lundi 23 décembre 2013

Phobos - Glorious grooves












ESA - Mars Express Mission patch.

Dec. 23, 2013

Glorious grooves

The innermost moon of Mars, Phobos, is seen here in full 360 degree glory. The images were taken by the High Resolution Stereo Camera (HRSC) on ESA’s Mars Express at various times throughout the mission’s 10 years.

The moon’s parallel sets of grooves are perhaps the most striking feature, along with the giant 9 km-wide Stickney impact crater that dominates one face of the 27 x 22 x 18 km moon.

The origin of the moon’s grooves is a subject of much debate. One idea assumes that the crater chains are associated with impact events on the moon itself.

Moon of Mars, Phobos by ESA's Mars Express

Another idea suggests they result from Phobos moving through streams of debris thrown up from impacts 6000 km away on the surface of Mars, with each ‘family’ of grooves corresponding to a different impact event.

Mars Express has imaged Phobos from a wide range of distances, but will make its closest flyby yet on 29 December 2013, at just 45 km above the moon.

Although this is too close to take images, gravity experiments will give insight into the interior structure of Phobos.

For more information about ESA's Mars Express Mission, visit: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Image, Video, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Greetings, Orbiter.ch

samedi 21 décembre 2013

Spacewalkers Remove Degraded Ammonia Pump















ISS - Expedition 38 Mission patch / EVA - Extra Vehicular Activities patch.

Dec. 21, 2013

Expedition 38 Flight Engineers Rick Mastracchio and Mike Hopkins wrapped up a 5-hour, 28 minute spacewalk outside the International Space Station at 12:29 p.m. EST Saturday, completing the first in a series of excursions aimed at replacing a degraded ammonia pump module associated with one of the station's two external cooling loops that keeps both internal and external equipment cool.

NASA Begins Series of Spacewalks to Fix Coolant Pump on ISS

During Saturday’s spacewalk, the two astronauts focused on removing a degraded pump module from Loop A of the station’s external Active Thermal Control System. That pump module encountered a problem Dec. 11 when an internal valve stuck in an incorrect position, causing temperatures in the station’s cooling lines to drop. On Monday, Mastracchio and Hopkins will venture outside the station again to begin the installation of a replacement pump module. If necessary a third spacewalk would occur on Christmas day to finalize the installation.


Image above: Astronaut Rick Mastracchio works outside the International Space Station during the first of a series of spacewalks to replace a degraded ammonia pump module. Image Credit: NASA TV.

After exiting the Quest airlock, Hopkins made his way out to Saturday’s worksite at center of the Starboard 1 truss segment. Mastracchio meanwhile attached himself to a foot restraint at the end of the station’s 57-foot robotic arm so that Flight Engineer Koichi Wakata, the robotics operator for the spacewalks, could fly Mastracchio to the worksite and position him for his various tasks.

The two spacewalkers first spent some time demating four ammonia fluid line “quick disconnects” from the pump module.

Once the four fluid lines were disconnected, Mastracchio and Hopkins worked to attach the fluid lines to a pump module jumper box, which allows the ammonia to reach the system’s plumbing in the ammonia and nitrogen tanks to keep it in a liquid state.


Image above: Spacewalker Rick Mastracchio works to disconnect the fluid lines from the degraded pump module in this view from the NASA astronaut's helmet camera. Image Credit: NASA TV.

Afterward the spacewalkers installed a generic thermal cover over the pump module jumper and ammonia fluid lines.

With the spacewalk proceeding well ahead of schedule, Mission Control in Houston informed Mastracchio and Hopkins that they could press ahead with the first task originally planned for Monday’s spacewalk –removing the degraded pump module from the starboard truss and attaching it to a stowage location on the Payload Orbital Replacement Unit Accommodation (POA) on the station’s railcar, or Mobile Base System.

While Hopkins set up the POA and an adjustable grapple fixture, Mastracchio removed the five electrical connectors from the pump module and unfastened the module from the truss.


