ESA Rosetta mission: Crippled Philae lander endeavours to transmit relevant data

Animator's picture of Philae on the comet 67/P now appears more idealistic and hugely optimistic.

A report on the Philae spacecraft's verified Twitter feed suggests the probe has successfully "hopped" into a new position which may enable its solar panels to work

There was fresh hope for the Rosetta mission after scientists reconnected with the probe which could be holding key information about how life on Earth began.

The 25-year mission was thrown into jeopardy after the Philae craft bounced away from its landing site on the comet 67P/Churyumov-Gerasimenko and became stuck under a cliff.

Scientists had been working on attempts to find and move the probe before it ran out of battery power.

But on Friday those plans were abandoned and instead they began drilling beneath the surface of the comet in an attempt to get some samples on board for analysis.

ESA Philae landers' instruments listed. Consert, Romap, SD2 and Mupus have been initiated but results are unknown.

Contact with the lander was lost before the data could be sent back to Earth, but late last night Philae re-established radio contact with its orbiting Rosetta satellite and is sending data from the surface.

However, less than an hour later scientist confirmed the lander was "getting tired" and the battery voltage was approaching the limit.

Daniel Scuka, Senior Editor for Spacecraft Operations at ESOC, said on the mission blog: "While the search for the final landing site is still on-going, the lander is racing against the clock to meet as many of the core science goals as possible before the primary battery is exhausted.

"Under the low illumination conditions at Philae's location, it is unlikely that the secondary batteries will charge up enough to enable extended surface operations."

They confirmed that they had received data from Philae, and that the drill had moved up and down, but they were unsure what data they had.

A report on the spacecraft's verified Twitter feed, Philae Lander @Philae2014, suggests the craft has successfully "hopped" into a new position, possibly one that will enable more sunlight to shine on its solar panels.

The first of two messages at about 11pm read: "I just started lifting myself up a little and will now rotate and try and optimise the solar power."

This was quickly followed by another which said: "My rotation was successful (35 degrees). Looks like a whole new comet from this angle."

Philae has imaged three different spots on the comet, it was confirmed.

This may be the sum total of knowledge taken out of the Rosetta Philae lander chapter of the mission.

However, in a less optimistic update just before midnight Mr Scuka added: "On board Philae, system voltage has fallen very close to 21.5V; below that, the battery won't last much longer. At this time, there is insufficient sunlight to provide power."

Rosetta The comet is a remnant from the early solar system and may hold clues about how life on Earth began.

Many scientists believe that comets were the driving force, delivering water and amino acids to the planet during the "bombardment phase" about four billion years ago.

If the link with the probe is lost, there is a faint possibility that the solar panels will begin working again when the comet's orbit brings it closer to the Sun.

"We can only hope that as we approach the Sun, maybe in August, if we don't have dust or a huge coma [a dust cloud around the comet] blocking the Sun, then perhaps there would be a chance we could come back and at least see how the lander is doing," said Valentina Lommats, of the German Space Agency.

Crucially, the team had still not located the lander on Friday. On Thursday, team members said they believed Philae had bounced twice before settling in a crater east of the original landing site.

However, scans by the Osiris camera on board the Rosetta mother ship failed to locate the probe.

Rosetta has now started scanning other areas.

An animated gif of the Philae lander departing from Rosetta on its risky but calamitous journey onto the comet 67/P.

However, scientists were confident that they had collected a huge amount of a data, around 90 per cent of what they were hoping for before the solar panels were needed to extend the mission.

Even if Philae's job is finished, the Rosetta mission is to continue.

Rosetta will remain alongside the comet as it moves closer to the Sun.

Instruments on board will analyse the gases of the tail and the comet's interior, measure dust grains and study its atmosphere and gravity.

The comet will reach its closest distance to the Sun on Aug 13 next year, at about 115 million miles, roughly between the orbits of Earth and Mars.

Orbital Sciences Cygnus: Launch Postponed after Antares rocket test failure

Orbital Sciences Corp. of Dulles, Va., mated the Cygnus Service Module to the Pressurized Cargo Module Friday, April 4, in Bldg. H-100, payload processing facility, at NASA's Wallops Flight Facility, Va. Image courtesy NASA/P. Black. 

Orbital Sciences Corporation has postponed the launch of the Orbital-2 mission to the International Space Station after an engine test aborted prematurely.

