A sweet martian treat

ESA - Mars Express Mission patch.

9 February 2015

Cappuccino swirls at Mars’ south pole

Swirls of chocolate, caramel and cream – this image is definitely one to trigger sweet-toothed cravings. Smooth cream-coloured plateaus surrounded by cocoa-dusted ridges interspersed with caramel-hued streaks create a scene reminiscent of a cosmic cappuccino.

This picture is, perhaps surprisingly, from ESA’s Mars Express, which has been exploring and imaging the martian surface and atmosphere since 2003. We may be used to seeing numerous images of red and brown-hued soil and ruddy landscapes peppered with craters, but the Red Planet isn’t always so red.

The bright white region of this image shows the icy cap that covers Mars’ south pole, composed of frozen water and carbon dioxide. While it looks smooth in this image, at close quarters the cap is a layered mix of peaks, troughs and flat plains, and has been likened in appearance to swiss cheese.

The southern cap reaches some 3 km thick in places, and is around 350 km in diameter. This icy region is permanent; in the martian winter another, thinner ice cap forms over the top of it, stretching further out across the planet and disappearing again when the weather warms up.

ESA's Mars Express spacecraft

The cap is around 150 km north of Mars’ geographical south pole and Mars Express has shed light on why this ice cap is displaced. Deep impact craters – notably the Hellas Basin, the largest impact structure on the entire planet at 7 km deep and 2300 km across – funnel the strong winds that blow across Mars towards its southern pole, creating a mix of different low- and high-pressure systems. The carbon dioxide in the polar cap sublimates at different rates in these regions with contrasting pressure, resulting in the cap’s lopsided structure.

Mars Express imaged this area of Mars on 17 December 2012, in infrared, green and blue light, using its High Resolution Stereo Camera. This image was processed by Bill Dunford, using data available from the ESA Planetary Science Archive: http://www.sciops.esa.int/index.php?project=PSA&page=mex

For more information about Mars Express mission, visit: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Images, Text, Credits: ESA/DLR/FU Berlin/Bill Dunford.

Greetings, Orbiter.ch

Retreating glaciers - 36 years of radar vision

ESA - Sentinel-1 Mission logo.

6 February 2015

ESA has recently recovered imagery from the oldest synthetic aperture radar – or SAR – in space, renewing our view of a changing Earth.

Greenland glaciers seen by three generations of radar missions

Comparing data from three generations of radar missions – Seasat, ERS and Sentinel-1 – the retreat of two large glaciers in southeast Greenland over a 36-year period is evident in the video above.

This preliminary analysis shows that the effects of climate change on the world’s second largest ice sheet have had a major impact over the past three decades. The glaciers show significant retreat, with the upper glacier receding by about 5.5 km over the past 36 years. This melt is contributing to sea-level rise and the release of more freshwater into the North Atlantic.

This is just one example of how scientists can exploit heritage satellite data such as the recently recovered and reprocessed radar data from the veteran Seasat mission.

Seasat

Launched in June 1978 and managed by NASA’s Jet Propulsion Laboratory, Seasat was the first to carry a SAR instrument to space – paving the way for the development of follow-on SAR missions like ESA’s ERS, Envisat and Sentinel-1.

During its brief lifetime of just over 100 days, the satellite acquired information on ocean phenomena, such as surface and internal waves, currents and sea-surface winds for the study of ocean circulation. It also captured imagery of glaciers, sea ice, coastal regions, volcanoes, forests and land cover.

Last year, NASA released newly reprocessed digital Seasat imagery. Today, ESA is releasing its own full digitally processed Seasat dataset acquired at the UK’s Oakhanger ground station, which supplements the NASA dataset.

Now available to the user community, this unique dataset holds high value, as only a few of ESA’s Seasat data holdings were digitally processed in the past.

ESA’s Seasat data holdings coverage

The majority of ESA’s Seasat data holdings cover parts of Europe, the North Atlantic and northern Africa from 13 July to 10 October 1978. The dataset also contains several scenes over North America and Guadeloupe.

