After a bit of a glitch delayed the launch by minutes, the space shuttle Discovery has started its final voyage.
The six man crew is now in orbit and heading to the international space station.
There were some tense moments before the historic blast off caused by a computer glitch but the NASA control centre decided to continue with the launch.
The mission is expected to last 11 days and will deliver a science rig and spare parts to the space station.
Crowds of people gathered outside the Kennedy Space Centre in Florida to witness the final lift off.
The shuttle will then be retired after 27-years of service, which makes the Discovery the most time spent in orbit with over 230-million kilometres under its belt since its first launch in 1984.
Commander Steve Lindsay says the mission is bitter sweet.
“For us it’s a privilege to be able to fly that last flight in Discovery but it’s also sad because after that it’s retired.”
A Canadian astronaut who’s flown aboard U.S. space shuttles also admitted to feeling a tad melancholic about the final mission.
Chris Hadfield looked on as the launch carried some Canadian science experiments into space and, with it, took the soon-to-be-retired U.S. shuttle program one step closer to extinction.
“It’s sad that this is the last flight of this great vehicle, but it’s wonderful that this vehicle has done what it’s supposed to do and done it magnificently,” Chris Hadfield said from Cape Canaveral, Fla.
While no Canadian astronauts are aboard Discovery, it will be helping out with a number of Canadian experiments, including a continuation of “Hypersole.”
The University of Guelph project, which has been described as the ultimate tickle test, is taking a closer look at why some astronauts experience a tingly sensation in their feet.
The life-sciences experiment, which began on an earlier shuttle mission, may help aging seniors back on Earth who have problems with their balance.
Discovery will also bring back samples from 24 Canadian white spruce seedlings which it shipped up to the space station in April 2010.
Samples grown in microgravity will be returned to Earth and scientists will analyze their DNA to help understand how trees make wood that are of benefit to the forestry industry.
A third Canadian experiment now going on aboard the space station has been to study changes in blood-vessel structure during long missions. It’s looking for anything that might reflect changes associated with the aging process.
Discovery will be returning to Earth with blood samples for analysis by University of Waterloo scientists.
It will also deliver a so-called “pry bar” which will be used to help deploy a spare arm for Dextre, a Canadian robotic system used outside the space station.