Pulse of a Dead Star Powers Intense Gamma Rays

NASA - NuStar Mission patch / ESA - XMM-Newton Mission patch.

September 16, 2014

Our Milky Way galaxy is littered with the still-sizzling remains of exploded stars.

When the most massive stars explode as supernovas, they don't fade into the night, but sometimes glow ferociously with high-energy gamma rays. What powers these energetic stellar remains?

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is helping to untangle the mystery. The observatory's high-energy X-ray eyes were able to peer into a particular site of powerful gamma rays and confirm the source: A spinning, dead star called a pulsar. Pulsars are one of several types of stellar remnants that are left over when stars blow up in supernova explosions.

Image above: The blue dot in this image marks the spot of an energetic pulsar -- the magnetic, spinning core of star that blew up in a supernova explosion. Image Credit: NASA/JPL-Caltech/SAO.

This is not the first time pulsars have been discovered to be the culprits behind intense gamma rays, but NuSTAR has helped in a case that was tougher to crack due to the distance of the object in question. NuSTAR joins NASA's Chandra X-ray Observatory and Fermi Gamma-ray Space Telescope, and the High Energy Stereoscopic System (H.E.S.S.) in Namibia, each with its own unique strengths, to better understand the evolution of these not-so-peaceful dead stars.

"The energy from this corpse of a star is enough to power the gamma-ray luminosity we are seeing," said Eric Gotthelf of Columbia University, New York. Gotthelf explained that while pulsars are often behind these gamma rays in our galaxy, other sources can be as well, including the outer shells of the supernova remnants, X-ray binary stars and star-formation regions. Gotthelf is lead author of a new paper describing the findings in the Astrophysical Journal.

In recent years, the Max-Planck Institute for Astronomy's H.E.S.S. experiment has identified more than 80 incredibly powerful sites of gamma rays, called high-energy gamma-ray sources, in our Milky Way. Most of these have been associated with prior supernova explosions, but for many, the primary source of observed gamma rays remains unknown.

The gamma-ray source pinpointed in this new study, called HESS J1640-465, is one of the most luminous discovered so far. It was already known to be linked with a supernova remnant, but the source of its power was unclear. While data from Chandra and the European Space Agency's XMM-Newton telescopes hinted that the power source was a pulsar, intervening clouds of gas blocked the view, making it difficult to see.

XMM-Newton space telescope. Image Credit: ESA

NuSTAR complements Chandra and XMM-Newton in its capability to detect higher-energy range of X-rays that can, in fact, penetrate through this intervening gas. In addition, the NuSTAR telescope can measure rapid X-ray pulsations with fine precision. In this particular case, NuSTAR was able to capture high-energy X-rays coming at regular fast-paced pulses from HESS J1640-465. These data led to the discovery of PSR J1640-4631, a pulsar spinning five times per second -- and the ultimate power source of both the high-energy X-rays and gamma rays.

How does the pulsar produce the high-energy rays?  The pulsar's strong magnetic fields generate powerful electric fields that accelerate charged particles near the surface to incredible speeds approaching that of light.  The fast-moving particles then interact with the magnetic fields to produce the powerful beams of high-energy gamma rays and X-rays.

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. Image Credits: NASA/JPL-Caltech

"The discovery of a pulsar engine powering HESS J1640-465 allows astronomers to test models for the underlying physics that result in the extraordinary energies generated by these rare gamma-rays sources," said Gotthelf.

"Perhaps other luminous gamma-ray sources harbor pulsars that we can't detect," said Victoria Kaspi of McGill University, Montreal, Canada, a co-author on the study. "With NuSTAR, we may be able to find more hidden pulsars."

The new data also allowed astronomers to measure the rate at which the pulsar slows, or spins down (about 30 microseconds per year), as well as how this spin-down rate varies over time. The answers will help researchers understand how these spinning magnets -- the cores of dead stars -- can be the source of such extreme radiation in our galaxy.

