and interstellar dust represent only a small fraction of the total mass in the universe. The rest is dark matter, invisible matter that cannot be directly detected but can be inferred. The Alpha Magnetic Spectrometer - 02 (AMS-02) is a state-of-the-art particle physics detector that uses the unique environment of space to advance knowledge of the universe and understanding of its origins by searching for antimatter and measuring cosmic rays. The crew reviewed procedures for an upcoming spacewalk planned to refurbish AMS so its important exploration can continue.


Image above: The Alpha Magnetic Spectrometer - 02 (AMS-02), mounted on the exterior of the space station, measures cosmic rays looking for evidence of dark matter and dark energy. Image Credit: NASA.

Other investigations on which the crew performed work:

- Veg-04B, part of a phased research project to address the need for a continuous fresh-food production system in space, focuses on the effects of light quality and fertilizer on a leafy crop, Mizuna mustard greens, as well as taste as assessed by the crew.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7895


Image above: NASA astronaut Andrew Morgan works on the Veg-04 investigation, which is growing Mizuna mustard greens as part of ongoing efforts to develop methods to provide food in space and on other planets. Image Credit: NASA.

- Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions. “Menu fatigue” from repeatedly consuming a limited choice of foods may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

- Standard Measures captures a consistent set of measures from crew members to characterize how their bodies adapt to living in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711

- BEST studies the use of DNA sequencing to identify unknown microbial organisms and improve understanding of how humans, plants and microbes adapt to living in space.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687

Space to Ground: Space Jam: 10/25/2019

Related links:

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

Artemis: https://www.nasa.gov/artemis

The ISS Experience: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7877

Ring Sheared Drop: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7383

Probiotics: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2047

Alpha Magnetic Spectrometer - 02 (AMS-02): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=729

ISS National Lab: https://www.issnationallab.org/

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

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

Images (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/John Love, Lead Increment Scientist Expedition 61.

Best regards, Orbiter.ch

jeudi 24 octobre 2019

Crew Explores Space Biology, Reviews Particle Detector Repairs













ISS - Expedition 61 Mission patch.

October 24, 2019

The six residents living aboard the International Space Station are busy today ensuring advanced microgravity research continues to provide benefits for citizens on Earth and in space. The Expedition 61 crew is also brushing up on repair techniques for a cosmic particle detector attached to the outside of the orbiting lab.


Image above: NASA astronaut Andrew Morgan watered plants earlier this week to help NASA learn how to provide fresh food for crews on long-term space missions. Image Credit: NASA.

NASA astronauts Jessica Meir and Christina Koch juggled an array of life science activities throughout Thursday. Meir cared for plants for a new field of botany research exploring how to provide fresh food for long-term space crews. Meir later swapped out a failed computer hard drive that supports combustion experiments. Koch organized biology hardware for a study seeking therapies for aging-related conditions. Koch then serviced microbial DNA samples to understand how microorganisms adapt to weightlessness.

The Alpha Magnetic Spectrometer (AMS-02) is due for an upgraded thermal control system after being installed on the outpost’s Starboard-3 truss structure in 2011. NASA is planning a series of spacewalks to restore the AMS-02 to full service. Commander Luca Parmitano of ESA (European Space Agency) and NASA Flight Engineer Andrew Morgan are reviewing the tools and techniques necessary to complete the AMS repair job.

International Space Station (ISS). Animation Credit: NASA

Over in the station’s Russian segment, composed of five modules, a pair of cosmonauts focused on hardware and systems maintenance. Alexander Skvortsov inspected lab windows and checked batteries. Fellow cosmonaut Oleg Skripochka worked on air conditioning and plumbing tasks inside the orbital lab. The duo also explored how to improve accuracy when detecting and photographing Earth landmarks.

Related links:

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

Botany research: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7895

Combustion experiments: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317

Aging-related conditions: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7992

Microbial DNA samples: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687

Alpha Magnetic Spectrometer (AMS-02): https://www.nasa.gov/mission_pages/station/research/alpha-magnetic-spectrometer.html

Outpost’s Starboard-3 truss structure: https://www.nasa.gov/mission_pages/station/structure/elements/truss-structure

Photographing Earth landmarks: https://www.energia.ru/en/iss/researches/develop/04.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/Mark Garcia.

Best regards, Orbiter.ch

Halfway towards LHC consolidation













CERN - European Organization for Nuclear Research logo.

24 October, 2019

One hundred and fifty people are hard at work upgrading the Large Hadron Collider’s superconducting magnets 


Image above: Two members of the LHC consolidation team inspect and clean a diode enclosure of the dipole magnets before improving the electrical isolation (Image: Maximilien Brice and Julien Ordan/CERN).

The Large Hadron Collider is such a huge and sophisticated machine that the slightest alteration requires an enormous amount of work. During the second long shutdown (LS2), teams are hard at work reinforcing the electrical insulation of the accelerator’s superconducting dipole diodes. The LHC contains not one, not two, but 1232 superconducting dipole magnets, each with a diode system to upgrade. That’s why no fewer than 150 people are needed to carry out the 70 000 tasks involved in this work.

