Stephen Hawking: 'Humankind Belongs in Space'

Technological advancements that took place over the past few decades have made the world a very dangerous place to live in. Nuclear missiles are just the tip of the iceberg when it comes to methods that humankind can employ to destroy itself. Global warming and chemical weapons are also high on the list, as are other natural factors. Famed physicist and scientist Stephen Hawking believes that the world needs to look at the stars for inspiration, and leave Earth before it's too late.

The famed expert believes that it's wrong for humankind to keep all of its eggs in a single basket, so to speak. “I believe that the long-term future of the human race must be in space. It will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load,” Hawking tells Big Think.

He also mentions the fact that the world's resources are currently being depleted at a massively-high rate, far beyond what can be replenished naturally or artificially. Greed and the quest for profits is making large corporations hinder innovation in fields of science investigation alternative energy sources, and this will soon manifest its effects on the planet. Hawking believes that we wouldn't want to be here when that happens. Plus, he adds, the Sun will only take a few billion years before it expands to envelop Earth, so we shouldn't be here at that time.

Speaking about situations such as the Cuban Missile Crisis, which almost saw the onset of global nuclear war between the US and the Soviet Union, Hawking says that “the frequency of such occasions is likely to increase in the future. We shall need great care and judgment to negotiate them all successfully.” Even if we are successful in doing so, the Sun will kill all life on Earth over a period of time. When it begins to swell, global warming will increase its effects, until all water is evaporated. Without the precious liquid, life as we know it will disappear.

“Life on Earth will have disappeared long before 7.6 billion years. Scientists have shown that the Sun's slow expansion will cause the temperature at the surface of the Earth to rise. Oceans will evaporate, and the atmosphere will become laden with water vapor, which (like carbon dioxide) is a very effective greenhouse gas. Eventually, the oceans will boil dry and the water vapor will escape into space. In a billion years from now the Earth will be a very hot, dry and uninhabitable ball,” says Dr. Robert Smith, an astrophysicist at the University of Sussex.

Largest Atlas Of Nuclear Galactic Rings Unveiled

An international team of astrophysicists has just unveiled the most complete atlas of nuclear rings, enormous star-forming ring-shaped regions that circle certain galactic nuclei. The catalogue, published in the Monthly Notices of the Royal Astronomical Society, includes 113 such rings in 107 galaxies.

"AINUR (the Atlas of Images of Nuclear Rings) is the most complete atlas of nuclear rings created to date", Sebastien Comeron, a researcher at the Institute of Astrophysics of the Canary Islands (IAC), and co-author of the joint study with other scientists from the universities of La Laguna, Oulu (Finland) and Alabama (United States), tells SINC.

The atlas has just been published in the journal Monthly Notices of the Royal Astronomical Society, and covers 113 nuclear rings in 107 different galaxies. Six are dust rings in elliptical galaxies, while the rest (the majority) are star-forming rings in disc galaxies.

The nuclear rings are ring-shaped, star-forming configurations located around galactic nuclei. They range in size on average from between 500 to 3,000 light years, and they are very bright because they contain an abundance of young stars, including some extremely massive ones. This kind of star has a short lifetime but shines very brightly before exploding as a supernova.

To find the rings, the astrophysicists used images from around 500 galaxies observed by the Hubble space telescope, which belongs to NASA and the European Space Agency, as well as using other references. The images were processed using filters, generating various kinds of maps to help identify the rings more easily.

Rings and Lindblad resonances
"The AINUR atlas has also looked for relationships between the properties of the nuclear rings and those of the galaxies in which they are found", says Comeron, "and we have been able to statistically prove that most rings are associated with Lindblad resonances (gravitational shoves that push objects out of certain orbits and into others)".

The astrophysicists have shown that when the rings are in a barred galaxy (within disc galaxies, which have a central cylinder or 'cigar' of stars), the maximum radius that a nuclear ring can attain is 25% of the length of the bar, and that the maximum radius is inversely proportional to the strength of the bar.

This is the behaviour that was predicted for the internal Lindblad resonances, which are determined by the size of the bar and their strength (how elliptical this is). If the bar is small or very elliptical, the resonance orbit becomes small, but if it is large or not very elliptical, the orbits become bigger.

The researchers also found that, contrary to what had been believed until now, a significant proportion of nuclear rings are to be found in non-barred galaxies (around 20%). The resonances needed to form the rings in these galaxies "are probably created by strong spiral arms, weak oval distortions of the disc and some lesser interaction with neighbouring galaxies", the scientists say.

Webb Telescope Passes Mission Design Review Milestone

NASA's Northrop Grumman-built James Webb Space Telescope has passed its most significant mission milestone to date, the Mission Critical Design Review, or MCDR. This signifies the integrated observatory will meet all science and engineering requirements for its mission.

"I'm delighted by this news and proud of the Webb program's great technical achievements," said Eric Smith, Webb telescope program scientist at NASA Headquarters in Washington.

"The independent team conducting the review confirmed the designs, hardware and test plans for Webb will deliver the fantastic capabilities always envisioned for NASA's next major space observatory. The scientific successor to Hubble is making great progress."

NASA's Goddard Space Flight Center, in Greenbelt, Md., manages the mission. Northrop Grumman, Redondo Beach, Calif., is leading the design and development effort.

"This program landmark is the capstone of seven years of intense, focused effort on the part of NASA, Northrop Grumman and our program team members," said David DiCarlo, sector vice president and general manager of Northrop Grumman Space Systems.

"We have always had high confidence that our observatory design would meet the goals of this pioneering science mission. This achievement testifies to that, as well as to our close working partnership with NASA."

The MCDR encompassed all previous design reviews including the Integrated Science Instrument Module review in March 2009; the Optical Telescope Element review completed in October 2009; and the Sunshield review completed in January 2010. The project schedule will undergo a review during the next few months.

The spacecraft design, which passed a preliminary review in 2009, will continue toward final approval next year.

The review also brought together multiple modeling and analysis tools. Because the observatory is too large for validation by actual testing, complex models of how it will behave during launch and in space environments are being integrated. The models are compared with prior test and review results from the observatory's components.

Although the MCDR approved the telescope design and gave the official go-ahead for manufacturing, hardware development on the mirror segments has been in progress for several years.

