Posted on by Fraser Cain

Young Star Gets Pushy

NGC 346 in the Small Magellenic Cloud. Image credit: Hubble. Click to enlarge.
This is a Hubble Space Telescope view of one of the most dynamic and intricately detailed star-forming regions in space, located 210,000 light-years away in the Small Magellanic Cloud (SMC), a satellite galaxy of our Milky Way. At the center of the region is a brilliant star cluster called NGC 346. A dramatic structure of arched, ragged filaments with a distinct ridge surrounds the cluster.

A torrent of radiation from the cluster’s hot stars eats into denser areas creating a fantasy sculpture of dust and gas. The dark, intricately beaded edge of the ridge, seen in silhouette by Hubble, is particularly dramatic. It contains several small dust globules that point back towards the central cluster, like windsocks caught in a gale.

Energetic outflows and radiation from hot young stars are eroding the dense outer portions of the star-forming region, formally known as N66, exposing new stellar nurseries. The diffuse fringes of the nebula prevent the energetic outflows from streaming directly away from the cluster, leaving instead a trail of filaments marking the swirling path of the outflows.

The NGC 346 cluster, at the center of this Hubble image, is resolved into at least three sub-clusters and collectively contains dozens of hot, blue, high-mass stars, more than half of the known high-mass stars in the entire SMC galaxy. A myriad of smaller, compact clusters is also visible throughout the region.

Some of these mini-clusters appear to be embedded in dust and nebulosity, and are sites of recent or ongoing star formation. Much of the starlight from these clusters is reddened by local dust concentrations that are the remnants of the original molecular cloud that collapsed to form N66.

An international team of astronomers, led by Dr. Antonella Nota of the Space Telescope Science Institute/European Space Agency in Baltimore, has been studying the Hubble data. In an upcoming issue of Astrophysical Journal Letters the team reports the discovery of a rich population of infant stars scattered around the young cluster NGC 346. These stars are likely to have formed 3 to 5 million years ago, together with the other stars in the NGC 346 cluster. These infant stars are particularly interesting as they have not yet contracted to the point where their interiors are hot enough to convert hydrogen to helium.

The Small and Large Magellanic Clouds are diffuse irregular galaxies visible to the naked eye in the southern hemisphere. They are two smallish satellite galaxies that orbit our own Milky Way Galaxy on a long slow journey inwards towards a future union with the Milky Way. Hubble has resolved many star formation regions in both of these neighboring galaxies that provide astronomers with laboratories other than our own Milky Way Galaxy to study how young stars interact with and shape their environments. The two satellites are named after the Portuguese seafarer Ferdinand Magellan (1480-1521) who sailed from Europe to Asia and is best known as the first person to lead an expedition to circumnavigate the globe.

This image of NGC 346 and its surrounding star formation region was taken with Hubble’s Advanced Camera for Surveys in July 2004. Two broadband filters that contribute starlight from visible and near-infrared wavelengths (shown in blue and green, respectively) have been combined with light from the nebulosity that has passed though a narrow-band hydrogen-alpha filter (shown in red).

Original Source: Hubble News Release

Posted on by Fraser Cain

Podcast: Larry Esposito and Venus Express

Venus is our nearest planetary neighbour. Compared to the Earth, it’s nearly identical in size and distance from the Sun. But that’s where the similarities end. While we enjoy our comfortable temperature, pressure and atmosphere, Venus’ environment is downright hostile to life. The European Space Agency’s Venus Express blasted off for our “evil twin” planet today, and will hope to help answer the question: what went wrong? My guest today is Larry Esposito from the Laboratory for Atmospheric and Space Physics at the University of Colorado. He’s a member of the Venus Express science team.
Continue reading “Podcast: Larry Esposito and Venus Express”

Posted on by Mark Mortimer

Book Review: Space Tourist’s Handbook

For these people, enamoured by flight and space travel, exciting new vacation retreats continually arise. There are converted aeroplanes that entice you with short tastes of weightlessness in parabolic flights. Fully bedecked astronaut wanna-be’s can experiment with neutral buoyancy while in swimming pools. Spinners rotate ever faster to experience the mind numbing pleasure of high g’s in a centrifuge. And speed demons can take flight in the fastest plane available. For those looking to the future, sub-orbital space flights are on the drawing boards of many companies. The richest elite can even experience the dream of a life time trip by taking a Soyuz taxi to the International Space Station. Certainly these wouldn’t be everyone’s idea of optimal leisure activities, but for some, they are just the needed escape from the boredom of cubicle land.