The project is now halfway to completion. One of the machine’s eight sectors, containing 154 magnets, is now closed and the final leak tests are under way. Work is ongoing in the seven other sectors and the teams are working at a rate of ten interconnections consolidated per day.


Image above: Replacement of one of the LHC superconducting dipole magnets during the accelerator consolidation campaign. (Image: Maximilien Brice and Julien Ordan/CERN).

The work is part of a broader project called DISMAC (“Diodes Insulation and Superconducting Magnets Consolidation”), which also includes the replacement of magnets and maintenance operations on the current leads, the devices that supply the LHC with electricity. Twenty-two magnets have already been replaced and two others have been removed from the machine in order to replace their beam screens, which are components located in the vacuum chamber.

A plethora of upgrade and maintenance work is also being carried out in the tunnel on all the equipment, from the cryogenics system to the vacuum, beam instrumentation and technical infrastructures.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related link:

Large Hadron Collider (LHC): https://home.cern/science/accelerators/large-hadron-collider

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Images (mentioned), Text, Credits: CERN/Corinne Pralavorio.

Best regards, Orbiter.ch

New Selfie Shows Curiosity, the Mars Chemist











NASA - Mars Science Laboratory (MSL) logo.

Oct. 24, 2019

NASA's Curiosity rover took this selfie on Oct. 11, 2019


Image above: NASA's Curiosity rover took this selfie on Oct. 11, 2019, the 2,553rd Martian day, or sol, of its mission. The rover drilled twice in this location, which is nicknamed "Glen Etive." Image Credits: NASA/JPL-Caltech/MSSS.

A new selfie taken by NASA's Curiosity Mars rover is breathtaking, but it's especially meaningful for the mission's team: Stitched together from 57 individual images taken by a camera on the end of Curiosity's robotic arm, the panorama also commemorates only the second time the rover has performed a special chemistry experiment.

The selfie was taken on Oct. 11, 2019 (Sol 2,553) in a location named "Glen Etive" (pronounced "glen EH-tiv"), which is part of the "clay-bearing unit," a region the team has eagerly awaited reaching since before Curiosity launched. Visible in the left foreground are two holes Curiosity drilled named "Glen Etive 1" (right) and "Glen Etive 2" (left) by the science team. The rover can analyze the chemical composition of rock samples by powderizing them with the drill, then dropping the samples into a portable lab in its belly called Sample Analysis at Mars (SAM).

About 984 feet (300 meters) behind the rover is Vera Rubin Ridge, which Curiosity departed nearly a year ago. Beyond the ridge, you can see the floor of Gale Crater and the crater's northern rim. Curiosity has been ascending Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain inside the crater.

The special chemistry experiment occurred on Sept. 24, 2019, after the rover placed the powderized sample from Glen Etive 2 into SAM. The portable lab contains 74 small cups used for testing samples. Most of the cups function as miniature ovens that heat the samples; SAM then "sniffs" the gases that bake off, looking for chemicals that hold clues about the Martian environment billions of years ago, when the planet was friendlier to microbial life.

But nine of SAM's 74 cups are filled with solvents the rover can use for special "wet chemistry" experiments. These chemicals make it easier for SAM to detect certain carbon-based molecules important to the formation of life, called organic compounds.

Image above: Annotated version. Image Credits: NASA/JPL-Caltech/MSSS

Because there's a limited number of wet-chemistry cups, the science team has been saving them for just the right conditions. In fact, the experiment at Glen Etive is only the second time Curiosity has performed wet chemistry since touching down on Mars in August 2012.

"We've been eager to find an area that would be compelling enough to do wet chemistry," said SAM Principal Investigator Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Now that we're in the clay-bearing unit, we've finally got it."

Clay-based rocks are good at preserving chemical compounds, which break down over time and when bombarded by radiation from space and the Sun. The science team is intrigued to see which organic compounds, if any, have been preserved in the rocks at Glen Etive. Understanding how this area formed will give them a better idea of how the Martian climate was changing billions of years ago.

While this marks Curiosity's second wet-chemistry experiment, it is the rover's first on a drilled sample. In December 2016, when Curiosity's drill malfunctioned, the rover still had a bit of sand that had been scooped up in a place called "Ogunquit Beach." It wasn't a drilled sample, but the team wasn't sure whether they'd get the drill working and be able to perform wet chemistry in the future. So they delivered the Ogunquit Beach sand into one of SAM's wet chemistry cups since there was still science to be gained.

Scientists consider Glen Etive a strategic location that will reveal more about how the clay-bearing unit formed. They built upon the valuable dress rehearsal at Ogunquit Beach to make adjustments that improved the recent experiment.

The results will be known next year. "SAM's data is extremely complex and takes time to interpret," Mahaffy said. "But we're all eager to see what we can learn from this new location, Glen Etive."

The individual images in this selfie were taken by the Mars Hand Lens Imager (MAHLI), a camera on the end of the rover's robotic arm. The images are stitched together into a panorama; the robotic arm isn't visible in the parts of the images used in the composite.

MAHLI was built by Malin Space Science Systems in San Diego. The SAM instrument suite was built at Goddard Space Flight Center with significant elements provided by industry, university, and national and international NASA partners. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate in Washington. JPL designed and built the project's Curiosity rover.

