vendredi 3 juin 2011

Rosetta to sleep through loneliest leg of comet mission

ESA - Rosetta Mission patch.

3 June 2011

On 8 June, mission controllers will have the first opportunity to switch ESA's Rosetta comet-hunter into deep-space hibernation for 31 months. During this loneliest leg of its decade-long mission, Rosetta will loop ever closer toward comet 67-P, soaring to almost 1000 million km from Earth.

Marking one of the most dramatic and distant stages of the probe's 10-year journey to rendezvous with Comet 67-P/Churyumov-Gerasimenko, ground controllers at ESOC, ESA's European Space Operations Centre, plan to issue the final command next week to switch Rosetta into hibernation mode.

Artist's impression of the Rosetta orbiter and lander

This will trigger the last steps in the shut-down of the spacecraft, turning off almost all flight control systems including telecommunications and attitude control. Rosetta's scientific instruments were already individually powered down during the first four months of this year.

"Rosetta is getting farther from the Sun, and soon there simply isn't going to be enough sunlight to power its systems," says Paolo Ferri, Head of ESOC's Solar and Planetary Mission Operations Division.

"We already achieved a record in July 2010 when we reached 400 million km from the Sun and became the most distant spacecraft ever to operate on solar power alone. Rosetta will double the record distance during the hibernation period."

Virtual shutdown of the entire spacecraft

The only devices left running will be the onboard computer and several heaters. These will be powered by the solar wings, and will be automatically switched on periodically to ensure that the entire satellite doesn't freeze up as its orbit takes it from 660 million km from the Sun out to 790 million km and back between now and January 2014.

Close-up Earth image during Rosetta swingby 2009

Prior to entering hibernation, Rosetta will be oriented so that its solar wings face the Sun and be placed into a slow spin, which will stabilise the satellite.

The window for issuing the hibernation command opens on 8 June, once the spacecraft status is confirmed. After the command is sent, there will be no signal sent to or from ground until 2014. A single computer timer will tick down the 136-week hibernation period.

Deep-space wake up call

At precisely 10:00 GMT on 20 January 2014, the timer will wake the spacecraft, which, seven hours later, will transmit a check signal to let mission controllers know that the spacecraft has woken.

Mars as seen by the lander's camera during swingby in 2007

"We've planned for hibernation for some time, and it's a complex phase of the mission," says Andrea Accomazzo, Spacecraft Operations Manager at ESOC.

"Still, for the flight control team, it's an emotional moment. We're essentially turning the spacecraft off. We're already looking forward to January 2014 when it wakes up and we get our spacecraft back."

In depth:

Rosetta in depth:

Max Planck Institute for Solar System Research:

ESA's comet chaser:

Take part in ESA's Cool Comet Campaign:

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


One year in isolation

ESA - Mars500 Mission patch.

3 June 2011

The six men in the Mars500 facility near Moscow have been in isolation now 365 days. The European crewmembers have been writing in their latest letters home about the highlights, monotonous life, team spirit and determination to go on.

“Wow, it’s already been a year,” begins Diego Urbina, one of the two Mars500 crewmembers from ESA, in his latest diary entry.

“One way to visualise it is if you think of what you were doing exactly one year ago, and then picture yourself living in a windowless metal box from then!”

The crew have not actually gone anywhere in those 12 months, but in theory they have been to Mars and are now on the way back.

Mars500 crew having a fun portrait with red protective goggles

The crew of six – three Russians, two Europeans and one Chinese – walked from the flashlights of a hectic press conference into their isolation modules on 3 June 2010 and began their virtual mission towards the Red Planet.

The facility faithfully mimics every aspect of an interplanetary flight, as far as it is possible without really flying into space. Their ‘craft’ is composed of four sealed interconnected cylinders with a total volume of 550 cubic metres. They have their own private cabins and they live and work very much like the astronauts on the Space Station.

Image above: Romain, Yue, Diego and Aleksandr preparing an EEG recording. EEG (electroencephalography) is a recording of electrical activity along the scalp produced by the firing of neurons within the brain).

“The dark side of this routine is that every day for the past year we woke up at the same time to do the same medical controls with the same devices: no weekend or holiday breaks for a year!” writes Romain Charles, another ESA crewmember, in his diary.

To Mars and back

After the first exciting months, life settled into a routine and the crew waited for Mars arrival at the end of January.

Image above: Crew training for 'Marswalk' at the simulated martian terrain of the Mars500 experiment. The terrain, about 10 m long and 6 m wide, is covered with reddish sand and is built to resemble the surface at Gusev crater. On the ‘surface’, they conducted simulated scientific research by driving a rover and working with sensors to gather physical and chemical measurements.

They ‘docked’ with a ‘lander’ (in reality, another module connected to their main habitation modules) that had been waiting with supplies in orbit around Mars.

After unloading the cargo, Diego settled into the lander with Wang Yue and Alexandr Smoleevskiy, and ‘landed’ on Mars.