In addition to providing us with a historical view, the decades-old data can be paired with SAR scans from other missions to observe long-term changes in coastal erosion, urban growth, land use and glaciers.

SAR data are especially suited to monitor glaciers, as they can measure flow speed and ice thickness, offering additional clues to what is happening in these sensitive ecosystems.

The efforts to retrieve, consolidate and reprocess the ESA Seasat SAR data holdings were carried out under the Long Term Data Preservation Programme. The data are now available to the user community and may be downloaded after fast registration via the online dissemination portal.

Related links:

Seasat dataset: https://earth.esa.int/web/guest/data-access/browse-data-products?selectedTags=seasat

ESA Seasat SAR data: https://earth.esa.int/aos/SEASAT

Related missions:

Seasat: https://earth.esa.int/web/guest/missions/3rd-party-missions/historical-missions/seasat

ERS overview: http://www.esa.int/Our_Activities/Observing_the_Earth/ERS_overview

ERS technical site: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/ers

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

Sentinel-1 technical site: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/sentinel-1

Images, Video, Text, Credits: ESA/NASA/JPL.

Best regards, Orbiter.ch

Hubble's Little Sombrero

NASA - Hubble Space Telescope patch.

February 6, 2015

Galaxies can take many shapes and be oriented any way relative to us in the sky. This can make it hard to figure out their actual morphology, as a galaxy can look very different from different viewpoints. A special case is when we are lucky enough to observe a spiral galaxy directly from its edge, providing us with a spectacular view like the one seen in this picture of the week.

This is NGC 7814, also known as the “Little Sombrero.” Its larger namesake, the Sombrero Galaxy, is another stunning example of an edge-on galaxy — in fact, the “Little Sombrero” is about the same size as its bright namesake at about 60,000 light-years across, but as it lies farther away, and so appears smaller in the sky.

Hubble and the sunrise over Earth

NGC 7814 has a bright central bulge and a bright halo of glowing gas extending outwards into space. The dusty spiral arms appear as dark streaks. They consist of dusty material that absorbs and blocks light from the galactic center behind it. The field of view of this NASA/ESA Hubble Space Telescope image would be very impressive even without NGC 7814 in front; nearly all the objects seen in this image are galaxies as well.

For more information about Hubble Space Telescope, visit: http://www.spacetelescope.org/ and http://hubblesite.org/

Image, Video, Text, Credits: ESA/Hubble & NASA/Acknowledgement: Josh Barrington.

Cheers, Orbiter.ch

Camera to record doomed ATV’s disintegration – from inside

ESA - ATV-5 Georges Lemaître logo / ESA-NASA - ATV-5 Re-Entry Observation Campaign logo.

6 February 2015

Next Monday, ESA astronaut Samantha Christoforetti will float into Europe’s space ferry to install a special infrared camera, set to capture unique interior views of the spacecraft’s break-up on reentry.

“The battery-powered camera will be trained on the Automated Transfer Vehicle’s forward hatch, and will record the shifting temperatures of the scene before it,” explains Neil Murray, overseeing the project for ESA.

ATV-5 free flight

“Recording at 10 frames per second, it should show us the last 10 seconds or so of the ATV. We don’t know exactly what we might see – might there be gradual deformations appearing as the spacecraft comes under strain, or will everything come apart extremely quickly?

“Our Break-Up Camera, or BUC, flying for the first time on this mission, will complement NASA’s Reentry Break-up Recorder.

“Whatever results we get back will be shared by our teams, and should tell us a lot about the eventual reentry of the International Space Station as well as spacecraft reentry in general.”

BUC Infrared Camera and SatCom

Every mission of ESA’s ATV ferry ends in the same way – filled with Space Station rubbish then burning up in the atmosphere, aiming at a designated ‘spacecraft graveyard’ in an empty stretch of the South Pacific.

But the reentry of this fifth and final ATV is something special. NASA and ESA are treating it as an opportunity to gather detailed information that will help future spacecraft reentries.

