Astronauts go on spacewalk to fix ISS's rail car
Tim Kopra performs a spacewalk outside the ISSReuters

Nasa astronauts Scott Kelly and Tim Kopra made an excursion into space when they stepped out of the International Space Station to fix a stuck rail car. The spacewalk was planned in a hurry as the task had to be completed before the arrival of a Russian cargo ship to dock at the ISS.

The ship, which will make its Christmas day delivery to the ISS, was launched from the Baikonur Cosmodrome in Kazakhstan at 3:44am EST (8:44 GMT) on Monday (21 December) morning.

Station commander Kelly and his colleague Kopra were allotted 3.5 hours by Nasa to complete all their tasks during their spacewalk. The rail car was reported to have been jammed about 4 inches (10cms) short of its predetermined latching point. The jamming was believed to have occurred on 16 December, when the car was left with its brake on, causing it to get jammed. The car serves as a base for a Canadian-built robotic crane that shifts rails outside the ISS.

The astronauts successfully latched the stuck rail car into a parking slot at the ISS's exterior in 15 minutes. They also prepared the ISS to take delivery of the Russian consignment which will include new equipment for the station. Besides, Kelly and Kopra retrieved tools from an outer toolbox for future use within the orbiting lab. This was Nasa's 191st successful spacewalk.