SEN News

Cassini creates the first global topographic map of Titan

Jenny Winder — Sun, 19 May 2013 12:00:00 UTC

Detail of the new topography map. Image credit: NASA/JPL-Caltech/ASI/JHUAPL/Cornell/Weizmann

(Sen) - Scientists from NASA's Cassini radar team have created the first global topographic map of Saturn's moon Titan.

Titan's thick haze means remote cameras can't "see" landscape shapes and shadows, the usual approach to measuring topography on planetary bodies. Virtually all the data we have on Titan comes from NASA's Cassini spacecraft, which has flown past the moon almost 100 times over the past decade. On many of those flybys, Cassini used a radar imager to peer through the haze, to estimate the surface height.

"Titan has so much interesting activity, like flowing liquids and moving sand dunes, but to understand these processes it's useful to know how the terrain slopes," said Ralph Lorenz, a member of the Cassini radar team based at the Johns Hopkins University Applied Physics Laboratory, Maryland, who led the map-design team. "It's especially helpful to those studying hydrology and modeling Titan's climate and weather, who need to know whether there is high ground or low ground driving their models."

"With this new topographic map, one of the most fascinating and dynamic worlds in our solar system now pops out in 3-D," said Steve Wall, deputy team lead of Cassini's radar team, based at NASA's Jet Propulsion Laboratory in California. "On Earth, rivers, volcanoes and even weather are closely related to heights of surfaces, we're now eager to see what we can learn from them on Titan."

The upper panel of this graphic show where radar images have been obtained over almost half of Titan's surface.The lower panel shows the new topography map. Image credit: NASA/JPL-Caltech/ASI/JHUAPL/Cornell/Weizman

"Cassini isn't orbiting Titan," Lorenz said. "We have only imaged about half of Titan's surface, and multiple 'looks' or special observations are needed to estimate the surface heights. If you divided Titan into 1-degree by 1-degree [latitude and longitude] squares, only 11 percent of those squares have topography data in them."

Lorenz's team used a process called splining, to "join" the areas between grids of existing data. "You can take a spot where there is no data, look how close it is to the nearest data, and use various approaches of averaging and estimating to calculate your best guess," he said. "If you pick a point, and all the nearby points are high altitude, you'd need a special reason for thinking that point would be lower. We're mathematically papering over the gaps in our coverage."

These polar maps show the first global, topographic mapping of Saturn's moon Titan, using data from NASA's Cassini mission. Image credit: NASA/JPL-Caltech/ASI/JHUAPL/Cornell/Weizmann

The estimations fit with current knowledge of the moon. Its polar regions are "lower" than areas around the equator, but connecting those points allows scientists to add new layers to their studies of Titan, especially those modelling Titan's rivers, and the seasonal distribution of its methane rainfall. "The movement of sands and the flow of liquids are influenced by slopes, and mountains can trigger cloud formation and therefore rainfall. This global product now gives modelers a convenient description of this key factor in Titan's dynamic climate system," Lorenz said.

Lorenz hopes to revise the map when the Cassini mission ends in 2017 when more data is available. "We felt we couldn't wait and should release an interim product," he says. "The community has been hoping to get this for a while. I think it will stimulate a lot of interesting work."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Cassini was launched in 1997 and entered Saturn's orbit in 2004. The Huygens space probe was launched with Cassini and landed successfully on Titan in 2005. Cassini continues to provide much information and stunning images of Saturn, its rings and its moons.

NASA's sample return mission to an asteroid moves into development

Jenny Winder — Sat, 18 May 2013 12:00:00 UTC

Artist concept of OSIRIS-REx. Image credit: NASA Goddard/University of Arizona

(Sen) - NASA's first mission to return sample from an asteroid is moving ahead into development and testing in preparation for its launch in 2016.

NASA officials recently reviewed detailed project assessments for the mission to the asteroid Bennu which is called OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, and Regolith Explorer). The review gave the green light to the spacecraft's continuation into the development phase.

"Successfully passing KDP-C [Key Decision Point] is a major milestone for the project," said Mike Donnelly, OSIRIS-REx project manager at NASA's Goddard Space Flight Center. "This means NASA believes we have an executable plan to return a sample from Bennu. It now falls on the project and its development team members to execute that plan."

OSIRIS-REx will rendezvous with the asteroid Bennu, which could hold clues to the origin of the solar system, in 2018. It will collect a minimum of 2 ounces (60 grams) of surface material and return the sample to Earth in 2023.

The mission will also map the asteroid's global properties, measure non-gravitational forces and provide observations that can be compared with data obtained by telescope observations from Earth. There is also a proposal to send a second spacecraft, ISIS, that would perform a high speed impact on the surface that the OSIRIS-REx cameras would watch.

"The entire OSIRIS-REx team has worked very hard to get to this point," said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson. "We have a long way to go before we arrive at Bennu , but I have every confidence when we do, we will have built a supremely capable system to return a sample of this primitive asteroid."

Bennu measures 575 meters (one-third of a mile) in diameter. It is classified as a B-type asteroid, a rare subgroup of the dark, carbonaceous C-type asteroids, which are called "primitive" having undergone little processing from their time of formation.

The mission could give scientists a greater understanding of planet formation and the origin of life, as well as improving our knowledge of asteroids that could impact Earth. It is a vital part of NASA's plans to find, study, capture and relocate an asteroid for exploration by astronauts. NASA recently announced an asteroid initiative proposing a strategy of human and robotic activities for the first human mission to an asteroid while also accelerating efforts to improve detection and characterization of asteroids.

Kepler enters safe mode after failure of orientation system

Jenny Winder — Fri, 17 May 2013 12:00:00 UTC

Artists composite image of Kepler. Image credit: NASA/ composite created by Wendy Stenzel

(Sen) - NASA's planet-hunting Kepler telescope has entered safe mode after it lost two of four reaction wheels needed to orient the telescope accurately.

The four reaction wheels enable the spacecraft to aim in different directions without firing thrusters. Kepler needs at least three reaction wheels to be able to aim precisely. Last year Kepler lost reaction wheel number 2 and now number 4 has failed.

On Tuesday May 14th the Kepler team found the spacecraft in a 'Thruster-Controlled Safe Mode' that turns the spacecraft's solar panels towards the Sun if the observatory has trouble with orientation.

They attempted to restore reaction wheel control as the spacecraft rotated into communication, and commanded a stop rotation, but reaction wheel 4 remained at full torque while the spin rate dropped to zero. This is a clear indication that there has been an internal failure within the reaction wheel, likely a structural failure of the wheel bearing.

The spacecraft is currently stable and safe. The team's priority is to complete preparations to enter Point Rest State, a loosely-pointed, thruster-controlled state that minimizes fuels usage while providing a continuous X-band communication downlink. In its current mode, the fuel will last for several months. Point Rest State would extend that period to years. They will closely monitor the spacecraft and take the next several days and weeks to assess their options and develop new command products.

"We're not ready to call the mission down and out just yet," said John Grunsfeld, NASA's associate administrator for the Science Mission Directorate, "but by any measure it's been a spectacular mission."