Image above: Astronaut Rick Mastracchio holds the degraded pump module while the International Space Station's robotic arm guides the module to a grapple fixture. Image Credit: NASA TV.

With Mastracchio holding the 780-pound pump while he was attached to the end of the robotic arm, Wakata guided the arm to attach the module to the grapple fixture and activated the snares to hold it in place.

Mastracchio now holds 43 hours and 58 minutes of spacewalking time during seven spacewalks, and Hopkins now holds 5 hours and 28 minutes during one spacewalk.

Saturday’s spacewalk was the 175th in support of space station assembly and maintenance.

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

Images (mentioned), Video, Text, Credit: NASA / NASA TV.

Greetings, Orbiter.ch

vendredi 20 décembre 2013

Curiosity Team Upgrades Software, Checks Wheel Wear












NASA - Mars Science Laboratory (MSL) patch.

Dec. 20, 2013

Rocky Mars Ground Where Curiosity Has Been Driving

Image above: NASA's Mars rover Curiosity captured this 360-degree view using its Navigation Camera (Navcam) after a 17-foot (5.3 meter) drive on 477th Martian day, or sol, of the rover's work on Mars (Dec. 8, 2013). Image Credit: NASA/JPL-Caltech.

The team operating NASA's Mars rover Curiosity has completed a software upgrade on the vehicle and is next planning a check of wear and tear on the rover's wheels.

"Curiosity is now operating on version 11 of its flight software," said Jim Erickson of NASA's Jet Propulsion Laboratory, project manager for the NASA Mars Science Laboratory Project, which operates Curiosity.

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

This is the third upgrade version since Curiosity's landing on Mars16 months ago. Completing the switch from version 10 took about a week.  An earlier switch to version 11 prompted an unintended reboot on Nov. 7 and a return to version 10, but the latest transition went smoothly.

These upgrades allow continued advances in the rover's capabilities. For example, version 11 brings expanded capability for using the Curiosity's robotic arm while the vehicle is on slopes. It also improves flexibility for storing information overnight to use in resuming autonomous driving on a second day.

An upcoming activity will be driving to a relatively smooth patch of ground to take a set of images of Curiosity's aluminum wheels, using the Mars Hand Lens Imager (MAHLI) camera at the end of the rover's arm. 

Left-Front Wheel of Curiosity Rover, Approaching Three Miles

Image above: The left-front wheel of NASA's Curiosity Mars rover shows dents and holes in this image taken during the 469th Martian day, or sol, of the rover's work on Mars (Nov. 30, 2013). Image Credit: NASA/JPL-Caltech/MSSS.

"We want to take a full inventory of the condition of the wheels," Erickson said. "Dents and holes were anticipated, but the amount of wear appears to have accelerated in the past month or so. It appears to be correlated with driving over rougher terrain. The wheels can sustain significant damage without impairing the rover's ability to drive. However, we would like to understand the impact that this terrain type has on the wheels, to help with planning future drives."

Curiosity's recent driving has crossed an area that has numerous sharp rocks embedded in the ground.  Routes to future destinations for the mission may be charted to lessen the amount of travel over such rough terrain, compared to smoother ground nearby.

Rocky Mars Ground Where Curiosity Has Been Driving (Stereo)

Image above: NASA's Mars rover Curiosity captured this stereo view using its Navigation Camera (Navcam) after a 17-foot (5.3 meter) drive on 477th Martian day, or sol, of the rover's work on Mars (Dec. 8, 2013). Image Credit: NASA/JPL-Caltech.

NASA's Mars Science Laboratory Project is using Curiosity inside Gale Crater 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.

More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity

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

Cheers, Orbiter.ch

Long March 3B/E rocket launch the Bolivian Tupac Katari satellite












CASC - China Aerospace Science and Technology Corporation logo.