In this handbook, Anderson and Piven have a lot of fun guiding readers on how to satisfy their taste of space. In a style that’s part travel brochure, technical document and instructional manual, there’s information on space ports, flight vehicles and adaptation to off-world climates. The presentation is reminiscent of an advertising brochure for a cruise ship, even to the possibility of day trip adventures at various way points. Handy references include the Russian pronunciation for useful phrases like ‘What does this button do?’as well as items to bring with you in order to make your time most memorable. Within are even details on a chance to win a sub-orbital space flight, at least for a resident of the U.S. This contest is as real as the hadnbook’s contents, as Space Adventures has already shown their ability to deliver by orchestrating many tasty space vacations.

The book’s layout is also fairly typical for a vacation brochure or guidebook. The authors give travel tips on choices, travel prerequisites and expectations. There’s lots of neat ideas on basic destination necessities like eating, drinking, bathing and sleeping. For instance, the water is certainly safe to drink but your stomach might still get upset from the unfamiliar micro-gravity. As well, a fairly detailed description gives the low-down on that ever lasting query, how to go to the toilet while in zero gravity. Copious pages of protocol would help newbies resolve issues like; how to dine without letting food loose in the cabin, what to do when you accidentally float into another vacationer or the correct response when asked to play chess by a crew member. As any good brochure should do, it gives the reader a leg up on what to expect and hopefully avoid making too many faux pas.

Given the writing style and the travel brochure like presentation, there’s not overly much technical information. After all this is for a vacationer! Simple, light wording and humourous anecdotes keep the reader smiling. The drawings are bright and humourous such as how to appear sane during the psychological exam. Even more diagrams would have been useful as sometimes the descriptions got too wordy. More photographs and quotes would have lent further authenticity to the feel of the book. As well, there’s an overly large concentration of information regarding micro-gravity living in places like the International Space Station. Yet, very, very few readers will ever get the opportunity. However, with the quirky font and bright off-beat colours, this handbook is a far cry from any government sanctioned document on space flight and much more the travel brochure any vacationer would hope for.

Vacations are equal part dreams and reality. Imagining yourself at your destination may be all that keeps you going through the drudgeries of day-to-day work.. To keep your imagination alive try out Eric Anderson and Joshua Piven’s book, The Space Tourist’s Handbook. With this, your dreams can take you right off this world and perhaps with a bit of real hard work you may be fortunate enough to follow these dreams and put yourself in an out of this world experience.

Review by Mark Mortimer

Read more reviews online, or purchase a copy from Amazon.com.

Posted on by Fraser Cain

Liftoff for Venus Express

Venus Express atop a Soyuz rocket. Image credit: ESA. Click to enlarge.
The European spacecraft Venus Express has been successfully placed into a trajectory that will take it on its journey from Earth towards its destination of the planet Venus, which it will reach next April.

A virtual twin sister of the Mars Express spacecraft which has been orbiting the Red Planet since December 2003, Venus Express is the second planet-bound probe to be launched by the European Space Agency.

Venus Express will eventually manoeuvre itself into orbit around Venus in order to perform a detailed study of the structure, chemistry and dynamics of the planet’s atmosphere, which is characterised by extremely high temperatures, very high atmospheric pressure, a huge ‘greenhouse effect’ and as-yet inexplicable ‘super-rotation’ which means that it speeds around the planet in just four days.

The European spacecraft will also be the first orbiter to probe the planet’s surface while exploiting the ‘visibility windows’ recently discovered in the infrared waveband.

The 1240 kg mass spacecraft was developed for ESA by a European industrial team led by EADS Astrium with 25 main contractors spread across 14 countries. It lifted off on board a Soyuz- Fregat rocket, the launch service being provided by Starsem.

The lift-off from the Baikonur Cosmodrome in Kazahkstan this morning took place at 09:33 local time (04:33 Central European Time).

