The Amazon founder and Star Trek fan, who has stepped back from e-commerce to concentrate on running his space company, shook hands with each of the crew as they boarded the rocket and closed the door to the capsule.
Former Nasa engineer Chris Boshuizen, clinical research entrepreneur Glen de Vries and Blue Origin vice president and engineer Audrey Powers rounded out the all-civilian crew.
The autonomous New Shepard rocket lifted off shortly after 10am ET (6pm GST), soaring into the clear skies over Blue Origin’s West Texas launch facility and past the Karman Line at an altitude of 100 kilometres – an internationally recognised boundary for the beginning of space.
Blue Origin, which Mr Bezos founded 21 years ago to advance his goals to have people living and working in space, said the astronauts would experience about three to four minutes of weightlessness.
After a flight lasting about 11 minutes, the capsule touched down in the desert under parachute canopies.
“Hello astronauts, welcome to Earth!” Mr Bezos said after unsealing the capsule door.
Live long and prosper
At age 90, Shatner became the oldest person ever to fly to space, beating the record set by 82-year-old female aviation pioneer Wally Funk, who flew on Blue Origin’s first passenger flight in July.
After clambering out of the capsule, a visibly emotional Shatner told Mr Bezos: “Everybody in the world needs to do this. Everybody in the world needs to see – it was unbelievable.”
Shatner, best known for playing Captain Kirk in the Star Trek television and film franchise, described the trip as similar to experiencing the difference between life and death, with the blue sky turning black as the rocket climbed higher.
“I’m so filled with emotion about what just happened. I hope I never recover from this – I hope I can maintain what I feel now. It’s so much larger than me.”
During the opening credits of each Star Trek episode, he called space “the final frontier” and promised “to explore strange new worlds, to seek out new life and new civilisations, to boldly go where no man has gone before”.
“Having played the role of Captain Kirk ... assigns me the knowledge that a futuristic astronaut would have, but I’ve always been consumed with curiosity,” Shatner said in a Blue Origin video before the flight.
“We’re just at the beginning – but how miraculous that beginning is, how extraordinary it is to be part of that beginning.”
For many space enthusiasts, Shatner’s voyage is a fitting coda for a pop culture phenomenon that inspired generations of astronauts, scientists and engineers.
“This is a pinch-me moment for all of us to see Capt James Tiberius Kirk go to space,” Blue Origin launch commentator Jacki Cortese said before liftoff.
Shatner’s participation in the flight has helped generate publicity for Blue Origin as it competes with rival companies Virgin Galactic and SpaceX, both of which have flown paying customers to space in recent months.
Virgin Galactic founder and its founder, British billionaire Richard Branson, beat Blue Origin to the honour of sending the first astronauts to space in a new kind of space race in the private sector.
Blue Origin had a successful debut space tourism flight on July 20, with Mr Bezos and three others aboard flying to the edge of space and back on a trip lasting 10 minutes and 10 seconds.
But Blue Origin was criticised for attacking its rivals’ achievements after it drew attention to the lower altitude reached by Mr Branson’s flight.
Weeks before Wednesday’s flight, 21 current and former Blue Origin employees published a scathing letter raising concerns over a “toxic” work culture at the company.
The company, they said, has a habit of prioritising launch schedules over safety in its New Shepard flights.
Blue Origin has pushed back on the allegations, saying its primary launch vehicle and capsule set the standard for safety. The company began its live stream of the launch with a video about the company’s safety culture and how robust it considers the design of its New Shepard spacecraft.
Wednesday’s flight had been delayed for wind-related reasons. The four crew members went through training on Tuesday and the mission team completed a flight-readiness evaluation to ensure “all systems are go for launch”, Blue Origin said on Twitter.