Preparations are underway for the scheduled launch of Nasa’s wide-field infrared survey explorer (WISE) spacecraft on 11 December from Vandenberg Air Force Base in California.

The spacecraft’s second stage has been loaded with propellant by technicians at Space Launch Complex 2 in preparation for its launch to the Earth’s orbit aboard a Delta II rocket.

The WISE spacecraft will circle the Earth over the poles and will scan the entire sky one-and-a-half times in nine months, during the mission, to uncover hidden cosmic objects, including the coolest stars, dark asteroids and the most luminous galaxies.

There is, however, an 80% chance that the launch will be prevented, as weather forecasts thick clouds, disturbed weather and precipitation, on the launch day.