Eighteen primary mirror segments are in the process of cryo-polishing and testing at Ball Aerospace in Huntsville, Ala. Manufacturing on the backplane, the structure that supports the mirror segments, is well underway at Alliant Techsystems, or ATK, in Magna, Utah.

This month ITT Corp. in Rochester, N.Y., demonstrated robotic mirror installation equipment designed to position segments on the backplane. The segments' position will be fine-tuned to tolerances of a fraction of the width of a human hair. The telescope's sunshield moved into its fabrication and testing phase earlier this year.

The three major elements of Webb - the Integrated Science Instrument Module, Optical Telescope Element and the spacecraft itself - will proceed through hardware production, assembly and testing prior to delivery for observatory integration and testing scheduled to begin in 2012.

The Webb is the premier next-generation space observatory for exploring deep space phenomena from distant galaxies to nearby planets and stars.

The telescope will provide clues about the formation of the universe and the evolution of our own solar system, from the first light after the Big Bang to the formation of star systems capable of supporting life on planets like Earth. The telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

US military launches top-secret robotic spacecraft

A US Air Force unmanned spacecraft blasted off on Thursday from Florida, amid a veil of secrecy about its military mission.

The robotic space plane, or X-37B, lifted off from Cape Canaveral atop an Atlas V rocket at 7:52 pm local time (2352 GMT), according video released by the military.

"The launch is a go," Air Force Major Angie Blair told AFP.

Resembling a miniature space shuttle, the plane is 8.9 meters (29 feet) long and has a wing-span of 4.5 meters.

The reusable space vehicle has been years in the making and the military has offered only vague explanations as to its purpose or role in the American military's arsenal.

The vehicle is designed to "provide an 'on-orbit laboratory' test environment to prove new technology and components before those technologies are committed to operational satellite programs," the Air Force said in a recent release.

Officials said the X-37B would eventually return for a landing at Vandenberg Air Force Base in California, but did not say how long the inaugural mission would last.

"In all honesty, we don't know when it's coming back," Gary Payton, deputy undersecretary for Air Force space programs, told reporters in a conference call this week.

Payton said the plane could stay in space for up to nine months.

Flight controllers plan to monitor the vehicle's guidance, navigation and control systems, but the Air Force has declined to discuss what the plane is carrying in its payload or what experiments are scheduled.

Pentagon officials have sidestepped questions about possible military missions for the spacecraft, as well as the precise budget for its development -- estimated at hundreds of millions of dollars.

The results of the test flight will inform "development programs that will provide capabilities for our warfighters in the future," Payton said.

The space plane -- manufactured by Boeing -- began as a project of NASA in 1999, and was eventually handed over to the US Air Force Rapid Capabilities Office.

The Air Force has plans for a second X-37B, scheduled to launch in 2011.

Making the invisible visible: New workhorse for the world’s largest optical telescope

A snapshot of a stellar nursery in our home galaxy, the Milky Way: a high-mass star forming region inside the giant molecular cloud S255, about 8,000 light-years away from Earth (1 light-year is roughly 10 trillion kilometers). Such clouds are typically opaque to visible light. However, infrared light can penetrate the dust, so that the LUCIFER image reveals the cluster of newly born stars and its complex environment in all their splendour. Image: Arjan Bik

The Large Binocular Telescope (LBT) partners in Germany, the U.S.A. and Italy are pleased to announce that the first of two new innovative near-infrared cameras/spectrographs for the LBT is now available to astronomers for scientific observations at the telescope on Mt. Graham in south-eastern Arizona. After more than a decade of design, manufacturing and testing, the new instrument, dubbed LUCIFER 1, provides a powerful tool to gain spectacular insights into the universe, from the Milky Way up to extremely distant galaxies. LUCIFER 1 has been built by a consortium of German institutes and will be followed by an identical twin instrument that will be delivered to the telescope in early 2011.

LUCIFER’s innovative design allows astronomers to observe in unprecedented detail, for example, star forming regions which are commonly hidden by dust clouds. The instrument provides unrivaled flexibility, with features such as a unique robotic arm that can replace spectroscopic masks within the instrument’s extreme sub-zero environment.

LUCIFER and its twin are mounted at the focus points of the LBT’s two giant 8.4-metre (27.6 foot) diameter telescope mirrors. Each instrument is cooled to a chilly -213 degrees Celsius in order to observe in the near-infrared (NIR) wavelength range. Near-infrared observations are essential for understanding the formation of stars and planets in our galaxy as well as revealing the secrets of the most distant and very young galaxies.

LUCIFER is a remarkable new multi-purpose instrument with great flexibility combining a large field of view with a high resolution. It provides three exchangeable cameras for imaging and spectroscopy in different resolutions according to observational requirements. Besides its outstanding imaging capability which presently makes use of 18 high-quality filters, LUCIFER allows the simultaneous spectroscopy of about two dozen objects in the infrared through laser-cut slit-masks. For highest flexibility the masks can be changed even at the cryogenic temperatures, through the innovative development of a unique robotic mask grabber which places the individual masks with absolute precision into the focal plane.

"Together with the large light gathering power of the LBT, astronomers are now able to collect the spectral fingerprints of the faintest and most distant objects in the universe." says Richard Green, the Director of the LBT. "After completion of the LBT adaptive secondary mirror system to correct for atmospheric perturbation, LUCIFER will show its full capability by delivering images with a quality that are otherwise only obtained from space-based observatories."

"Already the very first LUCIFER observations of star forming regions are giving us an indication of the enormous potential of the new instrument," said Thomas Henning, the chair of the German LBT-Partners.

The instruments have been built by a consortium of five German institutes led by the Center for Astronomy of Heidelberg University (Landessternwarte Heidelberg, LSW) together with the Max Planck Institute for Astronomy in Heidelberg (MPIA), the Max Planck Institute for Extraterrestrial Physics in Garching (MPE), the Astronomical Institute of the Ruhr-University in Bochum (AIRUB) as well as the University of Applied Sciences in Mannheim (Hochschule Mannheim).

Walter Seifert (LSW), Nancy Ageorges (MPE) and Marcus Jütte (AIRUB), responsible for the successful commissioning, spent more than half a year in several runs at the LBT site to make the telescope/instrument combination work efficiently. Holger Mandel, the Principal Investigator of LUCIFER said: "From the very beginning, there was uniform excitement about the promise of this instrument for cutting-edge science. Now, the amazing results speak for themselves."