Initial Fregat upper-stage ignition took place nine minutes into the flight, manoeuvring the spacecraft into a low-earth parking orbit. A second firing, one hour and 22 minutes later, boosted the spacecraft to pursue its interplanetary trajectory.

Contact with Venus Express was established by ESA’s European Space Operations Centre (ESOC) at Darmstadt, Germany approximately two hours after lift-off. The spacecraft has correctly oriented itself in relation to the sun and has deployed its solar arrays.

All on-board systems are operating perfectly and the orbiter is communicating with the Earth via its low-gain antenna. In three days’ time, it will establish communications using its high-gain antenna.

Full speed ahead for Venus
Venus Express is currently distancing itself from Earth at full speed, heading on its five-month, 350 million kilometre journey inside our Solar System. After check-outs to ensure that its on-board equipment and instrument payload are in proper working order, the spacecraft will be ‘mothballed’, with contact with Earth being reduced to once daily. If needed, trajectory correction manoeuvres can go ahead at the half-way stage in January.

When making its closest approach, Venus Express will face far tougher conditions than those encountered by Mars Express on nearing the Red Planet. For while Venus’s size is indeed similar to that of Earth, its mass is 7.6 times that of Mars, with gravitational attraction to match.

To resist this greater gravitational pull, the spacecraft will have to ignite its main engine for 53 minutes in order to achieve 1.3 km/second deceleration and place itself into a highly elliptical orbit around the planet. Most of its 570 kg of propellant will be used for this manoeuvre.

A second engine firing will be necessary in order to reach final operational orbit: a polar elliptical orbit with 12-hour crossings. This will enable the probe to make approaches to within 250 km of the planet’s surface and withdraw to distances of up to 66 000 km, so as to carry out close-up observations and also get an overall perspective.

Exploring other planets to better understand planet Earth
“The launch of Venus Express is a further illustration of Europe’s determination to study the various bodies in our solar system,” stressed Professor David Southwood, the Director of ESA’s science programmes.

“We started in 2003 with the launch of Mars Express to the Red Planet and SMART-1 to the Moon and both these missions have amply exceeded our expectations. Venus Express marks a further step forward, with a view to eventually rounding off our initial overview of our immediate planetary neighbours with the BepiColombo mission to Mercury to be launched in 2013.”

“With Venus Express, we fully intend to demonstrate yet again that studying the planets is of vital importance for life here on Earth,” said Jean Jacques Dordain, ESA Director General.

“To understand climate change on Earth and all the contributing factors, we cannot make do with solely observing our own planet. We need to decipher the mechanics of the planetary atmosphere in general terms. With Mars Express, we are studying the Martian atmosphere. With Huygens, we have explored that of Saturn’s satellite Titan.

“And now with Venus Express, we are going to add a further specimen to our collection. Originally, Venus and the Earth must have been very similar planets. So we really do need to understand why and how they eventually diverged to the point that one became a cradle for life while the other developed into a hostile environment.”

The Venus Express mission is planned to last at least two Venusian days (486 Earth days) and may be extended, depending on the spacecraft’s operational state of health.

Twin sister of Mars Express
Venus Express largely re-uses the architecture developed for Mars Express. This has reduced manufacturing cycles and halved the mission cost, while still targeting the same scientific goals. Finally approved in late 2002, Venus Express was thereby developed fast, indeed in record time, to be ready for its 2005 launch window.

However, Venusian environmental conditions are very different to those encountered around Mars. Solar flux is four times higher and it has been necessary to adapt the spacecraft design to this hotter environment, notably by entirely redesigning the thermal insulation.

Whereas Mars Express sought to retain heat to enable its electronics to function properly, Venus Express will in contrast be aiming for maximum heat dissipation in order to stay cool.

The solar arrays on Venus Express have been completely redesigned. They are shorter and are interspersed with aluminium strips to help reject some solar flux to protect the spacecraft from temperatures topping 250ºC.

It has even been necessary to protect the rear of the solar arrays – which normally remain in shadow – in order to counter heat from solar radiation reflected by the planet’s atmosphere.

