mardi 21 février 2017

Busy Traffic Week Ahead for Space Station Crew











ISS - Expedition 50 Mission patch.

February 21, 2017

International Space Station (ISS). Animation Credit: NASA

Two cargo craft are scheduled to deliver several tons of supplies and experiment hardware to the station this week.

SpaceX’s tenth commercial resupply mission lifted off at 9:39 a.m. EST on Sunday, Feb. 19. The rocket launched from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. This was the first commercial launch from Kennedy’s historic pad.

Astronauts Thomas Pesquet of ESA (European Space Agency) and Shane Kimbrough of NASA will use the space station’s robotic arm to capture Dragon when it arrives at the station. Live coverage of the rendezvous and capture will begin at 4:30 a.m. Wednesday, Feb. 22 on NASA TV and the agency’s website, with installation coverage set to begin at 8:30 a.m.


Image above: A SpaceX Falcon 9 rocket lifts off from Launch Complex 39A at NASA’s Kennedy Space Center in Florida. This is the company’s 10th commercial resupply services mission to the International Space Station. Liftoff was at 9:39 a.m. EST from the historic launch site now operated by SpaceX under a property agreement with NASA. Image Credit: NASA.

Meanwhile, the unpiloted Russian Progress 66 is scheduled for 12:58 a.m. Wednesday (11:58 a.m. Baikonur time) from the Baikonur Cosmodrome in Kazakhstan. The spacecraft is set to dock to the Pirs docking compartment at 3:34 a.m. Friday, Feb. 24.

Aboard the station, the crew continued preparations for the arrival of the vehicles and set up several scientific experiments and technology demonstrations.

The Miniature Exercise Device (MED-2) was installed for a technical evaluation. MED-2 aims to demonstrate if small robotic actuators can provide motion and resistance for crew workout sessions, reducing the size and weight of exercise equipment for long-duration space missions.

Related links:

Miniature Exercise Device (MED-2): https://www.nasa.gov/mission_pages/station/research/experiments/862.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

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

Best regards, Orbiter.ch

10 Years Strong with NASA's THEMIS Mission










NASA - THEMIS Mission patch.

Feb. 21, 2017

Artist concept of a THEMIS satellite. Image Credit: NASA

On Feb. 17, 2017, NASA's Time History of Events and Macroscale Interactions during Substorms, or THEMIS, mission marked its 10th anniversary in space. The spacecraft have now spent a decade discovering how mass and energy move through the near-Earth environment in order to determine the physical processes initiating auroras – and they’re still making new discoveries.

“THEMIS is morphing each year into a new journey of exploration,” said Vassilis Angelopoulos, principal investigator of THEMIS at the University of California, Los Angeles. “The instruments are as good as new and are still being utilized to expand NASA’s exploration of our space environment.”

The magical night lights of the aurora are known to be caused by a space weather phenomenon known as a substorm. But prior to THEMIS, no one understood what triggered these substorms. Thanks to the mission, scientists now understand how the constant outpouring of solar material, called the solar wind, tangles Earth’s magnetic field, initiating the substorms that cause auroras. Scientists also understand the mysteries of why there are different type of auroras – like diffuse and pulsating auroras – much better now.


Image above: THEMIS by the numbers (infographic)• 5 – Number of spacecraft (two now part of ARTEMIS mission)• 2 – Number of orbits (one around Earth, one near the moon)• 25 – Number of scientific instruments aboard• 20 – Number of ground-based observatories working with THEMIS• 37 watts – Average amount of power each spacecraft needs• 282 pounds – Weight of each spacecraft• 365 GB Data – Average amount collected annually and made publicly available. Image Credit: NASA.

THEMIS was initially launched as a five-satellite team, but in 2010, after the end of THEMIS’ prime mission, two of the spacecraft split off to start a new mission: Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun, or ARTEMIS. ARTEMIS studies the moon and its space environment to help contextualize THEMIS discoveries while simultaneously trailblazing new science at the moon. Meanwhile, THEMIS continues studying substorms near Earth with three spacecraft.

