Rejigging the Cluster quartet

ESA - Cluster II Mission patch.

16 January 2015

Aiming to study Earth’s ‘bow shock’ in the solar wind, the constellation of Cluster satellites is being rejigged to bring two of the four to within almost touching distance.

ESA’s Cluster quartet, in orbit since 2000, is studying the detailed structures of Earth’s magnetosphere – our protective magnetic bubble – and its environment in 3D.

Cluster quartet

The four identical satellites fly in highly elliptical orbits between 600 km and 20 000 km apart, depending on the regions that each satellite’s set of 11 identical instruments is studying.

This month, satellites 3 and 4 will be manoeuvred to within about 6 km of each other, adjusting the formation to observe activity at Earth's bow shock – the region where the solar wind decelerates from super- to subsonic speeds before being deflected around our planet.

Checking the maths

“The scientific aim is to have a pair of satellites orbiting a few kilometres apart in the free solar wind just ahead of the bow shock, to collect data at very small scales,” says Detlef Sieg, a flight dynamics specialist working on Cluster at ESA’s Space Operations Centre in Darmstadt, Germany.

This requires careful calculations of orbits and thruster burns, lining up Cluster 3 and 4 in almost the same orbit while ensuring they can’t collide during this close-formation period.

Earth’s bow shock and magnetosphere

Since there is no communication between the satellites and we know their positions only to within a few hundred metres, they must be flown carefully from the ground to prevent any collision risk.

“During each orbit, they cross almost the same two points just three seconds apart. Between, they are side by side and one overtakes the other.”

The ultra-close alignment was achieved on 7 January, and they will stay like this until mid-March.

During this two-month alignment, the other two satellites will maintain more or less steady positions with respect to the first two, about 5000 km away.

Plenty of teamwork

“Adjusting the formation requires plenty of teamwork and coordination, not only among teams in Darmstadt but also with the Joint Science Operations Centre in the UK and the Payload teams,” notes Cluster operations manager Bruno Sousa.

“We also work to optimise fuel usage and eliminate any risk of potential collision, though this only becomes really significant if we go down to 1–2 km separation.”

Detlef Sieg and Bruno Sousa

The two satellites will be so close that, as seen from a ground tracking station, both will be in the same slice of sky. This allows a single station to communicate with them simultaneously on different frequencies.

However, this time-saving technique requires validation so, for now, only one will be tracked at a time (more about Estrack: http://www.esa.int/Our_Activities/Operations/Estrack_tracking_stations).

Getting up close to Earth's bow wave

This is not the closest separation achieved between two Cluster satellites – that was just 4 km in 2013 – but it is the first time that two have come so close at the bow shock, which typically occurs some 90 000 km above Earth.

“This enables us to study physical processes such as plasma heating and acceleration at the bow shock,” says Philippe Escoubet, the mission’s project scientist.

“Previous studies of the bow shock have shown electron heating over distances as small as 16 km, but we want to see what is happening using two satellites at smaller scales.”

These observations one of the main aims for the 2015–16 mission extension, which was agreed by ESA’s Science Programme Committee in November 2014: http://www.esa.int/link%20to%20http://sci.esa.int/director-desk/54999-working-life-extensions-for-esas-science-missions

Exploring the Sun-Earth connection: http://www.esa.int/Our_Activities/Space_Science/Cluster

Cluster overview: http://www.esa.int/Our_Activities/Space_Science/Cluster_overview2

Cluster Operations: http://www.esa.int/Our_Activities/Operations

Images, Text, Credits: ESA/AOES Medialab.

Greetings, Orbiter.ch

Nothing to Squirm About: Space Station Worms Help Battle Muscle and Bone Loss

ISS - International Space Station patch.

January 16, 2015

It is said that great things can come in small packages. In this case, one key to keeping astronauts healthy on long-duration space missions may be found in a tiny roundworm barely a millimeter long.

Image above: Caenorhabditis elegans -- a millimeter-long roundworm with a genetic makeup scientists understand -- will be central to a pair of Japan Aerospace Agency investigations into muscle and bone loss of astronauts on the International Space Station in the first few months of 2015. Image Credit: NASA.

Two Japan Aerospace Exploration Agency (JAXA) investigations on the International Space Station help researchers seek clues to physiological problems found in astronauts by studying Caenorhabditis elegans -- a millimeter-long roundworm that, like the fruit fly, is widely used as a model for larger organisms. The results of the investigation could lead to new treatments for bone and muscle loss in humans living in space. Findings may also be beneficial to people on Earth suffering from muscle and bone diseases.