With the failure of a second reaction wheel, it's unlikely that the spacecraft will be able to return to the high pointing accuracy that enables its high-precision photometry, but no decision has been made to end data collection.

The $600m (£395m) Kepler mission was launched in 2009, and so far has identified 132 exoplanets outside our solar system, with another 2,700 possible candidates. Kepler successfully completed its primary three-and-a-half year mission and entered an extended mission phase in November 2012.

Even if data collection were to end, the mission has two years of data on the ground yet to be fully analysed, and the string of scientific discoveries is expected to continue for years to come.

Dream Chaser completes major safety review

Charles Black — Thu, 16 May 2013 12:00:00 UTC

Illustration of Dream Chaser docked at the ISS. Credit: Sierra Nevada Corporation

(Sen) - A new spaceship called Dream Chaser, which is being designed to ferry astronauts to low Earth orbit and the International Space Station, has completed its first major safety review under NASA's Commercial Crew Program.

The vehicle arrived at NASA's Dryden Flight Research Center in California on Wednesday May 15 for further tests.

The spacecraft is being built by Sierra Nevada Corporation (SNC), one of three beneficiaries under the latest round of funding from NASA's commercial crew outsourcing initiative called Commercial Crew Integrated Capability (CCiCap). SNC was awarded a CCiCap agreement worth $212.5 million last year. The other beneficiaries were Boeing and SpaceX.

The safety review is one of the performance related milestones under SNC's CCiCap agreement. The review covered the safety and reliability plans for the major components of the Dream Chaser space system, including the vehicle itself, its launcher and flight and ground systems.

Ed Mango, who heads up NASA's commercial crew program, said: "Safety review milestones are critical to ensuring safety and reliability techniques and methods are incorporated into space systems design. NASA's participation in these reviews provides our partners with critical design experiences from past human spaceflight activities."

The Dream Chaser is being built to carry up to 7 astronauts. It will launch atop a United Launch Alliance Atlas V rocket and land on a runway on its return from space, like the Space Shuttle. The concept is different from the other commercial crew capsules being developed by SpaceX and Boeing which are designed to splash down in the ocean.

"Dream Chaser is making substantial progress toward flight with the help of our NASA team" observed Mark Sirangelo, head of SNC's Space Systems. "As we begin our flight test program we have a better and stronger program due to our partnership with NASA."

A Dream Chaser vehicle has been transported from SNC in Louisville, Colorado to NASA's Dryden Flight Resarch Center at Edwards Air Force base in California for further testing, including its first autonomous free flight Approach and Landing Test (ALT) which is scheduled for later this year.

The Dream Chaser, which is the only shuttle-like vehicle being supported by NASA under its commercial crew program, will aim to follow in the footsteps of the Space Shuttle whose prototype named Enterprise also conducted an ALT at NASA Dryden in 1977.

SNC's Jim Voss commented: "This will be the first full scale flight test of the Dream Chaser lifting body and will demonstrate the unique capability of our spacecraft to land on a runway. Other flight tests will follow to validate the aerodynamic data used to control the vehicle in the atmosphere when it returns from space. This is a huge step forward for the SNC and NASA teams towards providing our nation with safe and reliable transportation to the International Space Station."

Dream Chaser had its first captive-carry flight - suspended from a helicopter rather than flying on its own power - last year. It is expected that commercial flights will begin by 2016 or 2017.

NASA's commercial spaceflight strategy is to outsource the transportation of astronauts to and from the International Space Station to US businesses SNC, Boeing and SpaceX, whilst developing its own spacecraft for deep space exploration. NASA is building the Orion space vehicle to take humans to an asteroid, the Moon and Mars, to be launched by its next big rocket, the Space Launch System.

Gallery: Sierra Nevada Corporation Dream Chaser

'Einstein's planet' discovered by relativistic beaming effect

Charles Black — Wed, 15 May 2013 12:00:00 UTC

Artist illustration of Kepler-76b, dubbed 'Einstein's planet'. Credit: David A. Aguilar (CfA)

(Sen) - Astronomers have discovered an exoplanet using a new method that relies on Einstein's special theory of relativity. The planet, Kepler-76b, is one of over 800 so far discovered outside our Solar System.

The two most common methods of detecting exoplanets to date are the radial velocity method, which looks for a star's wobble caused by the gravitational pull of an orbiting planet, and the transit method, which searches for dips in light caused by the transit of a planet across the face of its star.

The new technique looks for three effects that occur simultaneously as a planet orbits a star.

The first, Einstein's relativistic "beaming" effect, is the brightening of the star as it is tugged toward us by the planet and the dimming of the star as it is pulled away. As the star is tugged, light particles called photons pile up in the direction of the star's motion.

The second effect is the star being stretched into an American football or rugby ball shape by the gravitational tides from the orbiting planet. The third effect is due to light from the star being reflected by the planet itself.

The planet, nicknamed "Einstein's Planet", has been categorised as a "hot Jupiter". It has a diameter about 25 percent larger than Jupiter, but has twice the mass, and orbits its star very closely every 1.5 days and has a temperature of 3,600 degrees Fahrenheit. Its star is about 2,000 light years away in the constellation of Cygnus.

The discovery was made by a team at Tel Aviv University and The Harvard-Smithsonian Center for Astrophysics (CfA). Data from NASA's Kepler space telescope, which is monitoring over 150,000 stars for evidence of planets, was used to identify a planet candidate. On May 3, 2012, the beaming, stretching and reflection effects were noticed in one of the stars observed by Kepler.

Although Kepler data was used to identify Kepler-76b, it was the Einstein-based method which was used to detect the planet, rather than its transit. Professor Tsevi Mazeh of Tel Aviv University, co-author of the paper describing the findings, said: "This is the first time that this aspect of Einstein's theory of relativity has been used to discover a planet. We have been searching for this elusive effect for more than two years, and we finally found a planet!"

Simchon Faigler, a PhD student at Tel Aviv University and lead author of the paper, said in a statement: "The discovery proves the feasibility of the method. We hope to find more planets like Kepler-76b using the same technique. This is possible only because of the exquisite data NASA is collecting with the Kepler spacecraft from more than 150,000 stars."

Artist illustration of Kepler-76b's transit across its star. Credit: Dood Evan

Once the planet was detected using the new method, its existence was confirmed by ground based observations from the Whipple Observatory in Arizona and the Haute-Provence Observatory in France.

The new technique is suitable for finding large planets, but not Earth sized or smaller planets. However, the method does have advantages because it does not require high precision measurements of a star's velocity nor does it require the planet and star to be aligned from our line of sight around Earth.

Professor Avi Loeb from the Harvard-Smithsonian Center for Astrophysics, who with Professor Scott Gaudi proposed using the beaming effect in 2003, said in a statement: "each planet-hunting technique has its strengths and weaknesses. And each novel technique we add to the arsenal allows us to probe planets in new regimes."

The new methodology has been given the acronym BEER which stands for BEaming Ellipsoidal and Reflection/emission modulations. The paper with details of the discovery is being published in The Astrophysical Journal.

