Space Thread

[Grabthaw the Hammerslayer 4]

Well Jez, knowing some of the members here as I do, I think any person that admits to believing in, or witnessing UFO's, would get ripped to shreds. I do, and I have.

And are the clips something other than space rocks? Dunno. I've seen plenty of clips like that on the Beeb website, and I find it odd that there's no debris found afterwards - but maybe they didn't look hard enough. Also, seems to be fairly bad quality film, so it could be that most of the brightness is glare rather than the light reflected from ET's house whatever it is.

Well Meds...

They are Unidentified, they are Flying and they are Objects, so technically I guess they are UFOs.....

Whilst they may look a little extreme, they do look like meteorites. Yes, I think you are right, there is a lot of glare on the video (bear in mind that cameras struggle to show bright objects in low-light conditions and glare is natural). As far as finding debris is concerned, it is notoriously difficult to find meteorites, even where the path is relatively known. Several reasons for this:

- They burn up

- They fragment

- They fall into lakes/woods, etc

- They embed themselves in the ground

- Its hard to predict where they might land

Or all of the above.

Most bright meteorites, even something as bright as those filmed are tiny and even those filmed are probably not much bigger than a golf/tennis ball before entry into earth's atmosphere. But given the incredible speed of entry and heating effect of our atmosphere, they always look more impressive. In Victorian times meteorite collecting was a big pastime, but even then few examples came up. Which is why most serious meteorite hunters go to the antarctic where spotting them is a lot easier. Even then they are hard to find.

On the other hand....

- It could be a falling satellite

- It is the afterburner of a project aurora plane

- Little green men are visiting us

- Steve is lighting his farts again....

[Jez 0]

It's better to burn out, than to fade away..

I'd like them to be ufo's. Way more interesting than little rocks.

[Quiet One 15]

It's better to burn out, than to fade away..

I'd like them to be ufo's. Way more interesting than little rocks.

That's what Clinton said.

[Medilloni 6]

It's better to burn out, than to fade away..

I am rocking the ons in agreeingments. True Jez.

I'd like them to be ufo's. Way more interesting than little rocks.

Could be little alien's rocks? Ouch.

But what if? What would we do if disc-thingy landed, alien stepped out, asking directions to our nearest leader. Reactions from jubilation to stark terror?

Would they land in New York (if they're film buffs they will!)? The middle of the Shahara? Brighton Pier?

Would they do student exchanges?

[Schumikonen 2]

I am rocking the ons in agreeingments. True Jez.

Could be little alien's rocks? Ouch.

But what if? What would we do if disc-thingy landed, alien stepped out, asking directions to our nearest leader. Reactions from jubilation to stark terror?

Would they land in New York (if they're film buffs they will!)? The middle of the Shahara? Brighton Pier?

Would they do student exchanges?

I would quit my job to have time to watch the news.

[Grabthaw the Hammerslayer 4]

But what if? What would we do if disc-thingy landed, alien stepped out, asking directions to our nearest leader. Reactions from jubilation to stark terror?

Well if they landed in the UK and asked for our leader, they'd be screwed... before they knew it, their spacecraft would have lost a third in value, been repossessed by Galactic Central Bank, the cost of new Di-lithium crystals would have soared (especially after the Government applied a tax on them) and they with then have to deal with a blithering idiot (no, not you Meds, I mean his Gordon-ness) They would certainly have no illusions about whether there is intelligent life on earth...

Still, on the positive side as an illegal alien, they would be able to sign on, get benefits, a free council flat and would be more or less guaranteed a job in KFC or pushing a drinks trolley on the 09:15 express to Birmingham New Street....

...and longer term, they could guarantee a contract with Channel 4 in the new hit reality series Its All Alien To Me... where they put them all in a futuristic house, near a beach, in the jungle and Richard Branson decides after a series of cooking and exotic food-eating challenges which of them he is going to give a job, as a singing, ice dancing best mate and personal assistant.

[Jez 0]

I am rocking the ons in agreeingments. True Jez.

Could be little alien's rocks? Ouch.