They completed three sorties in Orlan spacesuits into a big hall that was built to look like the martian surface.

During these marswalks they collected samples, set up experiments and drove a rover, like real marsonauts will do one day.

After conquering the Red Planet, the trio ‘flew ‘back to the interplanetary ship, and the crew was reunited to begin their long trip back home on 2 March.

They will ‘arrive’ on 5 November, when the hatch of the isolation facility is opened. The mission will still go on some weeks after that with medical checks and debriefings.

Good spirit

The biggest problem of future exploration flights is not necessarily the technology, but the humans and interactions between the crewmembers. This is the main focus of the Mars500 experiment.

Mars500 crew lunch

“Our crew has been keeping up the dozens of experiments we have to do constantly, no matter the good times or the hard times, producing data of quality that helps some of Europe's best scientists to evaluate what the space travelers of the future will go through,” writes Diego.

“We still have 5 months ahead of us a lot of opportunities to make this trip to Mars even more special,” adds Romain.

“We have a great crew and although our backgrounds are significantly different, we never had any conflicts between us. That's why I'm full of optimism for our last days in the Mars500 modules. We'll see you on the 5th of November when we'll land on Earth after our 520 day's journey to the Red Planet, not before!”

Mars 500 one year inside

Read the newest diaries from Mars500: Romain’s last letter is here and Diego’s letter is here:

Watch also ESA TV's video about Mars500: 'One year inside':

Images, Video, Text, Credits: ESA / Mars500 crew / IPMB.


jeudi 2 juin 2011

New NASA Salt Mapper to Spice Up Climate Forecasts

NASA - SAC-D / Aquarius Mission patch.

2 June 2011

Salt is essential to human life. Most people don't know, however, that salt -- in a form nearly the same as the simple table variety -- is just as essential to Earth's ocean, serving as a critical driver of key ocean processes. While ancient Greek soothsayers believed they could foretell the future by reading the patterns in sprinkled salt, today's scientists have learned that they can indeed harness this invaluable mineral to foresee the future -- of Earth's climate.

Aquarius - Studying the Salt of the Sea

The oracles of modern climate science are the computer models used to forecast climate change. These models, which rely on a myriad of data from many sources, are effective in predicting many climate variables, such as global temperatures. Yet data for some pieces of the climate puzzle have been scarce, including the concentration of dissolved sea salt at the surface of the world's ocean, commonly called ocean surface salinity, subjecting the models to varying margins of error. This salinity is a key indicator of how Earth's freshwater moves between the ocean, land and atmosphere.

Image above: Global differences, on average, between evaporation and precipitation, the main elements of the global water cycle. Eighty-six percent of global evaporation is from the ocean surface, and 78 percent of global precipitation falls back over the ocean. Changes in these patterns affect the salinity of the ocean surface. Scientists plan to use Aquarius salinity data to incorporate these processes into computer models used to improve predictions of future climate. Image credit: Committee on Earth Observation Satellites.

Enter Aquarius, a new NASA salinity-measurement instrument slated for launch in 9 June 2011 aboard the Satélite de Aplicaciones Científicas (SAC)-D spacecraft built by Argentina's Comisión Nacional de Actividades Espaciales (CONAE). Aquarius' high-tech, salt-seeking sensors will make comprehensive measurements of ocean surface salinity with the precision needed to help researchers better determine how Earth's ocean interacts with the atmosphere to influence climate. It's a mission that promises to be, to quote the old saying, "worth its salt."

Improving Climate Forecasts

"We ultimately want to predict climate change and have greater confidence in our predictions. Climate models are the only effective means we have to do so," said Aquarius Principal Investigator Gary Lagerloef, a scientist at the Seattle-based independent laboratory Earth & Space Research. "But, a climate model's forecast skill is only as good as its ability to accurately represent modern-day observations."

Density-driven ocean circulation, according to Lagerloef, is controlled as much by salinity as by ocean temperature. Sea salt makes up only 3.5 percent of the world's ocean, but its relatively small presence reaps huge consequences.

Salinity influences the very motion of the ocean and the temperature of seawater, because the concentration of sea salt in the ocean's surface mixed layer -- the portion of the ocean that is actively exchanging water and heat with Earth's atmosphere -- is a critical driver of these ocean processes. It's the missing variable in understanding the link between the water cycle and ocean circulation. Specifically, it's an essential metric to modeling precipitation and evaporation.

Image above: A comparison of the level of detail available from averaged historical in-water ocean surface salinity data (top) with the detail that will be available from Aquarius ocean surface salinity measurements (bottom). This new information will be used to improve the accuracy of oceanic computer model simulations that contribute to future climate projections. Image credit: Gary Lagerloef / NOAA.

Accurate ocean surface salinity data are a necessary component to understanding what will happen in the future, but can also open a window to Earth's climate past. When researchers want to create a climate record that spans previous decades -- which helps them identify trends -- it's necessary to collect and integrate data from the last two to three decades to develop a consistent analysis.