An atmosphere of mystery
Following on from the twenty or so American and Soviet missions to the planet carried out since 1962, Venus Express will endeavour to answer many of the questions raised by previous missions but so far left unanswered.

It will focus on the characteristics of the atmosphere, its circulation, structure and composition in relation to altitude, and its interactions with the planet’s surface and with the solar wind at altitude.

To perform these studies, it has seven instruments on board: three are flight-spare units of instruments already flown on Mars Express, two are from comet-chaser Rosetta and two were designed specifically for this mission.

The PFS high-resolution spectrometer will measure atmospheric temperature and composition at varying altitudes. It will also measure surface temperature and search for signs of current volcanic activity.

The SPICAV/SOIR infrared and ultraviolet spectrometer and the VeRa instrument will also probe the atmosphere, observing stellar occultation and detecting radio signals; the former will in particular seek to detect molecules of water, oxygen and sulphuric compounds thought to be present in the atmosphere.

The VIRTIS spectrometer will map the various layers of the atmosphere and conduct multi-wavelength cloud observation in order to provide images of atmospheric dynamics.

Assisted by a magnetometer, the ASPERA 4 instrument will analyse interaction between the upper atmosphere and the solar wind in the absence of magnetospheric protection such as that surrounding Earth (for Venus had no magnetic field). It will analyse the plasma generated by such interaction, while the magnetometer will study the magnetic field generated by the plasma.

The VMC camera will monitor the planet in four wavelengths, notably exploiting one of the ‘infrared windows’ revealed in 1990 by the Galileo spacecraft (when flying by Venus en route for Jupiter), making it possible to penetrate cloud cover through to the surface. The camera will also be used to monitor atmospheric dynamics, notably to observe the double atmospheric vortex at the poles, the origin of which still remains a mystery.

Original Source: ESO News Release

Posted on by Fraser Cain

Lichen Can Survive in Space

Rhizocarpon geographicum, species of lichen. Image credit: ESA. Click to enlarge.
One of the main focuses in the search for living organisms on other planets and the possibilities for transfer of life between planets currently centres on bacteria, due to the organisms simplicity and the possibility of it surviving an interplanetary journey exposed to the harsh space environment.

This focus may develop to encompass more advanced organisms following the results of an ESA experiment on the recent Foton-M2 mission where it was discovered that lichens are very adept at surviving in open space.

Lichens are not actually single organisms but an association of millions of algal cells, which cooperate in the process of photosynthesis and are held in a fungal mesh. The algal cells and the fungus have a symbiotic relationship, with the algal cells providing the fungus with food and the fungus providing the alga with a suitable living environment for growth. Lichens are well known extremophiles, being able to survive the harshest environments on Earth. The most striking element of the finding is the complexity of this organism: it is multicellular, it is macroscopic and it is a eukaryote, meaning that on the evolutionary scale it is a much more modern organism than bacteria. In fact lichens can be considered as very simple ecosystems.

The experiment which took place during the Foton mission was called ‘Lichens’ and was one of the exobiology experiments that was located in the ESA Biopan facility. This exposure facility was located on the outer shell of the Foton return module and, once at the correct orbital altitude, opened to exposure the samples inside to open space, i.e. exposed to vacuum, wide fluctuations of temperature, the complete spectrum of solar UV light and bombarded with cosmic radiation. During the Foton-M2 mission, which was launched into low-Earth orbit on 31 May 2005, the lichens, which came from two different species (Rhizocarpon geographicum and Xanthoria elegans) were exposed for a total 14.6 days before being returned to Earth. At the conclusion of the mission the lid of Biopan was closed to protect the lichens from the conditions of reentry. The Biopan was thereafter transported back to ESA ‘s research facility, ESTEC, in Noordwijk, the Netherlands to be opened.

The results of the experiment were presented by one of the experiment team members, Dr. Rosa de la Torre from the Spanish Aerospace Research Establishment (INTA) in Madrid, at a post-flight review in October at ESTEC. Initial conclusions of the experiment, which is under the scientific leadership of Prof. Leopoldo Sancho from the Complutense University of Madrid, indicate that lichens have the capacity to resist full exposure to the harsh space conditions, especially high levels of UV radiation. Analysis post flight showed a full rate of survival and an unchanged ability for photosynthesis.

