By DAVID DERBYSHIRE

Last updated at 13:26 27 March 2008

The space shuttle Endeavour and its crew of seven have returned to Earth after a record 16-day mission that delivered part of a Japanese lab and a Canadian robot to the International Space Station.

After touching down at the Kennedy Space Center in Florida, Endeavour's commander, Dominic Gorie said: "It was a super-rewarding mission, exciting from the start to the ending."

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Endeavour was supposed to land before sunset, but at virtually the last minute, clouds moved in.

As the astronauts took an extra swing around the planet, the sky cleared enough to satisfy flight controllers and - after asking Gorie for his opinion - they gave him the green light to head home.

It was only the 22nd space shuttle landing in darkness. Less than one-fifth of all missions have ended at nighttime; the last one was in 2006.

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crew

Captured against the stunning backdrop of the Earth, an astronaut hangs precariously 250 miles above the Earth as the International Space Station hurtles through space at 17,000mph.

The £70billion structure - a giant network of pressurised cabins, solar panels and radiators - is now in its tenth year of construction yet still is only about 70 per cent complete.

Orbiting the Earth once every 90 minutes, it is the second-brightest thing in the night sky after the Moon and also the most expensive object ever built.

The station is designed to carry out scientific research and test the effects of life in space on humans - all in preparation for the day when mankind (eventually) ventures to Mars.

Due to be completed in 2010 and expected to operate until at least 2016, it has been continuously occupied by an average of three astronauts since the first crew arrived in November 2000.

While the scale of the space station has captured the imagination of many, it has also attracted its fair share of criticism.

Sceptics say the venture - a joint collaboration between America, Russia, Europe, Japan, Canada and Brazil - is a waste of money that could have gone to more useful experiments in space.

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Connected to the ISS by a wire and sweltering in a pressurised space suit, movement is cumbersome and difficult. Astronauts wear a rocket pack to control their movements

But whatever the arguments about its usefulness, the specifications are mind-boggling. When finished, it will be made of 14 pressurised modules which serve as living quarters, corridors, science laboratories, airlocks, storage and docking compartments.

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Power for the ISS comes from the sun - and is collected by four pairs of vast solar panels, one of which can be seen here

The modules are connected to a giant truss 231ft long.

Power comes from a giant solar panel array which stretches nearly 200ft from the ship and is constantly tilted by computers so the panels face the sun.

These stunning images were taken from the Space Shuttle Endeavour, which has just finished a mammoth two-week construction job.

The shuttle delivered the latest 14ft-long storage unit as well as a giant, two-armed robot called Dextre, which cost an eye-watering £100million.

Nasa has ten more flights scheduled to the space station before it retires its ageing Shuttle fleet in 2010.

After that, crews will be ferried to the station on Russian and European spacecraft.

In the meantime, constant work goes on inside ... and out.

Just don't drop the spanner.