Photo dated June 15, 2012 shows tightrope walker Nik Wallenda crossing Niagara Falls on a wire.

Agencies/Washington

He’s at it again. The US tightrope artist who crossed Niagara Falls last year will try to do the same at the Grand Canyon -- but this time much further up and without a safety harness.

Nik Wallenda will attempt his highest ever wire walk on June 23, the Discovery Channel, which will broadcast the event live, said on Monday.

The 34-year-old’s stunt will take him 1,500ft (457m) above the Little Colorado River -- that’s higher up than the top of New York’s Empire State Building, Discovery said in a statement.

On June 15, Wallenda, who hails from the Flying Wallendas family of tightrope walkers, crossed a wire suspended 200ft up between the roaring Niagara Falls’ US and Canadian banks cheered on by a rapturous audience.

But at the insistence of broadcaster ABC, which televised that event with a five second delay, he was attached to a harness that would have allowed him to climb back onto the high wire if he slipped and fell.

There will be no such safeguards this time around.

“The stakes don’t get much higher than this,” Discovery quoted Wallenda as saying of his Grand Canyon effort.

“The only thing that stands between me and the bottom of the canyon is a 2-in (5cm) thick wire. I’m looking forward to showing the audience a view of the canyon they’ve never seen before.”

The plan calls for Wallenda to spend about three weeks preparing for the event at his Florida training base, including using wind machines to help simulate conditions.