But what if? What would we do if disc-thingy landed, alien stepped out, asking directions to our nearest leader. Reactions from jubilation to stark terror?

Would they land in New York (if they're film buffs they will!)? The middle of the Shahara? Brighton Pier?

Would they do student exchanges?

Maybe they'll be less intelligent than us. Apelike in all brain activity other than the building and then piloting of amazing spaceships.

That'd be sweet.

I would quit my job to have time to watch the news.

Same here!

Well if they landed in the UK and asked for our leader, they'd be screwed... before they knew it, their spacecraft would have lost a third in value, been repossessed by Galactic Central Bank, the cost of new Di-lithium crystals would have soared (especially after the Government applied a tax on them) and they with then have to deal with a blithering idiot (no, not you Meds, I mean his Gordon-ness) They would certainly have no illusions about whether there is intelligent life on earth...

Still, on the positive side as an illegal alien, they would be able to sign on, get benefits, a free council flat and would be more or less guaranteed a job in KFC or pushing a drinks trolley on the 09:15 express to Birmingham New Street....

...and longer term, they could guarantee a contract with Channel 4 in the new hit reality series Its All Alien To Me... where they put them all in a futuristic house, near a beach, in the jungle and Richard Branson decides after a series of cooking and exotic food-eating challenges which of them he is going to give a job, as a singing, ice dancing best mate and personal assistant.

Those damn aliens get it good over there.

[Jez 0]

Dancing black hole twins spotted

A giant amalgam of black holes sits at the centre of the Virgo galaxy cluster

Reseachers have seen the best evidence yet for a pair of black holes orbiting each other within the same galaxy.

While such "binary systems" have been postulated before, none has ever been conclusively spotted.

The new black hole pair is dancing significantly closer than the prior best binary system candidate.

The work, published in the journal Nature, is in line with the theory of growth of galaxies, each with a black hole at its centre.

The theory has it that as galaxies near each other, their central black holes should orbit each other until merging together.

But evidence for black holes nearing and orbiting has so far been scant.

As matter falls into black holes, it emits light of a characteristic colour that in turn gives information about the direction in which the black hole is moving.

Because they are orbiting each other, astronomers have suggested that binary black hole systems would emit two beams, each a slightly different colour.

Todd Boroson and Tod Lauer of the National Optical Astronomy Observatory analysed some 17,500 spectra from the Sloan Digital Sky Survey, and found such a pair coming from a distant quasar.

The researchers estimate that the two light sources come from black holes between 20 million and one billion times heavier than the sun.

The black holes are separated by an estimated distance of less than a third of a light-year - cheek-to-cheek by black hole standards and significantly more than the postulated binary system spotted by the Chandra X-ray Observatory in 2003.

The pair are estimated to dance around one another every 100 years.

Because they are moving with respect to the Earth as well as to each other, observations of their movement over the next few years could prove that they are in fact the first partnered pair of black holes. "Previous work has identified potential examples of black holes on their way to merging, but the case presented by Boroson and Lauer is special because the pairing is tighter and the evidence much stronger," said Jon Miller, an astronomer at the University of Michigan.

[Jez 0]

This is great news for space enthusiasts! Watch the launch here It's a beautiful thing!

An unmanned Nasa mission to search the sky for Earth-like planets with the potential to host life has launched from Cape Canaveral in Florida.

The Kepler telescope will orbit the Sun to watch a patch of space thought to contain about 100,000 stars like ours.

It will look for the slight dimming of light from these "suns" as planets pass between them and the spacecraft.

Controllers took their first opportunity to launch the probe, at 0349GMT (2249EST) on 7 March.

Kepler blasted off atop a Delta II rocket from Cape Canaveral Air Force Station. Kepler will use the largest camera system ever launched into space

"This is a historical mission; it's not just a science mission," said Dr Edward Weiler, Associate Administrator for the Science Mission Directorate at Nasa.

"I maintain that it really attacks some very basic human questions that have been part of our genetic code since that first man or woman looked up into the sky and asked the question: 'are we alone?'."

