International Space Station gets new observation deck

The node was initially installed on the station on Friday

Astronauts have successfully installed an extension to the International Space Station in a series of spacewalks.

The so-called Tranquility Node includes a number of docking locations and will provide a breathtaking, 360-degree view of Earth through its "cupola".

The node was initially installed on Friday, with electrical connections and commissioning occurring in a series of spacewalks over the weekend.

A final spacewalk on Tuesday will complete the node's commissioning.

The US space agency Nasa has extended the mission of space shuttle Endeavour by a day to allow all the crew's tasks to be completed.

Installation of Tranquility and the cupola, both supplied by the European Space Agency, marks the end of major construction of the ISS, an international effort that first began in 1998.

Node out

The 14-tonne node will house core life-support systems, exercise equipment, robotic workstations and - in the form of its cupola - the best view of Earth and approaching spacecraft that the ISS has ever enjoyed.

A spacewalk of nearly six hours undertaken on Saturday saw Tranquility connected to the ISS's cooling system.

NODE 3 - 'TRANQUILITY' Key unit connects and helps manage other ISS modules Multiple docking ports for visiting vehicles or future modules 7m by 4.6m; a mass of 14 tonnes, but will be fitted out in orbit Sophisticated life support systems will include air cleaning unit Cupola to be fixed to an Earth-facing port once in orbit Panoramic views provide ideal control room for robotic arm Named after Sea of Tranquility, the Apollo 11 landing site

A small mishap occurred when ammonia from the system shot out on to mission specialist Nicholas Patrick's spacesuit.

The liquid ammonia had already solidified by the time it hit the suit and bounced off, but the spacewalk was cut short to carry out safety procedures.

With cooling in place, Tranquility's electrical systems could be powered up.

In a spacewalk late on Sunday, the crew moved the cupola into place on the Earth-facing side of the node.

Space station commander Jeffrey Williams found that several of the bolts holding the cupola in place were jammed.

With instructions from ground control, the crew increased the force applied and were able to free the bolts - only to find an electrical connector appearing to hang loosely from the dome.

Commander Williams assured crew that the wiring would not interfere with the cupola's Earth-side installation, and the cupola was put into place without further incident.

'Eagerly awaiting'

Tuesday's spacewalk will see the crew install a robotic workstation and a back-up cooling system on the node.

On Wednesday or Thursday, the cupola's shutters will be drawn back, giving a view through the largest window ever to be sent into space.

"The cupola, I think, is really one of the most spectacular viewing platforms that we will have had in space... so we're eagerly awaiting the release of the shutters and the first views," said flight director Kwatsi Alibaruho.

The shuttle is now due to land at Kennedy Space Center on 21 February.

There are four more shuttle missions to the ISS planned in the coming seven months before the shuttle fleet is retired.

Space rock contains organic molecular feast

The Murchison meteorite came down in Australia in 1969

Scientists say they have confirmed that a meteorite that crashed into earth 40 years ago contains millions of different organic compounds.

It is thought the Murchison meteorite could be even older than the Sun.

"Having this information means you can tell what was happening during the birth of the Solar System," said lead researcher Dr Philippe Schmitt-Kopplin.

The results of the meteorite study are published in the Proceedings of the National Academy of Sciences.

"We are really excited. When I first studied it and saw the complexity I was so amazed," said Dr Schmitt-Kopplin, who works at the Institute for Ecological Chemistry in Neuherberg, Germany.

We have to crush a few milligrams from the core of the meteorite Dr Philippe Schmitt-Kopplin

"Meteorites are like some kind of fossil. When you try to understand them you are looking back in time," he explained.

The researchers says the identification of many different chemicals shows the primordial Solar System probably had a higher molecular diversity than Earth.

The Murchison meteorite landed in a town of that name in Australia in 1969. It has been examined before by scientists looking for specific compounds but this is the first non-targeted analysis and has confirmed a huge variety of carbon-based chemicals.

A study using high resolution analytical tools including spectroscopy allowed the team to identify 14,000 different compounds including 70 amino acids in a sample of the meteorite.

They extrapolated this on the basis of knowledge of how similar organic molecules are arranged in space and calculated that the meteorite should contain several million different chemicals.

But the analysis technique is still limited, as Dr Schmitt-Kopplin explained: "We have to crush a few milligrams from the core of the meteorite to enable the extractions with solvents and thus we only see the extractable fraction."

"In addition we are only seeing the ions we can generate with the ionisation source of our mass spectrometer. With different types of ionisation sources we could see even more."

Burning question

Scientists believe the Murchison meteorite could have originated before the Sun was formed, 4.65 billion years ago. The researchers say it probably passed through primordial clouds in the early Solar System, picking up organic chemicals.

Dr Schmitt-Kopplin hopes the findings might contribute to the debate over how life on Earth originated.

"I guess many people working in these fields with access to this knowledge will have some further hypothesis and will possibly be having some of their hypotheses confirmed."

"Where did we come from and what happened before? We all have that question inside us."

The team is also analysing other meteorites but say Murchison is probably the most complex they have studied.