Source:- Max Planck Society

Discovery returns to Earth

HOUSTON, Texas (AFP) – Discovery made a safe return to Earth Tuesday after a two-week resupply mission to the International Space Station that broke new ground by putting four women in orbit for the first time.

The shuttle and its seven-member crew finally touched down at NASA's Kennedy Space Center in Florida at 9:08 am (1308 GMT) after a series of earlier delays due to rain and fog.

"Welcome home. Congratulations on an outstanding mission," Mission Control said after the Discovery put more women in orbit than ever before, with three female crew joining one woman already on the space station.

"What a great mission," replied Discovery commander Alan Poindexter. "We enjoyed it."

The mission also marked the first time that two Japanese astronauts were in space at the same time, with Discovery mission specialist Naoko Yamazaki joining Soichi Noguchi of the Japan Aerospace Exploration Agency.

And it signaled a growing awareness among NASA's ground team and astronauts that the vaunted shuttle program is winding down, marking the end of an era in human spaceflight.

"It's a little bit bittersweet, but we do have to recognize that like anything else, there does have to be an end to any major program," said Pete Nickolenko, NASA's launch director, during a post-landing news briefing.

"We recognize that we are facing that, that we are coming up to it," he said.

Meanwhile, Bryan Lunney, the NASA flight director who supervised Discovery's descent and will also oversee the final shuttle flight, said it is a bit too early to get misty-eyed.

"For me, we are heads down focused on the mission, trying to make sure it's safe and successful," he said.

"I haven't gotten too philosophical or concerned about the future. I'm just taking care of business," Lunney said.

Discovery dropped from orbit Tuesday over the Pacific Ocean and followed a rare course that took it over much of the US upper Midwest and Southeast, leaving a glowing contrail for ground observers.

The shuttle's crew delivered nearly eight tonnes of scientific equipment and other supplies intended to fortify the orbiting science laboratory for operations well beyond the final shuttle flight.

The new research gear includes an Earth observation rack to hold cameras and spectral scanners for studies of the atmosphere, geological formations, and weather-induced crop damage.

Another new experiment monitors changes in the muscle and joint health of the astronauts in the absence of gravity. A new freezer will store specimens for medical and biological experiments.

During three spacewalks, two of the astronauts wrestled with bulky bolts to replace a boxy coolant tank that is essential to the long-term function of the station's life support systems.

Discovery has only one more flight before it is mothballed, while NASA counts just three more missions until it retires its entire shuttle fleet and embarks on a new phase in human spaceflight.

The US space agency will have to turn to Russia to transport Americans to the orbiting science laboratory while it tries to foster a commercial space taxi industry.

President Barack Obama has drawn fire for shelving plans outlined by his predecessor George W. Bush -- which he argues are too costly -- for NASA to develop a new generation of spacecraft for missions to the moon and Mars.

Shuttle Atlantis will fly next, with a lift off tentatively scheduled for May 14.

During its 12-day mission, six astronauts will deliver a Russian mini-research module and external spare parts, including power storage batteries, a communications antenna and a radiator as well as Canadian and European robot arm components.

Endeavour is to follow, with a launch scheduled for July 29. Its cargo includes the Alpha Magnetic Spectrometer, an internationally-sponsored physics investigation for the study of cosmic radiation and anti-matter.

If the scheduling holds, Discovery will lift off for the station on September 16 for the final shuttle flight carrying yet more cargo and a pressurized storage module.

Space Telescope Moves on with One Detector

Mission engineers and scientists with NASA's Galaxy Evolution Explorer, a space telescope that has been beaming back pictures of galaxies for three times its design lifespan, are no longer planning science observations around one of its two ultraviolet detectors.

"The remaining, near-ultraviolet detector is still busy probing galaxies both nearby and distant," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena. "We've got lots of science data coming down from space."

The Galaxy Evolution Explorer rocketed into space from a jet aircraft in 2003. For four years of its primary mission, it mapped tens of millions of galaxies across the sky in ultraviolet light, some as far back as 10 billion years in cosmic time. Its extended mission began in 2008, allowing it to probe deeper into more parts of the sky, and pluck out more galaxies.

Last May, the spacecraft's far-ultraviolet detector experienced an over-current condition, or essentially "shorted out," via a process called electron field emission. This detector sees higher-energy ultraviolet light, and thus hotter and younger stars within galaxies, than the telescope's other, near-ultraviolet detector. (The far-ultraviolet detector sees light with wavelengths between 135 and 180 nanometers, while the near-ultraviolet detector sees wavelengths between 180 and 280 nanometers.)

The far-ultraviolet detector has contributed significantly to the Galaxy Evolution Explorer's quest to understand how galaxies, including those like our own spiral Milky Way galaxy, blossom into maturity. It specializes in studies of star formation in nearby and distant galaxies. Perhaps the most significant discovery in this area is the identification of a transitional phase of galaxies, the teenagers of the galactic world. Astronomers long knew of young galaxies churning out stars, in addition to older, or dead, galaxies. But they did not know for certain whether the young ones mature into the older ones until the Galaxy Evolution Explorer found the missing links - the transitional galaxies (see http://www.jpl.nasa.gov/news/features.cfm?feature=1524).

In addition, one of the far-ultraviolet detector's most stunning finds is the humungous comet-like tail behind a speeding star called Mira. (See picture and article at http://www.jpl.nasa.gov/news/news.cfm?release=2007-090).

While the discovery of Mira's tail required the now-offline detector, almost all of the mission's targets could be seen by both detectors. Astronomers used the detectors' observations at different wavelengths to get an idea of a star or galaxy's temperature, age and mass. Much of this research can now be done by comparing near-ultraviolet data from the Galaxy Evolution Explorer with catalogued visible-light data from other telescopes. In addition, the wealth of far-ultraviolet observations to date will continue to be mined for decades to come.

The California Institute of Technology in Pasadena leads the Galaxy Evolution Explorer mission and is responsible for science operations and data analysis. JPL manages the mission and assembled the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on this mission. Caltech manages JPL for NASA. ?

Graphics and additional information about the Galaxy Evolution Explorer are online at http://www.nasa.gov/galex and http://www.galex.caltech.edu.