Ground Control welcomes home space trio

Paul Sutherland — Tue, 14 May 2013 12:00:00 UTC

Chris Hadfield, Roman Romanenko and Tom Marshburn safely back on the ground early today. Credit: NASA/Carla Cioffi

(Sen) - Canadian astronaut Chris Hadfield arrived home an Internet hero early today from the International Space Station when he landed safely with colleagues Tom Marshburn and Roman Romanenko.

The Expedition 35 crew's Soyuz TMA-07M hit the ground in southern Kazakhstan at 02.21 GMT with Romanenko at the controls. As its parachute settled, recovery helicopters swooped in.

A small army of support workers clustered round as the three men were helped from their capsule, then given chairs while they underwent medical checks and adjusted to life after weightlessness.

Calling home on a mobile phone, Cmdr Hadfield said: “Boy, that was quite a ride home! It’s a great little spaceship, we were laughing. It was a lot of fun.”

One of the first reactions came from Canada’s Prime Minister Stephen Harper (@pmharper) on Twitter. He tweeted: “I’m pleased to see that @Cmdr_Hadfield is safely back on planet earth. A reminder that our potential is limitless when we aim high.”

Chris Hadfield calls home on his mobile phone from Kazakhstan. Credit: Roskosmos/NASA TV

Hadfield, with his famous demi-lune moustache, became a public relations wonder for the space station following his launch into space aboard a Soyuz rocket on December 19 with Tom Marshburn and Roman Romanenko.

He became a masterful user of social media, creating ever fascinating tweets on Twitter, as Sen reported earlier, and continually taking interesting photos of places on the ground and demonstrating how things work aboard the ISS.

But his biggest contribution to the public entertainment was to take the role of “Major Tom” in a rendition of David Bowie’s early hit Space Oddity. The performance was released on YouTube soon after he handed over command of the space station on Sunday.

Footage of him singing and playing his guitar was turned into a highly professional video, with backing music and splendid imagery of the ISS, and swiftly went viral across the Web.

Hadfield, Marshburn and Romanenko spent their last hours aboard the station packing some final items, including some experiments, for return to Earth aboard their Soyuz spacecraft. Then it was “commencing countdown, engines on”, in the words of the song, as they undocked at 23.08 GMT from the orbiting outpost’s Rassvet module for the 3h 13m flight home.

A replay of the astronauts' return to Earth early today. Credit: Roskosmos/NASA TV

The Station is now running with the three remaining crew members, commander Pavel Vinogradov, flight engineer Alexander Misurkin and shuttle veteran Christopher Cassidy, who arrived in March.

Saturday’s spacewalk to fix a leaking cooling network on a solar array appears to have been completely successful, NASA reported. Chris Cassidy and Tom Marshburn replaced a pump unit that sends liquid ammonia through external radiators to get rid of excess heat.

The next Soyuz is due to arrive on 29 May carrying ESA astronaut Luca Parmitano, NASA astronaut Karen Nyberg and cosmonaut Fyodor Yurchikhin. They will spend six months on the Station conducting scientific experiments.

Luca has two spacewalks of his own planned to install new equipment and maintain the Station. As Expedition 36/37 flight engineer, he will replace a camera mounted on Japan’s Kibo module, retrieve some experiments and help prepare for the arrival later this year of Russia’s Multipurpose Laboratory Module and the ESA-built European Robotic Arm.

Oh, and just in case you haven’t seen it . . .

How YOU can help grow a Mars garden

Paul Sutherland — Mon, 13 May 2013 12:00:00 UTC

One concept of how astronauts might grow their own plants on Mars. Credit: Pat Rawlings/NASA

(Sen) - With NASA looking forward to manned missions to Mars within a couple of decades, thoughts are turning to how astronauts there might sustain themselves.

Ferrying food supplies from Earth will be enormously expensive and if colonies are developed then their residents will surely need to become as self-sufficient as possible.

Some scientists are already devoting research into what plants might be cultivated on the Red Planet. It turns out that despite the thin and unbreathable atmosphere and lack of a protective shield against radiation, the soil itself is fit for crops.

One UK scientist who is investigating the potential for gardening on Mars is Dr Louisa Preston, of the UK’s Open University. After gaining her degree in geology, Louisa switched to astrobiology. Now she has joined forces with Canadian artist Vanessa Harden to design a Martian garden.

They envisage sending robots to Mars to set up space greenhouses where seed pills containing seeds, clay and nutrients could be scattered and then nurtured even before the first human residents arrive. And they are looking to Kickstarter on the Internet to raise funding to begin building their concept here on Earth.

Louisa told Sen: “It costs something like $80,000 just to deliver four litres of water to the Moon, let alone Mars. It is ridiculously expensive to ship things to other planets. And the journey takes so long that fresh fruit and vegetables just wouldn’t survive.

“So a Mars settlement would need to be self-sufficient. Fortunately, a number of plants should grow well in Martian soil, such as potatoes, tomatoes, asparagus and some seeds and grains. It has been shown that you can even grow some flowers like marigolds in ground-up meteorites.”

She added: “You can’t just plant seeds in Martian soil because of the lack of a decent atmosphere and the problem of radiation from space. You would also need to garden in self-contained units to avoid contaminating Mars - planetary protection is very important.”

Louisa sees geodesic domes as a way to go to building greenhouses for Mars, with plastic covers to protect from UV radiation but let light in. She now is planning with Vanessa to build prototypes which can be installed in museums and art galleries for people to visit.

An example of the seed pills that could be used to produce crops for astronauts. Credit: Louisa Preston and Vanessa Harden

As well as being a peaceful and tranquil area, there will be plants growing in red dirt that Louisa intends will simulate Martian soil as closely as possible. Interactive exhibits will entertain as well as educate youngsters. And the highlight will be to meet the robotic gardener.

Louisa told us: “We just want to open everyone’s minds to the idea of gardening on another planet. We also want them to think how, if Earth’s population continues to grow and if we keep playing around with the atmosphere, then we might have to think about living somewhere else.”

Louisa and Vanesse need to win pledges totalling £10,000 to get their Kickstarter project to the next stage. Last night they had raised more than a tenth of this with 17 days left to find the balance.

Backing the project can bring you rewards such as a postcard from Mars, your own seed pills, a stylish T-shirt and more. Plus the warm glow of supporting a really worthy project that will also help research into how humans might feed themselves on another world. You can read more about the AstroGardening venture on Kickstarter.

Twin servicing missions end on space station

Paul Sutherland — Sun, 12 May 2013 12:00:00 UTC

A view of Dextre attached to the ISS with a solar array in the background. Credit: NASA

(Sen) - As two astronauts worked to replace a faulty power pump outside the International Space Station yesterday, a robotic handyman nearby was quietly completing its own latest servicing tasks.

The five and a half hour spacewalk by Chris Cassidy and Tom Marshburn was an unscheduled operation following the leak of ammonia into space from a solar array’s cooling system.

But as they toiled, a Canadian-built robot called Dextre had come to the end of five days of work with tools to demonstrate how similar machines will in future repair satellites in orbit.

