Jeff Bezos' Blue Origin space tourism service has postponed until March 29 a flight initially set for next week, while "Saturday Night Live" comic will not be a passenger on the launch, the company said.
The company, in a brief notice first posted on Twitter, gave no immediate explanation for the change or Davidson's withdrawal from the manifest of Blue Origin's fourth commercial flight since last summer.
Davidson, 28, the boyfriend of reality TV star and socialite Kim Kardashian, had just been officially named on Monday as Blue Origin's "honourary guest" to join five paying customers on the flight initially set for March 23.
With "Davidson no longer able to join" the new flight, Blue Origin said it would announce the sixth crew member "in the coming days".
The five previously revealed are angel investor Marty Allen; real estate veteran Marc Hagle and his wife Sharon Hagle; University of North Carolina professor Jim Kitchen and George Nield, founder-president of Commercial Space Technologies.
Like the first three groups of Blue Origin passengers, they will ride to the edge on a six-storey-tall, fully autonomous spacecraft called the New Shepard, which will lift off from Blue Origin's launch site near the rural west Texas town of Van Horn.
The suborbital joyride, lasting about 10 minutes from liftoff to touchdown, will ascend to about 106 km, treating passengers to a few moments of weightlessness, before a descent back to Earth for a parachute landing.
Bezos, the billionaire founder of online retail giant Amazon tagged along himself on Blue Origin's inaugural crewed flight to space last July.
He accompanied his brother, Mark Bezos, trailblazing octogenarian female aviator Wally Funk and an 18-year-old Dutch high school graduate.
Later passengers included 90-year-old "Star Trek" actor William Shatner, who became the oldest person to fly to space, Good Morning America co-host Michael Strahan, and the eldest daughter of pioneering astronaut Alan Shepard, after whom Blue Origin's spacecraft is named.