Equipped with the largest camera ever launched into space, it is the first mission designed to find rocky worlds orbiting Sun-like stars. Planets located in a warm zone - known as the habitable zone - might host liquid water on their surfaces.

And where there is liquid water, scientists argue, there is at least the potential for life.

'Flea in headlights'

Of the 300-plus extrasolar planets discovered to date, only a handful are thought to be rocky like the Earth, and none are Earth-mass. The vast majority are gas giants like Jupiter or so-called ice giants like Neptune.

This is thought to be due to the technological limitations of current telescope technology, rather than a lack of Earth-mass planets in our galaxy. THE KEPLER SPACE TELESCOPE

Will study more than 100,000 sunsContinuously for 4 to 6+ yearsTuned to see Earth-size planetsWill target the habitable zoneAlso see Mars to Jupiter sizesFirst results within 3 months

Kepler will detect the periodic dimming of stars caused by transiting planets.

Some star systems are oriented in such a way that their planets cross in front of their stars, as seen from Earth's point of view. During these transits, the planets cause their star's light to slightly dim, or wink.

The orbiting observatory can register changes in brightness of only 20 parts per million.

"If Kepler were to look down at a small town on Earth at night from space, it would be able to detect the dimming of a porch light as somebody passed in front," said James Fanson, Kepler project manager at Nasa's Jet Propulsion Laboratory in California.

He commented: "Trying to detect Jupiter-size planets crossing in front of their stars is like trying to measure the effect of a mosquito flying by a car's headlight.

"Finding Earth-sized planets is like trying to detect a very tiny flea in that same headlight."

William Borucki, Kepler chief scientist from Nasa's Ames Research Center in California, said: "We will monitor a wide range of stars; from small cool ones, where planets must circle closely to stay warm, to stars bigger and hotter than the Sun, where planets must stay well clear to avoid being roasted." Closer to home: Venus is pictured making a transit of our Sun

If the mission does find Earth-size planets in the habitable zones of stars, it should find them first around suns that are smaller than our own. In the case of small stars, this habitable zone is located closer in, so planets circling in this comfortable region will take less time to complete one lap.

This means it will take less time for Kepler to find them and for other ground telescopes to confirm their existence.

Any Earth-size planets orbiting in the habitable zones of stars the size of our Sun would take at least three years to be confirmed.

The telescope has a very large field of view, which it needs in order to observe the necessary large number of stars.

Kepler will stare at the same star field for the entire mission monitoring the brightnesses of more than 100,000 stars for the mission's three-and-a-half-year lifetime.

The spacecraft will be launched into an orbit where it will drift behind Earth as it circles the Sun. This will ensure our planet does not block the stars which need to be observed continuously by the observatory.

Getting answers

Dr Borucki suggested the mission could make major contributions to understanding other star systems, including the unresolved question of how they form. But he cautioned that the knowledge still to be accumulated was vast.

"If you look at the giant planets, we have found 340 of these. People say: 'Why would you need any more?'

"My guess is that by understanding giant planets and small planets we are going to make dramatic discoveries about other planetary systems. But I don't expect us to have all the answers in three-and-a-half years."

Finding Earth-size planets is one thing, confirming life - even simple microbial life - exists on them is another matter altogether; and will require future telescopes capable of seeing trace gasses in the planets' atmospheres that are a possible signature for biology. "We certainly won't find ET but we might find ET's home by looking at all of these stars," said Bill Borucki.

[Jez 0]

Nasa space shuttle launch delayed

The leak was spotted as fuel tanks were being filled

Nasa has delayed the launch of its Discovery shuttle mission to complete the electricity generation system on the International Space Station (ISS).

A fuel leak meant Wednesday's launch would be delayed until Sunday at the earliest, the US space agency said.

The orbiter is due to deliver the fourth and final set of solar array wings to the platform and the last segment of its truss, or backbone.

Their electricity will support the expansion of the crew to six people.

The 73m-long arrays will also provide the power necessary to fully exploit the science labs now attached to the ISS.

Currently, the normal live-aboard complement is three individuals; and the station partners want to double this in May.