"Aquarius, and successor missions based on it, will give us, over time, critical data that will be used by models that study how Earth's ocean and atmosphere interact, to see trends in climate," said Lagerloef. "The advances this mission will enable make this an exciting time in climate research."

Taking Past Measurements with a Grain of Salt

Anyone who's splashed at the beach knows that ocean water is salty. Yet measuring this simple compound in seawater has been a scientific challenge for well over a century.

Until now, researchers had taken ocean salinity measurements from aboard ships, buoys and aircraft – but they'd done so using a wide range of methods across assorted sampling areas and over inconsistent times from one season to another. Because of the sparse and intermittent nature of these salinity observations, researchers have not been able to fine-tune models to obtain a true global picture of how ocean surface salinity is influencing the ocean. Aquarius promises to resolve these deficiencies, seeing changes in ocean surface salinity consistently across space and time and mapping the entire ice-free ocean every seven days for at least three years.

Aquarius satellite. Credit: NASA / JPL

The Age of Aquarius

Research modelers like William Large, an oceanographer at the National Center for Atmospheric Research in Boulder, Colo., will use Aquarius' ocean surface salinity data, along with precipitation and temperature observations, to round out the data needed to refine the numerical climate models he and his colleagues have developed.

"This mission is sure to mark a new era for end users like us," explained Large. "Aquarius puts us on the road to implementing a long-term, three-step plan that could improve our climate models. The first step will be to use Aquarius data to identify if there is a problem with our models -- what deficiencies exist, for example, in parts of the world where observations are sparse.

"Second, the data will help us determine the source of these problems," Large added. "Salinity helps us understand density -- and density, after all, makes ocean waters sink and float, and circulate around Earth.

"Third, Aquarius will help us solve the puzzle of what's going on in the ocean itself -- the ocean processes," he added. "We'll pair an ocean observation experiment with the satellite mission to explore the mixing and convection -- how things like salinity are stirred in the ocean -- to better determine what processes might be actually changing climate. Measuring salinity at the ocean surface will deliver a pioneering baseline of observations for changes seen by the next generation of missions in the coming decades."

Image above: At left, NASA's Glory spacecraft sets atop its Taurus XL rocket at California's Vandenberg Air Force Base, awaiting its scheduled March 4 launch, while at right, nearby at Vandenberg, erection of the Delta II rocket that will deliver NASA's Aquarius spacecraft to orbit this June has begun. Image credit: NASA / VAFB.

"We've done all of the advance work leading up to the launch of Aquarius, so the proof will be in the actual data," said Lagerloef. "Our intent is to put the data out immediately as soon as the satellite begins transmitting. Before the end of the first year, we'll be interpreting exactly what the data are telling us and how they will benefit climate modeling."

Aquarius Prepares for Launch

NASA's Aquarius spacecraft Set to Launch June 9 on Mission To Observe Salty Seas.

For more information on Aquarius, visit:

Images (mentioned), Videos, Text, Credit: NASA / JPL.


mercredi 1 juin 2011

Hot stuff: the making of BepiColombo

ESA / JAXA - BepiColombo Mission patch.

1 June 2011

Space Engineering, 10 facts about...

 BepiColombo- ESA's Mercury mission

For BepiColombo, ESA has had to extend the limits of existing design standards and develop altogether new design concepts as well. How to begin building a spacecraft that needs to endure sunlight 10 times more intense than in Earth orbit, with surfaces hotter than a kitchen hot plate – high enough, in fact, to melt lead?

Back in late 2000, when the mission was first selected, no-one knew for sure.

1. Achieving a close-up view of Mercury

 BepiColombo's pair of spacecraft in Mercury orbit

BepiColombo will be the third mission to visit the innermost planet after NASA’s Mariner 10 in the 1970s and the current Messenger.

It is three spacecraft in one: ESA’s Mercury Planetary Orbiter (MPO), Japan’s Mercury Magnetosphere Orbiter (MMO) plus ESA’s additional Mercury Transfer Module (MTM) to convey the other two across interplanetary space.

But BepiColombo will be taking a much closer look than its predecessors: Mariner 10 only flew past while Messenger has entered a highly-elliptical Mercury orbit. While MMO will also follow an elliptical orbit, the planet-mapping MPO will orbit much more tightly, coming as close as 400 x 1500 km from Mercury’s heat-radiating surface.

In certain orbital positions, when the orbiter comes between the Sun on one side and Mercury on the other, it will have to endure temperatures as high as 450°C.

2. Technology making the mission possible

BepiColombo's electric propulsion

“A considerable team of researchers was involved in making the mission feasible,” comments Jan van Casteren, BepiColombo Project Manager. “An exceptional amount of technology development and demonstrations has been needed across a variety of fields.”

Just reaching Mercury presents a major challenge: a new generation of highly efficient electric propulsion was required, capable of achieving the tens of thousands of hours of thrust needed to enter orbit.