Ten years on, THEMIS is no longer alone. NASA’s Van Allen Probes, since 2012, and NASA’s Magnetospheric Multiscale Mission, since 2014, study the near-Earth environment along with THEMIS to provide a wealth of observations on different aspects of near-Earth space and, in concert with other satellites in the Heliophysics System Observatory, provide a start-to-finish picture of physical processes in the region. THEMIS also has the ability to continue to adjust its orbit to better coordinate its measurements with the other missions and maximize its observational power.

Related Links:

Learn more about NASA’s THEMIS and ARTEMIS Missions: https://www.nasa.gov/artemis

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

Learn more about NASA’s MMS Mission: http://www.nasa.gov/mission_pages/mms/index.html

Heliophysics System Observatory: https://www.nasa.gov/content/goddard/heliophysics-system-observatory-hso/

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

Greetings, Orbiter.ch

Rays of Creusa










NASA - Cassini International logo.

Feb. 21, 2017


When viewed from a distance with the sun directly behind Cassini, the larger, brighter craters really stand out on moons like Dione.

Among these larger craters, some leave bright ray patterns across the moon, calling attention to their existence and to the violence of their creation.

The rayed crater seen here on Dione (698 miles, or 1,123 kilometers across) is named Creusa. The rays are brighter material blasted out by the impact that formed the crater. Scientists can use the patterns of ejecta (like these rays), to help determine the order of geological events on a moon's surface by examining which features lie on top of other features.

This view looks toward the Saturn-facing side of Dione. North on Dione is up and rotated 31 degrees to the right. The image was taken with the Cassini spacecraft narrow-angle camera on Nov. 26, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 727 nanometers.

The view was obtained at a distance of approximately 350,000 miles (560,000 kilometers) from Dione. Image scale is 1.8 miles (3 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius.

Greetings, Orbiter.ch

NASA's Fermi Finds Possible Dark Matter Ties in Andromeda Galaxy











NASA - Fermi Gamma-ray Space Telescope logo.

Feb. 21, 2017

NASA’s Fermi Gamma-ray Space Telescope has found a signal at the center of the neighboring Andromeda galaxy that could indicate the presence of the mysterious stuff known as dark matter. The gamma-ray signal is similar to one seen by Fermi at the center of our own Milky Way galaxy.

Gamma rays are the highest-energy form of light, produced by the universe’s most energetic phenomena. They’re common in galaxies like the Milky Way because cosmic rays, particles moving near the speed of light, produce gamma rays when they interact with interstellar gas clouds and starlight.

Surprisingly, the latest Fermi data shows the gamma rays in Andromeda — also known as M31 — are confined to the galaxy’s center instead of spread throughout. To explain this unusual distribution, scientists are proposing that the emission may come from several undetermined sources. One of them could be dark matter, an unknown substance that makes up most of the universe.

video
Fermi Detects Gamma-ray Puzzle from M31

Video above: NASA’s Fermi telescope has detected a gamma-ray excess at the center of the Andromeda galaxy that's similar to a signature Fermi previously detected at the center of our own Milky Way. Watch to learn more. Video Credits: NASA’s Goddard Space Flight Center/Scott Wiessinger, producer.

“We expect dark matter to accumulate in the innermost regions of the Milky Way and other galaxies, which is why finding such a compact signal is very exciting,” said lead scientist Pierrick Martin, an astrophysicist at the National Center for Scientific Research and the Research Institute in Astrophysics and Planetology in Toulouse, France. “M31 will be a key to understanding what this means for both Andromeda and the Milky Way.”

A paper describing the results will appear in an upcoming issue of The Astrophysical Journal.

Another possible source for this emission could be a rich concentration of pulsars in M31’s center. These spinning neutron stars weigh as much as twice the mass of the sun and are among the densest objects in the universe. One teaspoon of neutron star matter would weigh a billion tons on Earth. Some pulsars emit most of their energy in gamma rays. Because M31 is 2.5 million light-years away, it’s difficult to find individual pulsars. To test whether the gamma rays are coming from these objects, scientists can apply what they know about pulsars from observations in the Milky Way to new X-ray and radio observations of Andromeda.