"Spaceflight-induced health changes, such as decreases in muscle and bone mass, are a major challenge facing our astronauts," said Julie Robinson, NASA's Chief Scientist for the International Space Station Program Office at NASA's Johnson Space Center in Houston. "We investigate solutions on the station not only to keep astronauts healthy as the agency considers longer space exploration missions, but also to help those on Earth who have limited activity as a result of aging or illness."

We rely on gravity to develop stronger muscles and bones. Athletes will lift weights -- resisting the pull of gravity -- to make their bodies even stronger. When gravity is greatly reduced -- as in spaceflight -- we don't use those muscles to resist the force of gravity, and muscles and bones can slowly start to deteriorate. Even with assigned daily exercise, the bodies of astronauts in microgravity lose bone and muscle mass.

International Space Station. Image Credit: NASA

This is the same problem facing people who are on prolonged bed rest. The inactivity, even removing simple daily movement, can have a negative effect on the bones and muscles of the infirm or elderly. Patients on prolonged bed rest experience muscle atrophy, bone density loss and changes in metabolism, similar to the effects of long-duration spaceflight.

One investigation, scheduled for launch to the station on the SpaceX’s sixth space station resupply mission in 2015, is called Alterations of C. elegans muscle fibers by microgravity (Nematode Muscle). It will look into the muscle fibers and cytoskeleton of the roundworm to clarify how those physiological systems alter in response to microgravity. Space station crew members will grow these worms in microgravity, as well as another batch in one-g using a centrifuge. This will simulate the force of gravity while the C. elegans remain physically in orbit, allowing a direct comparison of the effects of different gravity levels on organisms in space.

A different JAXA investigation currently on station is taking a much closer look at C. elegans by examining their DNA. The Epigenetics in spaceflown C. elegans (Epigenetics) study launched to the space station on the SpaceX CRS-5 resupply mission. It requires astronauts on the orbiting laboratory to grow four generations of the worm, with adults and larvae from each generation preserved at different points during their lifespan. The worms will return to Earth in the SpaceX Dragon spacecraft in January.

Image above: A researcher prepares samples of the Japan Aerospace Exploration Agency’s Epigenetics investigation at the Kennedy Space Center in Florida for launch on the fifth SpaceX resupply mission to the International Space Station. Image Credit: JAXA/Tohoku University.

"The astronauts will cultivate multiple generations of the organism, so we can examine the organisms in different states of development," said Atsushi Higashitani, principal investigator for both investigations with Tohoku University in Miyagi, Japan. "Our studies will help clarify how and why these changes to health take place in microgravity and determine if the adaptations to space are transmitted from one cell generation to another without changing the basic DNA of an organism. Then, we can investigate if those effects could be treated with different medicines or therapies."

Worms grown in each investigation will be compared to similar batches grown in a laboratory in Japan. Understanding the molecular changes that take place in microgravity could help researchers develop treatments or therapies to counteract the physical changes associated with aging and extended bed rest, such as muscle atrophy or osteoporosis, and could help develop treatments or exercises for astronauts on long voyages.

This simple, tiny roundworm could lead to a cure for symptoms affecting millions of the aging and infirm population of Earth, and the astronauts orbiting it, potentially offering a solution to a major problem in an extremely small package.

Related links:

Japan Aerospace Exploration Agency (JAXA): http://global.jaxa.jp/

Model for larger organisms: https://blogs.nasa.gov/ISS_Science_Blog/2013/11/13/model-organisms-shining-examples-for-simple-effective-biology-research/

The Epigenetics in spaceflown C. elegans (Epigenetics) study: http://www.nasa.gov/mission_pages/station/research/experiments/1075.html

SpaceX CRS-5 resupply mission: http://www.nasa.gov/mission_pages/station/research/news/spacex_cats

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/International Space Station Program Science Office, By Bill Hubscher/NASA's Marshall Space Flight Center.

Best regards, Orbiter.ch

NASA’s New Horizons Spacecraft Begins First Stages of Pluto Encounter

NASA - New Horizons Mission logo.

January 15, 2015

NASA's New Horizons spacecraft recently began its long-awaited, historic encounter with Pluto. The spacecraft is entering the first of several approach phases that culminate July 14 with the first close-up flyby of the dwarf planet, 4.67 billion miles (7.5 billion kilometers) from Earth.