3. How the spacecraft keeps its cool

BepiColombo's Mercury Planetary Orbiter

Then comes the problem of thermal management, which drives the spacecraft design. Slice through MPO and you would see a complex labyrinth of heat pipes. Previously used on a variety of missions, these sealed pipes work like a closed-loop version of human sweat glands, containing liquid whose evaporation carries excess heat from MPO’s sunward-side to radiating plates facing deep space. The liquid then condenses, allowing the process to begin anew.

The heat pipe concept helps keep MPO’s interior within room temperature. What was new was the 2 x 3.6 m size of the radiator, and the operational constraints it faced: “Its radiating plates must remain cold and shaded for it to work,” explains Ulrich Reininghaus, BepiColombo Spacecraft Development Manager.

“If they ever come into sustained contact with sunlight, or the infrared radiation emitted from Mercury’s surface then they would stop working.”

The mission had to develop a unique set of coated louvres that prevent the radiator ‘seeing’ the hot planet below while not preventing its own radiation escaping to cold deep space.

4. Searching for material solutions

BepiColombo material samples after testing

Expelling internal heat only goes so far, however; much better if it never makes it inside the spacecraft at all.

The real technical challenge has been finding new materials for everything on the outside of the spacecraft in particular – including antennas, the solar array and its associated Sun-tracking sensors and mechanisms and again the radiator and protective multi-layer insulation (MLI) – which would be able to withstand the Sun’s tenfold increase in brightness and associated temperature extremes.

Examining exposure effects

“We began a critical materials technology programme for BepiColombo at the start of 2001,” comments Christopher Semprimoschnig, head of the Materials Space Evaluation and Radiation Effects Section of ESA’s Materials and Components Technology Division.

“We’ve kept busy for approaching a decade, gradually qualifying materials. It’s been a huge challenge because we had no previous experience of such a harsh environment. The closest we ever came was with Venus Express, though that meant handling two solar constants rather than 10.”

5. Testing, testing…

UV irradiation testing

ESA’s Materials and Processes engineers were involved because they had a good understanding of what materials could be candidates, as well as of related fields that might offer useful ‘spin-in’ technologies, such as protective coatings on jet engine turbines.

It took years to develop the laboratory facilities required for testing, however, adapting existing facilities wherever possible. “When you increase the light and heat intensities you are operating with 10 or 20 times compared to before, then failures can happen,” Christopher says.

“We had to deal with melted lamp holders, melted reflectors, but we gradually managed to build some representative simulation chambers like our Synergistic Temperature Accelerated Radiation (STAR) facility.”

6. A life in the Sun

Infrared view of BepiColombo materials UV testing

ESA’s materials experts needed to predict the end-of-life condition of all the materials in question. How might specific mission-critical properties change after years of intense solar glare? Would reflective coatings discolour, MLI crack, solar arrays lose electrical performance or thermal emittance – the crucial ability to radiate away heat?

“Total exposure will be something like 100 000 equivalent Sun hours,” explains Christopher. “Traditionally we boost illumination levels for accelerated lifetime testing. But a move up from 11 solar constants to 30 or 40 is not so easy.

“The accuracy is uncertain, due to non-linear effects – the materials might unexpectedly fail for some unknown reason.”

End-of-life estimates for Venus Express offered a starting point: the five-year-old mission remains in good health, showing the team’s original estimates had been broadly accurate.

7. Less air for more precise testing

STAR facility enables sample measurements without breaking vacuum

In such an extreme environment, everything degrades, like plastic left out in the Sun. But precisely how critical properties degraded over time in orbit needed to be exactly understood.

For example, it was found that when test items were removed from their vacuum chamber then their subsequent exposure to air would induce chemical interactions with radicals within the material.

Exposing UV-irradiated samples to air increases bleaching

“These radicals are basically degradation products, so this alters the state of degradation,” says Christopher. “A day later when a measurement is done, their condition could be very different. So if we extrapolate from these results we would get a performance curve, but the real curve would end up being much worse.

“So we set up a system to make measurements while still in vacuum, saving us time and letting us assess changes much more reliably.”

8. Testing to breaking point and beyond

Thermal ageing of materials

ESA needs to be sure that its chosen materials would function reliably for years on end.

“We are going to the limit of a material’s performance, seeing what happens when it breaks down,” Christopher adds. “The result is a wealth of information that could be of interest to many other industries as well.”

The programme continues to qualify all the materials needed for the mission, currently standing at around 75% complete.

Cover glass adhesive testing

The MLI covering the bulk of the spacecraft’s surface is foreseen to be a woven ceramic fabric. There are multiple layers kept apart by spacers, designed to be as light as possible – some of the layers have less than a tenth the thickness of printer paper, just 7.5 micrometres across.

“The result is much lighter than metallic foil but also more brittle,” says Christopher. “Now we need to look at processing issues: how to stack it, what shapes can it fit around and how to handle it without damage and release of particles.”