The Astrophysical Journal paper is online at: http://iopscience.iop.org/0004637X/788/2/155/pdf/apj_788_2_155.pdf 

NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory in Pasadena, California, for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation in Dulles, Virginia. Its instrument was built by a consortium including Caltech, JPL, the University of California, Berkeley, Columbia University, New York, NASA's Goddard Space Flight Center, Greenbelt, Maryland, the Danish Technical University in Denmark, Lawrence Livermore National Laboratory in Livermore, California, ATK Aerospace Systems in Goleta, California, and with support from the Italian Space Agency (ASI) Science Data Center.

NuSTAR's mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located in Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, California. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

For more information about NuStar Mission, visit: http://www.nasa.gov/mission_pages/nustar/main/

For more information about ESA's XMM-Newton Mission, visit: http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_overview and http://sci.esa.int/xmm-newton/

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Cheers, Orbiter.ch

NASA’s Chandra X-ray Observatory Finds Planet That Makes Star Act Deceptively Old

NASA - Chandra X-ray Observatory patch.

September 16, 2014

A planet may be causing the star it orbits to act much older than it actually is, according to new data from NASA’s Chandra X-ray Observatory. This discovery shows how a massive planet can affect the behavior of its parent star.

The star, WASP-18, and its planet, WASP-18b, are located about 330 light-years from Earth. WASP-18b has a mass about 10 times that of Jupiter and completes one orbit around its star in less than 23 hours, placing WASP-18b in the “hot Jupiter” category of exoplanets, or planets outside our solar system.

WASP-18b is the first known example of an orbiting planet that has apparently caused its star, which is roughly the mass of our sun, to display traits of an older star.

Image above: A new study from NASA’s Chandra X-ray Observatory shows that a giant exoplanet, WASP-18b, is making the star that it orbits very closely act much older than it actually is. This artist’s illustration depicts WASP-18b and its star, which are about 330 light years away. Image Credits: NASA/CXC/M. Weiss.

“WASP-18b is an extreme exoplanet," said Ignazio Pillitteri of the Istituto Nazionale di Astrofisica (INAF)-Osservatorio Astronomico di Palermo in Italy, who led the study. "It is one of the most massive hot Jupiters known and one of the closest to its host star, and these characteristics lead to unexpected behavior. This planet is causing its host star to act old before its time.”

Pillitteri’s team determined WASP-18 is between 500 million and 2 billion years old, based on theoretical models and other data. While this may sound old, it is considered young by astronomical standards. By comparison, our sun is about 5 billion years old and thought to be about halfway through its lifetime.

Younger stars tend to be more active, exhibiting stronger magnetic fields, larger flares, and more intense X-ray emission than their older counterparts. Magnetic activity, flaring, and X-ray emission are linked to the star’s rotation, which generally declines with age. However, when astronomers took a long look with Chandra at WASP-18 they didn’t detect any X-rays. Using established relations between the magnetic activity and X-ray emission of stars, as well as its actual age, researchers determined WASP-18 is about 100 times less active than it should be.

“We think the planet is aging the star by wreaking havoc on its innards,” said co-author Scott Wolk of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

WASP-18b: A 'Hot Jupiter'

Image above: A new study using data from NASA’s Chandra X-ray Observatory has shown that a planet is making the star that it orbits act much older than it actually is, as explained in our latest press release. The artist’s illustration featured in the main part of this graphic depicts the star, WASP-18, and its planet, WASP-18b. Image Credits: X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS.

The researchers argue that tidal forces created by the gravitational pull of the massive planet – similar to those the moon has on Earth’s tides, but on a much larger scale – may have disrupted the magnetic field of the star.

The strength of the magnetic field depends on the amount of convection in the star, or how intensely hot gas stirs the interior of the star.

“The planet’s gravity may cause motions of gas in the interior of the star that weaken the convection,” said co-author Salvatore Sciortino also of INAF-Osservatorio Astronomico di Palermo in Italy. “This has a domino effect that results in the magnetic field becoming weaker and the star to age prematurely.”

WASP-18 is particularly susceptible to this effect because its convection zone is narrower than most stars. This makes it more vulnerable to the impact of tidal forces that tug at it.

The effect of tidal forces from the planet may also explain an unusually high amount of lithium found in earlier optical studies of WASP-18. Lithium is usually abundant in younger stars, but over time convection carries lithium to the hot inner regions of a star, where it is destroyed by nuclear reactions. If there is less convection, the lithium does not circulate into the interior of the star as much, allowing more lithium to survive.