This experiment opens up many possibilities for future research into the possibility of transfer of life between planets. Follow up experiments could focus on questions such as to what extent lichen, if transported by a meteorite, can survive the reentry conditions into Earth’s atmosphere, i.e. what degree of shielding would be needed for lichen samples to survive? The outcome of this Biopan experiment also suggests that lichens might survive at the surface of Mars. Follow-up experiments on ground and in space are bound to provide further answers to these intriguing astrobiological questions.

Original Source: ESO News Release

Posted on by Fraser Cain

Star on the Run

Artist illustration of a star ejected from the Large Magellanic Cloud. Image credit: ESO. Click to enlarge.
Observations with Kueyen, one of the 8.2m telescopes composing the ESO Very Large Telescope (VLT), have led to the discovery of a short-lived massive star that is moving at a very high speed through the outer halo of the Milky Way galaxy and into intergalactic space. This finding could provide evidence for a previously unknown massive black hole in the heart of the Milky Way’s closest neighbour, the Large Magellanic Cloud.

The star, named HE 0437-5439, was discovered by the Hamburg/ESO sky survey [1] , a project aimed at detecting quasars but which discovered many faint blue stars as well. Scientists [2] at the Dr. Remeis-Sternwarte (University of Erlangen-Nürnberg, Germany) and the Centre for Astrophysics Research (University of Hertfordshire, UK) found what is likely to be a hot massive main-sequence star, far out in the halo.

This came as a great surprise. Massive stars have lifetimes of only some tens or hundreds of million years, short lived for astronomical standards, but the halo does not usually host stars as young as this. In fact, it contains the oldest stars in the Milky Way that are more than ten billion years old. Massive stars are usually found in or near star forming regions in the Galactic disc such as the famous Orion nebula: HE 0437-5439 is indeed similar to the trapezium stars that make the Orion nebula shine.

Data were obtained with the ESO VLT and its high resolution UVES spectrograph. This allowed the chemical composition to be measured which turned out to be similar to that of the Sun, confirming that HE0437-5439 is a young star. Its mass is eight times larger than that of the Sun and the star is only 30 million years old. It is almost 200,000 light years away from us in the direction of the Doradus Constellation (“the Swordfish”).

Even more exciting was the fact that the data indicated the star to be receding at a velocity of 723 km/s, or 2.6 million kilometres per hour. HE0437-5439 moves so fast that the gravitational attraction of the Milky Way is too small to keep it bound to the Galaxy. Hence the hyper-velocity star will escape into intergalactic space.

As the star is moving so fast, it must have been born far away from its present position and accelerated to where we observe it today. What accelerated the star to such a high speed? Calculations carried out already in the late 1980s showed that a so-called massive black hole (SMBH), i.e. a black hole a million times as massive as the Sun, or larger, could provide the enormous acceleration. If a binary star approaches the SMBH, one star falls towards the SMBH while its companion is ejected. The Galactic Centre of the Milky Way hosts such a black hole of about 2.5 million solar masses, and this might have accelerated HE0437-5439.

But the necessary travel time was found to be more than three times the age of the star. Hence the star is too young to have travelled all the way from the Galactic centre to its present location. Either the star is older than it appears or it was born and accelerated elsewhere.

A different clue to the origin of HE0457-5439 comes from its position in the sky. HE0437-5439 is 16 degrees away from the Large Magellanic Cloud (LMC), one of the nearest neighbouring galaxies to the Milky Way. This galaxy lies at a distance of 156,000 light years. HE0457-5439 is even more distant than the LMC and is much closer to the LMC than to the galaxy. The astronomers showed that the star could have reached its present position within its lifetime if it were ejected from the centre of the LMC. This, in turn, would provide evidence for the existence of a SMBH in the LMC.

Another explanation would require the star to be the result of the merging of two stars, belonging to so-called blue stragglers class of stars, which are older than standard evolution models predict them to be. Indeed, its age could then be as much as the lifetime of a 4 solar mass star which is more than 6 times the lifetime of an 8 solar mass star.