Baby stars in the Rosette cloud

Infrared image of the Rosette molecular cloud. Herschel collects the infrared light given out by dust and this image is a three-colour composite made of wavelengths at 70 microns (blue), 160 microns (green) and 250 microns (red). It was made with observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE). The bright smudges are dusty cocoons containing massive protostars. The small spots near the centre of the image are lower mass protostars.

Credits: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

Herschel’s latest image reveals the formation of previously unseen large stars, each one up to ten times the mass of our Sun. These are the stars that will influence where and how the next generation of stars are formed. The image is a new release of ‘OSHI’, ESA’s Online Showcase of Herschel Images.

The Rosette Nebula resides some 5,000 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each colour represents a different temperature of dust, from –263ºC (only 10ºC above absolute zero) in the red emission to –233ºC in the blue.

The bright smudges are dusty cocoons hiding massive protostars. These will eventually become stars containing around ten times the mass of the Sun. The small spots near the centre and in the redder regions of the image are lower mass protostars, similar in mass to the Sun.

ESA’s Herschel space observatory collects the infrared light given out by dust. This image is a combination of three infrared wavelengths, colour-coded blue, green and red in the image, though in reality the wavelengths are invisible to our eyes. It was created using observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE).

Herschel is showing astronomers such young, massive protostars for the first time, as part of the ‘Herschel imaging survey of OB Young Stellar objects’. Known as HOBYS, the survey targets young OB class stars, which will become the hottest and brightest stars.

“High-mass star-forming regions are rare and further away than low-mass ones,” says Frédérique Motte, Laboratoire AIM Paris-Saclay, France. So astronomers have had to wait for a space telescope like Herschel to reveal them.

It is important to understand the formation of high-mass stars in our Galaxy because they feed so much light and other forms of energy into their parent cloud they can often trigger the formation of the next generation of stars.

When astronomers look at distant galaxies, the star-forming regions they see are the bright, massive ones. Thus, if they want to compare our Galaxy to distant ones they must first understand high-mass star-formation here.

“Herschel will look at many other high-mass star-forming regions, some of them building stars up to a hundred times the mass of the Sun,” says Dr Motte, who plans to present the first scientific results from HOBYS at ESA’s annual ESLAB symposium to be held in the Netherlands, 4–7 May.

Source: ESA

13 astronauts celebrate 2 big space anniversaries

The nose and forward cabin of the Space Shuttle Discovery is featured in this image photographed by a spacewalker during the mission's second spacewalk, in this image from NASA taken April 11, 2010.

CAPE CANAVERAL, Fla. – The astronauts aboard the orbiting shuttle-station complex celebrated two big anniversaries Monday as they geared up for the third and final spacewalk of their mission.

And the world was treated to the first recital of traditional Japanese music and poetry in space.

Monday marked the 49th anniversary of the first human spaceflight — by Soviet cosmonaut Yuri Gagarin on April 12, 1961 — and the 29th anniversary of the first shuttle launch.

In honor of Russia's Cosmonauts Day, Russian President Dmitry Medvedev called the residents of the International Space Station to wish them well. Three are Russian, two are American and one is Japanese.

"Space is something that unites all of us. It's a global issue," Medvedev told them.

He added: "Space is our highest priority, regardless of how hard the economic situation was in the country and will be, I'm sure."

Later in the morning, the two Japanese on board — the space station'sSoichi Noguchi and visiting shuttle astronaut Naoko Yamazaki — took a call from Japanese dignitaries and schoolchildren in Tokyo.

This is the first time two Japanese astronauts have flown together in space.

Yamazaki shared a haiku — or Japanese poem — she wrote after seeing Earth for the first time from space. Then, with Noguchi accompanying her on an electric keyboard, she performed a Japanese folk music springtime piece, "Sakura Sakura," which translates as "Cherry Blossom." Noguchi opened the piece with a few notes on a traditional wooden flute.

"This is probably the first time that you are going to hear the historic performance from space," Noguchi said.

The recital took place in Japan's big science lab, Kibo, or Hope.

Yamazaki will depart the space station Saturday, along with her six U.S. shuttle colleagues.

One more spacewalk still needs to be conducted to finish installing a new ammonia tank, on Tuesday. The astronauts will place a big cargo carrier back aboard Discovery on Thursday, after it's stuffed with old equipment and trash. Then on Friday, the shuttle will be inspected for any signs of micrometeorite damage.

This survey of the shuttle wings and nose usually is conducted after undocking. But Discovery's main antenna is broken, and there would be no way to transmit all the laser 3-D images to Mission Control for analysis.NASA added a day to the shuttle's visit so the inspection could be carried out at the station and the data could be sent using station resources.

Shuttle inspections became mandatory in space following the 2003 Columbia disaster.

Columbia lifted off on the first shuttle flight on April 12, 1981.

Source:- http://www.nasa.gov/mission_pages/shuttle/main/index.html

Particles That Form Auroras Finally Observed Directly

Image comment: Image of the auroral oval taken by the IMAGE spacecraft in ultraviolet
Image credits: IMAGE-FUV team / NASA

Researchers at the University College London (UCL), in the United Kingdom, recently managed to observe the energetic particles that form the brightest auroras. This is the first time such a feat was accomplished, and the team behind the research says that their accomplishment was made possible through the use of the Cluster spacecraft. Details of the discovery were presented today, April 12, at the RAS National Astronomy Meeting (NAM2010), in Glasgow, Scotland, AlphaGalileo reports.

The science team that made the observations was led by UCL expert Dr Colin Forsyth, who also presented the findings at the meeting. He explains that auroras are formed as charged particles from the Sun slam into the upper portions of our planet's atmosphere. As this happens, they lose energy, and heat the molecules that exist at high altitudes, making them glow in beautiful red, green and blue nuances. The particles then flow along the Earth's magnetic lines, which is why some of them have a curtain-like appearance. Generally, the auroras can only be seen at the north and south poles.

At a height of 50,000 kilometers (31,000 miles) above the planet, some peculiar processes take place. Particles are accelerated considerably, before they have sufficient energy to excite the auroras. These phenomena are not well understood, and researchers know that they are key to understanding the atmospheric lights themselves. In order to gain more insight into these phenomena, the UCL team used the four identical satellites of the Cluster mission, which is a collaboration of NASA and the European Space Agency (ESA). The constellation was launched 10 years ago, and it orbits the planet in close formation, with one spacecraft trailing closely after the other.