These results were published in the July issue of Astronomy and Astrophysics and are available online.

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.

An interactive image, podcast, and video on these findings are available at: http://chandra.si.edu

For a preprint of the study results in The Astrophysical Journal, visit: http://arxiv.org/abs/1406.2620

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Images (mentioned), Text, Credits: NASA / Felicia Chou / Marshall Space Flight Center / Janet Anderson / Chandra X-ray Center / Megan Watzke.

Greetings, Orbiter.ch

Galileo satellites - Status update

ESA - Galileo Mission logo.

16 September 2014

The fifth and sixth Galileo satellites have been in a safe state since 28 August, fully under control from ESA’s centre in Darmstadt, Germany, despite having been released on 22 August into lower and elliptical orbits instead of the expected circular orbits.

Galileo orbits viewed from above

The potential of exploiting the satellites to maximum advantage, despite their unplanned injection orbits and within the limited propulsion capabilities, is being investigated.

Galileo orbits viewed side-on

The various ESA specialists, supported by industry and France’s CNES space agency, are analysing different scenarios that would yield maximum value for the programme and safeguard, as much as possible, the original mission objectives.

More detailed analysis, alongside consultations with industry, is under way, checking for a potential ‘improved orbit’ where they could both provide operational services.

Related links:

About satellite navigation: http://www.esa.int/Our_Activities/Navigation/About_satellite_navigation2

How satellite navigation works: http://www.esa.int/Our_Activities/Navigation/How_satellite_navigation_works

Galileo and EGNOS: http://www.esa.int/Our_Activities/Navigation/Galileo_and_EGNOS

The story so far: http://www.esa.int/Our_Activities/Navigation/The_story_so_far

Graphics, Text, Credit: ESA.

Cheers, Orbiter.ch

TRMM Satellite Sees Hurricane Odile Strike Baja California

NASA / JAXA - TRMM Mission patch.

September 15, 2014

NASA"s Tropical Rainfall Measuring Mission satellite known as TRMM captured data on powerful Hurricane Odile revealing heavy rainfall from powerful thunderstorms as it made landfall in Baja California. Odile tied a record for strongest hurricane to hit the Baja in over 40 years.

Odile made landfall near Cabo San Lucas at 0445 UTC (12:45 a.m. EDT) and was moving northwest along the length of the peninsula of Baja California, then northeast to the northern end of the Sea of Cortez.

Image above: NASA's TRMM Satellite measured rainfall in Odile on Sept. 15. Odile contained intense thunderstorms around the eye above 12.5 km (about 7.8 miles) high dropping rain at a rate of over 188.4 mm (about 7.4 inches) per hour. Image Credit: NASA/SSAI, Hal Pierce.

TRMM passed directly above hurricane Odile on September 15, 2014 at 0344 UTC (Sept. 14 at 1:44 p.m. EDT). That was about an hour before the strong hurricane hit Baja California near Cabo San Lucas. 

The National Hurricane Center (NHC) hurricane discussion on September 15, 2014 said, "The estimated intensity of 110 knots at landfall ties Odile with Olivia (1967) as the strongest hurricane to make landfall in the satellite era in the state of Baja California Sur."

NASA's TRMM Satellite Sees Heavy Rainfall in Hurricane Odile

Video above: NASA's TRMM Satellite measured rainfall in Odile on Sept. 15. Odile contained intense thunderstorms around the eye above 12.5 km (about 7.8 miles) high dropping rain at a rate of over 188.4 mm (about 7.4 inches) per hour. Image Credit: NASA/SSAI, Hal Pierce.

TRMM's Precipitation Radar (PR showed that Odile contained intense thunderstorms dropping rain at a rate of over 188.4 mm (about 7.4 inches) per hour in the hurricane's nearly circular eye wall.

One of the TRMM satellites most useful features has been its ability to provide vertical profiles of the rain and snow from the surface up to a height of about 12 miles (20 kilometers). At NASA's Goddard Space Flight Center in Greenbelt, Maryland a simulated 3-D view of Hurricane Odile's rainfall structure was created using the satellite's radar reflectivity data. This view showed that the tops of many intense thunderstorms in Odile's eye wall were reaching heights above 12.5 km (about 7.8 miles).