“NASA first mission to distant Pluto will also be humankind’s first close up view of this cold, unexplored world in our solar system,” said Jim Green, director of NASA’s Planetary Science Division at the agency’s Headquarters in Washington. “The New Horizons team worked very hard to prepare for this first phase, and they did it flawlessly.”

NASA New Horizons animations

Video above: NASA’s New Horizons is the first mission to Pluto and the Kuiper Belt of icy, rocky mini-worlds on the solar system’s outer frontier. This animation follows the New Horizons spacecraft as it leaves Earth after its January 2006 launch, through a gravity-assist flyby of Jupiter in February 2007, to the encounter with Pluto and its moons in summer 2015. Video Credit: NASA/JHUAPL.

The fastest spacecraft when it was launched, New Horizons lifted off in January 2006. It awoke from its final hibernation period last month after a voyage of more than 3 billion miles, and will soon pass close to Pluto, inside the orbits of its five known moons. In preparation  for the close encounter, the mission’s science, engineering and spacecraft operations teams configured the piano-sized probe for distant observations of the Pluto system that start Sunday, Jan. 25 with a long-range photo shoot.

The images captured by New Horizons’ telescopic Long-Range Reconnaissance Imager (LORRI) will give mission scientists a continually improving look at the dynamics of Pluto’s moons. The images also will play a critical role in navigating the spacecraft as it covers the remaining 135 million miles (220 million kilometers) to Pluto.

Image above: Artist’s concept of NASA’s New Horizons spacecraft as it passes Pluto and Pluto’s largest moon, Charon, in July 2015. Image Credit: NASA/JHU APL/SwRI/Steve Gribben.

“We’ve completed the longest journey any spacecraft has flown from Earth to reach its primary target, and we are ready to begin exploring,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado.

LORRI will take hundreds of pictures of Pluto over the next few months to refine current estimates of the distance between the spacecraft and the dwarf planet. Though the Pluto system will resemble little more than bright dots in the camera’s view until May, mission navigators will use the data to design course-correction maneuvers to aim the spacecraft toward its target point this summer. The first such maneuver could occur as early as March.

“We need to refine our knowledge of where Pluto will be when New Horizons flies past it,” said Mark Holdridge, New Horizons encounter mission manager at Johns Hopkins University’s Applied Physics Laboratory (APL) in Laurel, Maryland. “The flyby timing also has to be exact, because the computer commands that will orient the spacecraft and point the science instruments are based on precisely knowing the time we pass Pluto – which these images will help us determine.”

The “optical navigation” campaign that begins this month marks the first time pictures from New Horizons will be used to help pinpoint Pluto’s location.

Throughout the first approach phase, which runs until spring, New Horizons will conduct a significant amount of additional science. Spacecraft instruments will gather continuous data on the interplanetary environment where the planetary system orbits, including measurements of the high-energy particles streaming from the sun and dust-particle concentrations in the inner reaches of the Kuiper Belt. In addition to Pluto, this area, the unexplored outer region of the solar system, potentially includes thousands of similar icy, rocky small planets.

Graphic above: Timeline of the approach and departure phases — surrounding close approach on July 14, 2015 — of the New Horizons Pluto encounter. Image Credit: NASA/JHU APL/SwRI.

More intensive studies of Pluto begin in the spring, when the cameras and spectrometers aboard New Horizons will be able to provide image resolutions higher than the most powerful telescopes on Earth. Eventually, the spacecraft will obtain images good enough to map Pluto and its moons more accurately than achieved by previous planetary reconnaissance missions.

APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern, of the Southwest Research Institute (SwRI), headquartered in San Antonio, is the principal investigator and leads the mission. SwRI leads the science team, payload operations, and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. APL designed, built and operates the spacecraft.

For more information about the New Horizons mission, visit:
http://www.nasa.gov/newhorizons and http://pluto.jhuapl.edu

Image & Graphic (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/Johns Hopkins University Applied Physics Laboratory/Michael Buckley/Southwest Research Institute/Maria Stothoff.

Cheers, Orbiter.ch

NEOWISE: A Yearlong Look at the Sky

NASA - NEO WISE Mission logo.

January 15, 2015

NASA's Near-Earth Object Wide-field Survey Explorer (NEOWISE) spacecraft discovered and characterized 40 near-Earth objects (NEOs) in the first year after the mission was re-started in December 2013. Eight of the discoveries have been classified as potentially hazardous asteroids (PHAs), based on their size and how close their orbits could come to Earth's orbit.