Sitting at the end of the station’s Canadarm robotic arm, Dextre was finishing the first phase of the tasks set for it when it was launched into orbit by Atlantis, making the final space shuttle flight, in July 2011. Further operations by Dextre - otherwise known as NASA’s Robotic Refueling Mission (RRM) - are planned for the summer and early next year.

It is intended to show how robot technology could extend the lives of hundreds of satellites in the remote geosynchronous orbit 36,000 km (22,000 miles) above Earth where weather, TV and communications satellites reside.

A refuelling test had previously been carried out successfully by Dextre in January, as reported by Sen at the time. This time, the robot used tools to show how it could work with tiny items such as screws without losing them and adding to the debris in orbit.

The design of the equipment ensures that any screw removed from a satellite is trapped within a cage surrounding the robot’s electric screwdriver. Other tests showed how it could remove and stow tiny coaxial radio frequency connector caps and how it could handle protective thermal blankets that are wrapped around many satellites.

Benjamin Reed, deputy project manager of the Satellite Servicing Capabilities Office (SSCO) at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said: “Some RRM tasks may sound straightforward at first.

Chris Cassidy and Tom Marshburn are pictured on their spacewalk. Credit: NASA TV

“What may seem mundane can actually be quite tricky. Having remote-controlled robots service satellites on orbit - satellites that were never designed to be accessed, refuelled or fixed in space - is a new frontier.”

Fortunately for NASA, the human spacewalk also went well. It was completed in an hour’s less time than the six and a half hours that had been envisaged. A little more than 2.5 hours into the spacewalk, Cassidy and Marshburn removed the pump controller box from the portside P6 truss and replaced it with a spare that had been stowed nearby. They were aided from within the ISS by Expedition 35 commander Chris Hadfield.

Mission Control fired up the new pump while the spacewalkers watched for any ammonia snowflakes, but no new signs of a leak were detected. Further monitoring will be carried out to make sure the pump replacement has fixed the leak.

Volunteers will power the search for warps in space

Paul Sutherland — Fri, 10 May 2013 12:00:00 UTC

This Hubble space telescope image shows examples of gravitational lenses. Credit: ESA/NASA

(Sen) - In recent years, astronomers have found they can harness the brainpower of thousands of volunteers on the Internet to make fresh discoveries about the Universe.

From classifying galaxies to discovering new exoplanets, citizen scientists have shown their huge value in analysing vast quantities of images and other data.

The latest in a growing list of Zooniverse projects is called Space Warps and has been set up to identify examples of a phenomenon called gravitational lensing in deep space.

These are distorted and often multiple images of distant galaxies that are produced when the pulling power of closer galaxies, or clusters of galaxies in the same line of sight, bend and magnify their light.

Some examples of these gravitational lenses are fairly obvious, as in our main picture, above, of a rich field of galaxies taken by the Hubble space telescope. The Space Warps project, launched this week, will begin by using sky survey images taken with the Canada-France-Hawaii Telescope (CFHT), a 3.6 meter optical/infrared telescope on Mauna Kea, Hawaii.

These images have already been scanned by computer to pick out the clearer natural lenses, but there are expected to be many more which have been missed and need human eye and judgement to spot. Previous studies have shown that the human brain is much better at identifying lenses than computer algorithms, and that members of the public are as good at spotting astronomical objects as experts.

Space Warps is being organised by scientists at the University of Oxford in the UK and the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo.

Dr Phil Marshall, co-leader of the project at Oxford, said: “Not only do space warps act like lenses, magnifying the distant galaxies behind them, but also the light they distort can be used to weigh them, helping us to figure out how much dark matter they contain and how it’s distributed.”

It will also help the astronomers discover how many very low mass stars – that are not bright enough to detect directly – are lurking in distant galaxies.

Dr Aprajita Verma, also at Oxford, said: “Even if individual visitors only spend a few minutes glancing over 40 or so images each, that’s really helpful to our research - we only need a handful of people to spot something in an image for us to say that it’s worth investigating.”

A wide-angle and zoomed-in image show an example of a distant blue galaxy being distorted by the lensing effect of a closer red galaxy. Credit: Zooniverse

Taking part in the project is easy. Visitors to www.spacewarps.org are first shown examples of what gravitational lenses, or space warps, look like and are shown how to mark potential candidates on each image. Then they can start identifying possible candidates in images for themselves. There is also an online forum where they can discuss their findings with fellow volunteers and experts, and create computer models of their discoveries.

This latest Zooniverse project is already exciting interest among scientists producing other sky surveys. The Dark Energy Survey led by the United States and the Hyper Suprime-Cam survey led by Japan are both interested in getting involved.

The process will also be useful to future large-scale surveys such as with the Large Synoptic Survey Telescope, an 8.4-metre instrument to be built in Chile, and a European Space Agency (ESA) space telescope called Euclid which will map the distribution of dark matter.

Unscheduled spacewalk set to fix space station leak

Paul Sutherland — Fri, 10 May 2013 12:00:00 UTC

The ISS in March 2009 after its full set of eight solar arrays had been fitted. Credit: NASA

(Sen) - Astronauts on board the International Space Station are preparing for an unscheduled spacewalk today (Saturday) after the orbiting outpost began leaking ammonia.

NASA stressed the six astronauts on board were in no danger, following the observation that the gas was escaping from a port-side section of the truss on Thursday.

The ammonia is used as a coolant for power channels that provide electricity to the space station’s systems. As mission managers discussed the leak with the crew, work began to reroute power.

The station continued normal operations on Friday while the astronauts used handheld cameras to take pictures to download for analysis and described what they could see outside. They were then asked to close shutters all windows not in use to avoid them being contaminated by the ammonia.

ISS Expdition 35 commander Chris Hadfield told mission control he had been watching from a docking compartment and saw “a very steady stream of flakes or bits” escaping as the truss holding the solar array rotated.

Flight controllers at Houston examined photos taken by the crew together with pictures from external cameras fitted to the ISS and other data and confirmed that the amount of ammonia leaking from that section of the cooling system had increased.

Crew members Chris Cassidy and Tom Marshburn began preparing for a possible spacewalk by checking out their NASA spacesuits. Each of them has made three previous spacewalks on an earlier trip, the STS-127 mission by the shuttle Endeavour to the ISS in 2009.

Flight controllers on the ground gave the final go-ahead for the spacewalk late on Friday. Cassidy and Marshburn will exit the Quest airlock to inspect the area of truss labelled P6 from which the leak appeared to be coming. They will examine and possibly replace a pump controller box that is thought to be to blame for the leaking ammonia.

A video from the ISS shows flakes of ammonia floating past the station. Credit: NASA

The spacewalk, which is due to begin at around 8.15am EDT, is expected to last 6.5 hours and will be broadcast live on NASA TV.

Commander Hadfield, who will assist with the spacewalk from within the station, seemed quite unfazed by the drama. He tweeted yesterday: “Good Morning, Earth! Big change in plans, spacewalk tomorrow, Chris Cassidy and Tom Marshburn are getting suits and airlock ready. Cool!”

Then he added: “The whole team is ticking like clockwork, readying for tomorrow. I am so proud to be Commander of this crew. Such great, capable, fun people.”

