By Alastair Leithead
The crew were happy to be back
"Good day sunshine" rang out aboard Discovery in the early hours of the morning as Mission Control's musical alarm clock woke the astronauts for their last day in space.
"It's a day for sunshine and for feet on the ground," the message said. But at Cape Canaveral, optimism was fast fading for a Florida landing as lightning lit up the horizon.
The first opportunity to land was turned down well ahead of time and shuttle commander Eileen Collins was told to "go around again" and do another earth orbit while the weather planes and forecasters watched and hoped.
Then, just 45 minutes before Discovery's engines were due to fire it into re-entry, Kennedy Space Center was abandoned in favour of the clear weather conditions at Edwards Air Force Base in the southern California desert.
It was a disappointment for those in Florida, including the astronauts' relatives, who had gathered to welcome them home.
And it was a hassle for Nasa, who now have to hitch Discovery to the back of a jumbo jet and piggyback her home.
But the caution paid off - and an hour before the first of two landing windows, the shuttle began the 27,360km/h (17,000mph) drop to earth.
'Good to be us'
Twenty minutes before touch down, in the hottest part of re-entry, Mission Control held its breath.
SHUTTLE LANDING SITES
Kennedy Space Center - the shuttle's "home" and preferred site for landing
Edwards Air Force Base - the shuttle has landed a total of 50 times at the base
White Sands - back-up known as Northrup Strip lies 45 miles north of US Army missile range
It was at this point two and a half years ago that Columbia's heat shield was breached and hot gases tore the spacecraft apart.
But this was the most photographed and monitored shuttle mission in history. Every tile had been checked.
Banking side to side four times on the approach, Discovery passed over the Pacific and north of Los Angeles on its way to the desert landing strip.
The quickfire twin sonic booms rang out over California as the shuttle dropped below the speed of sound and Commander Collins took the helm to guide her spaceship-turned-glider home.
You only get one go at the landing. With a plume of smoke visible from Nasa's night-time cameras, the wheels hit the ground and Discovery rolled 2,000ft (610m) to a standstill.
Mission Control was jubilant: "Today we honoured the Columbia crew," said Bill Parsons, the head of the shuttle programme in a post-landing briefing.
"We brought Discovery home safely - it's a great day.
"If you want to know how I feel, I feel fantastic - it's good to be us today."
It was always going to be a test flight - the first of two that have been planned to bring the shuttle programme back on track.
But while the astronauts get a well-earned rest, the technical teams have a lot of work to do.
The fleet is still grounded after a recurrence of the problem which struck Columbia its fatal blow.
"I think this was a wildly successful mission in so many ways," Mr Parsons said.
"We have some things we have learned and have to go and work on, but now it's clear what it is we have to go and work on."
Ensuring foam insulation does not fly off the fuel tanks on lift off is, of course, the priority.
But no one at Nasa could be pushed on when Atlantis, the next shuttle in line, will make its journey into space.
It is easy to forget quite how routine the space shuttle launches had become - this is the 112th successful return since the first shuttle blasted off in April 1981.
It is hoped the return to space after a two-and-a-half-year absence will restore people's faith in the shuttle programme and boost American expectations for further exploration of space.