The engine being tested at NASA's Stennis Space Center was slated to be used for a launch in 2015, but Orbital has taken the action to investigate the mishap before attempting to launch Orb-2.

Orbital now is looking no earlier than June 17 for the Orb-2 launch.

Orbital published the following message on their website:

Orbital has rescheduled the launch of its Antares rocket for the Orb-2 mission to a date of no earlier than (NET) June 17, 2014. Orb-2 is the second of eight cargo resupply missions to the International Space Station under Orbital's Commercial Resupply Services (CRS) contract with NASA.

The new launch schedule has been established to allow the engineering teams from the main stage propulsion supplier Aerojet Rocketdyne and Orbital to investigate the causes of an AJ26 (NK33) engine failure that occurred last week at NASA's Stennis Space Center during customary acceptance testing.

That engine was designated for use in a mission slated for 2015 and was undergoing hot fire testing that all Antares AJ26 engines are subject to to ensure nominal performance and acceptance for use in Antares missions.

The NET June 17 is a planning date. The determination of a new firm date will depend on progress of the investigation team, so please check back to this page for further updates.

Orbital Science: Antares rocket engine suffers significant failure during test

Hotfire test of Aerojet Rocketdyne AJ26 engines on the E-1 Test Stand at NASA’s Stennis Space Center on Jan 17, 2014. 

Credit: NASA

A Russian built rocket engine planned for future use in the first stage of Orbital Sciences Corp. commercial Antares rocket launching to the International Space Station failed during pre-launch acceptance testing on Thursday afternoon, May 22, at NASA's Stennis Space Center in Mississippi.

"There was a test failure at Stennis yesterday afternoon (May 22)," Orbital Sciences spokesman Barry Beneski told reporters.

The Aerojet Rocketdyne AJ26 engine failed with extensive damage about halfway through the planned test aimed at qualifying the engine for an Antares flight scheduled for early next year.

"Engineers are examining data to determine the cause of the failure," Beneski said.


The test was initiated at about 3:00 p.m. EDT on Thursday and the anomaly occurred approximately 30 seconds into the planned 54-second test.

"It terminated prematurely, resulting in extensive damage to the engine," Orbital said in a statement.

An investigation into the incident by Aerojet and NASA has begun. The cause of the failure is not known.

"During hot-fire testing on May 22 at NASA's Stennis Space Center, Aerojet Rocketdyne's AJ26 engine experienced a test anomaly. The company is leading an investigation to determine the cause," Aerojet spokesperson Jessica Pieczonka told reporters.

Fortunately no one was hurt.

"There were no injuries," Pieczonka confirmed.

Up close view of two AJ26 first stage engines at the base of an Antares rocket at NASA Wallops. 

These engines powered the successful Antares liftoff on Jan. 9, 2014 at NASA Wallops, Virginia. 

Credit: Ken Kremer

A team of NASA, Orbital Sciences Corporation, Aerojet Rocketdyne and Lockheed Martin engineers tests all of the AJ26 engines on the E-1 Test Stand at NASA's Stennis Space Center before delivering them to the launch site at NASA's Wallops Flight Facility in Virginia.

The testing program began in November 2010.

"Stennis will perform checkouts to the facility to ensure its operational integrity," NASA Stennis spokesperson Rebecca Strecker told reporters.

Antares first stage is powered by a pair of liquid oxygen and kerosene fueled AJ26-62 engines that deliver a combined 734,000 pounds (3265 kilonewtons) of sea level thrust.

To date, the AJ26 engines have performed flawlessly through a total of three Antares launches from NASA's Wallops Flight Facility in Virginia.

They measure 3.3 meters (10.9 feet) in height and weigh 1590 kg (3,500 lb.).

The next Antares rocket is slated to blastoff on June 10 with the Cygnus cargo freighter on the Orb-2 resupply mission to the ISS.

As of today, it's not known whether the June flight will have to be postponed.

"It is too early to tell if upcoming Antares flights will be affected," Beneski said.

Side view of two AJ26 first stage engines at the base of an Antares rocket. 

These engines powered the successful Antares liftoff on Jan. 9, 2014 at NASA Wallops, Virginia. 

Credit: Ken Kremer

The most recent launch of the two stage rocket took place this past winter on Jan. 9, 2014 on the Orb-1 resupply mission.

The AJ26 engines were originally known as the NK-33 and built in the Soviet Union for their manned moon landing program.

