You remember, Nik right?  He's the guy who crossed Niagara Falls on a tightrope last year.

Well, he's announced his next stunt, and this time, he WON'T be wearing a safety harness.

On Sunday, June 23, he'll cross the GRAND CANYON on a tightrope.  You read that right...with NO safety harness.  It'll be broadcast "live" on the Discovery Channel.

Here's video of his Niagara Falls stunt.