Dec. 20, 2013

Long March 3B/E launch

A Chinese Long March 3B/E launched the the TKSat-1 satellite for Bolivia on Friday. The launch took place at 16:42 UTC (17:02 GMT / 12:02 p.m. EST) from the LC2 Launch Complex of the Xichang Satellite Launch Center, Sichuan province.

TKSat-1, also known by Tupac Katari, is the result of an agreement signed on December 13, 2010, by the China Great Wall Industry Corporation (CGWIC) and the Bolivia Aerospace Bureau.

With 30 transponders on board (26 Ku-band, 2 C-band and 2 Ka-band), the Tupak Katari satellite is designed for a 15 year mission duration.

Tupak Katari satellite

Tupak Katari will begin orbit operations at 87.2 degrees West longitude in March 2014.

The satellite’s launch mass was 5,100 kg, with 30 transponders, four of which will be used for TV transmission only and the rest for transmission and reception. The satellite will also service Venezuela, Colombia, Ecuador, Peru, Bolivia, Paraguay, Uruguay, North of Chile and Argentina, and the East of Brazil.

The spacecraft is the first communications satellite of Bolivia. It will not only provide communications and broadcasting services to the whole territory of Bolivia and the surrounding areas, but also facilitate the development of civil projects like remote education and telemedicine.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Images, Text, Credits: CASC / Xinhua.

Greetings, Orbiter.ch

Beatles Legend John Lennon Among Those Honored with Mercury Craters












NASA - Messenger Mission to Mercury patch.

Dec. 20, 2013

It’s unlikely that Mercury’s surface is populated with tangerine trees and marmalade skies, but the famous British musician who coined that phrase now has a physical presence on the planet closest to the Sun. The International Astronomical Union (IAU) has named an impact crater on the planet after John Lennon, the British pop music sensation who helped make The Beatles the most popular group of their generation.

Lennon is one of ten newly named craters on the planet, joining 114 other craters named since NASA’s MESSENGER spacecraft's first Mercury flyby in January 2008.


Image above: Mercury's Lennon crater, named for Beatle John Lennon, as seen from NASA's MESSENGER spacecraft. Image Credit: NASA/Johns Hopkins Applied Physics Lab/Carnegie Institution.

“The MESSENGER team is delighted that the IAU has named an additional 10 impact craters on Mercury,” said MESSENGER Principal Investigator Sean Solomon of Columbia University, who suggested Lennon. “We are particularly pleased that eight of the 10 individuals honored made all or many of their artistic contributions in the Twentieth Century, the same century in which the MESSENGER mission was conceived, proposed, and approved for flight. Imagine.”

The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919.  In keeping with the established naming theme for craters on Mercury, all of the newly designated features are named after “deceased artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years.”

Messenger spacecraft. Image Credit: NASA

While the notoriety and fame of the namesakes is fun, David Blewett, a MESSENGER participating scientist, says there is a practical reason for naming craters. “After a while, identifying craters by their latitude and longitude becomes laborious,” Blewett says. “Assigning names to the craters makes it easier for scientists to communicate about them, share notes and observations.”

In addition to Lennon, the newly named craters are:

- Barney, for Natalie Clifford Barney (1876-1972), an American-French playwright, poet, and novelist.

- Berlioz, for Hector Berlioz (1803-1869), a French Romantic composer best known for his compositions Symphonie fantastique and Grande messe des morts.

- Calder, for Alexander Calder (1898-1976), an American sculptor best known as the originator of the mobile, a type of kinetic sculpture made with delicately balanced or suspended components that move in response to motor power or air currents.

- Capote, for Truman Capote (1924-1984), an American author whose short stories, novels, plays, and nonfiction include the novella Breakfast at Tiffany's and the true-crime novel In Cold Blood.

- Caruso, for Enrico Caruso (1873-1921), an Italian tenor who sang to great acclaim at the major opera houses of Europe and the Americas and appeared in a wide variety of roles from the Italian and French repertoires that ranged from the lyric to the dramatic.