One of Cluster's outstanding features is that is allows experts to create a 3D picture of the magnetosphere, the atmosphere's protective layer, that shields us from cosmic radiation and most solar flares. This is only possible through the multi-point perspective that the four satellites provide. “The Cluster spacecraft have been maneuvered such that one of them was at a higher altitude than the others when they passed over the auroral regions. We were then able to simultaneously measure the particle energies at different heights and thus their acceleration. These exciting new results will give us new insight into the accelerating processes and the transfer of energy from the magnetosphere into the atmosphere,” the team leader said at the meeting.

Discovery astronauts complete second spacewalk

In this image provided by NASA-TV astronauts Rick Mastracchio, left, and Clay Anderson work on the International Space Station early Sunday morning April 11, 2010. Mastracchio and Anderson earlier had trouble bolting down the new ammonia tank assebly on the sprawling framework that serves as the backbone of the space station. The 215-mile-high action unfolded on the 40th anniversary of the launch of Apollo 13. (AP Photo/NASA)

Expedition 23 crew members share a meal at the galley in the Zvezda Service Module of the International Space Station. Pictured from the left are Russian cosmonauts Oleg Kotov, commander; Mikhail Kornienko, flight engineer, and Alexander Skvortsov, Soyuz commander and flight engineer. Image Credit: NASA

Two astronauts from the US shuttle Discovery completed Sunday a second spacewalk as part of efforts to replace a depleted ammonia coolant tank outside the International Space Station.

Mission specialists Rick Mastracchio and Clay Anderson finished their seven-hour, 26-minute walk in open space at 8:56 am EDT (1256 GMT), after installing a new ammonia tank on a space station truss, NASA officials said.

Due to a "troublesome bolt," NASA said the walkers ran out of time and were unable to complete all their scheduled work, including retrieving two micrometeoroid debris shields that were to return to Earth.

The spacewalk -- on the 40th anniversary of the launch of Apollo 13, the famously aborted 1970 mission to the moon -- was the second of the three scheduled walks for this mission, and was the 142nd in service of the orbiting outpost's construction.

During the first spacewalk on Friday, Anderson and Mastracchio retrieved an experiment from the Japanese Kibo Laboratory on the station's porch and replaced a Rate Gyro Assembly, part of the station's navigation system.

The final spacewalk of the mission is scheduled for Tuesday.

The Discovery, which blasted off from Kennedy Space Center at Cape Canaveral, Florida on Monday, docked on Thursday with the International Space Station.

Eight tonnes of supplies, gear and racks of science experiments were transferred from the shuttle to the space station in an Italian-made module known as Leonardo.

Besides the replacement ammonia tank, the gear included a freezer to preserve samples of blood, urine, saliva, plants or microbes used in micro-gravity experiments for later analysis back on Earth.

Meanwhile, the US National Aeronautics and Space Administration announced Saturday that Discovery's mission had been extended by an extra 24 hours for routine heat shield inspections.

Landing was now scheduled for Monday, April 19, at 1254 GMT (8:54 am local time) to cap what will be a 14-day mission.

"Since Discovery's Ku-Band communications system is not functioning correctly, the space station's Ku system will transmit the heat shield video and laser scan to Mission Control for imagery experts to analyze," NASA said in a statement.

Discovery's Ku-Band system has been down since the shuttle reached orbit April 5.

Normally the shield inspection is done before reentry but after undocking from the ISS. It is aimed at making sure heat shields have not been damaged by space debris or small meteorites.

The shuttle's heat shield is subjected to temperatures as high as 1,500 degrees Celsius (2,732 Fahrenheit) due to friction on reentry.

Up close and phenomenal – the Hubble telescope at 20

This image of object NGC 6302, known as the Butterfly Nebula, was taken recently by the Hubble space telescope. Photograph: AP

The brilliant tracers pouring from the centre of this image may have a dainty, colourful appearance. Their origins are anything but peaceful, however. These are rolling cauldrons of gas, heated to more than 20,000C, and they are pouring from a dying star five times bigger than our own Sun. The star – which lies within our own galaxy, the Milky Way – has blasted off its outer envelope of gases and is now unleashing a stream of ultraviolet radiation that is causing those gases to glow.

This is astronomical object NGC 6302, although it is better known, simply, as the Butterfly Nebula. Its image was captured recently by the Hubble space telescope, which was launched by the space shuttle 20 years ago, on 24 April 1980.

Although hampered by a lens that had been ground to the wrong shape, the telescope – named after US astronomer Edwin Hubble (1889–1953) – has proved to be one of the most spectacularly successful spacecraft ever built by Nasa. It was repaired in 1993 and thanks to a further four service missions the Hubble has gone on to generate thousands of images of the heavens, ranging from pictures of the universe's remotest galaxies to photographs of planets inside the solar system. These are the mostly widely used and most popular images produced by any space agency.

When Nasa announced it would no longer service the Hubble following the destruction of the shuttle Columbia in 2003, there was a public outcry in the United States. Nasa was forced to reinstate the mission which took place in May 2009 and which is expected to keep the Hubble operational until 2014 when it will replaced by another orbiting telescope, the James Webb.

By that time, the Hubble – which orbits 350 miles above the Earth – will have produced breathtaking photographs of space for almost a quarter of a century, captivating the public while also playing a crucial role in providing astronomers with precise measurements of the heavens.

Indeed, its studies of galaxies billions of light years away have generated a wealth of scientific papers and provided a new window on the early universe as well as a fresh understanding of its age and rate of expansion. We now know the universe is 13.75 billion years old while the Hubble has also revealed that its expansion, far from slowing down as had been expected, is in fact accelerating due to the influence of a mysterious force known simply as dark energy.

It is intriguing stuff. Nevertheless, it will be for its collection of breathtaking photographs, such as this image of the Butterfly Nebula, that will be the telescope's enduring legacy.

Source:- Guardian.co.uk

Is densest Kuiper belt object a wayward asteroid?

Quaoar, a large object in the outer solar system, is mostly made of rock, unlike its icy neighbours (Illustration: NASA/G. Bacon/STScI)

A giant rock is walking among the "dirty iceballs" in the outer solar system, a new study suggests. Researchers say it may have journeyed there from the asteroid belt near Mars, or it may have been the victim of a cosmic crash that blasted away its once-icy exterior.