Accordingly, ATV-5 will be steered into a shallow descent compared to the standard deorbit path.

Camera calibration targets

This ATV’s fiery demise will be tracked with a battery of cameras and imagers, on the ground, in the air and even from the Station itself, and this time on the vehicle itself.

ESA’s camera will not survive the reentry, expected to occur some 80–70 km up, but it is linked to the ‘SatCom’ sphere with a ceramic thermal protection system to endure the searing 1500°C.

Once SatCom is falling free, it will transmit its stored data to any Iridium communication satellites in view.

ATV-1 reentry

Plunging through the top of the atmosphere at around 7 km/s, it will itself be surrounded by scorching plasma known to block radio signals, but the hope is that its omnidirectional antenna will be able to exploit a gap in its trail.

If not, signalling will continue after the plasma has cleared – somewhere below 40 km altitude.

Japan’s i-Ball camera managed to gather images of its Station supply ferry breaking up in 2012. Another i-Ball was planned to fly with ATV-5, but was lost in the Antares rocket explosion last October.

ESA’s camera team had to develop flight-ready hardware in just nine months. The camera and capsule was constructed by Ruag in Switzerland, with thermal protection contributed by the DLR German Aerospace Center, Switzerland’s ETH Zurich contributing software, Switzerland’s Viasat responsible for antenna and electronics and Denmark’s GomSpace delivering batteries.

“Between us and the NASA side, there are a lot of fingers crossed at the moment,” Neil adds.

ATV cutaway

“For the future, now the development has already been done, the camera has broader potential as a ‘blackbox for reentry’, flyable on a wide range of satellites and launchers.”

The camera will be activated by a set sequence of acceleration by ATV. Some 10 seconds’ worth of 320x256 frames from the camera will be buffered in the SatCom memory at a time plus about one-frame-per-second reference images of the previous set, and progressively overwritten as fresh imagery arrives.

Related links:

ATV 5 Georges Lemaître: http://www.esa.int/Our_Activities/Human_Spaceflight/ATV

ATV-5 ESA/NASA reentry observation campaign: http://atv5.seti.org/

About Propulsion and Aerothermodynamics: http://www.esa.int/Our_Activities/Space_Engineering_Technology/esaTQM/1079452419720_mechanical_0.html

NASA Re-entry Break-up Recorder: http://www.nasa.gov/mission_pages/station/research/news/rebr.html

JAXA i-Ball images of HTV break-up: http://www.spacesafetymagazine.com/reentry-images-show-htv-breakup/

RUAG Space Switzerland: http://www.ruag.com/space/RUAG_Space_Switzerland

DLR: http://www.dlr.de/dlr;internal&action=_setlanguage.action?LANGUAGE=en

ETH Zurich: http://www.ethz.ch/index_EN

ViaSat Antenna Systems: https://www.viasat.com/company/locations/switzerland

GomSpace: http://gomspace.com/index.php?p=home

Images, Video, Text, Credits: ESA/D. Ducros/Roscosmos/O. Artemyev.

Greetings, Orbiter.ch

Venus Climate Orbiter “AKATSUKI” Re-injection to Venus Orbit and Observation Plan

JAXA - Venus Climate Orbiter PLANET-C logo.

February 6, 2015

The Japan Aerospace Exploration Agency has decided the schedule for the Venus Climate Orbiter “AKATSUKI” to be injected into the Venus orbit in the winter of 2015, as well as its observation plan.

After failing to be inserted into the Venus orbit in December 2010, JAXA has been carefully studying another attempt opportunity for the injection when the orbiter meets Venus in the winter of 2015.

Venus Climate Orbiter “AKATSUKI” (PLANET-C) spacecraft

After being injected into the orbit, the AKATSUKI will observe the atmosphere of Venus, which is often referred to as a twin sister of the Earth, through remote sensing. Its observations are expected to develop “Planetary Meteorology” further by elucidating the atmospheric circulation mechanism and studying the comparison with the Earth.