Discovery had been due to lift off from the Kennedy Space Center in Florida on Wednesday evening.

But in a statement Nasa said lift-off was now scheduled for Sunday evening, though the "exact launch date is dependent on the work necessary to repair the problem".

A progress assessment would be made on Thursday, Nasa said.

'Waiting'

The 14-day mission is due to feature four spacewalks to help install the S6 truss segment to the starboard, or right, side of the station and the deployment of its solar arrays.

Discovery's astronauts will also replace a failed unit for a system that converts urine to drinking water.

Another key task is ISS crew rotation. Discovery will drop off the Japanese space agency's (Jaxa) first resident crew member.

Dr Koichi Wakata is an experienced astronaut, having flown on two previous shuttle missions. He is expected to stay on the ISS until June.

"This week will be an historic week for Japan's space programme," said Kuniaki Shiraki, executive director of Jaxa's human space programme.

"We have been waiting a long time."

Dr Wakata takes the place of Nasa astronaut Sandra Magnus, who has served as a flight engineer on the platform since November.

Last missions

Discovery's delayed flight would be the 125th to be made by a shuttle; the 28th to the ISS; and the 36th flight for Discovery itself.

Once the final truss segment is installed, the station's backbone - which supports not just the arrays, but radiators and other equipment - will be 102m long. Koichi Wakata: The first Japanese long-duration ISS resident

When viewed from the Earth's surface shortly after sunset, the ISS appears as a very bright star moving swiftly across the sky. The addition of a larger reflective area will make the platform an even more brilliant spectacle.

Altogether, the station's arrays can generate as much as 120 kilowatts of usable electricity, says Nasa.

The addition of the final set of solar arrays will nearly double the amount of power available for scientific experiments aboard the station - from 15kW to 30kW.

Eight more flights are required to finish construction of the station and to fill it with supplies prior to the retirement of the shuttle fleet in 2010.

Nasa also plans one additional shuttle mission to repair and upgrade the Hubble Space Telescope.

The agency is still awaiting the appointment of an administrator following the departure of the Mike Griffin. President Obama has yet to fill the post. Discovery's mission had earlier been delayed by several weeks to give engineers time to investigate the cause of a fractured fuel valve on the last shuttle mission.

[Grabthaw the Hammerslayer 4]

Discovery's astronauts will also replace a failed unit for a system that converts urine to drinking water.

Ew you wouldn't want to be the first astronaut to discover that.... "Hey, this coffee tastes a bit strange....."

Actually I take that back, McDonalds have been using this technology in their coffee machines for years

[Max Mosley 2]

[Jez 0]

Still, in thr deepness of space, a drink of anything id refreshing!

Edit- too many drinks lastnight!!!

[Jez 0]

Junk alert for space station crew

The crew had to move into the Russian Soyuz capsule

The crew of the International Space Station has been forced to shelter in the Russian Soyuz capsule after a close call with a piece of space debris.

The three crew members are now out of danger and have returned to the ISS, Russian mission control officials told Reuters news agency.

Nasa said news of the debris threat had come too late for flight controllers to move the space station out of the way.

The scare comes just over a month after two satellites collided over Siberia.

Officials said the decision to move the astronauts had been a precaution and that the probability of an impact with the ISS had been low.

The space station's operating rules require crew members to be evacuated when debris is detected within a set distance.

Russian Yury Lonchakov and Americans Michael Fincke and Sandra Magnus took refuge for about nine minutes in the Soyuz TMA-13 escape capsule.

Tiny fragment

"The crew have returned to the station. They are in absolutely no danger and the debris has already passed by the station," a spokesman for Russia's mission control said after the incident.

Nasa Spokesman William Jeffs says the evacuation was a rare event

"They didn't even close the hatch between the station and the Soyuz."

They were told the time of closest approach to the station would be 1639 GMT (1239 EDT).

The debris was about 1cm (0.3in) in size and part of an old "payload assist motor" that was previously on either a Delta rocket or on the space shuttle, Nasa public affairs officer Laura Rochon told journalists.