More information about Curiosity:

https://mars.nasa.gov/msl/

http://nasa.gov/mission_pages/msl

Images (mentioned), Text, Credits: NASA/Tony Greicius/Alana Johnson/JPL/Andrew Good.

Greetings, Orbiter.ch

NASA, Industry Partner for Space-based Study of Potential Alzheimer’s Key













ISS - International Space Station patch.

Oct. 24, 2019

An innovative experiment underway on the International Space Station could help researchers make new progress in the fight against aggressive neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

The Ring-Sheared Drop experiment, developed and led by Teledyne Brown Engineering of Huntsville, Alabama, will be housed in the station’s Microgravity Science Glovebox to enable study of the formation of potentially destructive amyloid fibrils, or protein clusters, like those found in the brain tissue of patients battling neurodegenerative diseases. Such illnesses may cause neurons, the drivers of the human nervous system, to become damaged or inoperative.

Normal brain functions may be disrupted by amyloid fibrils. These proteins can denature -- or lose characteristic properties -- and precipitate out of solution. As they accumulate over time, they may disrupt the healthy function of tissues and organs. In cases of brain function and diseases such as Alzheimer’s, that disruption can be profoundly debilitating and even fatal.


Image above: The Ring-Sheared Drop experiment hardware, installed inside the Microgravity Science Glovebox, will help investigators understand protein aggregation associated with devastating neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Image Credits: NASA/Kevin Depew.

“This project is a prime example of the amazing discoveries and advancements possible with partnering between NASA, research and industry,” said Jan Hess, president of Teledyne Brown. “Our hope is that this experiment brings the scientific community closer to unlocking the mysteries of this life-altering disease that affects so many people worldwide every day.”

In Earth-based experiments, researchers determined that amyloid fibrils may be created by shear flow, or the difference in flow velocity between adjacent layers of a liquid. In the case of ground experiments, that formation is affected by the presence of container walls and by convection, or the circular motion that occurs when warmer liquid rises while cooler liquid descends.

The goal now is to conduct experiments in microgravity -- in a containerless reactor -- where the liquid specimens form spherical drops, containing themselves via surface tension. Researchers will “pin” a droplet of liquid between two rings and cultivate amyloid fibrils for study.

“Experimentation in microgravity affords the opportunity to study amyloid fibril formation under conditions that eliminate unwanted effects such as contact with solid walls which can affect the results of normal laboratory experiments,” said Kevin Depew, a researcher in the ISS Projects Office, part of the Human Exploration Development and Operations Office at NASA’s Marshall Space Flight Center in Huntsville. “The team has worked very hard and we are expecting a great return.”

The project partners, led by principal investigator Amir Hirsa at Rensselaer Polytechnic Institute of Troy, New York, also seek to extend the value of their innovative experiment hardware for other uses, adapting the Ring-Sheared Drop facility as a space-based bioreactor, customizable for other fluid studies or to grow and study cells, bacteria, algae and other materials.

The experiment was launched to the station in July on a SpaceX commercial resupply services mission. Experiments began in September, and the study is expected to continue at least two years. Under contract to Marshall, Teledyne Brown developed the hardware with funding from the Space Life & Physical Sciences Research & Applications Division of NASA’s Human Exploration & Operations Mission Directorate. Rensselaer Polytechnic Institute and Emerald City Initiatives of Huntsville also partnered on the project. Marshall manages the Microgravity Science Glovebox for NASA.

To learn more about science on the International Space Station, visit: https://www.nasa.gov/iss

Related links:

Microgravity Science Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=341/

SpaceX commercial resupply services: https://www.nasa.gov/mission_pages/station/structure/launch/index.html

NASA's Space Life & Physical Sciences Research & Applications Division: https://www.nasa.gov/directorates/heo/slpsra

NASA's Human Exploration & Operations Mission Directorate: https://www.nasa.gov/directorates/heo/index.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), Text, Credits: NASA/Jennifer Harbaugh.

Greetings, Orbiter.ch

mercredi 23 octobre 2019

Spacesuits, Science and Maintenance on Crew Schedule Today













ISS - Expedition 61 Mission patch.

October 23, 2019

The Expedition 61 crew tackled a variety of maintenance jobs and microgravity science onboard the International Space Station today. The orbital residents are also gearing up for the departure of a Japanese cargo ship and more spacewalks tentatively scheduled for November.

Flight Engineer Christina Koch continued loading trash and obsolete gear in Japan’s resupply ship before stowing spacewalk tools and hardware today. Commander Luca Parmitano began his day getting up to speed on future spacewalks planned for the repair of the Alpha Magnetic Spectrometer. Koch and Parmitano later joined together and installed new stowage racks inside the Permanent Multipurpose Module.


Image above: NASA astronauts Jessica Meir (left) and Christina Koch (right) are suited up and ready to go on the first all-woman spacewalk and posing with their Expedition 61 crewmates. Image Credit: NASA.

NASA astronaut Jessica Meir spent all day Wednesday cleaning cooling loops inside the U.S. spacesuits she and Koch wore last week. Parmitano and Flight Engineer Andrew Morgan were also on spacesuit duty checking tethers and recharging the metal oxide canisters that scrub carbon dioxide from the suit atmosphere.