Aerojet extensively modified, checked and tested the NK-33 engines now designated as the AJ26-62 to qualify them for use in the first stage Antares core, which is manufactured in Ukraine by the Yuznoye Design Bureau and based on the Zenit launch vehicle.

"Each test of an AJ26 engine is exciting and affirming because it is in direct support of NASA's commercial space flight efforts, as well as a continuation of a very successful Stennis partnership with Orbital and Aerojet Rocketdyne," Stennis Director Rick Gilbrech said in an earlier statement.

Orbital Sciences technicians at work on two AJ26 first stage engines at the base of an Antares rocket. 

These engines powered the successful Antares liftoff on Jan. 9, 2014 at NASA Wallops, Virginia bound for the ISS. 

Credit: Ken Kremer

Orbital Sciences was awarded a $1.9 Billion supply contract by NASA to deliver 20,000 kilograms of research experiments, crew provisions, spare parts and hardware for 8 flights to the ISS through 2016 under the Commercial Resupply Services (CRS) initiative.

The June mission would be the second operational Antares/Cygnus flight.

GLONASS Outage: Satellite Navigation Failure - No Backup

Russian authorities have not reported the exact cause of the GLONASS outage. 

Theories are circulating that blame faulty system and/or software upgrades, recent solar flares that could cause radio communication outages, or even the possibility that this was a targeted cybersecurity attack. 

No matter the cause, fixing the outage took close to 13 hours. 

During that time, Russia's version of the GPS was crippled and unusable.

The world's global positioning industry watched in disbelief on April 2, 2014, as all of the 24 GLONASS satellites that make up Russia's equivalent of the GPS system failed at once.

This unprecedented and deeply worrying total disruption of what is one half of the world's operational global navigation satellite constellations shook the industry, and unequivocally confirmed the public warnings that have been voiced for years by Locata Corporation and other prominent industry experts.

"There is no way you can misinterpret this clear sign of the elephant in the room," said Nunzio Gambale, CEO of Locata Corporation.

"We have been telling the industry for years that you cannot have a critically important capability like GPS without also having a backup!

What is Plan B if the satellite systems fail? What replaces the space signal when there is a problem?

If anyone needed a sign to understand why Locata has spent years inventing and developing the world's first local terrestrial equivalent of the GPS system, then Wednesday's meltdown of a complete global satellite navigation system is it.

This event should terrify every nation, government, and company that depends on navigation satellites for their business or, in some cases, their very lives."

The navigation and timing functions of the global positioning systems are integrated into the core of almost every modern technology.

Society has come to rely on these technologies as a foundation for global commerce and communication.

Everyone has become very familiar with the signals being used for personal applications, such as navigating to an address or finding the closest sushi restaurant.

Yet few understand that satellite navigation and timing signals now underpin the world's banking systems, stock exchanges, digital TV and Internet, cell phone networks, and, in some cases, the national electricity supply.

GPS, in particular, plays a crucial role in transportation, shipping, and logistics, serving as the enabling technology for critical functions like air traffic control.

Reliability is therefore not just important; it is essential across all applications.

SCRAMSPACE: Autopsy of a space disaster turns failure to success

The scramjet crashed, but the experiment was a success. 

Credit: Janelle Kirkland (UQ)

On September 18 this year, far above the Arctic Circle at Norway's Andoya Rocket Range, the SCRAMSPACE hypersonic scramjet flight experiment was about to launch.

Three and a half years of intense effort by a small team of young scientists and engineers had gone into this moment.

Millions of dollars of investment were at stake. The international aerospace community and the broader public were watching in anticipation.

The team had seen three of this type of rocket launch during the HyShot program at Woomera. So when they looked skyward to see a corkscrew smoke trail from the lower stage rocket motor, they knew instantly the experiment was over before it had begun.

Disappointment and dismay, for many of the team, quickly turned to disbelief. What had been one chaotic smoke trail turned into two – the upper stage motor was now firing at the same time.

One insane minute later, the 150kg scramjet payload dived at 700km per hour into the water a few kilometres from the launch range.

But was it a total failure? Absolutely not. Despite the loss of precious scientific data, the project and flight experiment had been an amazing success.

What was the purpose of the SCRAMSPACE?
The SCRAMSPACE program was funded by the Australian Space Research Program to build a human talent pool – the capability and capacity to support an awakening Australian space sector.

