Watch if you dare: Daredevil to attempt high-wire Grand Canyon crossing

Nik Wallenda will cross the Grand Canyon with cameras rigged to his body (Rex Features)

Armchair thrill-seekers will be able to watch a high-wire walker cross the Grand Canyon, Arizona without a harness on television late tonight.

Nik Wallenda, 34, will walk 427m on a 5cm-diameter steel wire, with the Little Colorado River a quarter of a mile below. It will be the same cable Wallenda used last year when the seventh generation member of the "Flying Wallendas" acrobat family successfully crossed Niagara Falls.

The attempt will be shown on the Discovery Channel at 1am with a 10-second time delay, in case of disaster.