GOES Video of Odile Making Landfall in Baja

Video above: This animation of NOAA's GOES-West satellite imagery from September 13 through September 15 shows Hurricane Odile's movement and landfall near Cabo San Lucas on Mexico's Baja California. TRT 0:42. Video Credit: NASA/NOAA GOES Project.

By 2 p.m. EDT on September 15, Hurricane Odile's wind speeds decreased to about 90 mph (150 kph) after hitting land and winds are forecast by the NHC to slowly decrease to below hurricane force tomorrow. Odile is moving to the northwest at 13 mph (20 kph).  It was centered near 25.1 north and 111.6 west, about 45 miles (70 km) east-northeast of Cabo San Lazaro, Mexico.

Torrential rainfall is predicted to continue near the weakening system. Flash floods and landslides with rainfall totals of over 152-305 mm (6-12 inches) are predicted by the NHC as Odile travels over the Baja California Peninsula. Western Mexico is expected to feel the effects of Hurricane Odile today and tomorrow as the hurricane continues to hug the coast.  A Hurricane Warning is in effect for Baja California Sur from Punta Abreojos to Santa Rosalia. A Hurricane Watch remains in effect for the west coast of Baja California Sur from north of Punta Abreojos to Punta Eugenia. A Tropical Storm Warning is in effect for the East Coast of the  Baja Peninsula from north of Santa Rosalia to Bahia De Los Angeles, the west coast of the Baja Peninsula from north of Punta Eugenia to San Jose De Las Palomas and mainland Mexico from Altata to Bahia Kino.

A Tropical Storm Watch is in effect for the west coast of The Baja Peninsula North of San Jose De Las Palomas to Cabo San Quintin, the east coast of the Baja Peninsula From North of Bahia De Los Angeles to San Felipe and mainland Mexico from north of Bahia Kino to Puerto Libertad.

Although Odile continues to weaken heavy rainfall and flooding pose serious threats.

For more information about TRMM satellite mission, visit: http://trmm.gsfc.nasa.gov/ and http://pmm.nasa.gov/node/158 and http://global.jaxa.jp/projects/sat/trmm/

For more information about NOAA's GOES-West satellite, visit: http://www.ssd.noaa.gov/goes/west/

For more information about Odile (Eastern Pacific) thunderstorms. visit: http://www.nasa.gov/content/goddard/odile-eastern-pacific/index.html

Image (mentioned), Videos (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Hal Pierce / Rob Gutro.

Greetings, Orbiter.ch

‘J’ marks the spot for Rosetta’s lander

ESA - Rosetta Mission patch.

15 September 2014

Rosetta’s lander Philae will target Site J, an intriguing region on Comet 67P/Churyumov–Gerasimenko that offers unique scientific potential, with hints of activity nearby, and minimum risk to the lander compared to the other candidate sites.

Site J is on the ‘head’ of the comet, an irregular shaped world that is just over 4 km across at its widest point. The decision to select Site J as the primary site was unanimous. The backup, Site C, is located on the ‘body’ of the comet.

Philae’s primary landing site

The 100 kg lander is planned to reach the surface on 11 November, where it will perform indepth measurements to characterise the nucleus in situ, in a totally unprecedented way.

But choosing a suitable landing site has not been an easy task.

“As we have seen from recent close-up images, the comet is a beautiful but dramatic world – it is scientifically exciting, but its shape makes it operationally challenging,” says Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.

Philae’s primary landing site in context

“None of the candidate landing sites met all of the operational criteria at the 100% level, but Site J is clearly the best solution.”

“We will make the first ever in situ analysis of a comet at this site, giving us an unparalleled insight into the composition, structure and evolution of a comet,” says Jean-Pierre Bibring, a lead lander scientist and principal investigator of the CIVA instrument at the IAS in Orsay, France.

“Site J in particular offers us the chance to analyse pristine material, characterise the properties of the nucleus, and study the processes that drive its activity.”

The race to find the landing site could only begin once Rosetta arrived at the comet on 6 August, when the comet was seen close-up for the first time. By 24 August, using data collected when Rosetta was still about 100 km from the comet five candidate regions had been identified for further analysis.