1. Injection schedule to Venus orbit

Planned date: Dec. 7 (Mon.), 2015 (Japan Standard Time).

2. Observation plan

The observation plan of the AKATSUKI is to measures the following with a multiple number of wave lengths from an elliptical orbit around Venus whose period is eight to nine days.

- When flying further away from Venus, or about 10 times the radius of Venus from the planet, the AKATSUKI will continuously observe Venus as a whole to understand its clouds, deep atmosphere, and surface conditions.

- When flying closer to Venus, or less than 10 times the radius of Venus, the orbiter will conduct close-up observations to clarify cloud convection, the distribution of minute undulatory motions and their changes.

- When the AKATSUKI comes closest to Venus, it will observe the layer structure of clouds and the atmosphere from a lateral direction.

- When the orbiter is in the shade of the sun, it will monitor lightning and airglow (night glow.).

- The AKATSUKI will also observe to capture the atmospheric layer structure and its changes by emitting radio waves that penetrates the atmosphere of Venus and receiving them on the ground.

For more information about Venus Climate Orbiter "AKATSUKI" (PLANET-C): http://global.jaxa.jp/projects/sat/planet_c/

Image, Text, Credit: Japan Aerospace Exploration Agency (JAXA).

Greetings, Orbiter.ch

NASA's Curiosity Analyzing Sample of Martian Mountain

NASA - Mars Science Laboratory (MSL) patch.

February 5, 2015

-- Analysis underway of Curiosity's second drilled rock sample at Mount Sharp

-- Preliminary results suggest acidic ancient conditions

-- New drilling technique uses less-forceful hammering on fragile rock

The second bite of a Martian mountain taken by NASA's Curiosity Mars rover hints at long-ago effects of water that was more acidic than any evidenced in the rover's first taste of Mount Sharp, a layered rock record of ancient Martian environments.

The rover used a new, low-percussion-level drilling technique to collect sample powder last week from a rock target called "Mojave 2."

Curiosity reached the base of Mount Sharp five months ago after two years of examining other sites inside Gale Crater and driving toward the mountain at the crater's center. The first sample of the mountain's base layer came from a target called "Confidence Hills," drilled in September.

Image above: Gray cuttings from Curiosity's drilling into a target called "Mohave 2" are visible surrounding the sample-collection hole in this Jan. 31, 2015, image from the rover's MAHLI camera. This site in the "Pahrump Hills" outcrop provided the mission's second drilled sample of Mars' Mount Sharp. Image Credit: NASA/JPL-Caltech/MSSS.

A preliminary check of the minerals in the Mojave 2 sample comes from analyzing it with the Chemistry and Mineralogy (CheMin) instrument inside Curiosity. The still-partial analysis shows a significant amount of jarosite, an oxidized mineral containing iron and sulfur that forms in acidic environments.

"Our initial assessment of the newest sample indicates that it has much more jarosite than Confidence Hills," said CheMin Deputy Principal Investigator David Vaniman, of the Planetary Science Institute, Tucson, Arizona. The minerals in Confidence Hills indicate less acidic conditions of formation.

Open questions include whether the more acidic water evident at Mojave 2 was part of environmental conditions when sediments building the mountain were first deposited, or fluid that soaked the site later.

Both target sites lie in a outcrop called "Pahrump Hills," an exposure of the Murray formation that is the basal geological unit of Mount Sharp. The Curiosity mission team has already proposed a hypothesis that this mountain, the size of Mount Rainier in Washington, began as sediments deposited in a series of lakes filling and drying.

In the months between Curiosity's drilling of these two targets, the rover team based at NASA's Jet Propulsion Laboratory, Pasadena, California, directed the vehicle through an intensive campaign at Pahrump Hills. The one-ton roving laboratory zig-zagged up and down the outcrop's slope, using cameras and spectrometer instruments to study features of interest at increasing levels of detail. One goal was to select which targets, if any, to drill for samples to be delivered into the rover's internal analytical instruments.