9. A way to save the solar arrays

Solar cell arrays tilted to prevent melting

Solar cells became the single most challenging material question. Dramatic degradation in solar cell performance was detected: just one simulated month saw a 20% power loss.

“This failure brought the mission to the brink of cancellation,” recounts Christopher. The effect was due to a combination of material degradation from ultraviolet radiation and high temperatures driving down cell efficiency.

A combination of protective coatings and carefully solar array tilting offers a workable solution. If the solar arrays directly face the Sun then they would heat up and fail. So instead they stay tilted at an optimum angle. Their power production stays lower, but so does the temperature.

Casting light on solar cells

The main antenna also requires protective coatings, though for a different reason. It is made of thin titanium for maximum performance: it needs to perform highly accurate radio science experiments to determine how spacetime curves around the Sun.

By itself it would warm up like any other metal in the Sun – to as high as 700°C. But temperature-driven deformations have to be prevented. A specially-tailored coating should keep its temperature 300°C lower while allowing electromagnetic signals to pass through freely.

10. Spacecraft-level testing has begun

BepiColombo's MMO and sunshield being tested at ESTEC

A test model of Japan’s MMO arrived in the Netherlands in mid-September 2010 for testing in the Large Space Simulator (LSS) at the ESTEC Test Centre, the largest vacuum chamber in Europe. The LSS’s Solar Simulator was carefully adjusted to attain 10 solar constants, its light beam being brought into much tighter focus.

“To safely remove the resulting heat from the chamber walls we installed an extra thermal shroud with a more than six times greater flow of liquid nitrogen than the existing system,” explains Alexandre Popovitch, overseeing modifications. “That required around 5000 litres of liquid nitrogen per hour of each two-week test.”

MMO tested spinning, without sunshield

There were two sets of tests, one with MMO free-spinning – as it will operate during its active life – then one with an ESA sunshield that will keep it cool as it rides as a passenger to Mercury.

This summer, test models of Europe’s BepiColombo spacecraft will go through the same experience. Follow-up versions incorporating any lessons learnt will be ready for evaluation in 2012, with the launch of BepiColombo scheduled for 2014.

The materials team, meanwhile, is looking forward to ESA’s Solar Orbiter mission – destined to venture even closer to the Sun.

More information:

BepiColombo in a nutshell:

Materials and Electrical Components Laboratories:

Test Centre:

For more information on the BepiColombo mission please click on the following link :

Images, Video, Text, Credits: ESA / C. Carreau / P. Carril / JAXA.

Best regards,

NASA'S Shuttle Atlantis At Launch Pad, Liftoff Practice Set

NASA - STS-135 Mission patch.

June 01, 2011

After safely reaching its launch pad at NASA's Kennedy Space Center in Florida, space shuttle Atlantis awaits the next major milestone for its upcoming STS-135 mission to the International Space Station, the final flight of the Space Shuttle Program. The mission with four veteran astronauts is targeted to launch July 8.

STS-135 Atlantis' Final Roll to Launch Pad 39A

Atlantis arrived at the pad early Wednesday morning on top of a giant crawler-transporter. The crawler-transporter left Kennedy's Vehicle Assembly Building at 8:42 p.m. EDT Tuesday, May 31, and travelled less than 1 mph during the 3.4-mile journey. The shuttle was secured on the launch pad at 3:29 a.m. Wednesday.

Atlantis rollout

During the 12-day flight, Atlantis and its crew will deliver the Raffaello multi-purpose logistics module filled with supplies and spare parts to sustain station operations once NASA's shuttle fleet is retired.

STS-135 will be Atlantis' 33rd mission and the 37th shuttle flight dedicated to station assembly and maintenance. It will be the 135th and final mission of NASA's Space Shuttle Program.

NASA Announces New Homes for Space Shuttle Orbiters After Retirement

After 30 years of spaceflight, more than 130 missions, and numerous science and technology firsts, NASA's space shuttle fleet will retire and be on display at institutions across the country to inspire the next generation of explorers and engineers.NASA Administrator Charles Bolden on Tuesday announced the facilities where four shuttle orbiters will be displayed permanently at the conclusion of the Space Shuttle Program.

Image above: Enterprise, first Space Shuttle Orbiter, is pictured at the National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Virginia. Credit: NASA / Renee Bouchard.

- Shuttle Enterprise, the first orbiter built, will move from the Smithsonian's National Air and Space Museum Steven F. Udvar-Hazy Center in Virginia to the Intrepid Sea, Air & Space Museum in New York.

- The Udvar-Hazy Center will become the new home for shuttle Discovery, which retired after completing its 39th mission in March.

- Shuttle Endeavour, which is preparing for its final flight at the end of the month will go to the California Science Center in Los Angeles.

- Shuttle Atlantis, which will fly the last planned shuttle mission in June, will be displayed at the Kennedy Space Center Visitor’s Complex in Florida.