Philae’s primary landing site close-up

Since then, the spacecraft has moved to within 30 km of the comet, affording more detailed scientific measurements of the candidate sites. In parallel, the operations and flight dynamics teams have been exploring options for delivering the lander to all five candidate landing sites.

Over the weekend, the Landing Site Selection Group of engineers and scientists from Philae’s Science, Operations and Navigation Centre at France’s CNES space agency, the Lander Control Centre at DLR, scientists representing the Philae Lander instruments and ESA’s Rosetta team met at CNES, Toulouse, France, to consider the available data and to choose the primary and backup sites.

A number of critical aspects had to be considered, not least that it had to be possible to identify a safe trajectory for deploying Philae to the surface and that the density of visible hazards in the landing zone should be minimal. Once on the surface, other factors come into play, including the balance of daylight and nighttime hours, and the frequency of communications passes with the orbiter.

Philae’s primary landing site in 3D

The descent to the comet is passive and it is only possible to predict that the landing point will place within a ‘landing ellipse’ typically a few hundred metres in size.

A one square kilometre area was assessed for each candidate site. At Site J, the majority of slopes are less than 30º relative to the local vertical, reducing the chances of Philae toppling over during touchdown. Site J also appears to have relatively few boulders, and receives sufficient daily illumination to recharge Philae and continue science operations on the surface beyond the initial battery-powered phase.

Provisional assessment of the trajectory to Site J found that the descent time of Philae to the surface would be about seven hours, a length that does not compromise the on-comet observations by using up too much of the battery during the descent.

Both Sites B and C were considered as the backup, but C was preferred because of a higher illumination profile and fewer boulders. Sites A and I had seemed attractive during first rounds of discussion, but were dismissed at the second round because they did not satisfy a number of the key criteria.

Philae landing site context

A detailed operational timeline will now be prepared to determine the precise approach trajectory of Rosetta in order to deliver Philae to Site J. The landing must take place before mid-November, as the comet is predicted to grow more active as it moves closer to the Sun.

“There’s no time to lose, but now that we’re closer to the comet, continued science and mapping operations will help us improve the analysis of the primary and backup landing sites,” says ESA Rosetta flight director Andrea Accomazzo.

“Of course, we cannot predict the activity of the comet between now and landing, and on landing day itself. A sudden increase in activity could affect the position of Rosetta in its orbit at the moment of deployment and in turn the exact location where Philae will land, and that’s what makes this a risky operation.”

Once deployed from Rosetta, Philae’s descent will be autonomous, with commands having been prepared by the Lander Control Centre at DLR, and uploaded via Rosetta mission control before separation.

During the descent, images will be taken and other observations of the comet’s environment will be made.

Philae’s backup landing site

Once the lander touches down, at the equivalent of walking pace, it will use harpoons and ice screws to fix it onto the surface. It will then make a 360° panoramic image of the landing site to help determine where and in what orientation it has landed.

The initial science phase will then begin, with other instruments analysing the plasma and magnetic environment, and the surface and subsurface temperature. The lander will also drill and collect samples from beneath the surface, delivering them to the onboard laboratory for analysis. The interior structure of the comet will also be explored by sending radio waves through the surface towards Rosetta.

“No one has ever attempted to land on a comet before, so it is a real challenge,” says Fred Jansen, ESA Rosetta mission manager. “The complicated ‘double’ structure of the comet has had a considerable impact on the overall risks related to landing, but they are risks worth taking to have the chance of making the first ever soft landing on a comet.”

The landing date should be confirmed on 26 September after further trajectory analysis and the final Go/No Go for a landing at the primary site will follow a comprehensive readiness review on 14 October.

More about Rosetta:

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI. Rosetta is the first mission in history to rendezvous with a comet. It will escort the comet as it orbits the Sun and deploys a lander.

Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System, as well as answering questions regarding the origin of Earth’s water and perhaps even life.

Related links:

Rosetta Mission: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions

Rosetta at Astrium: http://www.astrium.eads.net/en/programme/rosetta-1go.html

Rosetta at DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10394/

Ground-based comet observation campaign: http://www.rosetta-campaign.net/home

Images, Text, Credits: Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Best regards, Orbiter.ch

Three-Person Station Crew Preps for Spacecraft Traffic

ISS - Expedition 41 Mission patch.