One Year of NEOWISE Observations Mapped

Video above: This movie shows the progression of NASA's NEOWISE survey in the year after its Dec. 2013 restart.

The mission has further observed and characterized 245 previously known near-Earth objects. From December 2013 to December 2014, NEOWISE discovered three new comets and observed 32 others. One of the others has turned into the brightest comet in Earth's night sky in early 2015, comet C/2014 Q2 (Lovejoy).

NEOWISE always looks in the dawn and twilight skies – the direction perpendicular to a line between Earth and the sun. This unique vantage point makes it easy for NEOWISE to spot NEOs that get particularly close to Earth.

Image above: Comet C/2014 Q2 (Lovejoy) is one of more than 32 comets imaged by NASA's NEOWISE mission from December 2013 to December 2014. This image of comet Lovejoy combines a series of observations made in November 2013. Image Credit: NASA/JPL-Caltech.

Originally called the Wide-field Infrared Survey Explorer (WISE), the spacecraft was placed in hibernation in 2011 after its primary mission was completed. In September 2013, it was reactivated, renamed NEOWISE and assigned a new mission to assist NASA's efforts to identify the population of potentially hazardous near-Earth objects. NEOWISE is also characterizing previously known asteroids and comets to provide information about their sizes and compositions.

NEOWISE is a space telescope that scans the skies for asteroids and comets. The telescope sees infrared light, which allows it to pick up the heat signature of asteroids and obtain better estimates of their true sizes. As a result, NEOWISE can see dark asteroids that are harder for visible-light surveys to find. Nearly all of the NEOWISE discoveries have been large (hundreds of yards, or meters, wide) and very dark, similar to printer toner. When NEOWISE's infrared data on an object is combined with that of a visible-light optical telescope, it helps scientists understand the object's composition.

Image above: On clear nights in January 2015, comet C/2014 Q2 (Lovejoy) is visible in the Taurus region of the sky to observers using binoculars. This chart indicates where to look for it on different dates during the month. Image Credit: NASA/JPL-Caltech.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the NEOWISE mission for NASA's Science Mission Directorate in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For more information about NEOWISE, visit: http://www.nasa.gov/neowise

More information about asteroids and near-Earth objects is at: http://www.jpl.nasa.gov/asteroidwatch

Images (mentioned), Video, Text, Credits: NASA/Dwayne Brown/JPL/DC Agle.

Greetings, Orbiter.ch

Cracks in the Swiss Air Force F-5E Tiger

Swiss Air Force - Patrouille Suisse patch.

January 15, 2015

The Swiss Air Force Team Patrouille Suisse

La Patrouille Suisse will simply steal some with gray planes over the next years: the Swiss Air Force discovered cracks in two Tiger F-5E single-seat aircraft.

During an inspection, a crack was found in the supporting structure of a Tiger F-5E and resulted in an order to control 30 devices of this type still in service. On this occasion, another crack "very serious" was found on another plane, the Swiss Air Force said Monday.

Pending be controlled, thirteen machines are suspended flight. Audits require about two weeks per machine and should be completed by the summer. Both devices are damaged repair.

Swiss Air Force Northrop F-5E Tiger II

The temporary flight restriction also affects Tiger painted in the colors of the Patrouille Suisse. During the air show scheduled next weekend at Lauberhorn (BE), the pilots will probably have to settle for flying with four red appliances white cross and two gray, said the head of communications of the Swiss Air Force Jürg Nussbaum.

The commitment of the Swiss Air Force at the Davos Economic Forum will however ensured by the F/A 18. As to aircraft F-5E Tiger grounded, they are not concerned with issues affecting the air security.

For more information about the Patrouille Suisse, visit: http://www.lw.admin.ch/internet/luftwaffe/de/home/verbaende/einsatz_lw/kunstflugteam/ps.html

Images Text, Credits: ATS/Wikimedia/Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

International Space Station: Responding to the Unexpected

ISS - International Space Station logo.

January 14, 2015

Space Station Live: Responding to the Unexpected

NASA Public Affairs Officer Dan Huot talks with International Space Station Program Manager Mike Suffredini about the quick response on orbit and in Mission Control Houston to indications of a possible ammonia leak in the U.S. Operating Segment of the vehicle which prompted evacuation of the crew members to the Russian segment of the station.