Morgan was back in the Japanese Kibo laboratory module this morning installing an incubator into the Saibo biology research rack. He then watered plants for a space agriculture study exploring how to provide fresh food for long-term space crews.

International Space Station (ISS). Animation Credit: NASA

In the Russian segment of the orbiting lab, veteran cosmonaut Alexander Skvortsov researched ways to improve geographic accuracy when photographing the Earth. Flight Engineer Oleg Skripochka continued testing acoustic gear to detect and locate micrometeoroid impacts on the station.

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/alpha-magnetic-spectrometer.html

Permanent Multipurpose Module (PMM): https://www.nasa.gov/mission_pages/station/structure/elements/permanent-multipurpose-module

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

Saibo: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=335

Space agriculture study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7895

Geographic accuracy: https://www.energia.ru/en/iss/researches/develop/04.html

Micrometeoroid impacts: https://www.energia.ru/en/iss/researches/develop/17.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/Mark Garcia.

Greetings, Orbiter.ch

First identification of a heavy element born from neutron star collision













ESO - European Southern Observatory logo.

23 October 2019

Newly created strontium, an element used in fireworks, detected in space for the first time following observations with ESO telescope

Artist’s impression of strontium emerging from a neutron star merger

In 2017, following the detection of gravitational waves passing the Earth, ESO pointed its telescopes in Chile, including the VLT, to the source: a neutron star merger named GW170817. Astronomers suspected that, if heavier elements did form in neutron star collisions, signatures of those elements could be detected in kilonovae, the explosive aftermaths of these mergers. This is what a team of European researchers has now done, using data from the X-shooter instrument on ESO’s VLT.

Following the GW170817 merger, ESO’s fleet of telescopes began monitoring the emerging kilonova explosion over a wide range of wavelengths. X-shooter in particular took a series of spectra from the ultraviolet to the near infrared. Initial analysis of these spectra suggested the presence of heavy elements in the kilonova, but astronomers could not pinpoint individual elements until now.

X-shooter spectra montage of kilonova in NGC 4993

“By reanalysing the 2017 data from the merger, we have now identified the signature of one heavy element in this fireball, strontium, proving that the collision of neutron stars creates this element in the Universe,” says the study’s lead author Darach Watson from the University of Copenhagen in Denmark. On Earth, strontium is found naturally in the soil and is concentrated in certain minerals. Its salts are used to give fireworks a brilliant red colour.

Astronomers have known the physical processes that create the elements since the 1950s. Over the following decades they have uncovered the cosmic sites of each of these major nuclear forges, except one. “This is the final stage of a decades-long chase to pin down the origin of the elements,” says Watson. “We know now that the processes that created the elements happened mostly in ordinary stars, in supernova explosions, or in the outer layers of old stars. But, until now, we did not know the location of the final, undiscovered process, known as rapid neutron capture, that created the heavier elements in the periodic table.”

The galaxy NGC 4993 in the constellation of Hydra

Rapid neutron capture is a process in which an atomic nucleus captures neutrons quickly enough to allow very heavy elements to be created. Although many elements are produced in the cores of stars, creating elements heavier than iron, such as strontium, requires even hotter environments with lots of free neutrons. Rapid neutron capture only occurs naturally in extreme environments where atoms are bombarded by vast numbers of neutrons.

“This is the first time that we can directly associate newly created material formed via neutron capture with a neutron star merger, confirming that neutron stars are made of neutrons and tying the long-debated rapid neutron capture process to such mergers,” says Camilla Juul Hansen from the Max Planck Institute for Astronomy in Heidelberg, who played a major role in the study.

The sky around the galaxy NGC 4993

Scientists are only now starting to better understand neutron star mergers and kilonovae. Because of the limited understanding of these new phenomena and other complexities in the spectra that the VLT’s X-shooter took of the explosion, astronomers had not been able to identify individual elements until now.

“We actually came up with the idea that we might be seeing strontium quite quickly after the event. However, showing that this was demonstrably the case turned out to be very difficult. This difficulty was due to our highly incomplete knowledge of the spectral appearance of the heavier elements in the periodic table,” says University of Copenhagen researcher Jonatan Selsing, who was a key author on the paper.

Neutron star merger animation and elements formed in these events

The GW170817 merger was the fifth detection of gravitational waves, made possible thanks to the NSF's Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and the Virgo Interferometer in Italy. Located in the galaxy NGC 4993, the merger was the first, and so far the only, gravitational wave source to have its visible counterpart detected by telescopes on Earth.

With the combined efforts of LIGO, Virgo and the VLT, we have the clearest understanding yet of the inner workings of neutron stars and their explosive mergers.

Animation of spectra of kilonova in NGC 4993

More information:

This research was presented in a paper to appear in Nature on 24 October 2019.