Each of the eight arrays of solar panels on the ISS has its own independent cooling loop. The loop that is giving trouble is the same one where spacewalkers attempted to troubleshoot a leak in November last year, though it is not certain that the leak is in the same place. The loop was expected to have lost all its ammonia before any spacewalk.

The P6 truss is one of the oldest parts of the ISS's structure. It was carried into space by Endeavour on the STS-97 mission in November 2000, then moved from its original installation position during the STS-120 mission of the shuttle Discovery in October/November 2007.

The other astronauts currently aboard the ISS are Tom Marshburn, Roman Romanenko, Pavel Vinogradov and Alexander Misurkin. Hadfield, Marshburn and Romanenko are due to return to Earth on Monday.

Herschel finds hot gas surrounding the black hole at the heart of our Galaxy

Jenny Winder — Thu, 9 May 2013 12:00:00 UTC

Artist’s impression of the dense torus of gas and dust that orbits close within a few light years of the supermassive balck hole at the heart of our Milky Way galaxy. Image credit: ESA/C.Carreau.

(Sen) - Astronomers examining data collected by the Herschel Space Observatory have found a cloud of incredibly hot gas that may be orbiting or falling towards the supermassive black hole at the heart of our Milky Way galaxy.

The black hole is located in a region known as Sagittarius A* (Sgr A*). It has a mass about four million times that of the Sun and lies around 26 000 light-years away, at the very centre of our galaxy.

Its relative proximity makes it the ideal target for studying these extreme environments in detail. By studying it in far-infrared light, Herschel was able to see through the dense clouds of dust obscuring our view and examine the surroundings of the black hole itself. Herschel discovered the black hole to be surrounded by a ring of gas around 30 light years across, but right in the centre is a mini spiral of gas flowing inwards.

The observations, which were taken in 2011 and 2012 using Herschel's SPIRE and PACS instruments, allowed astronomers to examine the region within around a light year of the black hole itself. The data showed the presence of elements such as carbon, nitrogen and oxygen, and simple molecules including water, carbon monoxide and hydrogen cyanide.

The ring of material (blue) around the central black hole surrounds a spiral of gas (orange). Also shown is the spectrum towards the very centre at far-infrared wavelengths seen by Herschel. Image credit: radio image: NRAO/VLA/C.Lang; spectrum: ESA/Herschel/SPIRE/PACS/ J.R. Goicoechea et al. (2013).

By analysing the signature from these molecules, astronomers have been able to probe some of the fundamental properties of the interstellar gas surrounding the black hole.

"Herschel has resolved the far-infrared emission within just 1 light-year of the black hole, making it possible for the first time at these wavelengths to separate emission due to the central cavity from that of the surrounding dense molecular disc," says Javier Goicoechea of the Centro de Astrobiologia, Spain, and lead author of the paper.

Some of the material in the inner spiral is moving at speeds of over 300 km/s (1 million km per hour), and must be very close to the black hole itself, possibly on the verge of falling in.

The biggest surprise was how hot the molecular gas in the central region of the Galaxy gets. At least some of it is around 1000°C. Typical interstellar clouds are usually only a few tens of degrees above the -273°C of absolute zero.

Some of the heating is due to intense light from nearby stars, and from hot material close to the black hole itself, but this only accounts for a relatively small temperature increase. The most likely cause is intense shockwaves and turbulence, due to fast-moving gas from young stars, causing the material to heat up as it is thrown around.

"The observations are consistent with streamers of hot gas speeding towards Sgr A*, falling towards the very centre of the Galaxy," says Dr Goicoechea."Our Galaxy's black hole may be cooking its dinner right in front of Herschel's eyes."

Herschel was launched in 2009. The liquid helium coolant that enabled instruments on board the space observatory to collect images and spectra finally ran out at the end of April 2013.

"This is a fascinating study with Herschel of what goes on right at the centres of galaxies. Even though Herschel has now finished observing, there's still a huge amount of work to be done," commented Matt Griffin, of Cardiff University and lead scientist of the SPIRE instrument. "Over the next few years, as we process the full archive of Herschel data, we know there will be many more results like this."

Spitzer puts exoplanets in the lab

Jenny Winder — Wed, 8 May 2013 12:00:00 UTC

An Astronomer's Fantasy Planets in the Lab. Image credit: NASA/JPL-Caltech

(Sen) - Thanks to NASA's Spitzer Space Telescope, researchers are beginning to dissect one of the first "species" of exoplanets to be discovered, revealing raging winds and their turbulent nature.

"The hot Jupiters are beasts to handle. They are not fitting neatly into our models and are more diverse than we thought," said Nikole Lewis of the Massachusetts Institute of Technology, Cambridge, lead author of a new Spitzer paper in the Astrophysical Journal examining one such hot Jupiter called HAT-P-2b. "We are just starting to put together the puzzle pieces of what's happening with these planets, and we still don't know what the final picture will be."

Hot Jupiters are gas giants that orbit closely to their stars. The first exoplanet discovered was a hot Jupiter, 51 Pegasi b, detected in 1995 using the radial velocity technique, which measures the wobble of a star caused by the tug of a planet. Because hot Jupiters are heavy and whip around their stars quickly, they are the easiest to find using this strategy. Dozens of hot Jupiter discoveries soon followed. Researchers thought there might be a common configuration for other planetary systems, but new research has shown that they are relatively rare.

In 2005, Spitzer became the first telescope to detect infrared light coming from a star and its planet, a hot Jupiter, as the planet disappeared behind the star in an event known as a secondary eclipse. Once again, this technique works best for hot Jupiters because they are the biggest and hottest planets. The team has now made the longest Spitzer observation yet of a hot Jupiter. The infrared telescope stared at the HAT-P-2 system continuously for six days, as it made a full orbit.

Hot Jupiters are frequently tidally locked, with one side always facing the star. Monitoring planets as they orbit all the way around a star reveals how the planets' atmospheres vary from their hot, sun-facing sides to their cooler, night sides.

What makes the observation even more exciting is that the planet has a comet-like eccentric orbit, coming as close as 2.8 million miles (4.5 million kilometres) to the star and out to as far as 9.3 million miles (15 million kilometres). HAT-P-2b takes about a day to heat up as it approaches the hottest part of its orbit, and four to five days to cool down as it swings away.

"These planets are much hotter and more dynamic than our own Jupiter, which is sluggish by comparison. Strong winds are churning material up from below, and the chemistry is always changing," said Lewis.

Using multiple wavelengths of infrared light to watch a full orbit of HAT-P-2b enables the scientists to peer down into different layers of the planet.

"It's as if nature has given us a perfect lab experiment with this system," said Heather Knutson, a co-author of the new paper at the California Institute of Technology, Pasadena, California. "Because the planet's distance to the sun changes, we can watch how fast it takes to heat up and cool down. It's as though we're turning the heat knob up on our planet and watching what happens."

'Pillownauts' are halfway through bedrest study

Jenny Winder — Tue, 7 May 2013 12:00:00 UTC

Bedsuit. Image credit: CNES/E. Grimault, 2013

(Sen) - Twelve volunteer 'pillownauts' are currently halfway through their second three-week session lying down with their heads angled at 6 degrees below the horizontal, to help research the effects of weightlessness on the human body.