Quaoar was discovered in 2002 in the Kuiper belt, a ring of icy bodies beyond Neptune. At about 900 kilometres across, or 40 per cent as wide as Pluto, it is not the biggest denizen of the belt, but researchers now say it may be the densest.

Wesley Fraser and Michael Brown of Caltech confirmed its size by studying archival images from the Hubble Space Telescope. They also used Hubble images to study the motion of its moon, Weywot, which allowed them to calculate Quaoar's mass.

Combining the size and mass revealed Quaoar's density to be between 2.9 and 5.5 grams per cubic centimetre. That is much higher than that of other Kuiper belt residents like Pluto, which has a density of about 2.0 grams per cubic centimetre.

Quaoar's high density suggests it is made almost entirely of rock, unlike its neighbours, which are a mixture of ice and rock, the researchers conclude. They say the rocky world may be a refugee from the asteroid belt between Mars and Jupiter, thrown outwards early in the solar system's history, when the orbits of the giant planets are thought to have shifted.

'Far-fetched' scenario

Previously, other researchers have suggested that the same upheaval threw some Kuiper belt objects into the asteroid belt, so the new study suggests the migration may have been a two-way street.

But Renu Malhotra of the University of Arizona in Tucson says that hurling Quaoar from the asteroid belt to the Kuiper belt would have left it with an elongated orbit, making it hard to explain why Quaoar is on a nearly circular orbit today.

"I think that's pretty far-fetched," she says.

She favours the other possible explanation that Fraser and Brown suggest – that a collision with another Kuiper belt object blasted off most of Quaoar's ice, leaving behind only its dense, rocky core.

"That kind of thing seems a lot more possible to me," she says, noting that there were probably far more objects in the early Kuiper belt than there are today, making collisions more common in the past.

Journal reference: Astrophysical Journal Letters (in press)

Source:- NewScientist.com

Happy 50th Birthday SETI

SETI's Allen Telescope Array via SETI Institute

Fifty years ago today, on April 8th, 1960, a Cornell astronomy professor named Frank Drake pointed a radio telescope at the star Tau Ceti in the hope of hearing broadcasts from extraterrestrial intelligence. Naturally, he didn't hear anything out of the ordinary. But with this experiment, Drake began the decades-long search for aliens, known as the Search for Extraterrestrial Intelligence (SETI), that celebrates its 50th anniversary today. Over the last half century, SETI has failed at its initial goal of contacting aliens, but succeeded mightily in bringing new attention to astronomy, helping to develop cloud computing, and inspiring generations of new scientists.

In the 1960s, SETI drew considerable interest from NASA, the National Science Foundation, and the famous astronomer Carl Sagan, but 1977 marked the high point for SETI. In that year, Drake and Sagan successfully lobbied NASA to equip the the Voyager Probe with a golden disc inscribed with information about Earth on one side, and recordings of pop, classical, and traditional music on the other. Ideally, when Voyager left our solar system, it would be found by aliens who would decode the disc, learning about our planet's life. It remains the only physical SETI message every sent out into deep space.

Also in 1977, the SETI-operated Big Ear radio telescope received the historic "Wow!" signal, a 72-second-long burst of powerful radio waves. At the time, the scientists interpreted the Wow signal as the only burst ever detected that might have actually originated in an extraterrestrial civilization. Subsequent searches failed to find a repeat of the signal, and in the years since scientists have produced a number of more likely explanations for the signal's source. However, the Wow signal is still the closest SETI ever got to receiving a message from ET.

While SETI obviously failed at finding actual alien intelligence, it continues to inspire to this day. SETI At Home, a screen saver that helped scientists parse through huge amounts of data, set the stage for programs used today by Berkley's biology lab and the Large Hadron Collider. And closer to SETI's original mission, the development of telescope technology advanced enough to detect exoplanets has revitalized the search for ET's in recent years by locating Earth-like planets circling distant stars.

So happy 50th, SETI! Here's to another 50 years as productive as the last, and maybe even finding some little green men in your next half century of groundbreaking research.

Workshop Highlights Advantages of Orbital Refueling

Image comment: The Canadarm2 (seen here with its Dextre maintenance robot attached) could be used for orbital refueling
Image credits: NASA

Though many people might not know this, we currently have the technology to perform in-orbit repairs on satellites, and also to refuel them as they go. The best example of this is the Hubble Space Telescope, one of the more renowned satellites in the world, which has thus far received five servicing missions, all of them conducted by NASA space shuttles. Being able to use platforms such as the International Space Station (ISS) for refueling could boost our orbital capabilities, but senior officials and government representatives need to acknowledge that this is possible, Space reports.

This is the conclusion of a new workshop that was held at the University of Maryland University College in Adelphi, between March 24-26. The event, which was sponsored by the NASA Goddard Space Flight center (GSFC), united numerous space and aeronautics experts in the same room. It also allowed the specialists to devise potential plans for seeing orbital refueling becoming a reality relatively soon. “It's pretty clear. The time for study is over. We have now got to move forward,” the GSFC Space Service Capabilities Office Deputy Associate Director, Frank Cepollina, says.

What NASA plans to do is essentially demonstrate that refueling processes can be conducted in orbit autonomously, without too much human intervention. For example, at the workshop, many said that satellites might benefit from the aid of the Canadarm2, one of the robotic arms aboard the orbital facility that was constructed by the Canadian Space Agency (CSA). Experts say that existing spacecraft may benefit from the refueling system as well, and not only those built specifically for this purpose. At this point, the feasibility and potential costs of in-orbit satellite servicing are being assessed in a new scientific study, whose results will be presented to the Congress in September.

“We are trying to develop the dexterity of robots to fix spacecraft so they can continue to do their jobs. You would never buy a car that was not repairable, why should we buy a satellite that's not?” Cepollina, who has been the lead engineer for the repair missions destined for Hubble, adds. The challenge is to include spacecraft that revolve around the planet in geosynchronous orbits in the new plan. These machines travel some 14,000 kilometers above the surface of the planet, whereas the ISS orbits at much lower altitudes.

Quasars don't show Time Dilation

This X-ray image shows the quasar PKS 1127-145, a highly luminous source of X-rays and visible light located about 10 billion light years from Earth. Its X-ray jet extends at least a million light years from the quasar. Credit: NASA.