September 15, 2014

Commander Max Suraev and Flight Engineers Reid Wiseman and Alexander Gerst began their first full workweek Monday as a three-person crew aboard the International Space Station, while the three additional flight engineers who will round out the Expedition 41 crew spent the day training for next week’s launch to the orbiting complex.

Following the station crew’s usual 2 a.m. EDT reveille and a daily planning conference with the flight control teams around the work to discuss the activities on tap for the day, Suraev, Wiseman and Gerst conducted a fit check of the Kazbek seat liners inside their Soyuz TMA-13M spacecraft docked at the Rassvet Mini-Research Module-1. The trio is scheduled to return to Earth on Nov. 10 aboard that Soyuz after nearly six months in space.  They have been operating as a three-person crew since the departure of their Expedition 40 crewmates – Commander Steve Swanson and Flight Engineers Alexander Skvortsov and Oleg Artemyev – on Wednesday.

Image above: European Space Agency astronaut Alexander Gerst (left), Russian cosmonaut Maxim Suraev (center) and NASA astronaut Reid Wiseman pose for a portrait in the Harmony node of the International Space Station. Image Credit: NASA.

Suraev spent the remainder of his morning performing routine maintenance in the Russian segment of the station, which included cleaning the ventilation system in the Zvezda service module.

Wiseman meanwhile conducted some scheduled maintenance on the Waste and Hygiene Compartment -- the station’s toilet located in the Tranquility node.

Afterward, Wiseman gathered the equipment needed to outfit the vestibule of the Harmony node where the SpaceX Dragon cargo vehicle will be berthed next week. The fourth SpaceX cargo mission to the station is slated to launch Saturday at 2:16 a.m. from the Cape Canaveral Air Force Station in Florida. The SpaceX Dragon will carry about 5,000 pounds of experiments, equipment and supplies to the orbiting laboratory.

Wiseman and Gerst will use the 57-foot Canadarm2 robotic arm to capture Dragon for its berthing to Harmony when the cargo craft rendezvous with the station on Monday, Sept. 22. Dragon will remain attached to the station for more than four weeks before it is released for a splashdown in the Pacific Ocean off the coast of Baja California with almost two tons of experiment samples and equipment returning from the station.

While Wiseman gathered vestibule hardware, Gerst routed cables and powered up the Robotics Work Station in the seven-windowed cupola and the backup workstation inside the Destiny lab. The crew will use the work station to command Canadarm2 for the grapple of the Dragon cargo craft.

After a break for lunch, Wiseman spent the afternoon performing annual maintenance on the COLBERT treadmill. Keeping the station’s exercise equipment in tip-top condition is a priority because each crew member needs to exercise 2.5 hours every day to prevent the loss of bone density and muscle mass that occurs during long-duration spaceflight.

Gerst meanwhile stowed one of the two spacesuits located in the Quest airlock and retrieved a third one to prepare it for some upcoming cooling loop maintenance and resizing. The next set of U.S. spacewalks from the Quest airlock is slated for October.

Afterward, Gerst used the Total Organic Carbon Analyzer to check the quality of the station’s recycled water. He then spent several hours using a sound level meter to conduct a detailed survey of the noise levels that the crew is exposed to throughout the orbiting complex.

Suraev worked with the Vizir experiment, which is designed improve the targeting of Earth photography by cosmonauts through the use of ultrasonic angle measurements. The commander rounded out his workday stowing equipment for disposal inside the ISS Progress 56 cargo ship docked to the Pirs docking compartment.

Image above: At the Baikonur Cosmodrome in Kazakhstan, Expedition 41/42 Flight Engineer Elena Serova of the Russian Federal Space Agency (Roscosmos) is seen inside the Soyuz TMA-14M spacecraft Sept. 13 performing test procedures during the first of two "fit check" dress rehearsal activities. Image Credit: NASA/Victor Zelentsov.

Meanwhile at the Baikonur Cosmodrome in Kazakhstan, the three flight engineers who will return the station’s crew to its full six-person complement spent the day preparing for their upcoming launch. NASA astronaut Barry Wilmore, Soyuz Commander Alexander Samokutyaev and Russian cosmonaut Elena Serova brushed up on rendezvous and docking training on laptop simulators in their Cosmonaut Hotel crew quarters.