"The crew is safe and back in the space station and they are resuming normal operations," Ms Rochon added.

A Nasa spokesperson told BBC News that the space agency had been notified about the possible threat last night. The short lead time forced officials to move the crew into the capsule rather than manoeuvring the space station out of the way.

Two Americans and one Russian are aboard the stationThe reason for the short notice is unclear, but the small size of the object and its erratic orbital path may have been factors.

"It's a bit like a swarm of bees in a beehive up there," said William Jeffs, a spokesperson at Nasa's Johnson Space Center in Houston, "the trajectories can sometimes be erratic."

It is unclear how many times crew members had been told to enter the Soyuz, but officials said this was "not the first" occasion. Flight controllers have moved the ISS eight times over the past 10 years in order to avoid debris.

Growing threat

Objects in orbit travel at tens of thousands of kilometres per hour. At these speeds, even a small piece of debris can knock out a satellite or, potentially, cause damage to the space station.

Experts recognise a growing threat to satellites and manned spacecraft from orbital debris and several events over the past three years have drawn attention to the problem.

On 10 February, the US Iridium 33 communications satellite collided with Cosmos 2251, a retired Russian intelligence comms sat. About 18,000 objects bigger than 10cm are orbiting Earth

The chances of such an event had been estimated at millions or billions to one. The impact produced two expanding clouds of debris in intersecting orbits.

In January 2007, China caused international alarm when it destroyed one of its defunct satellites in a missile test. The US military estimates that this event created 2,500 new pieces of debris in orbit.

In total, there are said to be about 18,000 pieces of orbiting junk larger than 10cm in size. On Wednesday, Nasa postponed its launch of the space shuttle Discovery from Florida when a hydrogen leak was detected during fuelling.

[Jez 0]

Nasa's space shuttle Discovery has blasted off from the Kennedy Space Centre in Florida on a 14-day mission to the International Space Station.

Its crew will deliver and install the space station's fourth and final set of solar arrays, which will provide the power for it to expand.

The seven astronauts include Koichi Wakata, who will be Japan's first long-term resident on the space station.

The shuttle's launch was postponed last month because of mechanical problems.

Electricity from the new solar arrays will support the expansion of the crew to six people.

It will also provide the power necessary to fully exploit the science labs now attached to the ISS.

Currently, the normal live-aboard complement is three individuals; and the station partners want to double this in May.

Brilliant spectacle

The mission is due to feature four spacewalks to help install the S6 truss segment to the starboard, or right, side of the station and the deployment of its solar arrays.

Koichi Wakata: The first Japanese long-duration ISS residentDiscovery's astronauts will also replace a failed unit for a system that converts urine to drinking water.

Another key task is ISS crew rotation. Discovery will drop off the Japanese space agency's (Jaxa) first resident crew member.

Discovery's delayed flight is the 125th to be made by a shuttle; the 28th to the ISS; and the 36th flight for Discovery itself.

Once the final truss segment is installed, the station's backbone - which supports not just the arrays, but radiators and other equipment - will be 102m long.

When viewed from the Earth's surface shortly after sunset, the ISS appears as a very bright star moving swiftly across the sky. The addition of a larger reflective area will make the platform an even more brilliant spectacle.

Altogether, the station's arrays can generate as much as 120 kilowatts of usable electricity, says Nasa.

The addition of the final set of solar arrays will nearly double the amount of power available for scientific experiments aboard the station - from 15kW to 30kW.

Eight more flights are required to finish construction of the station and to fill it with supplies prior to the retirement of the shuttle fleet in 2010.

Nasa also plans one additional shuttle mission to repair and upgrade the Hubble Space Telescope.

The agency is still awaiting the appointment of an administrator following the departure of the Mike Griffin. President Obama has yet to fill the post. Discovery's mission had earlier been delayed by several weeks to give engineers time to investigate the cause of a fractured fuel valve on the last shuttle mission.

[Jez 0]

'Supermodel' satellite set to fly

By Jonathan Amos

Science reporter, BBC News

Neil Wallace reveals the inner workings of Goce's ion engine

Europe is set to launch one of its most challenging space missions to date.