In 2010, the core SCRAMSPACE flight team began to assemble at the University of Queensland to work on the experiment's design.

By late 2012, a rather weary but nevertheless committed, enthusiastic and increasingly skilled team set out to turn a detailed design into the most sophisticated hypersonics flight experiment Australia has ever flown.

SCRAMJETS
Scramjets are jet engines that will one day power aircraft that cruise at ultra-high speed in the atmosphere or even form part of space launch systems. Australia is a world leader in the research.

The SCRAMSPACE flight was intended to use rockets to take a generic scramjet experiment to the right speed and altitude (Mach 8 at 27km) to obtain a few seconds of concentrated data on the fundamental science - the flow physics and the way it affects combustion of the hydrogen fuel - that underpins such technology.

The data in turn would have been used to improve our understanding of the science and to test and validate our ability to simulate such engines in our shock tunnels and on our supercomputers.

That’s a nice looking jet: SCRAMSPACE before launch. 

Credit: AAP Image/Dan Peled

By mid 2013, the scramjet payload was assembled and the team started the exhaustive series of pre-flight tests to make sure the experiment was functioning properly and ready to fly.

These included thermal cycling, vibration in all axes, bend testing, spin balancing and pneumatic system calibration.

In parallel, the flight code had to be programmed. Some 13,000 lines of C and C++ were added to existing code supplied by partner Defence Science and Technology Organisation so that flight computers could control the on-board systems, and acquire, package and deliver data to the ground.

The most complex part of this was the use of our Reaction Control System thrusters to control roll, pitch and yaw, re-orient the payload prior to re-entry, and stabilise it during the early re-entry stage.

Scheduling the pulsed fuel system to maintain a fixed fuel-air ratio was also a key aspect of the code.

Computer-simulated flow patterns in and around the scramjet (image credit Dr Melrose Brown)

Despite the inevitable teething problems and bugs along the way, the hardware and software for a free-flying scramjet science experiment was ready for flight.

The experience was an unforgettable example of the reality that if something is hard to do, when you are pushing the boundaries in pursuit of new knowledge and innovation, then there is a real risk of something going dramatically wrong.

This is when the lessons learnt and experience gained are the most valuable.

The team did miss out on a few seconds of scramjet flight data but, despite withstanding incredible aerodynamic forces, the scramjet functioned perfectly all the way from launch to splash down.

It was a tribute to the quality of the payload that the team had designed and built.

The engineering was a success, and the research that surrounded it brought and continues to bring advances and new insight into hypersonics science and technology.

But above all, the talent pool that assembled and grew in skills and know-how, and the international credibility and partnerships and friendships that have resulted from that, have been a huge success.

Read the full story here

Returning ISS Astronauts 'flew blind' after Soyuz sensors failed

The three crew of the International Space Station (ISS) who returned to Earth this week endured a hair-raising descent after their height sensors failed, a Russian cosmonaut revealed on Friday.

Pavel Vinogradov said that he and the two other crew of the Soyuz capsule which touched down in Kazakhstan Wednesday had groped their way through the landing after they lost all data about their height from the ground.

"There were problems. For some reason after the undocking all our parameters disappeared. Essentially, after the undocking, we flew blind," he said at the Star City cosmonaut training centre outside Moscow, quoted by Russian news agencies.

He said that the only data the crew could receive about their approach to the earth -- crucial for knowing when to fire the engines to soften the landing -- came from the salvage team on the ground.

He said the rescue teams were able to radio to the crew that they were 300 metres (1,000 feet) and then 100 metres (330 feet) from the ground in the Soyuz capsule, which lands vertically with the help of a parachute after reentering the atmosphere.

"I managed to count eight seconds and we touched down very softly," he said, adding that aside from the usual G-forces and jolting "everyone felt normal".

Vinogradov, fellow Russian cosmonaut Alexander Misurkin and NASA astronaut Chris Cassidy touched down on the Kazakh steppe on Wednesday morning, in a landing that at the time seemed hitch-free.

Russia is currently the only nation capable of transporting humans to the ISS in its Soyuz rocket and capsule system after the withdrawal of the US shuttle.

UPDATE
However, the head of Russia's Federal Space Agency denied the cosmonaut's claim Friday, RIA Novosti reported.