The phenomenon of time dilation is a strange yet experimentally confirmed effect of relativity theory. One of its implications is that events occurring in distant parts of the universe should appear to occur more slowly than events located closer to us. For example, when observing supernovae, scientists have found that distant explosions seem to fade more slowly than the quickly-fading nearby supernovae.

The effect can be explained because (1) the speed of light is a constant (independent of how fast a light source is moving toward or away from an observer) and (2) the universe is expanding at an accelerating rate, which causes light from distant objects to redshift (i.e. the wavelengths to become longer) in relation to how far away the objects are from observers on Earth. In other words, as space expands, the interval between light pulses also lengthens. Since expansion occurs throughout the universe, it seems that time dilation should be a property of the universe that holds true everywhere, regardless of the specific object or event being observed. However, a new study has found that this doesn’t seem to be the case - quasars, it seems, give off light pulses at the same rate no matter their distance from the Earth, without a hint of time dilation.

Astronomer Mike Hawkins from the Royal Observatory in Edinburgh came to this conclusion after looking at nearly 900 quasars over periods of up to 28 years. When comparing the light patterns of quasars located about 6 billion light years from us and those located 10 billion light years away, he was surprised to find that the light signatures of the two samples were exactly the same. If these quasars were like the previously observed supernovae, an observer would expect to see longer, “stretched” timescales for the distant, “stretched” high-redshift quasars. But even though the distant quasars were more strongly redshifted than the closer quasars, there was no difference in the time it took the light to reach Earth.

This quasar conundrum doesn’t seem to have an obvious explanation, although Hawkins has a few ideas. For some background, quasars are extreme objects in many ways: they are the most luminous and energetic objects known in the universe, and also one of the most distant (and thus, oldest) known objects. Officially called “quasi-stellar radio sources,” quasars are dense regions surrounding the central supermassive black holes in the centers of massive galaxies. They feed off an accretion disc that surrounds each black hole, which powers the quasars’ extreme luminosity and makes them visible to Earth.

One of Hawkins’ possible explanations for quasars’ lack of time dilation is that light from the quasars is being bent by black holes scattered throughout the universe. These black holes, which may have formed shortly after the big bang, would have a gravitational distortion that affects the time dilation of distant quasars. However, this idea of “gravitational microlensing” is a controversial suggestion, as it requires that there be enough black holes to account for all of the universe’s dark matter. As Hawkins explains, most physicists predict that dark matter consists of undiscovered subatomic particles rather than primordial black holes.

There’s also a possibility that the explanation could be even more far-reaching, such as that the universe is not expanding and that the big bang theory is wrong. Or, quasars may not be located at the distances indicated by their redshifts, although this suggestion has previously been discredited. Although these explanations are controversial, Hawkins plans to continue investigating the quasar mystery, and maybe solve a few other problems along the way.

Source:- Physorg.com | On time dilation in quasar light curves, M. R. S. Hawkins, DOI:10.1111/j.1365-2966.2010.16581.x

Poor Pluto: Number of dwarf planets increases

In space, objects tend to conform to one of five shapes: (clockwise from left) spheres, dust, potatoes, halos and disks. Image: Lineweaver, Norman and Chopra

New research from the Australian National University has further reduced the status of Pluto by suggesting there are many more dwarf planets in the Solar System than previously thought.

ANU astronomers have just published results that would reclassify what it is to be a dwarf planet, increasing the number of Pluto’s fellow travellers by a factor of ten.

The International Astronomical Union classifies objects in the Solar System into three groups: planets, dwarf planets, and small solar system bodies. In 2006, Pluto was demoted from planet to dwarf planet, leaving eight planets, five dwarf planets and thousands of small solar system bodies orbiting the Sun.

Dr Charley Lineweaver and Dr Marc Norman from the ANU Planetary Science Institute looked at how spherical the icy moons in our solar system are, and recalculated the size of objects at the boundary between dwarf planets and small solar system bodies. Previous estimates have classified icy objects with radii larger than 400km as dwarf planets. The new research suggests that this radius should be closer to 200 km, which would increase the number of objects classified as dwarf planets to roughly 50.

The boundary between dwarf planets and small solar system bodies is based on whether the object is round or not.

"Small solar system objects are irregularly shaped, like potatoes,” Dr Lineweaver said. “If an object is large enough that its self-gravity has made it round, then it should be classified as a dwarf planet. We calculated how big rocky objects (like asteroids) have to be, and how big icy objects (like the moons of the outer planets and objects further out than Neptune) have to be, for their self-gravity to make them round. For icy objects we found a ‘potato radius’ of roughly 200km – about half as large as the roughly 400km radius now used to classify dwarf planets.

“The boundary between dwarf planets and small solar system bodies is somewhat arbitrary, but is based on the concept of hydrostatic equilibrium, or how round an object is. Whether the self-gravity of an object is strong enough to make the object round depends on the strength of its material. That is why strong rocky objects need to have a radius of roughly 300km before they turn from lumpy, potato-shaped bodies into spheres, while weaker icy objects can be spheres with a radius of only roughly 200km.”

Source:- here.

Venus is alive – geologically speaking

This figure shows the volcanic peak Idunn Mons (at 46°S, 214.5°E) in the Imdr Regio area of Venus. The topography derives from data obtained by NASA’s Magellan spacecraft, with a vertical exageration of 30 times. Radar data (in brown) from Magellan has been draped on top of the topographic data. Bright areas are rough or have steep slopes. Dark areas are smooth.

The coloured overlay shows the heat patterns derived from surface brightness data collected by the visible and infrared thermal imaging spectrometer (VIRTIS) aboard ESA’s Venus Express spacecraft. Temperature variations due to topography were removed. The brightness signals the composition of the minerals that have been changed due to lava flow. Red-orange is the warmest area and purple is the coolest. The warmest area is situated on the summit, which stands about 2.5 km above the plains, and on the bright flows that originate there. Idunn Mons has a diameter of about 200 km.

The VIRTIS data was collected from May 2006 to the end of 2007.

Credits: ESA/NASA/JPL

ESA's Venus Express has returned the clearest indication yet that Venus is still geologically active. Relatively young lava flows have been identified by the way they emit infrared radiation. The finding suggests the planet remains capable of volcanic eruptions.

It has long been recognised that there are simply not enough craters on Venus. Something is wiping the planet's surface clean. That something is thought to be volcanic activity but the question is whether it happens quickly or slowly? Is there some sort of cataclysmic volcanic activity that resurfaces the entire planet with lava, or a gradual sequence of smaller volcanic eruptions? New results suggest the latter.

