Nasa video explaining what the osiris satellite which is targetting an asteroid called 1999 is hoping to achieve

Nasa is planning a $2.6 billion robotic mission to catch an asteroid in a giant bag and tow it to the Moon as part of a long-term programme that could one day lead to the permanent settlement of humans in space.

The US space agency has included $100 million in its 2014 budget request, due to be announced next week, to start planning the project.

The mission, which is said to have found favour with the White House, would aim to snare a 500-ton asteroid using an unmanned spacecraft, taking four years to get there, 90 days to wrangle the rock and anything between two and six years to haul it into a high orbit around the Moon. There, astronauts could study it, take samples,