The bedsuit shown in the image above, is part of a system to estimate energy requirements. It measures how much oxygen is consumed and how much carbon dioxide is exhaled by the volunteer. These measurements allow scientists to get an idea of the relationship between food, the lungs and the energy consumption when at rest.

Bedrest studies are helping to develop countermeasures against the unwanted physical effects on astronauts during long spaceflights and bedridden people on Earth. Astronaut's bones lose density by up to 2% a month during a stay in space. On Earth, similar bone loss is seen over a longer period of time, commonly known as osteoporosis.

Other changes that occur both in astronauts and bedrest volunteers include loss of muscle, changes in blood pressure and differences in how food is digested.

Bedrest resistive vibration exercise machine. Image credit: CNES - Emmanuel Grimault, 2012.

During bedrest studies, techniques to combat changes in our bodies are tested, from strict diets to specific exercise routines. For this study, in collaboration with France's CNES space agency, three bedrest campaigns are spread out over a year with 12 volunteers in each of three groups.

"ESA sends us the experiments they want to conduct. From there we start to look for volunteers, which is the most critical part of the organisation" says Marie-Pierre Bareille from the Medes institute in Toulouse, France, running this study.

The study requires many sacrifices from the volunteers. Not only are they expected to give up small pieces of their thigh muscles in regular biopsies, but they also have to remove themselves from their normal lives three times over the course of the year. The pillownauts undergo regular and intensive daily activities, including tests and examinations. They are not allowed to get up, not even for a shower or to use the toilet. Meals are strictly controlled during the study and cannot be tailored to participants. If you require a special diet for whatever reason, you cannot take part. During their time in bed, they cannot receive visitors and are expected to complete the session no matter what emergency at home.

Bedrest volunteer. Image credit: ESA

"We try to exclude people who we think are incapable of completing the study," says Marie-Pierre.

Rehabilitation after surgery or serious illness can mean weeks spent recuperating in bed. The research done on bedrest volunteers directly applies to these situations and is shared freely with scientists in all disciplines.

After this current 21 day study the pillownauts will have four months to recuperate, before returning for their final bedrest session later this year.

NASA's Orion passes difficult parachute test

Jenny Winder — Mon, 6 May 2013 12:00:00 UTC

A test model version of NASA's Orion spacecraft durng the parachute test. Credit: NASA

(Sen) - NASA's Orion spacecraft, which is being designed to take humans to deep space, passed further milestones May 1 when a test version of the capsule landed safely during a simulation of two types of parachute failures.

The test capsule was dropped from a plane 25,000 feet above the Arizona desert. Engineers rigged one of the test capsule's two drogue parachutes not to deploy and one of its three main parachutes to skip its first stage of inflation. Drogue parachutes are used to slow and reorient Orion while the main parachutes inflate in three stages to gradually slow the capsule further as it descends.

Orion has the largest parachute system ever built for a human-rated spacecraft. The canopies of the three main parachutes can cover almost an entire football field. After re-entering Earth's atmosphere, astronauts will use the parachutes to slow the spacecraft before splashing down in the Pacific Ocean.

The test capsule was traveling at 250 mph when the parachutes were deployed, the highest speed the craft has experienced as part of the test series. This failure scenario, one of the most difficult simulated so far, will provide data engineers need for human rating the parachute system.

Testing allows engineers to verify the parachutes are reliable even when something goes wrong. Changes to the design and materials used in Orion's parachute system have already been made based on previous tests. Other government or commercial spacecraft using a similar parachute system also can benefit from the work done to validate Orion.

"Parachute deployment is inherently chaotic and not easily predictable," said Stu McClung, Orion's landing and recovery system manager. "Gravity never takes any time off, there's no timeout. The end result can be very unforgiving. That's why we test. If we have problems with the system, we want to know about them now."

A model of NASA's Orion spacecraft is loaded into the C-17 airplane that then dropped it from an altitude of 25,000 feet above the Arizona desert. Image credit: NASA

Orion's next Earth-based parachute test is scheduled for July, when the test capsule will be released from 35,000 feet, a higher altitude than ever before.

The first test of the parachutes after traveling in space will be during Exploration Flight Test-1 (EFT-1) in 2014, when an uncrewed Orion will be returned from 3,600 miles above Earth's surface. The spacecraft will be traveling at about 340 mph when the parachutes deploy.

EFT-1 will be followed by Exploration Mission-1 in 2017, another unmanned flight but the first to combine Orion with NASA's new big rocket the Space Launch System. The 2017 fllight will be followed by Exploration Mission-2, which will launch Orion and a crew of four astronauts on a space mission.

"The tests continue to become more challenging, and the parachute system is proving the design's redundancy and reliability," said Chris Johnson, NASA's project manager for the Orion parachute assembly system. "Testing helps us gain confidence and balance risk to ensure the safety of our crew."

Astronomers detect record breaking gamma ray burst

Jenny Winder — Sun, 5 May 2013 12:00:00 UTC

Before and after Fermi LAT views of GRB 130427A, centered on the north galactic pole. Image credit: NASA/DOE/Fermi LAT Collaboration

(Sen) - A record-setting gamma ray burst (GRB) from a dying star in a distant galaxy has produced the highest-energy light ever detected from such an event.

On Saturday April 27, NASA's Fermi space telescope detected an eruption of high-energy light in the constellation Leo. The gamma ray burst, designated GRB 130427A, was also detected by NASA's Swift telescope.

Fermi's Large Area Telescope (LAT) recorded one gamma ray with an energy of at least 94 billion electron volts (GeV), 35 billion times the energy of visible light, and about three times greater than the LAT's previous record. The GeV emission from the burst lasted for hours, and it remained detectable by the LAT for the better part of a day, setting a new record for the longest gamma-ray emission from a GRB.

Swift's X-Ray Telescope took this 0.1-second exposure of GRB 130427A just moments after Swift and Fermi triggered on the outburst. The image is 6.5 arcminutes across. Image credit: NASA/Swift/Stefan Immler

"We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright," said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope at NASA's Goddard Space Flight Center. "The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing."

The burst was detected in optical, infrared and radio wavelengths by ground-based observatories, based on the rapid accurate position from Swift. Astronomers quickly located the GRB to about 3.6 billion light-years away, which for these events is relatively close.

Gamma-ray bursts are the universe's most luminous explosions. Astronomers think most occur when massive stars run out of nuclear fuel and collapse under their own weight. As the core collapses into a black hole, jets of material shoot out at nearly the speed of light. The jets bore through the collapsing star and continue into space, where they interact with gas previously shed by the star and generate bright afterglows that fade with time. If the GRB is near enough, a supernova is usually discovered at the site a week or so after the outburst. Ground-based observatories are monitoring the location of GRB 130427A and expect to find an underlying supernova by midmonth.

"This GRB is in the closest 5 percent of bursts, so the big push now is to find an emerging supernova, which accompanies nearly all long GRBs at this distance," said Goddard's Neil Gehrels, principal investigator for Swift.