"It wasn't a blind landing," Vladimir Popovkin said, explaining mission control simply switched off an information display in the landing module of the Soyuz TMA-08M spacecraft.

The cosmonauts still had enough readings to complete the landing procedure without problems, he said.

"Two dates simply overlapped in a program, and we had to turn off the [information] display so that [the readings] would not be patchy on the screen," Popovkin said.

SKA Super telescope costs Skyrocket: Risk Management Failure

The estimated cost of the first construction phase of the world's largest radio telescope has jumped to 400 million euros ($530 million), the project's director general said Tuesday.

The increase of 50 million euros takes six years of accumulated inflation into account, and the figure could escalate further once additional costs of splitting the project between Africa and Australia are factored in.

This sudden and dramatic increase in the costings can only be attributed to poor financial risk management and a failure to complete a stringent risk assessment at the outset.

The Square Kilometre Array (SKA) will be the world's largest and most sensitive radio telescope, with thousands of receptors spread over an area of a square kilometre (0.4 square miles).

Once completed, the project will allow astronomers to study distant galaxies in their quest to answer some fundamental questions about our Universe -- how it began, why it is expanding and whether it contains life beyond our planet.

The SKA will be able to detect a radio signal from a planet 50 light years away.

"What we are undergoing over the coming months is a review of how much Phase 1 will cost," Philip Diamond told AFP by phone from the English city of Manchester, where the SKA scheme is headquartered.

"What we are working towards is... presenting to the board at their July board meeting our informed estimates of the cost of the first phase of the SKA," he said.

"The board will then look at that, decide if they like it, and this will be part of the process then of going out to raise money from governments for the construction."

The project's original cost estimate, 1.5 billion euros in total for phases one and two, was made in 2007, and "we decided we should update the numbers to 2013 euros", said Diamond.

The Curious Case of the Wrong Monkey - Iran

Iran's announcement that it had successfully sent a monkey into space stirred questions on the Internet.

Curious people pointed to differences between official images of the primate before takeoff and after landing.

On January 28, official Iranian media published pictures of a monkey named Pishgam (Pioneer) prior to the launch.

The animal had light grey fur and a red mole above its right eye.

But later, the ISNA news agency released photos taken during presenting the monkey to the press after its landing which showed a darker fur and no mole.

These differences have been pointed out by Western media, which have questioned the success of the monkey space mission. A previous attempt by Iran, to send a primate into space, failed in 2011.

On Facebook, a comment underneath the monkey's pictures reads: the monkey "went into space and met a doctor who removed its mole," an ironic reference to some Iranians passion for cosmetic surgery (and misleading information regarding their scientific and aerospace capabilities).

Iranian authorities did not directly respond to these questions.

Report: Russia’s Phobos Grunt Probe to Fall to Earth January 15 - International Business Times

Russia's stranded Phobos Grunt spacecraft could fall to Earth on January 15, according to the spokesman of Russia's military space forces.

Spokesman Alexei Zolotukhin told Russian news agencies that fragments of Russia's stranded Mars probe Phobos-Grunt could fall to Earth on January 15.

"As of Wednesday morning, the fragments of Phobos-Grunt are expected to fall January 15, 2012. The final date could change due to external factors," said spokesman Alexei Zolotukhin.

In November, the military space forces" monitoring centre had predicted that the probewould fall to Earth in January or February.

Between 20 to 30 fragments of the Phobos Grunt spacecraft are expected to fall to Earth, but Russian space officials said the spacecraft's highly toxic fuel will burn up on entering the Earth's atmosphere.

Earlier, a Russian space official said that while the 13.5 ton probe, which is carrying highly toxic fuel, could also crash into the earth, it is impossible to predict the exact position of such an event.

"The crash area of any craft can only be estimated in the final 24 hours," said Vitaly Davydov, deputy head of Roscosmos in the first official acknowledgment on failed probe Davydov said. "Before then, saying what will fall and where is pointless."

Russia launched the Phobos-Grunt research probe to the Martian moon Phobos on Nov. 9, in an attempt to reinvigorate its interplanetary program which had not seen a successful mission since the fall of the Soviet Union.

Because of the failed probe, Davydov said that in the future Russia may just focus on sending probes to the Earth's moon and researching on Mars in cooperation with its international partners.

It will be recalled that towards the end of 2010, Russia's already troubled space industry was further shaken by the failure of the Proton rocket sending a trio of GLONASS satellites, costing more than $138 million, to crash down into the ocean.