Over the weekend, the trio climbed aboard their Soyuz TMA-14M spacecraft in the Cosmodrome Integration Facility for the first of two “fit check” dress rehearsals of the Soyuz systems. Wilmore, Samokutyaev and Serova are scheduled to launch from Baikonur on Sept. 25, U.S. time (Sept. 26, Kazakh time) to begin a six-hour, four-orbit trek to the station.

To adjust the station’s orbit for the arrival of the TMA-14M spacecraft, ground controllers conducted a reboost of the complex Saturday night using the thrusters on the “Georges Lemaitre” Automated Transfer Vehicle docked to Zvezda. The 3-minute, 44-second firing raised the perigee of the station’s orbit by 1.2 statute miles. The station is now in a 262.8 x 253.9 mile orbit.

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA.

Greetings, Orbiter.ch

First Map of Rosetta's Comet

ESA - Rosetta Mission patch.

September 11, 2014

Scientists have found that the surface of comet 67P/Churyumov-Gerasimenko -- the target of study for the European Space Agency's Rosetta mission -- can be divided into several regions, each characterized by different classes of features. High-resolution images of the comet reveal a unique, multifaceted world.

ESA's Rosetta spacecraft arrived at its destination about a month ago and is currently accompanying the comet as it progresses on its route toward the inner solar system. Scientists have analyzed images of the comet's surface taken by OSIRIS, Rosetta's scientific imaging system, and defined several different regions, each of which has a distinctive physical appearance. This analysis provides the basis for a detailed scientific description of 67P's surface. A map showing the comet's various regions is available at: http://go.nasa.gov/1pU26L2

"Never before have we seen a cometary surface in such detail," says OSIRIS Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Science (MPS) in Germany. In some of the images, one pixel corresponds to a scale of 30 inches (75 centimeters) on the nucleus. "It is a historic moment -- we have an unprecedented resolution to map a comet," he says.

Image above: This view of the "belly" and part of the "head" of comet 67P/Churyumov-Gerasimenko indicates several morphologically different regions. Image Credit: ESA/Rosetta/MPS for OSIRIS Team/MPS/UPD/LAM/IAA/SSO/INTA/UPM.

The comet has areas dominated by cliffs, depressions, craters, boulders and even parallel grooves. While some of these areas appear to be quiet, others seem to be shaped by the comet's activity, in which grains emitted from below the surface fall back to the ground in the nearby area.

"This first map is, of course, only the beginning of our work," says Sierks. "At this point, nobody truly understands how the surface variations we are currently witnessing came to be."

As both comet 67P and Rosetta travel closer to the sun during the next few months, the OSIRIS team and other instruments on the payload will monitor the surface to look for changes. While scientists do not expect the borderlines they have identified for the comet's different regions to vary dramatically, even subtle transformations of the surface may help to explain how cometary activity created such a breathtaking world.

The new comet maps will offer valuable insights for members of the Rosetta team, who plan to gather in Toulouse, France, on September 13 and 14, to determine a primary and backup landing site from five candidates they previously had selected.

Illustration above: Rosetta orbiting comet 67P (photo-montage by Orbiter.ch Aerospace, the distance and sizes between the comet and the probe are not realistic) original images credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

The scientific imaging system, OSIRIS, was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with Center of Studies and Activities for Space, University of Padua (Italy), the Astrophysical Laboratory of Marseille (France), the Institute of Astrophysics of Andalusia, CSIC (Spain), the Scientific Support Office of the European Space Agency (Netherlands), the National Institute for Aerospace Technology (Spain), the Technical University of Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden) and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain, and Sweden and the ESA Technical Directorate.

Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI. Rosetta will be the first mission in history to rendezvous with a comet, escort it as it orbits the sun, and deploy a lander to its surface.

For more information on the U.S. instruments aboard Rosetta, visit: http://rosetta.jpl.nasa.gov

More information about Rosetta is available at: http://www.esa.int/rosetta

Images (mentioned), Text, Credit: NASA.

Cheers, Orbiter.ch