The team chose a target called "Mojave," largely due to an abundance of slender features, slightly smaller than rice grains, visible on the rock surface. Researchers sought to determine whether these are salt-mineral crystals, such as those that could result from evaporation of a drying lake, or if they have some other composition. In a preparatory drilling test of the Mojave target, the rock broke. This ruled out sample-collection drilling at that spot, but produced chunks with freshly exposed surfaces to be examined.     

Mojave 2, an alternative drilling target selected at the Mojave site, has the same type of crystal-shaped features. The preliminary look at CheMin data from the drilled sample material did not identify a clear candidate mineral for these features. Possibly, minerals that originally formed the crystals may have been replaced by other minerals during later periods of wet environmental conditions.

The drilling to collect Mojave 2 sample material might not have succeeded if the rover team had not recently expanded its options for operating the drill.

Image above: Self-Portrait by Curiosity Rover Arm Camera square. Image Credit: NASA/JPL-Caltech/MSSS.

"This was our first use of low-percussion drilling on Mars, designed to reduce the energy we impart to the rock," said JPL's John Michael Morookian, the team's surface science and sampling activity lead for the Pahrump Hills campaign. "Curiosity's drill is essentially a hammer and chisel, and this gives us a way not to hammer as hard."

Extensive tests on Earth validated the technique after the team became concerned about fragility of some finely layered rocks near the base of Mount Sharp.

The rover's drill has six percussion-level settings ranging nearly 20-fold in energy, from tapping gently to banging vigorously, all at 30 times per second. The drill monitors how rapidly or slowly it is penetrating the rock and autonomously adjusts its percussion level. At the four targets before Mojave 2 -- including three before Curiosity reached Mount Sharp -- sample-collection drilling began at level four and used an algorithm that tended to remain at that level. The new algorithm starts at level one, then shifts to a higher level only if drilling progress is too slow. The Mojave 2 rock is so soft, the drill reached its full depth of about 2.6 inches (6.5 centimeters) in 10 minutes using just levels one and two of percussion energy.

Curiosity has also delivered Mojave 2 powder to the internal Sample Analysis at Mars (SAM) suite of instruments, for chemical analysis. The rover may drive to one or more additional sampling sites at Pahrump Hills before heading higher on Mount Sharp.

NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA's Science Mission Directorate in Washington.

For more information about Curiosity, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

Images (mentioned), Text, Credits: NASA/Dwayne Brown/JPL/Guy Webster.

Cheers, Orbiter.ch

Dawn Gets Closer Views of Ceres

NASA - Dawn Mission patch.

February 5, 2015

NASA's Dawn spacecraft, on approach to dwarf planet Ceres, has acquired its latest and closest-yet snapshot of this mysterious world.

At a resolution of 8.5 miles (14 kilometers) per pixel, the pictures represent the sharpest images to date of Ceres.

Animation above: This animation showcases a series of images NASA's Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles (145,000 kilometers) from the dwarf planet. Animation Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.

After the spacecraft arrives and enters into orbit around the dwarf planet, it will study the intriguing world in great detail. Ceres, with a diameter of 590 miles (950 kilometers), is the largest object in the main asteroid belt, located between Mars and Jupiter.

Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. of Dulles, Virginia, designed and built the spacecraft. 

Image above: This image is one several images NASA's Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles (145,000 kilometers) from the dwarf planet. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

JPL is managed for NASA by the California Institute of Technology in Pasadena. The framing cameras were provided by the Max Planck Institute for Solar System Research, Gottingen, Germany, with significant contributions by the German Aerospace Center (DLR) Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig.

The visible and infrared mapping spectrometer was provided by the Italian Space Agency and the Italian National Institute for Astrophysics, built by Selex ES, and is managed and operated by the Italian Institute for Space Astrophysics and Planetology, Rome. The gamma ray and neutron detector was built by Los Alamos National Laboratory, New Mexico, and is operated by the Planetary Science Institute, Tucson, Arizona.

For more information about Dawn, visit: http://dawn.jpl.nasa.gov

Image (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Elizabeth Landau.

Greetings, Orbiter.ch