The Goce satellite will map minute variations in the pull of gravity experienced across the planet.

Scientists will use its data to improve their understanding of how the oceans move, and to frame a universal system to measure height anywhere on Earth.

The super-sleek spacecraft will go into orbit on a modified intercontinental ballistic missile from the Plesetsk Cosmodrome in north-west Russia.

http://news.bbc.co.uk/2/hi/science/nature/6919016.stmLift-off for the Rockot vehicle is timed for 1421 GMT on Monday.

Most satellites launched into space are ugly boxes. The European Space Agency's (Esa) Goce satellite is very different.

"This is the most beautiful satellite that has ever been built - and for good reason," enthused one of the scientists who conceived the mission, Reiner Rummel, from the Technical University of Munich, Germany.

Goce's striking good-looks are a requirement of the extremely testing environment in which it will have to operate.

The arrow shape and fins are necessary to keep the spacecraft stable as it flies through the wisps of air still present at an altitude just under 270km.

This orbit is much lower than for most Earth observation missions but will be essential if Goce is to sense the very subtle gravity anomalies that exist across the planet.

"Our current knowledge of the Earth's gravity is incomplete," explained Danilo Muzi, Esa's Goce programme manager.

"Gravity is the force we experience daily; it keeps our feet on the ground. But there is this general misconception that it is constant everywhere on the globe, which is not true. If we go to the North Pole we will weigh more than if we are at the equator." Goce data will be used to construct an idealised surface called a geoid

This extraordinary phenomenon is explained in part by the shape of the planet. It is not a perfect sphere - it is flatter at the poles, fatter at the equator. Its interior layers are also not composed of uniform shells of homogenous rock - some regions are thicker or denser.

This leads to an irregular distribution of mass; and as everything that has mass is pulled by gravity, its tug becomes irregular, too.

The variations, though, are miniscule - almost imperceptible.

Meeting the measurement challenge in itself resulted in two years' delay for the Gravity Field and Steady-State Ocean Circulation Explorer (Goce). Engineers have had to work through immense technical difficulties.

At the heart of the spacecraft is a device known as a gradiometer.

"This is a very complex instrument," said Andrea Allasio, who led the production of the satellite at Thales Alenia Space in Italy. "It is, for sure, the most sophisticated gradiometer which has ever been prepared for a satellite."

It consists of three pairs of "proof masses", or accelerometers. They are aligned at 90 degrees, across each axis. The entire set-up is mounted inside an ultra-stable casing.

As Goce bumps through the Earth's gravity field, the accelerometers will sense the fantastically small disturbances.

"We have one comparison that we often make," explained Rune Floberghagen, Esa's Goce mission manager.

"Imagine a snowflake, which has a fraction of a gram, slowly falling down on to the deck of a supertanker. The acceleration that the supertanker experiences from that snowflake is comparable to the sensitivity of our instrument," he told BBC News.

There is however a potential showstopper: the low altitude Goce must fly to get the detail it seeks in the gravity signal. The constant buffeting the satellite receives from the residual air still present in the thermosphere would ordinarily drown out the data.

So Goce employs an ion engine to maintain a steady path - a sort of cruise control. The engine is throttled up and down, producing exquisite levels of thrust by accelerating charged atoms of xenon through nozzles at the rear of the spacecraft.

"We are an enabling technology on this mission; it couldn't happen without us," said Neil Wallace from Qinetiq, the UK technology firm which supplied the engine. "But then this mission has many such technologies."