- Ensor, for James Sidney Ensor (1860-1949), a Belgian painter and printmaker, considered an important influence on expressionism and surrealism.

- Giambologna, for Jean Boulogne Giambologna (1529-1608), a Dutch sculptor known for his marble and bronze statuary in a late Renaissance or Mannerist style.

- Remarque, for Erich Maria Remarque (1898-1970), a German author best known for his novel All Quiet on the Western Front, which depicted the horrors of war from the viewpoint of young German soldiers.

- Vieira da Silva, for Maria Elena Vieira da Silva (1908-1992), a Portuguese-born French painter of intricate, semiabstract compositions.

More information about the names of features on Mercury and the other objects in the Solar System can be found at the U.S. Geological Survey's planetary nomenclature web site: http://planetarynames.wr.usgs.gov/index.html.

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

Images (mentioned), Text, Credit: NASA.

Greetings, Orbiter.ch

Look out below – Design for Demise study aims to cut satellite reentry risk












ESA - Clean Space logo.

20 December 2013

Even in space, what goes up does sometimes come down – potentially endangering people on the ground. So ESA’s Clean Space initiative is commissioning a study on ‘Design for Demise’ techniques, aimed at reducing the risk of satellite fragments surviving atmospheric reentry.

Below about 600 km the vestigial atmosphere drags the sky clear of derelict satellites over a period of months or years. Friction between a fast-moving orbiting item and the air starts to slow it and pull it lower, at the same time generating heat.

GOCE reenters atmosphere

By the time an object reaches an altitude below 80 km, aerodynamic stresses should cause the item to break into smaller pieces, which in turn melt then vapourise, in the same way meteors burn up to become shooting stars.

But a surprising quantity of material actually survives its scorching plunge through the atmosphere. Dozens of items have been recovered over the years: while low-melt-rate materials such as aluminium do not generally make it, components made of titanium, steel and glass are more resilient.

The majority of such fragments fall unwitnessed into the oceans. Of the remaining land, only about a quarter is inhabited, so the odds of a human being struck per single fragment should be extremely low – the chance of any injury is truly minuscule compared to, say, a car accident. That has not stopped it happening, at least once: in 1997 lightweight mesh from a Delta II stage harmlessly hit the shoulder of Lottie Williams in Turley, Oklahoma, USA.

The hardiest spacecraft components are more prone to making it back. Fuel tanks, for instance, have variously landed in Thailand, Argentina, Saudi Arabia and the US state of Texas – the woman who found a 260 kg launcher tank on her farm just 50 metres from her home described it as looking like an ‘upside down rhinoceros’.

Debris fallen in Saudi Arabia

Since April 2008 all ESA satellites and launcher upper stages intended to be disposed of by atmospheric reentry at the end of their working lives must demonstrate that the risk from fragments surviving reentry to cause casualties on the ground is less than one in 10 000.

Ideally a mission would retain enough propellant to direct itself downwards in a controlled manner, increasing the likelihood of either total incineration or else steering down to an uninhabited area, but this is not always possible within the limited design margin of many spacecraft.

As an alternative, the multidisciplinary ‘Design for Demise’, D4D, approach is the intentional design of spacecraft systems and/or hardware to reduce the casualty risk on the ground, especially in the case of uncontrolled reentry.

So ESA’s Clean Space initiative has issued an invitation to tender for a new study to better quantify the satellite re-entry risk using various re-entry analysis tools, and consider how D4D can best reduce it.

Design for Demise technology roadmap (Click on the image for enlarge)

The study includes identifying which parts of a satellite pose the greatest risk and identify ways D4D can be applied to reduce it, from system to subsystem down to equipment level. These D4D techniques will also be applied to a pair of actual ESA missions, to assess their feasibility in practice.