Landslide bunched up terrain near massive Mars volcano

Elizabeth Howell — Sat, 4 May 2013 12:00:00 UTC

Sulci Gordii as seen through the eyes of Mars Express. Credit: ESA/DLR/FU Berlin (G. Neukum)

(Sen) - Scars and wrinkles mark the landscape in an area some 200 kilometres east of Olympus Mons -- a giant dormant volcano on Mars -- in new pictures released by the European Space Agency's Mars Express spacecraft.

The rumples came after part of the lower part of the now two-kilometre-high volcano collapsed, perhaps due to changes in water beneath the surface, scientists stated.

"During the collapse, rocky debris slid down and out over hundreds of kilometres of the surrounding volcanic plains, giving rise to the rough-textured aureole seen today," ESA stated.

An aureole is a term from the Latin "circle of light." This particular region, called Sulci Gordii, is just one of several surrounding the massive volcano.

The geologic word sulci refers to hills and valleys that are approximately parallel on Mars. This ragged landscape probably occurred when rocks and other debris came off the volcano, then expanded and compressed during its journey across the surface. Rougher crags appeared as erosion eliminated the lighter bits of the debris between the apexes.

"By studying complex regions like this – and by comparing them to similar examples here on Earth – planetary scientists learn more about the geological processes that dominated ancient Mars, when it was an active planet," ESA stated.

"Just as on Earth, the scene at Sulci Gordii tells us that volcanoes can suffer dramatic collapses that transport vast quantities of material across hundreds of kilometres, where it is subsequently sculpted by wind, water and tectonic forces."

The latest set of pictures comes on the eve of the Mars probe's 10th anniversary of its June 2, 2003 launch. Mars Express, so called because it was built rapidly, was based upon similar technology to that of the failed Mars 96 probe, and the Rosetta mission that is on its way to Comet 67P/Churyumov-Gerasimenko.

Mars Express included two components, an orbiter and a lander that was called Beagle 2. The lander failed to make it to the surface safely, but the orbiter has been returning pictures and information now for close to a decade.

Mars Express is supposed to help scientists understand the role of subsurface water on Mars in shaping the Red Planet. Several rovers deployed by NASA have shown water flowing on the surface at some point in the recent past. A few months ago, for example, the Curiosity rover found evidence that it was wandering in what used to be a hip-high streambed.

Underwater channels are less known on Mars as they are invisible to the surface and require special equipment to look at. In March, however, NASA released images of a 1,000-kilometre subsurface trench mapped by its Mars Reconnaissance Orbiter. The agency speculated that a volcano or earthquake pushed water out onto the surface at some point in the past half-billion years.

Other notable discoveries by Mars Express include evidence of processes such as methane gas, volcanism and possible alteration of the landscape by glaciation.

Planet hunting Kepler faces pointing problem

Elizabeth Howell — Fri, 3 May 2013 12:00:00 UTC

An artists's impression of the Kepler spacecraft watching for new planets. Credit: NASA

(Sen) - As the Kepler space telescope's planet-hunting mission continues to work past its design life, NASA managers are trying to manage a problem that could threaten the observatory's ability to point at targets.

A reaction wheel, which assists the spacecraft with pointing in the right direction, is now deterioriating, NASA said. The team is seeing signs of increased friction and periodic torque spikes, which engineers believe may be due to a failing wheel bearing.

With no way to service the telescope -- it's in orbit around the Sun, about 75 million kilometers from Earth -- NASA is trying to figure out how to wring more discoveries out of the aging telescope.

"All appropriate mitigation steps to prolong wheel life have now been taken. While the wheel may still continue to operate for some time yet, the engineering team has now turned its attention to the development of contingency actions should the wheel fail sooner, rather than later," wrote Roger Hunter, Kepler's mission manager, in a blog update.

"Initially, these contingencies will focus on preserving fuel, but subsequent goals will be to return the failed wheels to service, perhaps at reduced performance levels, and investigating opportunities for gathering science data using a combination of wheels and thrusters."

Kepler launched in March 2009 on a mission to find planets outside of the solar system, with its primary goal to seek Earth-sized worlds.

Pointing at one fixed region in the sky, the telescope now has a large catch: 122 confirmed planets and more than 2,700 candidates in an area that encompasses 160,000 stars in the Cygnus and Lyra constellations that are visible from the northern hemisphere.

It finds these planets by monitoring changes in brightness from the stars they orbit; as a planet passes in front of the star, it blocks a tiny portion of the light that shines through to Earth.

Just last month, scientists using the observatory announced they had found three "super Earths" in the Kepler 62- and -69 systems. The telescope's cornicopia of potential worlds include worlds that are even smaller than Earth's moon.

The mission hasn't been without its glitches, though. In January, NASA shut down operations for 10 days due to the same balky wheel, hoping that giving the spacecraft a rest would spread the lubricant more evenly across the wheel.

Kepler launched with four reaction wheels, giving it a spare if one should fail. However, one wheel already stopped working in 2012.

The current mission extension for Kepler calls for it to keep seeking new worlds until at least 2016.

Vega's second launch will deploy multiple payloads into different orbits

Jenny Winder — Thu, 2 May 2013 12:00:00 UTC

Fully assembled Vega VV02 on pad. Image credit: ESA–S. Corvaja, 2013

(Sen) - The European Space Agency (ESA) is planning the second launch of its Vega rocket on May 3 from its spaceport at Kourou, French Guiana.

Vega is a single-body rocket with three solid-propellant stages and a liquid-propellant upper module for attitude and orbit control, and satellite release. Unlike most small launchers, Vega is able to place multiple payloads into orbit and ESA hope aims to make access to space easier, quicker and cheaper for smaller 300 to 2000 kg satellites used for many scientific and Earth observation missions.

After the first Vega (VV01) lifted off on February 13, 2012 on a flawless qualification flight, Antonio Fabrizi, ESA's Director of Launchers, said, "Today is a moment of pride for Europe as well as those around 1000 individuals who have been involved in developing the world's most modern and competitive launcher system for small satellites."

The extended capabilities of Vega beyond the mission that was performed in the VV01 qualification flight have been made possible in part by the addition of Vespa (VEga Secondary Payload Adapter). Vespa allows for multiple payloads and their deployment into different orbits. On this mission, it will release three satellites into two different orbits.

Compared to the first Vega flight, VV02 will change both the inclinations and orbital altitudes for the satellites. This is a complex procedure and will result in a much longer mission, at 160 minutes it is more than double that of VV01.

Proba-V on Vespa adapter. Image credit ESA - Karim Mellab.

Proba-V carries a reduced version of the Vegetation camera currently flying on the Spot satellites to provide a daily overview of global vegetation growth. This will be the first payload released by Vespa into a Sun-synchronous polar orbit at 820 km altitude and an inclination of 98.73 degrees. At this point, the Vespa adapter will separate and Vega, through a series of five burns and coasts, moves into a second orbit at 668 km altitude and an inclination of 98.13 degrees for the second deployment of the two remaining payloads:

The Vietnam Natural Resources, Environment and Disaster Monitoring Satellite (VNRedsat) was built by Astrium for the Vietnamese government.