Now that Fermi has detected a similar gamma-ray signature in both M31 and the Milky Way, scientists can use this information to solve mysteries within both galaxies. For example, M31 emits few gamma rays from its large disk, where most stars form, indicating fewer cosmic rays roaming there. Because cosmic rays are usually thought to be related to star formation, the absence of gamma rays in the outer parts of M31 suggests either that the galaxy produces cosmic rays differently, or that they can escape the galaxy more rapidly. Studying Andromeda may help scientists understand the life cycle of cosmic rays and how it is connected to star formation.


Image above: The gamma-ray excess (shown in yellow-white) at the heart of M31 hints at unexpected goings-on in the galaxy's central region. Scientists think the signal could be produced by a variety of processes, including a population of pulsars or even dark matter. Image Credits: NASA/DOE/Fermi LAT Collaboration and Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF.

“We don’t fully understand the roles cosmic rays play in galaxies, or how they travel through them,” said Xian Hou, an astrophysicist at Yunnan Observatories, Chinese Academy of Sciences in Kunming, China, also a lead scientist in this work. “M31 lets us see how cosmic rays behave under conditions different from those in our own galaxy.”

The similar discovery in both the Milky Way and M31 means scientists can use the galaxies as models for each other when making difficult observations. While Fermi can make more sensitive and detailed observations of the Milky Way’s center, its view is partially obscured by emission from the galaxy’s disk. But telescopes view Andromeda from an outside vantage point impossible to attain in the Milky Way.

“Our galaxy is so similar to Andromeda, it really helps us to be able to study it, because we can learn more about our galaxy and its formation,” said co-author Regina Caputo, a research scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s like living in a world where there’s no mirrors but you have a twin, and you can see everything physical about the twin.”

While more observations are necessary to determine the source of the gamma-ray excess, the discovery provides an exciting starting point to learn more about both galaxies, and perhaps about the still elusive nature of dark matter.

Fermi Gamma-ray Space Telescope. Image Credit: NASA

“We still have a lot to learn about the gamma-ray sky,” Caputo said. “The more information we have, the more information we can put into models of our own galaxy.”

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

For more information on Fermi, visit: http://www.nasa.gov/fermi

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center, by Claire Saravia/Rob Garner.

Greetings, Orbiter.ch

A New Crater on a Dusty Slope












NASA - Mars Reconnaissance Orbiter (MRO) patch.

Feb. 21, 2017


This image shows a new impact site originally detected by the Context Camera onboard MRO. The crater is on a dusty slope, which also has several dark slope streaks due to dust avalanches.

A previous impact at another place on Mars triggered a major dust avalanche, but this one did not. This tells us that the dust here is more stable (stronger and/or on a lower slope).

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 27.1 centimeters (9.8 inches) per pixel (with 1 x 1 binning); objects on the order of 81 centimeters (30 inches) across are resolved.] North is up.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html

Image, Text, Credits: NASA/JPL-Caltech/Univ. of Arizona/Tony Greicius.

Greetings, Orbiter.ch

The brightest, furthest pulsar in the Universe












ESA - XMM-Newton Mission patch.

21 February 2017

ESA’s XMM-Newton has found a pulsar – the spinning remains of a once-massive star – that is a thousand times brighter than previously thought possible.

The pulsar is also the most distant of its kind ever detected, with its light travelling 50 million light-years before being detected by XMM-Newton.

Pulsars are spinning, magnetised neutron stars that sweep regular pulses of radiation in two symmetrical beams across the cosmos. If suitably aligned with Earth these beams are like a lighthouse beacon appearing to flash on and off as it rotates. They were once massive stars that exploded as a powerful supernova at the end of their natural life, before becoming small and extraordinarily dense stellar corpses.

NGC 5907 X-1: record-breaking pulsar

This X-ray source is the most luminous of its type detected to date: it is 10 times brighter than the previous record holder. In one second it emits the same amount of energy released by our Sun in 3.5 years.

XMM-Newton observed the object several times in the last 13 years, with the discovery a result of a systematic search for pulsars in the data archive – its 1.13 s periodic pulses giving it away.

