Tuesday, 01 July 2014 - 11:27
Satellite to seek 'missing carbon'
The US space agency (Nasa) will make a second attempt on Tuesday to put a high-resolution carbon dioxide observatory in orbit.
The first satellite was destroyed on launch in 2009.
Since then, scientists and engineers have built a near identical spacecraft, which will launch from the Vandenberg Air Force Base in California.
"It's been a long walk back to where we are now," David Crisp, the mission's Science Team Leader, told BBC News.
"We've delivered the spacecraft, but we've still got a number of challenging steps ahead of us before this system is on orbit, operating and returning science data."
The Orbiting Carbon Observatory-2 (OCO-2) will ride to orbit on a Delta II rocket
Lift-off is timed for a 30-second window at 02:56 local time (09:56 GMT; 10:56 BST).
The $468m ($275m) OCO-2 mission is going to trace the global geographic distribution of carbon dioxide in the atmosphere - to try to identify precisely where it is emitted and absorbed.