The astronomers propose two additional observations to distinguish between the two options. The abundance of certain elements in stars belonging to the LMC is only half that of the Sun. A more precise measurement with UVES would indicate whether the star has a metal abundance appropriate to LMC stars or not. The second is to measure how much the star moves in the transverse direction on the sky, using astrometric measurements.

The research presented here is detailed in a paper to be published in Astrophysical Journal Letters.

Notes
[1]: The Hamburg/ESO sky survey is a collaborative project of the Hamburger Sternwarte and ESO to provide spectral information for half of the southern sky using photographic plates taken with the now retired ESO-Schmidt telescope. These plates were digitized at Hamburger Sternwarte.

[2]: The astronomers are Heinz Edelmann (Dr. Remeis-Sternwarte of the University of Erlangen-Nürnberg, Germany, now at University of Texas, Austin, USA), Ralf Napiwotzki (Centre for Astrophysics Research, University of Hertfordshire, UK), Uli Heber (Dr. Remeis-Sternwarte of the University of Erlangen-Nürnberg, Germany), Norbert Christlieb and Dieter Reimers (Hamburger Sternwarte, Germany).

Original Source: ESO News Release

Posted on by Fraser Cain

Dione Beneath the Rings

Dione underneath Saturn’s wispy F ring. Image credit: NASA/JPL/SSI. Click to enlarge.
Saturn’s moon Dione is about to swing around the edge of the thin F ring in this color view. More than one thin strand of the F ring’s tight spiral can be seen here.

The terrain seen on Dione is on the moon’s Saturn-facing hemisphere. The diameter of Dione is 1,126 kilometers (700 miles).

Images taken using infrared, green and ultraviolet spectral filters were composited to create this color view. The images were taken with the Cassini spacecraft narrow-angle camera on Sept. 20, 2005, at a distance of approximately 2 million kilometers (1.2 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 48 degrees. The image scale is 12 kilometers (7 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Original Source: NASA/JPL/SSI News Release

Posted on by Fraser Cain

Inmarsat-4 Blasts Off from Sea Launch

Zenit-3SL blasting off from the Odyssey Launch Platform. Image credit: Boeing. Click to enlarge.
Sea Launch Company today successfully delivered the Inmarsat-4 (I-4) communications satellite to geosynchronous transfer orbit (GTO). Early data indicate the spacecraft is in excellent condition.

A Zenit-3SL vehicle lifted off at 6:07 am PT (14:07 GMT), from the Odyssey Launch Platform, positioned at 154 degrees West Longitude. All systems performed nominally throughout the flight. The Block DM-SL upper stage inserted the 5,958 kg (13,108 lb.) satellite to geosynchronous transfer orbit, on its way to a final orbital position of 53 degrees West Longitude. A ground station at Lake Cowichan, in British Columbia, acquired the first signal from the satellite less than 25 minutes after spacecraft separation, as planned.

Inmarsat-4 is designed to provide high-speed mobile service to people throughout the Americas during its 13-year service life. It is one in a series of satellites designed to support the Broadband Global Area Network (BGAN) for high-speed delivery of Internet and intranet content and solutions, video-on-demand, videoconferencing, fax, e-mail, phone and LAN access. One of a family of three similar spacecraft, this Inmarsat-4 F2 satellite carries a single global beam that covers up to a third of the Earth’s surface, 19 wide spot beams and 228 narrow spot beams. It has a total end-of-life power of 13kW.

Following acquisition of the spacecraft’s signal, Jim Maser, president and general manager of Sea Launch, congratulated Inmarsat and EADS Astrium. “We have marked several milestones in this mission such as our first mission for Inmarsat and our first European-built spacecraft, and our successful mission is the most significant milestone of all! Our customer is satisfied that we have met all of their requirements,” Maser said. “Once again, we have done what we said we would do. We look forward to future missions with Inmarsat as well as with EADS Astrium. I want to thank every member of the Sea Launch team for making this mission success possible.”

Andrew Sukawaty, Chairman and Chief Executive of Inmarsat plc (LSE:ISAT), said, “We thank the team at Sea Launch for this innovative and highly professional launch. Years of preparation have come together. With the launch of our second I-4 satellite, we look forward to offering up to half megabit internet connection covering up to 90% of the Earth’s land mass – truly Broadband for a mobile planet.”