The team is composed of D. Watson (Niels Bohr Institute & Cosmic Dawn Center, University of Copenhagen, Denmark), C. J. Hansen (Max Planck Institute for Astronomy, Heidelberg, Germany), J. Selsing (Niels Bohr Institute & Cosmic Dawn Center, University of Copenhagen, Denmark), A. Koch (Center for Astronomy of Heidelberg University, Germany), D. B. Malesani (DTU Space, National Space Institute, Technical University of Denmark, & Niels Bohr Institute & Cosmic Dawn Center, University of Copenhagen, Denmark), A. C. Andersen (Niels Bohr Institute, University of Copenhagen, Denmark), J. P. U. Fynbo (Niels Bohr Institute & Cosmic Dawn Center, University of Copenhagen, Denmark), A. Arcones (Institute of Nuclear Physics, Technical University of Darmstadt, Germany & GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany), A. Bauswein (GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany & Heidelberg Institute for Theoretical Studies, Germany), S. Covino (Astronomical Observatory of Brera, INAF, Milan, Italy), A. Grado (Capodimonte Astronomical Observatory, INAF, Naples, Italy), K. E. Heintz (Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Reykjavík, Iceland & Niels Bohr Institute & Cosmic Dawn Center, University of Copenhagen, Denmark), L. Hunt (Arcetri Astrophysical Observatory, INAF, Florence, Italy), C. Kouveliotou (George Washington University, Physics Department, Washington DC, USA & Astronomy, Physics and Statistics Institute of Sciences), G. Leloudas (DTU Space, National Space Institute, Technical University of Denmark, & Niels Bohr Institute, University of Copenhagen, Denmark), A. Levan (Department of Physics, University of Warwick, UK), P. Mazzali (Astrophysics Research Institute, Liverpool John Moores University, UK & Max Planck Institute for Astrophysics, Garching, Germany), E. Pian (Astrophysics and Space Science Observatory of Bologna, INAF, Bologna, Italy).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with 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. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. 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”.

Links:

ESOcast 210 Light: First identification of a heavy element born from neutron star collision: https://www.eso.org/public/videos/eso1917a/

Research paper: https://www.eso.org/public/archives/releases/sciencepapers/eso1917/eso1917a.pdf

ESO Telescopes Observe First Light from Gravitational Wave Source: https://www.eso.org/public/news/eso1733/

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

NSF's Laser Interferometer Gravitational-Wave Observatory (LIGO): https://www.ligo.caltech.edu/

Virgo Interferometer: https://www.ego-gw.it/public/about/whatIs.aspx

X-shooter: https://www.eso.org/public/germany/teles-instr/paranal-observatory/vlt/vlt-instr/x-shooter/

Images, Videos, Text, Credits: ESO/Bárbara Ferreira/Cosmic Dawn Center (DAWN) Darach Watson, Niels Bohr Institute, University of Copenhagen/Jonatan Selsing/Max Planck Institute for Astronomy/Camilla J. Hansen/ESO/L. Calçada/M. Kornmesser/E. Pian et al./S. Smartt & ePESSTO/IAU and Sky & Telescope/Digitized Sky Survey 2.

Best regards, Orbiter.ch

mardi 22 octobre 2019

Station Focusing on Japanese Ship Departure and Space Biology













ISS - Expedition 61 Mission patch.

October 22, 2019

Japan’s resupply ship is nearing the end of its month-long stay at the International Space Station. Meanwhile, the Expedition 61 crew is exploring how microgravity impacts humans and plants today.

Fresh off her fourth spacewalk last Friday, NASA astronaut Christina Koch is packing the Japanese HTV-8 cargo craft with discarded hardware and trash for disposal. Commander Luca Parmitano of ESA (European Space Agency) joined Koch for the cargo transfers today.


Image above: With the Earth 250 miles below, NASA astronaut Jessica Meir is pictured tethered to the outside of the International Space Station during a seven-hour, 17-minute spacewalk she conducted with fellow NASA astronaut Christina Koch (out of frame). Image Credits: NASA.

Koch and NASA Flight Engineer Jessica Meir will be in the cupola on Friday, Nov. 1 commanding the Canadarm2 robotic arm to release the HTV-8. It will reenter Earth’s atmosphere the following day for a fiery, but safe demise above the Pacific Ocean.

Parmitano and Koch switched roles during the afternoon from space movers to crew medical officers (CMO) examining Meir and NASA Flight Engineer Andrew Morgan. The CMOs operated an ultrasound scanner looking at the cornea, lens and optic nerve inside the eyes of Meir and Morgan.

International Space Station (ISS). Image Credit: NASA

Koch also researched surface tension in space to understand afflictions such as Alzheimer’s disease and design advanced materials. Meir tended to plants for an ongoing space agriculture study. Morgan installed new life science hardware inside the Kibo lab module’s Saibo biology research rack.

Cosmonauts Alexander Skvortsov and Oleg Skripochka set up acoustic gear testing the detection and location of micrometeoroid impacts on the space station. The duo spent the rest of the afternoon checking docking hardware on the Zvezda service module and the Pirs docking compartment.

Related links:

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

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

Surface tension in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7383

Space agriculture study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7895

Saibo: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=335

Micrometeoroid impacts: https://www.energia.ru/en/iss/researches/develop/17.html

Zvezda service module: https://www.nasa.gov/mission_pages/station/structure/elements/zvezda-service-module.html

Pirs docking compartment:
https://www.nasa.gov/mission_pages/station/structure/elements/pirs-docking-compartment

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

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

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

Best regards, Orbiter.ch

How the International Space Station is Helping Us Get to the Moon













ISS - International Space Station logo.