Orbiter's New Homes

"We want to thank all of the locations that expressed an interest in one of these national treasures," Bolden said. "This was a very difficult decision, but one that was made with the American public in mind. In the end, these choices provide the greatest number of people with the best opportunity to share in the history and accomplishments of NASA's remarkable Space Shuttle Program. These facilities we've chosen have a noteworthy legacy of preserving space artifacts and providing outstanding access to U.S. and international visitors."

NASA also announced that hundreds of shuttle artifacts have been allocated to museums and education institutions.

For more information about the STS-134 mission and the upcoming STS-135 flight, visit:

For information about the space station, visit:

Images, Video, Text, Credit: NASA / NASA TV / National Air and Space Museum.


ESA - Keeping the power on in space

ESA / CNES - European Space Power Conference (ESPC) 2011 logo.

1 June 2011

All space missions have one inescapable dependency: the electricity flowing through their systems to keep them alive. Take away its power and a spacecraft is nothing more than space debris – an eventuality the space power professionals strive to avoid.

Next week sees more than 250 experts come together at an ESA-organised conference on power systems. The Ninth European Space Power Conference (ESPC) will take place on 6–10 June in Saint Raphaël on France’s Côte d'Azur, jointly organised by ESA and the French space agency, CNES.

Herschel: among ESA missions under discussion

The sun-drenched Mediterranean surroundings are appropriate for a discipline that places such importance on solar cells as a power source – space of course enjoying a limitless supply of sunlight. All the key players in the worldwide solar generator community will attend.

Other important elements of power system architecture under discussion include batteries for energy storage – crucial for those times when solar power is unavailable or for comparatively short-lived vehicles such as launchers – as well as electronics for power management, conversion and conditioning.

BepiColombo solar panels

These must ensure that power is made available to sensitive instruments and other systems at just the right current and voltage, avoiding dangerous surges or undercurrents.

“The ESPC is a key event for Europe’s space power community, taking place roughly every three years,” explained Olivier Mourra, organising the event for ESA.

“Space agencies, business and academia come together to obtain a complete overview of current activities.

ESA aims for 30% plus efficient solar cells

“ESA, CNES and European space companies (including telecom firms) will be sharing lessons learned from their current missions and communicating future plans, while the 250 -plus attendees will also include representatives from CNES, the German Aerospace Center DLR, the Japanese space agency JAXA, the US Naval Research Laboratory and NASA’s Jet Propulsion Laboratory.”

This broad interest reflects the importance of power systems as the core element of any spacecraft. Technological progress in the field offers enhanced performance to science missions as well as a competitive edge to industry, with satellites becoming especially power-hungry in the fiercely-contested telecom market.

The conference will include presentations of lithium-ion technology – the emerging technical standard for satellite batteries, first flown by ESA’s Proba-1 – and a new generation of solar cell technology boasting an efficiency higher than 30%.

Proba-1's pioneering lithium-ion battery

The evolution of space power systems has traditionally been driven by ‘spin-in’ from terrestrial industry, but products need careful customising to withstand the extreme conditions of space – a challenging and costly process that cannot always be left to the market alone.

“At the last conference in Germany in 2008, participants made the point that they needed efficient and recurrent products and new space power system components to remain competitive,” added Olivier.

“ESA and the European companies took note and this time around will be presenting innovative solutions and new European products of that request.”

Solar cells retrieved from Hubble

ESA will present findings from current missions such as Herschel, Planck and Meteosat Second Generation while also giving details of new technology being developed for the Agency’s Mercury probe BepiColombo, – which must withstand solar intensities 10 times stronger than in Earth orbit.

For the first time, this ESPC will include a full-scale exhibition, with a total of 25 companies presenting their products including specialist equipment for power system testing on the ground. The event will also include another first, offering a practical tutorial on reliable power system design.

Participants will also have the opportunity of joining a field trip to the Thales Alenia Space plant in nearby Cannes to visit their power system testing facilities. As an on-site alternative, ESA’s Hubble solar array specialist Lothar Gerlach will offer a presentation detailing his three decades of work on the space telescope.

Online video:

Carla Signorini talks about the European Space Power Conference:

Related link:

For more information on the BepiColombo mission please click on the following link :


Power and Energy Conversion:

How satellites live off sunlight:

Batteries at the heart of ESA space missions:

How Hubble got its wings:

Images, Text, Credits: ESA - C. Carreau / CNES.


ESO - A Postcard from Extragalactic Space?

ESO - European Southern Observatory logo.

1 June 2011

A spiral galaxy that resembles our Milky Way

 Wide Field Imager view of a Milky Way look-alike, NGC 6744

ESO astronomers have used the Wide Field Imager on the MPG/ESO 2.2-metre telescope to capture an image of NGC 6744. This impressive spiral galaxy lies about 30 million light-years away in the southern constellation of Pavo (The Peacock). But this view could almost be a picture postcard of our own Milky Way, taken and sent by an extragalactic friend, as this galaxy closely resembles our own.