This was followed by the failed launch of the Rockot booster, which left a new-generation Geo-IK-2 military satellite in a useless orbit.

In August 2011 the agency again suffered the loss of the Ekspress-AM4 communications satellite and the unprecedented crash of a Progress cargo ship heading to the International Space Station.

Then came the Phobos-Grunt fiasco which is expected to re-enter the Earth's atmosphere next week

Another Russian Soyuz-2 Rocket Fails to reach Orbit

An unmanned Soyuz-2 rocket carrying a Russian communications satellite lifted off from Russia's Plesetsk space center at 7:08 a.m. EST (1208 GMT), but failed to reach orbit after a third-stage engine failure.

The rocket and its payload crashed in Siberia, according to the Russian state news agency RIA Novosti.

There was no immediate word about whether the Soyuz-2 failure will impact upcoming launches, including a Soyuz flight slated for Wednesday to put six Globalstar mobile communications satellites into orbit.

The engine on the Soyuz-2 rocket lost Friday is different than the one used on the rocket that launches space station cargo and crews, NASA said.

"This is unlikely to have any effect on operations to the International Space Station," said NASA spokesman Joshua Buck.

FARS: Iran Fails Attempt to Launch Monkey Into Space

Safir-2 rocket launch in February 2009

An Iranian attempt to launch a rocket carrying a live monkey into space in September has failed.

The mission, announced last summer in the website of the Iranian Space Agency, consisted in launching a capsule with a life support system and reentry capability on top of a Kavoshgar-5 rocket to an altitude of 120 kilometers for a 20-minute sub-orbital flight.

Deputy Science Minister Mohammad Mehdinejad-Nouri has reportedly commented: ”The Kavoshgar-5 rocket carrying a capsule with a live animal (a monkey) was launched during Shahrivar (Note: Shahrivar is an Iranian calendar month spanning August 23 to September 22). However, the launch was not publicised as all of its anticipated objectives were not accomplished.”

The launch of a live animal into space was considered “strategic, and a priority,” by the Iranian government.

In 2010, the country launched a Kavoshgar-3 rocket carrying a rat, two turtles and a worm into space.

According Hamid Fazeli, head of Iran’s Space Organisation, the plan to fly live monkeys has been put on hold indefinitely: ”One cannot give a set date for this project and as soon as our nation’s scientists announce the readiness (of the project) it will be announced,” he said.

The Iranian republic, which put a satellite into orbit successfully in 2009, is pursuing an ambitious space program, which poses concerns in the Western world for possible links to the development of nuclear capable ballistic missiles.

NASA Shuttle Atlantis Computers: Navigate Record of Reliability

The space shuttle's five general purpose computers computers, or GPCs, are slow and have little memory compared to modern home computers. On the other hand, no one straps the latest-and-greatest desktop computer inside a machine that vibrates like an old truck on a washboard road while requiring it to get a spacecraft into orbit and back safely.

In other words, when it comes to flying the shuttle, reliability means far more than performance.

"The environment of space is very harsh and unfriendly and not just space, but getting into space," said Roscoe Ferguson, a space shuttle flight software operating system engineer for the United Space Alliance.

"Something like a desktop might not even survive all the vibration. Then once you get into space you have the radiation."

Even after a major computer upgrade in 1991, the primary flight system has a storage capacity of one megabyte and runs at a speed of 1.4 million instructions per second. While this was more memory and much faster computing speed than could be achieved with the original 1970s-era Shuttle flight computers, it doesn't compare to today's desktop computers.

"The GPCs serve as the brains of the space shuttle," Ferguson said. "It’s really the heart of the control system."

The GPCs include 24 input/output links that collect the signals from the shuttle's myriad sensors and sends them to the GPCs. The computers plug the readings from the sensors into elaborate mathematical algorithms to determine when to swivel the three main engines during launch, how much to move the elevons on the wings for landing and which thrusters to fire in space to set up a rendezvous with the International Space Station, for example. That process is completed about 25 times every second.

The shuttle's computer-driven flight control system was a first for a production spacecraft. The fly-by-wire design, tested on modified research aircraft, does not have any mechanical links from the pilot to the control surfaces and thrusters. Instead, the pilot moves the control stick in the cockpit and the computers transmit signals to the control mechanisms to make them move.