Guidelines will be drawn up for applying D4D in future, and the technology developments needed for its use in future mission platforms will be outlined in a roadmap.

For more information check the invitation to tender package, accessible via ESA’s Electronic Mailing Invitation to Tender System (EMITS).

About Clean Space: 

What is Clean Space?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/What_is_Clean_Space

Why is it needed?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/Why_is_it_needed

What are its objectives?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/What_are_its_objectives

Q & A on Clean Space: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/Q_A_on_Clean_Space

Images, Text, Credits: ESA / Bill Chater / NASA Orbital Debris Program Office.

Best regards, Orbiter.ch

jeudi 19 décembre 2013

Astronauts Finalizing Spacewalk Preparations
















ISS - Expedition 38 Mission patch / EVA - Extra Vehicular Activities patch.

Dec. 19, 2013

NASA astronauts Rick Mastracchio and Mike Hopkins and Japanese astronaut Koichi Wakata gathered together Thursday to review spacewalk procedures. Mastracchio and Hopkins will exit the station to replace a faulty pump module over a series of spacewalks. Wakata will operate the station’s robotic arm to maneuver the spacewalkers at the worksite.

The first spacewalk is scheduled for Saturday at 7:10 a.m. EDT when the spacewalkers will set up the worksite on the S1 truss. Monday’s spacewalk will include the removal of the old pump module and the installation of a spare pump module. If necessary a third spacewalk would occur on Christmas day to finalize the installation of the new pump module.

Station Spacewalks to Replace Pump Module

Video above: Lead U.S. Spacewalk Officer Allison Bolinger discusses the details of the three spacewalks the Expedition 38 crew will conduct to replace a faulty pump module on the International Space Station. Image Credit: NASA TV.

NASA Television will begin coverage of the spacewalks an hour before their 7:10 a.m. scheduled start times. The spacewalks are scheduled to last about six hours and 30 minutes. Shortly after the spacewalks conclude, mission controllers will participate in a briefing at Johnson Space Center to discuss the day’s activities.

A briefing was held Wednesday with International Space Station program manager Mike Suffredini, Flight Director Dina Contella and Lead Spacewalk Officer Allison Bolinger. The mission managers discussed how a faulty pump module forced the launch delay of the Cygnus resupply craft and led to the planning for the contingency spacewalks.

View spacewalk briefing graphics: http://www.flickr.com/photos/nasa2explore/sets/72157638802205565/

Read more about the news conference: http://www.nasa.gov/press/2013/december/nasa-postpones-orbital-launch-sets-spacewalks-to-repair-faulty-station-pump/

Read more about the Orbital 1 mission: http://www.nasa.gov/mission_pages/station/structure/launch/orbital.html

The astronauts are also preparing for the possibility of ammonia leaks during their spacewalk. The pump modules are filled with ammonia for cooling and leaks have occurred while disconnecting cables during previous repair spacewalks. If ammonia flakes get on a crew member’s suit, the spacewalkers would go through a series of decontamination steps before re-entering the space station.


Image above: Rick Mastracchio (foreground) checks U.S. spacesuits inside the Quest airlock. Image Credit: NASA TV.

In the Russian side of the space station, Commander Oleg Kotov and Sergey Ryazanskiy are preparing for a Dec. 27 pre-planned spacewalk. The cosmonauts with assistance from Flight Engineer Mikhail Tyurin resized their Orlan spacesuits, checked batteries and reviewed their translation paths to the external worksites.

The duo will install a foot restraint; install medium and high resolution cameras; jettison gear from a pair of external experiments; and install a new experiment as well as a payload boom on the Zvezda service module.

Kotov and Ryazanskiy also participated in a study that monitored their cardiovascular system. Tyurin later worked on the Russian radiation detection experiment Matryeshka that observes radiation absorption in a mannequin.

Read more about Matryeshka: http://www.nasa.gov/mission_pages/station/research/experiments/643.html

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

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

Greetings, Orbiter.ch