Oct. 22, 2019

The International Space Station is a stepping stone for NASA’s Artemis program that will land the first woman and next man on the Moon by 2024. As the only place for conducting long-duration research on how living in microgravity affects living organisms, especially humans, as well as testing technologies to allow humans to work at the Moon, the space station serves as a unique asset in the effort establish a sustainable presence at the Moon. Missions to the Moon will include a combination of time aboard the Gateway, on the lunar surface, and in multiple spacecraft including Orion and the human landing system. The skills and technologies developed to explore the Moon will help build the capabilities needed for future missions to Mars. Here are some of the ways this orbiting laboratory is contributing to the path forward to the Moon and Mars.

 The Moon seen from Space Station. Image Credit: NASA

The human element

Keeping crew members safe in space is a top priority of lunar missions, and it requires a broad understanding of how living in microgravity affects humans. The space station has offered close to two decades of human research opportunities in a way that no other platform has been able to accomplish. Here is some of what we’re learning:


Image above: Japan Aerospace Exploration agency (JAXA) astronaut Norishige Kanai using the Advanced Resistive Exercise Device (ARED), which provides loading so that crew members experience load and maintain muscle strength and mass during long periods in space. Image Credit: JAXA.

Bone and Muscle loss

In weightlessness, bones and muscles have less to do, and astronauts experience bone and muscle loss during extended stays in space. Researchers continue to investigate the underlying mechanisms and contributing factors of this loss. One investigation scans the hip bones of astronauts to assess the likelihood of bone fracture following exposure to microgravity. Other studies compare subjects on the ground to those aboard the station or in simulated conditions of spaceflight in ground-based laboratories. Researchers also have used the space station to understand how to use diet and exercise to counteract some of the negative effects of life in microgravity.


Image above: NASA astronaut Serena Auñón-Chancellor conducts an eye exam aboard the space station, part of ongoing crew health maintenance activities. Image Credit: NASA.

Vision

One of the most valuable tools an astronaut will have for gathering information during a Moon mission will be his or her own eyes. Long-duration spaceflight, though, often causes changes to a crew member’s vision. Scientists monitor spaceflight-induced visual impairment, as well as changes believed to arise from elevated pressure in the head, to characterize how living in microgravity affects the visual, vascular and central nervous systems. These studies could help develop measures to help prevent lasting changes in vision and eye damage.


Image above: ESA (European Space Agency) astronaut Alexander Gerst exhales into an ultra-sensitive gas analyzer for the Airway Monitoring experiment, a study of airway inflammation in crew members. Results help flight surgeons plan safer long-term missions to the Moon and Mars and may help patients on Earth with asthma or other airway
inflammatory diseases. Image Credit: NASA.

Health Monitoring

Missions to the Moon will prepare astronauts for missions to Mars, which will require greater self-sufficiency and independence from Earth, including monitoring health and wellness so that crew members can recognize and avoid risky health conditions on their own. For example, the Personal CO2 Monitor investigation attempted to demonstrate a system which can unobtrusively collect and monitor crew members’ exposure to carbon dioxide. Humans produce the gas naturally by breathing, but exposure to high concentrations can cause health issues. Wearable monitors can help the crew track their exposure to carbon dioxide and keep it within safe levels during long-duration stays in space. Similarly, research on airway inflammation in crew members seeks to help astronauts identify early signs of health conditions caused by free-floating dust and particles in the microgravity environment.


Image above: ESA astronaut Thomas Pesquet performing the Gravitational References for Sensimotor Performance (GRASP) experiment, which looks at how the central nervous system integrates information from different sensations. This investigation provides further insight into how the brain adapts to the lack of traditional up and down in microgravity. Image Credit: NASA.

Physical and mental function 

Exposure to space flight changes many systems in the body in ways that could make it harder for crew members to perform critical mission tasks immediately after landing on a planetary surface. Crews traveling to the Moon or Mars will have little time to recover from these changes upon arrival and will lack access to Earth’s medical and rehabilitation facilities. One study identifies tasks that may be affected, and supports design of countermeasures to overcome any impairments. Another study validated a battery of tests for measuring cognitive performance in space. Other research looked at the complexity, severity and duration of physical changes in order to improve recovery time and prevent injury.

Technologies to support the mission to – and on – the Moon

In order to travel through space or set up sustainable bases on the Moon or other planetary bodies, crew members need technology and hardware that provide basic human needs, including oxygen and water, along with the ability to maintain and repair those systems. They also require the tools to conduct mission operations.


Image above: NASA astronaut Jack Fischer sets up hardware for the Capillary Structures investigation into ways to manage fluid and gas mixtures for water recycling and carbon dioxide removal. Results benefit design of lightweight, more reliable life support systems for future space missions. Image Credit: NASA.

Life support systems

The space station has provided the impetus for development of state-of-the-art life support systems for space, and has served as a testbed for refining those systems. The Environmental Control and Life Support System (ECLSS) currently on station supplies oxygen, potable water, and appropriate cabin pressure and temperature and removes carbon dioxide, traces of gases, and particles. A set of hardware is used to monitor the station’s water supply and other hardware generates oxygen from recovered carbon dioxide. A recent project tested a new technology using evaporative cooling to maintain appropriate temperatures in spacesuits.