ESTCube-1 will test advanced solar sail technologies and help to establish an Estonian infrastructure for future space projects. It also showcases the possibility offered by this launcher to carry cubesats.

A final burn will deorbit the upper stage to ensure that it does not remain as a debris threat.

This second Vega launcher also has new flight software. To receive telemetry during the early phase of the flight, a new ground station has been built in the north of French Guiana.

This will be the first Vega launch operated by Arianespace on behalf of ESA, although ESA still remains responsible for the mission. Arianespace has been responsible for the procurement, acceptance and integration of the vehicle, managing the launch service and marketing. This launch should ease the way towards full autonomy of Arianespace and industry in exploiting this light-lift launcher.

Comet ISON pictured on its way to the inner solar system

Charles Black — Wed, 1 May 2013 12:00:00 UTC

Comet ISON imaged by Hubble on April 10 when the comet was 394 million miles from Earth. Credit: NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team

(Sen) - Comet ISON, which is making its way to the inner Solar System for the first time, has been imaged by the Hubble Space Telescope.

The Comet, C/2012 S1 ISON, which will pass within 1.2 million km (730,000 miles) of the Sun on November 28 this year, was pictured by Hubble's Wide Field Camera 3 on April 10 when the comet was 621 million km (386 million miles) from the Sun and 634 million km (394 million miles) from Earth. The comet is now slightly closer than Jupiter.

The comet originated in the Oort cloud, a band of icy bodies beyond the orbit of Neptune in the outer Solar System. Astronomers believe that this is ISON's first trip to the inner Solar System and are excited to have the opportunity to study the change in the comet as it heads toward the Sun. The comet's flyby of the Sun is close enough for ISON to be labelled as 'sungrazer'.

As Comet ISON approaches the Sun it is expected to become an extremely bright object in the night sky as its icy nucleus begins to melt creating a tail of gas and dust - a process known as sublimation. The jets powered by sublimating ice also release dust which reflects sunlight and makes the comet brighter.

Jian-Yang Li of the Planetary Science Institute who led a team that imaged the comet, said: "As a first-time visitor to the inner solar system, Comet C/ISON provides astronomers a rare opportunity to study a fresh comet preserved since the formation of the solar system. The expected high brightness of the comet as it nears the Sun allows for many important measurements that are impossible for most other fresh comets."

Measurements from Hubble and from NASA's Swift space telescope calculate the comet's icy nucleus at about 5 km (3 miles) across. However, the head of the comet, or 'dusty coma', is about 5,000 km (3,100 miles) across. Comet ISON's tail already extends about 92,000 km (57,000 miles). From the sunward-facing side of the comet's nucleus is a jet extending out about 3,700 km (2,300 miles).

Computerised view of Comet ISON. In this computer-processed view, the Hubble image has been divided by a computer model coma that decreases in brightness proportionally to the distance from the nucleus. Credit: NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team

On October 1 the comet will pass within 10.8 million km (6.7 million miles) of Mars. Data may be captured by spacecraft operated by NASA and the European Space Agency as it makes its way past the Red Planet.

After Mars it will head towards its close encounter with the sun, passing within 1.2 million km (730,000 miles) of the the sun on November 28.

It will make its closest approach to Earth on December 26, coming within 64 million km (40 million miles).

The comet was discovered on Setpember 21, 2012 by Russian astronomers Vitali Nevski and Artyom Novichonok using the International Scientific Optical Network (ISON) telescope. Its progress was recently studied by NASA's Swift space telescope.

Virgin Galactic spaceship has first rocket-powered flight

Charles Black — Tue, 30 Apr 2013 12:00:00 UTC

SpaceShipTwo during its first rocket-powered flight. Credit: MarsScientific.com/Clay Center Observatory

(Sen) - Virgin Galactic's suborbital space vehicle SpaceShipTwo had its first rocket-powered flight on April 29, going supersonic during its 16 second engine burn. The flight is an important step forward towards commercial operations.

The spaceline's founder, Sir Richard Branson, was on the ground at Mojave to witness the test flight. Branson said: “The first powered flight of Virgin Spaceship Enterprise was without any doubt, our single most important flight test to date. For the first time, we were able to prove the key components of the system, fully integrated and in flight. Today’s supersonic success opens the way for a rapid expansion of the spaceship’s powered flight envelope, with a very realistic goal of full space flight by the year’s end. We saw history in the making today and I couldn’t be more proud of everyone involved.”

Branson helped fuel speculation about the flight earlier in the day when he tweeted "Occasionally you have days that are ridiculously exciting. Today is such a day." The reason for his excitement soon became clear when he wrote on Twitter "Planning something truly momentous with @virgingalactic today - watch this space".

The flight launched from the Mojave Air and Space Port at 7.02 am local time. After reaching an altitude of 47,000 feet the mothership released SpaceShipTwo. The rocket was then ignited, with the main oxidizer valve opening and igniters firing the fuel case. The rocket burn lasted 16 seconds, as planned, sufficient to propel the spacecraft, called Enterprise, to supersonic speed, reaching Mach 1.2. Click here to watch a video of the rocket burn.

The rocket powered test flight time was just over 10 minutes, after which Enterprise landed on the runway at Mojave at about 8 am local time.

Virgin Galactic President and CEO George Whitesides, who was also present at Mojave, said: “The rocket motor ignition went as planned, with the expected burn duration, good engine performance and solid vehicle handling qualities throughout. The successful outcome of this test marks a pivotal point for our program. We will now embark on a handful of similar powered flight tests, and then make our first test flight to space.”

The flight was not a full test run to space, with SpaceShipTwo achieving a maximum altitude of 55,000 feet. SpaceShipTwo was piloted Dave Mackay, Clint Nicols and Brian Maisler.

The company is aiming for a full powered test flight to space before the end of 2013.

The test programme began back in 2008 with flights of the mothership named Eve after Branson's mother. SpaceShipTwo has also had a number of test 'glide' flights without its rocket motor fitted. A separate test program has also been running for the rocket motor.

The rocket engine was recently fitted to SpaceShipTwo and a "cold flow" test flight - everything except igniting the rocket - took place on April 12, 2013.

About 550 future passengers have signed up with Virgin Galactic. These space tourists, dubbed "future astronauts" by Virgin, have been eagerly awaiting powered test flights.

Virgin Galactic's suborbital vehicle consists of a mothership, known as WhiteKnightTwo, and a rocket ship called SpaceShipTwo. SpaceShipTwo, which will be operated by two professional pilots, has been designed to carry six passengers. The ride will begin with SpaceShipTwo attached to the mothership, which takes off from a runway like an aeroplane and carries the rocket ship to about 50,000 feet. SpaceShipTwo will then detach itself from its carrier and the rocket will be ignited, accelerating the vehicle to a speed of about 2,500 mph. Its destination will be an altitude of about 110 km (65 miles, 360,000 feet) thereby qualifying as a space flight in accordance with the rules of the Fédération Aéronautique Internationale, an international standards and record keeping organisation for aeronautics and astronautics. This 100 km boundary is known as the Kármán Line.

Gallery: Virgin Galactic SpaceShipTwo