The shuttle system is so dependent on computers that a fraction of a second without them could be catastrophic during the critical parts of flight.

"We have a range where if you can't control the vehicle for 120 milliseconds, you could lose the vehicle," said Andrew Klausman, the United Space Alliance technical manager for the backup flight system and multifunction electronic display subsystem. He's been working with the shuttle computers since 1986.

That's why engineers put so much time into testing and improving the system. A software change typically goes through about nine months of in-house simulator testing and then another six months of testing in a unique NASA lab before it is accepted for flight. The results of the strenuous testing regimen? Well, it has been 24 years since the last time a software problem required an on-orbit fix during a mission. In the last 12 years, only three software errors have appeared during a flight. But perhaps the most meaningful statistic is that a software error has never endangered the crew, shuttle or a mission's success.

"The current quality of this software system is really almost unimaginable," said USA's Jim Orr, who has been working with the shuttle's computer systems and software in different positions since 1978. "It's that good."

The networked computers are set up so that four are operational and one is a backup that could fly the launch and entry if the others failed. The computers receive their information from a host of sensors and actuators throughout the orbiter, external fuel tank and solid rocket boosters.

It sounds like a lot of work for any electronic device, let alone ones that are running on far less memory than a cell phone. And keep in mind that the first few dozen shuttle missions used the first-generation GPCs, which boasted memory capacities of 416 kilobytes and were a third as fast. They also weighed twice as much and it took two boxes to do the job of one of today's GPCs.

That's where the software comes in.

NASA Shuttle Atlantis Crew: Computer glitch wakes crew

After getting a little free time, the Atlantis space shuttle crew was woken up to deal with a second computer failure.

The astronauts switched to another of the shuttle's five main computers, and Nasa said the shuttle was in "stable condition with no concerns for the crew's safety".

A computer had also failed on Sunday.

The crew had gone to bed late on Thursday afternoon, but Mission Control woke them up about one and a half hours later because of the computer trouble. Nasa said they would troubleshoot the problem.

Sunday's computer failure occurred just before the shuttle linked up with the International Space Station. Engineers said the problem was likely caused by a bad switch throw. That computer was working again after new software was installed.

The check-and-balance network of computers provides redundancy during the most critical phases of the mission, and will be needed when Atlantis lands next week to wrap up the 30-year shuttle era.

Earlier on Thursday, the crew got some time off after a hectic week to savour their historic experience.

Until Thursday, the workload in orbit was so intense that the four astronauts had only fleeting moments of realising "wow, this is really it", astronaut Rex Walheim said in a series of TV interviews.

Atlantis first rocketed into orbit in 1985. This is its 33rd flight and the 135th shuttle mission overall. Atlantis will join Discovery and Endeavour in retirement, following its landing next week.

South Korean Rocket Launch Fails to reach orbit

South Korea's first rocket launch failed to push a satellite into orbit but may still anger rival North Korea, coming just months after the communist nation's own launch drew international condemnation.

Vice Science Minister Kim Jung-hyun told reporters Wednesday that one of two covers for the satellite apparently failed to come off, making it drop back toward Earth. The satellite is thought to have burned up while re-entering the atmosphere, he said.

The failure Tuesday dealt a blow to Seoul's quest to become a regional space power. It comes against the complex backdrop of relations on the Korean peninsula — and recent signs that months of heightened tension over the North's nuclear program may be easing.

A South Korean newspaper reported Tuesday that North Korea has invited two U.S. envoys for the first nuclear negotiations between the two countries during President Barack Obama's administration, but Washington quickly said it has no immediate plans to send the envoys to Pyongyang.

North Korea gave no immediate reaction to the rocket launch but has said it would be "watching closely" to see if the U.S. and regional powers refer the matter to the U.N. Security Council. A launch by North Korea in April was suspected to be a disguised test of long-range missile technology and drew a U.N. rebuke.

NASA Hubble (HST) Off-line again! Cntrl-ALt Re-boot!

The 19-year-old Hubble Space Telescope is back to normal after an alarming hiccup earlier this week.

A vital unit stopped communicating with the telescope's main computer on Monday, a development that sent the observatory into standby, or "safe", mode.

The device, which is needed to communicate with the telescope's science instruments, was installed in May during a mission to repair and upgrade the telescope in the hopes of extending Hubble's life until at least 2014.

The unit replaced the original, which was hobbled in September 2009. (Image: NASA)