Waste management systems

Everyone “goes,” and space presents challenges for managing human waste. Decades of human occupation of the space station have contributed to improvements in design of toilets and waste management systems. The new Universal Waste Management System (UWMS) incorporates the best features from previous designs on the space shuttle and existing space station hardware with new technology to improve hygiene, crew comfort and sustainability. It includes a double stall enclosure that provides privacy for a Toilet System and a Hygiene Compartment.

Fire safety

Understanding how fire spreads and behaves in space is crucial for the safety of astronauts, especially as humans travel farther from Earth. The Combustion Integrated Rack (CIR) and facilities such as the Microgravity Science Glovebox provide a secure and safe environment in which to study combustion aboard the space station. The CIR has supported a wide range of combustion and flame experiments. One major discovery resulting from this research came from an analysis of fire suppressants: researchers identified the existence of “cool flames” that apparently continue "burning" after flame extinction under certain conditions.


Image above: NASA Astronaut Kate Rubins prepares the Biomolecule Sequencer experiment, which first demonstrated DNA sequencing in a spacecraft. Space-based DNA sequencing can identify microbes, diagnose diseases and monitor crew member health, as well as potentially help detect DNA-based life elsewhere in the solar system. Image Credit: NASA.

Operations in space

Astronauts have tested and used three-dimensional (3D) printers on the space station, advancing the ability to manufacture parts on-demand either aboard a spacecraft or on the surface of the Moon or Mars. Such manufacturing could even use recycled waste plastic materials to reduce the mass and number of tools or spare parts a crew would need to bring from Earth.

Thanks to other research, we can now perform DNA sequencing in space. This technology makes it possible to identify microbes and diagnose diseases to help maintain crew member health, as well as to potentially detect DNA-based life on the Moon, Mars or elsewhere in the solar system.

Space station research also has tested navigation techniques that use the Moon and stars. These techniques could serve as an emergency backup or confirm navigation information on future missions.

Large-scale international and commercial partnerships

The International Space Station represents the most politically complex space exploration program ever undertaken, involving the space agencies of the United States, Russia, Europe, Japan and Canada. It brings together international flight crews; multiple launch vehicles; launch, operations, training, engineering, communications and development facilities around the globe; and the international scientific research community.

In addition, space station research has evolved from relying almost solely on government funding and operations to involving a variety of commercial players. This commercialization drives future growth and innovation, including payload integration and the small satellite market.

International Space Station (ISS). Animation Credit: NASA

The space station’s international and commercial partnerships provide valuable experience for achieving human presence on the Moon by 2024, part of Artemis. This larger, sustainable exploration campaign with international and commercial partners unifies nations, creates new economic opportunities and inspires future generations.

For more information about NASA’s Moon to Mars plans, visit: https://www.nasa.gov/specials/moon2mars/

Related links:

Artemis: https://www.nasa.gov/artemis

Gateway: https://www.nasa.gov/topics/moon-to-mars/lunar-gateway

Scans: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=25

Understand: https://www.nasa.gov/home/hqnews/2012/aug/HQ_12-291_ISS_Bone_Density.html

visual impairment: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=197

Elevated pressure in the head: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1126

Personal CO2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1839

Monitor: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1839

Airway inflammation: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1067

One study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=122

Cognitive performance: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1125

Recovery time: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1546

Recovered carbon dioxide: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7404

Evaporative cooling: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7514

Combustion Integrated Rack (CIR): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317

Combustion: https://www.nasa.gov/mission_pages/station/research/news/combustion-research-microgravity-clean-burning-fuel-space-station/

Fire suppressants: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=655

Recycled waste plastic: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7321

DNA sequencing in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1917

Navigation techniques: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7646

Humans in Space: https://www.nasa.gov/topics/humans-in-space

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

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

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

Best regards, Orbiter.ch

Ten Highlights From NASA’s Van Allen Probes Mission











NASA - Van Allen Probes Mission patch.

Oct. 22, 2019

After seven years of operations, and upon finally running out of propellant, the second of the twin Van Allen Probes spacecraft will be retired on Friday, Oct. 18, 2019. Spacecraft A of the Van Allen Probes mission will be shut down by operators at the Johns Hopkins University Applied Physics Lab in Laurel, Maryland. The command follows one three months previously that terminated operations for spacecraft B, the second spacecraft of the mission.

Illustration of Van Allen Probes. Image Credit: JHUAPL

“This mission spent seven years in the radiation belts, and broke all the records for a spacecraft to tolerate and operate in that hazardous region, all with no interruptions,” said Nelofar Mosavi, Van Allen Probes project manager at Johns Hopkins APL. “This mission was about resiliency against the harshest space environment.”

Originally slated for a two-year mission, the spacecraft flew through the Van Allen belts — rings of charged particles trapped by Earth’s magnetic field — to understand how particles were gained and lost by the belts. The spacecraft made major discoveries that revolutionized how we understand our near-Earth environment.

The Van Allen Probes Explore Earth's Radiation Belts

Video above: The Van Allen Probes flew through Earth’s geomagnetic field and radiation belts. Video Credits: NASA's Goddard Space Flight Center.