The signal was also identified in NASA’s Nustar archive data, providing additional information.

“Before, it was believed that only black holes at least 10 times more massive than our Sun feeding off their stellar companions could achieve such extraordinary luminosities, but the rapid and regular pulsations of this source are the fingerprints of neutron stars and clearly distinguish them from black holes,” says Gian Luca Israel, from INAF-Osservatorio Astronomica di Roma, Italy, lead author of the paper describing the result published in Science this week.

The archival data also revealed that the pulsar’s spin rate has changed over time, from 1.43 s per rotation in 2003 to 1.13 s in 2014. The same relative acceleration in Earth’s rotation would shorten a day by five hours in the same time span

“Only a neutron star is compact enough to keep itself together while rotating so fast,” adds Gian Luca.

Although it is not unusual for the rotation rate of a neutron star to change, the high rate of change in this case is likely linked to the object rapidly consuming mass from a companion.

XMM-Newton x-ray observatory

“This object is really challenging our current understanding of the ‘accretion’ process for high-luminosity stars,” says Gian Luca. “It is 1000 times more luminous than the maximum thought possible for an accreting neutron star, so something else is needed in our models in order to account for the enormous amount of energy released by the object.”

The scientists think there must be a strong, complex magnetic field close to its surface, such that accretion onto the neutron star surface is still possible while still generating the high luminosity.

“The discovery of this very unusual object, by far the most extreme ever discovered in terms of distance, luminosity and rate of increase of its rotation frequency, sets a new record for XMM-Newton, and is changing our ideas of how such objects really ‘work’,” says Norbert Schartel, ESA’s XMM-Newton project scientist.

Notes for Editors

“An accreting pulsar with extreme properties drives an ultraluminous X-ray source in NGC 5907” by G.L. Israel is published in Science: http://science.sciencemag.org/content/early/2017/02/17/science.aai8635

The discovery was made as a result of the “Exploring the X-ray Transient and variable Sky” (EXTraS) project.

More about...

XMM-Newton overview: http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_overview

XMM-Newton image gallery: http://xmm.esac.esa.int/external/xmm_science/gallery/public/index.php

In depth:

XMM-Newton in-depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=23

Images, Text, Credits: ESA/Markus Bauer/Norbert Schartel/INAF, Osservatorio Astronomico di Roma/Gian Luca Israel/XMM-Newton; NASA/Chandra and SDSS.

Best regards, Orbiter.ch

lundi 20 février 2017

SpaceX Mission Launches New Era for Premier, Multi-user Spaceport











NASA logo.

Feb. 20, 2017


The SpaceX launch of a Falcon 9 rocket at Launch Complex 39-A is another milestone for NASA's Kennedy Space Center in Florida as a premier, multi-user spaceport. Lifting off from the historic launch site in the photo on the right, SpaceX CRS-10 is the company's 10th commercial resupply services mission to the International Space Station.

Pad 39-A now is operated by SpaceX under a property agreement with NASA.

The first ever launch from Kennedy's Pad 39-A was Apollo 4, in the image on the left. Lifting off on Nov. 9, 1967, it was the first test flight of the Saturn V rocket that took Apollo astronauts to the moon.

The first space shuttle lifted off April 12, 1981 from Pad 39-A for STS-1 -- the center picture. NASA astronauts John Young and Bob Crippen flew the shuttle Columbia for two days, landing at Edwards Air Force Base, California.

The SpaceX CRS-10 launch of a Dragon spacecraft is the first from Pad 39-A since the final space shuttle mission on July 8, 2011. The Dragon will deliver about 5,500 pounds of supplies to the space station, such as Stratospheric Aerosol and Gas Experiment (SAGE) III instrument to further study ozone in the atmosphere.

Related links:

Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html

Commercial Space: http://www.nasa.gov/exploration/commercial/index.html

Kennedy Space Center: https://www.nasa.gov/centers/kennedy/home/index.html

Image, Text, creditS: NASA/Bob Granath.

Greetings, Orbiter.ch