"Now we have strong evidence right at the surface for recent eruptions," says Sue Smrekar, a scientist at NASA's Jet Propulsion Laboratory in California.

That strong evidence comes in the form of compositional differences compared to the surrounding landscape in three volcanic regions. The data were collected by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on ESA's Venus Express spacecraft, which has been orbiting the planet since April 2006.

VIRTIS records the brightness of surface rocks, providing an estimate of 'emissivity'. In 2008, Jörn Helbert and Nils Müller, Institute of Planetary Research, German Aerospace Center, Berlin and co-authors on this new work, published a map of the variation of infrared emissivity across the southern hemisphere of Venus.

Dr Smrekar and her colleagues targeted three regions that geologically resemble Hawaii, well known for its active volcanism. They show that the regions on Venus have higher emissivities than their surroundings, indicating different compositions.

On Earth, lava flows react rapidly with oxygen and other elements in the atmosphere, changing their composition. On Venus, the process should be similar, though more intense because of the hotter, denser atmosphere, chiefly of carbon dioxide.

The researchers interpret the fact that the lava flows appear to have different compositions from their surroundings as being evidence of a lack of surface weathering, indicating that the flows erupted relatively recently. They estimate that the flows are possibly as geologically recent as 2 500 000 years - and likely much less, possibly even currently active. "This is a significant result," says Hľkan Svedhem, ESA Venus Express Project Scientist.

Whilst the gradual resurfacing scenario might not be the most spectacular, it does make Venus look a little more Earth-like.

"There are some intriguing models of how Venus could have completely covered itself in kilometres of volcanic lava in a short time, but they require that the interior of Venus behaves very differently from Earth. If volcanism is more gradual, this implies that the interior may behave more like Earth, though without plate tectonics," says Dr Smrekar.

Source:- http://www.esa.int/esaCP/SEMUKVZNK7G_index_0.html

Shooting for Shooting Stars

2001 Leonid fireball recorded from Hawaii. Credit: NASA

You know them as "shooting stars," or meteors. Space scientists know them as the fiery end of tiny visitors from space. Those momentary streaks of light across the night sky are nothing more than small to almost-microscopic pieces of space debris whose trip through the void has ended in a kamikaze run into Earth's atmosphere. Of course, with 100 tons of space rock and rubble bombarding the planet each and every day, you'd think you could stick your head out the window any night of the week and easily catch a glimpse of a space rock's final moments.

"It doesn't really work that way," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Sure, there are a lot of space rocks entering our atmosphere each day, but take into account that only half of the world is in darkness at any one time and two-thirds of that is over water where almost nobody lives. Then, factor in that the weather and city-lighting conditions where most people live are less than conducive for meteor viewing, and few people are even looking up at the appropriate moment. When you put it all together, it's almost notable that anybody notices these meteors at all."

Which begs the question -- if spotting shooting stars is so tough, what is a person with both good visual acuity and a passion for celestial light displays to do?

"Meteor showers are definitely the way to go," said Yeomans. "We know pretty much when they are going to occur and where to look in the night sky."

A meteor shower is the entertaining end game of a comet's passage into the inner solar system. Each time one of these big blobs of ice and dust ventures into the relatively toasty confines of the inner solar system (called a perihelion passage), the sun's rays cook off part of its frozen surface, releasing particles of dust. Each swing through the inner solar system by a comet can leave trillions of small particles in its wake. If Earth's orbit intersects with this trail of debris, the result is a meteor shower.

"The comet trails that result in meteor showers can be from comet flybys that occurred hundreds of years ago," said Yeomans. "Remarkably, we can pin down the cosmic perpetrators. For example, we know from the similarity of their orbits that the Geminid showers that occur each December result from the debris of a dead comet called 3200 Phaethon. "

Along with the source of the Geminids, astronomers know that comet C/1861 G1 Thatcher supplied the particles for April's Lyrids; famous comet Halley is responsible for both May's Eta Aquarids and October's Orionids; 55P/Tempel-Tuttle funded November's Leonids; and 109P/Swift-Tuttle is the origin of the most celebrated shower of them all – August's Perseids.

By now, you may have noticed that the names of all the showers listed are associated with that of a constellation. Meteor shower particles travel through space at the same relative velocity and in parallel paths. When they are sucked in by Earth's gravity and light up in our atmosphere, a viewer on the ground would note they appear to radiate from a single point in the sky. A shower's name is usually associated with the nearest constellation in the sky to that single point at the time of shower maximum.

"Usually, the first couple of nights of a meteor shower have light activity," said Yeomans. "Then, the number of meteors can increase dramatically as Earth approaches the densest portion of the stream. After peaking for anywhere from a few hours to a few nights, it decreases back down to a level where you couldn't distinguish it from a normal night's meteor activity.

"The end of the line for a particle from space can be a great opportunity for scientists to study the nature of comets," said Yeomans. "But it is more than that. It is a great reminder that what we live on is essentially a big spacecraft traveling through the solar system and interacting with many of its parts. And as free entertainment, you can't beat it."

Indian space mission advances with satellite plan

Scientists check data at the Indian Space Research Organisation (ISRO) center in Bangalore in 2008. India plans to put a satellite into orbit using its indigenously built cryogenic rocket engine, marking another step in the nation's ambitious space programme, officials said.

BANGALORE, India (AFP) – India plans to put a satellite into orbit using its indigenously built cryogenic rocket engine, marking another step in the nation's ambitious space programme, officials said.

Cryogenic rocket motors, which use supercooled liquid fuel, have been built by only six countries or regions in the world, with India joining this club in October 2006, according to Indian space researchers.

The engine will now be used to put a communications satellite into orbit with a launch scheduled for April 15, Indian Space Research Organisation (ISRO) chairman K. Radhakrishnan told reporters here on Wednesday.

The launch will take place at India's space centre at Sriharikota on the coast of the eastern state of Andhra Pradesh, he said.

India began its space programme in 1963 and has developed its own satellites and launch vehicles to cut dependence on other countries.

Government funding of around 2.8 billion dollars has been secured for an attempt on its first manned space mission in 2016.

In September, India's Chandrayaan-1 satellite discovered water on the moon, boosting its credibility among established space-faring nations.