“Van Allen Probe observations have been the subject of over 600 publications to date in refereed journals, and over 55 Ph.D. theses have used Van Allen Probe observations,” said David Sibeck, Van Allen Probes mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

With instruments measuring electromagnetic fields and charged particles, the Van Allen Probes explored the invisible phenomena shepherding particles in and around the belts. It made discoveries about the architecture of the belts and the forces shaping them. Just as ocean storms on Earth can create giant waves, space weather, caused by the Sun, can create plasma waves, where seas of particles are tossed by electromagnetic fields. The Van Allen Probes pioneered new explorations into the dynamics of these waves and their effects on our near-Earth environment.

“The Van Allen Probes rewrote the textbook on radiation belt physics,” said Sasha Ukhorskiy, Van Allen Probes project scientist at Johns Hopkins APL, which also designed and built the spacecraft. “The spacecraft used uniquely capable instruments to unveil radiation belt features that were all but invisible to previous sensors, and discovered many new physical mechanisms of radiation belt acceleration and loss.”

In celebration of the mission’s success, here are ten select discoveries, listed in chronological order, made by the Van Allen Probes.

- The Van Allen belts were first discovered in 1958 and for decades scientists thought there were only two concentric belts. But days after the Van Allen Probes launched, scientists discovered that during times of intense solar activity, a third belt can form.


Image above: Van Allen Probes image showing three radiation belts first seen around Earth in 2012. Image Credits: NASA's Goddard Space Flight Center/Johns Hopkins University, Applied Physics Laboratory.

- The belts, which are composed of charged particles and electromagnetic fields, can be energized by different types of plasma waves. One type, called electrostatic double layers, appear as short blips of enhanced electric field. During one observing period, Probe B saw 7,000 such blips repeatedly pass over the spacecraft in a single minute. These individually small events added up to one million volts over six minutes, capable of accelerating electrons up toward the relativistic energies commonly seen in radiation belt particles.   

- During big space weather storms, which are ultimately caused by activity on the Sun, ions — electrically charged atoms or molecules — can be pushed deep into Earth’s magnetosphere in a series of impulsive events. These particles carry electromagnetic currents that circle around the planet and can dramatically distort Earth’s magnetic field.

Supercharging the Radiation Belts

Image above: On March 17, 2015, Van Allen Probe A detected a pulse of high energy electrons in the radiation belts, generated by the impact of a recent coronal mass ejection striking Earth's magnetosphere. The gradient drift speed of the electron pulse was high enough, that it propagated completely around Earth and was detected by the spacecraft again as the pulse spread out in the radiation belt. Because the particles have a range of energies, the pulse spread out as it moved around Earth, generating a weaker signal the next time it hit the spacecraft. Video Credits: NASA's Goddard Space Flight Center.

- Across space, fluctuating electric and magnetic fields can create what are known as plasma waves. These waves intensify during space weather storms and can accelerate particles to relativistic speeds. The Van Allen Probes found that one type of plasma wave known as hiss can contribute greatly to the loss of electrons from the belts.

- The Van Allen belts are composed of electrons and ions with a range of energies. In 2015, research from the Van Allen Probes found that, unlike the outer belt, there were no electrons with energies greater than a million electron volts in the inner belt.

- Plasma waves known as whistler chorus waves are also common in our near-Earth environment. These waves can travel parallel or at an angle to the local magnetic field. The Van Allen Probes demonstrated the two types of waves cannot be present simultaneously, resulting in greater radiation belt particle scattering in certain areas.

- Very low frequency chorus waves, another variety of plasma waves, can pump up the energy of electrons to millions of electron volts. During storm conditions, the Van Allen Probes found these waves can hugely increase the energy of particles in the belts in just a few hours. 

- Scientists often use computer simulation models to understand the physics behind certain phenomena. A model simulating particles in the Van Allen belts helped scientists understand how particles can be lost, replenished and trapped by the Earth’s magnetic field.

- The Van Allen Probes observed several cases of extremely energetic ions speeding toward Earth. Research found that these ions’ acceleration was connected to their electric charge and not to their mass.

- The Sun emits faster and slower gusts of charged particles called the solar wind. Since the Sun rotates, these gusts — the fast wind — reach Earth periodically. Changes in these gusts cause the extent of region of cold ionized gas around Earth — the plasmasphere — to shrink. Data from the Van Allen Probes showed that such changes in the plasmasphere fluctuated at the same rate as the solar rotation ­— every 27 days.

Related Links:

NASA Mission Surfs through Waves in Space to Understand Space Weather: https://www.nasa.gov/feature/goddard/2017/nasa-mission-surfs-through-waves-in-space-to-understand-space-weather

NASA's Van Allen Probes Spot Man-Made Barrier Shrouding Earth: https://www.nasa.gov/feature/goddard/2017/nasas-van-allen-probes-spot-man-made-barrier-shrouding-earth

Learn more about NASA’s Van Allen Probes: https://www.nasa.gov/van-allen-probes

Research: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JA025556

Images (mentioned), Videos (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, By Mara Johnson-Groh.

Greetings, Orbiter.ch