GRAVITY FIELD AND STEADY-STATE OCEAN CIRCULATION EXPLORER 1. The 1,100kg Goce is built from rigid materials and carries fixed solar wings. The gravity data must be clear of spacecraft 'noise'2. Solar cells produce 1,300W and cover the Sun-facing side of Goce; the near side (as shown) radiates heat to keep it cool3. The 5m-by-1m frame incorporates fins to stabilise the spacecraft as it flies through the residual air in the thermosphere4. Goce's accelerometers measure accelerations that are as small as 1 part in 10,000,000,000,000 of the gravity experienced on Earth5. The UK-built engine ejects xenon ions at velocities exceeding 40,000m/s; Goce's mission will end when the 40kg fuel tank empties6. S Band antenna: Data downloads to the Kiruna (Sweden) ground station. Processing, archiving is done at Esa's centre in Frascati, Italy7. GPS antennas: Precise positioning of Goce is required, but GPS data in itself can also provide some gravity field information

Goce's quest is to produce a snapshot of the Earth's gravity field at an unprecedented resolution. The data will inform a multitude of science disciplines:

understanding how the mass of ocean waters circulate, moving heat around the planet, will assist climate prediction

a better knowledge of the way mass is distributed inside the Earth will be useful to those who study geo-hazards such as volcanoes and earthquakes

and because gravity defines what is meant by "up", "down" and "level", the new data can underpin a truly universal system to compare heights the world over

Goce is the first of Esa's Earth Explorers, a series of spacecraft that will provide quick answers to key environmental questions.

Six missions have so far been approved; a seventh is in discussion. All will use cutting-edge space technology to acquire their data. Cryosat has been re-built and will launch later this year

Europe ice mission failure probed

The Goce mission has experienced a series of frustrating delays. It was sent to Plesetsk in August last year and should have orbited in September, but the satellite was then held on the ground because of niggling concerns about the readiness of its launcher system.

The ghost that haunts this mission is the Cryosat satellite. The Esa spacecraft built to map the world's ice fields was supposed to be first Earth Explorer but it was destroyed on launch in 2005 when its Rockot failed and ditched in the Arctic Ocean.

"From the information we have seen from Eurockot (operator) and Khrunichev (manufacturer), we have seen they have done extensive testing," said Danilo Muzi.

"On the basis of all the testing that has been done, and the fact that these tests were successful, then the confidence in the good status of the launcher has been restored," he told BBC News.

Goce will be put into a sun-synchronous orbit, meaning the spacecraft will be kept in daylight for a sustained period of time. The Breeze-KM upper-stage booster will release Goce at an altitude of about 285km.

The satellite will then gradually fall to its operational altitude of 263km, where its ion engine will maintain a steady orbit for the science campaign.

Two major data-gathering periods are planned, each lasting about six months. The first should start in early September after all the in-orbit testing is complete.

The mission will probably be extended if sufficient xenon is left, although some propellant will be needed to take the spacecraft safely out of the sky in a controlled burn-up over ocean waters.

GRAVITY FIELD AND STEADY-STATE OCEAN CIRCULATION EXPLORER 1. Goce senses tiny variations in the pull of gravity over Earth 2. The data is used to construct an idealised surface, or geoid3. It traces gravity of equal 'potential'; balls won't roll on its 'slopes'4. It is the shape the oceans would take without winds and currents5. So, comparing sea level and geoid data reveals ocean behaviour6. Gravity changes can betray magma movements under volcanoes7. A precise geoid underpins a universal height system for the world8. Gravity data can also reveal how much mass is lost by ice sheets

[email protected]

[freaky2 1]

The first article has made me think of a very bright star I always see when I go to my friend's house. Maybe next time I can keep a watch on it to see if it moves.

[Rainmaster 7]

The first article has made me think of a very bright star I always see when I go to my friend's house. Maybe next time I can keep a watch on it to see if it moves.

Just make sure to watch where you're walking

[freaky2 1]

Just make sure to watch where you're walking

I already never do it

[Jez 0]

Any luck spotting that star again?

[freaky2 1]

Been buried under work for uni, no time to visit friends. Maybe this weekend

[Argento Reloaded 1]

I

[pumpdoc 2]

http://www.nasa.gov/multimedia/nasatv/

Anybody besides me that watches this stuff, space walks are especially cool

[Jez 0]

Been buried under work for uni, no time to visit friends. Maybe this weekend

What are you studying?

I

[Rainmaster 7]

Extreme DIY: http://news.bbc.co.uk/1/hi/world/7953792.stm