Sea Launch Company, LLC, headquartered in Long Beach, Calif., is the world’s most reliable heavy-lift commercial launch service. This international partnership offers the most direct and cost-effective route to geostationary orbit. With the advantage of a launch site on the Equator, the reliable Zenit-3SL rocket can lift a heavier spacecraft mass or provide longer life on orbit, offering best value plus schedule assurance. For additional information and images of this successfully completed mission, visit the Sea Launch website at: www.sea-launch.com

Original Source: Boeing News Release

Posted on by Fraser Cain

Expedition 12 Completes First Spacewalk

Expedition 12 Flight Engineer Valery Tokarev and Commander Bill McArthur. Image credit: NASA. Click to enlarge.
NASA astronaut Bill McArthur and Russian cosmonaut Valery Tokarev performed the first spacewalk of their six-month stay on the international space station. They installed a new camera and discarded an inactive science probe.

McArthur, the Expedition 12 commander, and Tokarev, the expedition flight engineer, began their spacewalk from the Quest Airlock at 10:32 a.m. EST. The spacewalk lasted five hours, 22 minutes. Their spacewalk was the first using U.S. space suits since April 2003.

It started about an hour later than planned, because the crew had to re-pressurize the Quest airlock to open a misaligned valve. The valve was in the interior portion of the two-chambered module. With the valve properly positioned, they again depressurized the outer chamber to begin their work outside.

Once out the door, the crew easily made up the time. They completed all primary tasks and some get-ahead jobs. They installed a television camera on the outboard end of the port truss segment. The camera will be an important aid during future assembly work when additional truss segments are added to the port side of the complex.

The crew retrieved the camera’s stand from an external tool platform attached to Quest, brought the equipment out to the port truss, installed the camera and hardware on its stand. The camera was powered and provided its first views from space just before 1 p.m. EST.

Next, flight controllers asked the crew to complete a get-ahead task by removing a failed electronics box called a Rotary Joint Motor Controller. The controller will be returned on the next space shuttle mission so engineers can determine why it failed. The analysis will be used to evaluate similar hardware shipped to the station.

The pair then moved hand over hand to the highest point of the station, the P6 truss. It’s approximately 50 feet above the U.S. Destiny Lab. McArthur removed an old experiment called the Floating Potential Probe from its stand and pushed it away from the station. It is expected to burn up in the Earth’s atmosphere in about 100 days.

The experiment was installed during an assembly mission in 2000 to characterize the electrical environment around the station’s solar arrays. Imagery from the last shuttle showed pieces of the experiment were missing or out of place. Since it was no longer used, it was removed and discarded.

The crew moved ahead with the final get-ahead task before calling it a day. They quickly removed a failed circuit breaker from the Mobile Transporter and installed a new one. Called a Remote Power Control Module, the breaker provides power for redundant heating on the transporter. The transporter is a type of space rail car that moves along the station’s truss structure.

With all tasks completed, McArthur and Tokarev entered the airlock and began re-pressurizing it at 3:54 p.m. EST. It was the 63rd spacewalk in support of station assembly and maintenance; the 35th staged from the station; and 18th staged from Quest. It was the third spacewalk for McArthur and the first for Tokarev.

Original Source: NASA News Release

Posted on by Fraser Cain

Ultraviolet Haze at Titan

Thin haze around Titan. Image credit: NASA/JPL/SSI. Click to enlarge.
Looking back toward the sun brings out the thin haze that hovers 500 kilometers (310 miles) above Saturn’s moon Titan.

The haze is composed of small particles whose diameter is comparable to the wavelength of light, which is ultraviolet light centered at 338 nanometers. Particles of this scale scatter sunlight most effectively in the direction opposite to the direction of sunlight. Scientists are still trying to understand what processes produce this thin, high-altitude haze layer.

North on Titan is up and tilted 10 degrees to the right. Titan is 5,150 kilometers (3,200 miles) across.

This image was taken with the Cassini spacecraft narrow-angle camera on Sept. 24, 2005, at a distance of approximately 917,000 kilometers (570,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 145 degrees. Image scale is 5 kilometers (3 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Original Source: NASA/JPL/SSI News Release