We see NGC 6744 almost face on, meaning we get a dramatic bird’s eye view of the galaxy’s structure. If we had the technology to escape the Milky Way and could look down on it from intergalactic space, this view is close to the one we would see — striking spiral arms wrapping around a dense, elongated nucleus and a dusty disc. There is even a distorted companion galaxy — NGC 6744A, seen here as a smudge to the lower right of NGC 6744, which is reminiscent of one of the Milky Way’s neighbouring Magellanic Clouds.

The spiral galaxy NGC 6744 in the constellation of Pavo

One difference between NGC 6744 and the Milky Way is their size. While our galaxy is roughly 100 000 light-years across, the galaxy pictured here extends to almost twice this diameter. Nevertheless, NGC 6744 gives us a tantalising sense of how a distant observer might see our own galactic home.

This dramatic object is one of the largest and nearest spiral galaxies. Although it has a brightness of about 60 billion Suns, its light spreads across a large area in the sky — about two thirds the width of the full Moon, making the galaxy appear as a hazy glow with a bright centre through a small telescope. Still, it is one of the most beautiful objects in the southern sky, and it can be identified by amateur astronomers as an oval shape contrasting with a rich background of stars.

Wide-field view of the sky around NGC 6744

With professional telescopes such as the MPG/ESO 2.2-metre telescope at La Silla, which captured this image, NGC 6744 can be seen in all its glory. The dusty spiral arms are home to many glowing star-forming regions (seen in red) and give this Milky Way look-alike its striking spiral form.

This picture was taken by the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. The picture was created from exposures taken through four different filters that passed blue, yellow-green and red light and the glow coming from hydrogen gas. These are shown in this picture as blue, green, orange and red, respectively.

Zooming in on the spiral galaxy NGC 6744

This sequence starts with a view of the southern part of the Milky Way. As we zoom in we can first see the globular star cluster NGC 6752 and then the spiral galaxy NGC 6744, lying about 30 million light-years from us in the constellation of Pavo (The Peacock). We also catch a glimpse of the small irregular galaxy NGC 6744A, which lies close to NGC 6744. The final detailed view shows a new image of NGC 6744 from the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile.

More information

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and VISTA, the world’s largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.


    Photos of La Silla Observatory:

    The MPG/ESO 2.2-metre telescope:

Images, Text, Credits: ESO, IAU and Sky & Telescope / Video: ESO/S. Brunier and Digitized Sky Survey 2 / Music: John Dyson (from the album Moonwind).

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Space Shuttle Endeavour Sails To Home Port For Final Time

NASA - STS-134 Mission patch.

June 01, 2011

Space shuttle Endeavour and its six-astronaut crew sailed home for the final time, ending a 16-day journey of more than 6.5 million miles with a landing at 2:34 a.m. EDT on Wednesday at NASA's Kennedy Space Center in Florida.

Endeavour's Final Journey Home

STS-134 was the last mission for the youngest of NASA's space shuttle fleet. Since 1992, Endeavour flew 25 missions, spent 299 days in space, orbited Earth 4,671 times and traveled 122,883,151 miles.

"We are very proud of Endeavour's legacy, and this penultimate flight of the space shuttle program once again demonstrated the amazing skill and dedication of our astronauts and the entire workforce," said NASA Administrator Charles Bolden. "As we begin the transition from the shuttle program to the commercial transportation of our crews and cargo, our ability to tackle big challenges remains steadfast and will ensure that NASA reaches even more destinations farther in the solar system."

Mark Kelly commanded the flight and was joined by Pilot Greg H. Johnson and Mission Specialists Mike Fincke, Drew Feustel, Greg Chamitoff and the European Space Agency's Roberto Vittori. Endeavour delivered the Alpha Magnetic Spectrometer-2 (AMS), beginning a scientific voyage of discovery to our solar system and beyond from the International Space Station. By measuring cosmic rays, AMS is designed to help researchers understand the origin of the universe and search for evidence of dark matter, strange matter and antimatter.

Endeavour also delivered the Express Logistics Carrier-3, a platform carrying spare parts that will sustain space station operations once the shuttles are retired from service. The astronauts performed four spacewalks to maintain station systems and install new components.

These were the last scheduled spacewalks by shuttle crew members and brought the final number of shuttle excursions to 164. During 159 spacewalks for assembly and maintenance of the space station, astronauts and cosmonauts have spent a total of 1,002 hours and 37 minutes outside.

Fincke set a new record for time a U.S. astronaut has spent in space when he reached his 377th day on May 27, surpassing previous record holder Peggy Whitson. With today's landing, Fincke's record now is at 382 days in space.

STS-134 Endeavour Comes Home

A welcome ceremony for the astronauts will be held Thursday, June 2, in Houston. The public is invited to attend the 4 p.m. CDT event at Ellington Field's NASA Hangar 990. Gates to Ellington Field will open at 3:30 p.m. Highlights from the ceremony will be broadcast on NASA Television's Video File. For NASA TV downlink information, schedules and links to streaming video, visit:

STS-134 was the 134th shuttle flight and the 36th shuttle mission dedicated to station assembly and maintenance. With Endeavour and its crew safely home, the stage is set for the launch of shuttle Atlantis on its STS-135 mission, targeted to begin July 8.