ISS - International Space Station

The latest indications are that there was not an actual leak of ammonia, and flight controllers are working through the procedures to get all systems back to full operation so the crew can return to the US segment of the station.

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

Image, Video, Text, Credits: NASA/NASA TV.

Greetings, Orbiter.ch

Crystal-Rich Rock 'Mojave' is Next Mars Drill Target

NASA - Mars Science Laboratory (MSL) patch.

January 14, 2015

A rock target where NASA's Curiosity Mars rover is using its sample-collection drill this week may have a salty story to tell.

This target, called "Mojave," displays copious slender features, slightly smaller than grains of rice, that appear to be mineral crystals. A chance to learn their composition prompted the Curiosity science team to choose Mojave as the next rock-drilling target for the 29-month-old mission investigating Mars' Gale Crater. The features might be a salt mineral left behind when lakewater evaporated.

Image above: This view from the wide-angle Hazard Avoidance Camera on the front of NASA's Curiosity Mars Rover shows the rover's drill in position for a mini-drill test to assess whether a rock target called "Mojave" is appropriate for full-depth drilling to collect a sample. It was taken on Jan. 13, 2015. Image Credit: NASA/JPL-Caltech.

This week, Curiosity is beginning a "mini-drill" test to assess the rock's suitability for deeper drilling, which collects a sample for onboard laboratory analysis.

A weeklong pause in science operations to install a new version of rover flight software is scheduled to begin early next week, possibly before completion of the drilling and sample delivery. This is the fourth new version of the onboard software since the rover's August 2012 landing.

The Mojave drilling begins Curiosity's third round of investigating the basal layer of Mount Sharp exposed at an area called "Pahrump Hills." In the first round, the rover drove about 360 feet (110 meters) and scouted sites ranging about 30 feet (9 meters) in elevation. Then it followed a similar path, investigating selected sites in more detail. That second pass included inspection of Mojave in November 2014 with the dust-removal brush, close-up camera and Alpha Particle X-Ray Spectrometer on the rover's arm. The results put Mojave at the head of the list of targets for the rover's most intensive inspection, using laboratory instruments that ingest powdered rock collected by the drill.

Image above: This Jan. 13, 2015, view from the Mars Hand Lens Imager on NASA's Curiosity Mars rover shows outcomes of a mini-drill test to assess whether the "Mojave" rock is appropriate for full-depth drilling to collect a sample. Cracking of the rock has made freshly exposed surfaces available for inspection. Image Credit: NASA/JPL-Caltech/MSSS.

"The crystal shapes are apparent in the earlier images of Mojave, but we don't know what they represent," said Curiosity Project Scientist Ashwin Vasavada at NASA's Jet Propulsion Laboratory, Pasadena, California. "We're hoping that mineral identifications we get from the rover's laboratory will shed more light than we got from just the images and bulk chemistry."

Curiosity's Chemistry and Mineralogy instrument, or CheMin, can identify specific minerals in rock powder from a drilled sample. Analysis of the drill hole and drill tailings may also reveal whether the crystals are only at the surface, like a salty crust, or are also deeper in the rock.

"There could be a fairly involved story here," Vasavada said. "Are they salt crystals left from a drying lake? Or are they more pervasive through the rock, formed by fluids moving through the rock? In either case, a later fluid may have removed or replaced the original minerals with something else."

Curiosity's work at Pahrump Hills may include drilling one or more additional rocks before heading to higher layers of Mount Sharp.

Next week's planned software revision, like the mission's earlier ones, adds protections against vulnerabilities identified in rover testbed activities on Earth. It also adds improvements to make planning drives more efficient.

Image above: Lozenge-shaped crystals are evident in this magnified view of a Martian rock target called "Mojave," taken by the Mars Hand Lens Imager (MAHLI) instrument on the arm of NASA's Curiosity Mars rover. Image Credit: NASA/JPL-Caltech/MSSS.

"The files have already been uplinked and are sitting in the rover's file system to be ready for the installation," said JPL's Danny Lam, the deputy engineering operations chief leading the upgrade process.  

One change in the new software is to enable use of the rover's gyroscope-containing "inertial measurement unit" at the same time as the rover's drill, for better capability to sense slippage of the rover during a drilling operation. Another is a set of improvements to the rover's ability to autonously identify and drive in good terrain.

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/JPL/Guy Webster.

Greetings, Orbiter.ch