Four veteran astronauts will deliver supplies and spare parts to the space station. The 12-day mission also will install an experiment designed to demonstrate and test the tools, technologies and techniques needed to refuel satellites in space robotically -- even satellites not designed to be serviced.

Chris Ferguson, a veteran of two previous shuttle missions, will command the flight. Doug Hurley will be the pilot, a role he filled on the STS-127 mission in 2009. Sandy Magnus and Rex Walheim will be the mission specialists. Magnus spent four and a half months aboard the station beginning in November 2008. Walheim flew on the STS-110 mission in 2002 and the STS-122 mission in 2008.

STS-135 will be Atlantis' 33rd mission and the 37th shuttle flight dedicated to station assembly and maintenance. It will be the 135th and final mission of NASA's Space Shuttle Program.

For more information about the STS-134 mission and the upcoming STS-135 flight, visit:

For information about the space station, visit:

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


mardi 31 mai 2011

ESA - Looking at the volatile side of the Moon

ESA logo.

31 May 2011

Image above: This image of the Moon was taken with by Rosetta's OSIRIS Narrow Angle Camera (NAC) at 07:36 CET on 13 November 2007. Credits: ESA ©2007 MPS for OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA.

Four decades after the first Moon landing, our only natural satellite remains a fascinating enigma. Specialists from Europe and the US have been looking at ESA’s proposed Lunar Lander mission to find out how to seek water and other volatile resources.

Europe is developing the technology for the Lunar Lander mission, a precursor voyage to the Moon in preparation for human exploration beyond low Earth orbit. 

Image above: The ESA's lunar lander mission aims to land in the mountainous and heavily cratered terrain of the lunar south pole, possibly in 2018.

“Our ambition is to see one day a European astronaut working on the Moon,” says ESA’s Bruno Gardini.

Expected to be launched in 2018, the unmanned craft will land near the lunar South Pole.

In Bruno’s words, “It is the mission that will provide Europe with the planetary landing technology of the future.”

Specialists, including prestigious scientists who worked on the Apollo programme, recently gathered at ESA’s ESTEC space technology centre in the Netherlands to discuss the mission.

The ESA's lunar lander

The lander’s scientific payload addresses a number of key aspects of the unique environment on the Moon: radiation, dust and volatiles and.

Volatiles, such as water, are those delicate chemical components that under certain conditions would just disappear.

Volatiles may be readily extracted from lunar soil and provide valuable resources such as carbon, nitrogen, phosphorus or sulphur to aid future human exploration.

Like water, these chemical elements have been implanted by billions of years of exposure to the solar wind and are especially likely to be found at the poles.

Ground truth

“To analyse the volatiles or the water that is all over the Moon in very small quantities, we have to take samples of the materials we find on the surface and analyse them in situ”, says Bruno.

Bruno Gardini

Recent missions have transformed our view of the Moon. This new era of lunar science was well represented by Colin Pillinger. Having begun his career analysing samples of moon rock for the Apollo programme, he is now professor of planetary science at the Open University in the UK.

“We certainly don’t know where the water comes from until we get down there and do more experiments. That’s why the Lunar Lander is so important,” notes Prof. Pillinger.

Colin Pillinger

“I play the devil’s advocate,” says Larry Taylor, from the University of Tennessee, a scientist who guided the US astronauts in the quest for samples on the Moon.

Larry Taylor

“I’m giving my knowledge about lunar soil, something that I’ve been working on for 40 years. I have a different perspective, so I’m saying to the engineers: are you sure you are going to find this?”

Go south

Finding the right landing site is also crucial for science. “You have to go to the exact places where we think these valuable resources might be concentrated,” says Prof. Pillinger.

Image above: The lunar south pole region is one of the possible reservoirs of the volatile materials. Credits: ESA / SMART-1 / Space-X (Space Exploration Institute), ESA / SMART-1 / AMIE camera team.

ESA has selected the South Pole as a landing site for two main reasons. First, there are long periods of illumination that would allow the lander to rely on solar power alone.

Secondly, concludes Bruno, “We will go to a very different place from the equatorial regions explored during the Apollo era, giving the scientists the opportunity to do new experiments and get completely new insights.”

ESA - Moon Lander Programme

Video above: Mission description: land autonomously with pinpoint precision near the Moon’s south pole, a region full of dangerous boulders and high ridges. The aim of ESA’s proposed precursor is to probe the moonscape’s unknowns and test new technology to prepare for future human landings.

Related links:


Lunar Reconnaissance Orbiter (LRO):



The Gravity Recovery and Interior Laboratory (GRAIL):

Lunar Atmosphere and Dust Environment Explorer (LADEE):

Images (mentioned), Text, Video, Credits: ESA.

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