William Shatner and Blue Origin Crew Prepare to take Flight: Live Updates

The full mission lasts about 10 minutes. New Shepard launches to an altitude of roughly 63 miles, a widely recognized marker of where space begins and known as the Kármán line.

At peak altitude, the booster rocket releases its crewed capsule. The booster then begins a descent back toward the ground, reigniting its single engine to land vertically on a slab of concrete five miles from where it launched.

Back in space at the same time, the crew capsule is suspended in a free fall some 63 miles high. The passengers experience roughly four minutes of weightlessness in microgravity as well as views of Earth’s slightly curved horizon where its atmosphere meets space. Each seat has its own window of 3.5 feet by 2.3 feet.

“I’m thrilled and anxious, and a little nervous and a little frightened, about this whole new adventure,” Mr. Shatner said during an interview on NBC’s “Today” show on Monday.

During Blue Origin’s first crewed flight in July, passengers unbuckled and floated throughout the 530-cubic-foot capsule, amused by the weightlessness. They tossed candies to one another and did somersaults before getting back in their seats.

During the capsule’s free fall toward land, it deploys an initial set of parachutes to brake its speed, then another set of three bigger parachutes to carry the capsule softly to land at about 15 miles per hour. Milliseconds before landing in the desert — also not far from the launchpad — the capsule releases a burst of air from its underside to cushion the touchdown. The seats inside are supported by a scissor-like mechanism that further limits the impact.

Blue Origin had boasted that the windows on New Shepard’s crew capsule are the biggest to fly in space, but Elon Musk’s SpaceX snatched that superlative in September when it launched its Crew Dragon capsule to low-Earth orbit with a new glass dome that stretches 46 inches wide and 18 inches deep, covering 2,000 square inches in all.

As the Trek media empire expanded since the original series (it now encompasses a growing multiverse of films and shows, as well as video games, merchandise, conventions and more), Mr. Shatner’s place as a bona fide science-fiction celebrity has only strengthened.

“It looks like there’s a great deal of curiosity in this fictional character, Captain Kirk, going into space,” Mr. Shatner said in a promotional video posted on Twitter by Blue Origin. “So let’s go along with it. Enjoy the ride.”

But his life in the public eye is far from limited to “Star Trek.”

For years, Mr. Shatner played a hyperbolized version of himself as “The Negotiator” in commercials (some with a Trek twist) for the travel agency Priceline.

He won two Emmy Awards and snagged nominations for his roles in the interconnected legal dramas “The Practice” and “Boston Legal” in the 1990s and 2000s (his “Star Trek” work never received Emmy or Oscar nods). He also received an outstanding guest actor nomination for a series of cameos as The Big Giant Head in “3rd Rock From the Sun.”

His age has not halted his work. Earlier this year, he was the lead actor in the romantic comedy “Senior Moment” alongside Jean Smart, 20 years his junior at 70.

Offscreen, Shatner has released several albums that straddle the line between music and spoken word poetry (a style that produced a particularly memorable performance of Elton John’s “Rocket Man” at the 1978 Science Fiction Film Awards). In 2012, he came to Broadway with a one-man show that traversed his life and career. And even as a nonagenarian, he’s kept up with the kids and brought his distinct personality to Twitter, which has served as an ideal platform to hype his latest adventure.

Mr. Shatner, in an interview with CNN last week, said he’s bringing along on his jaunt to space a “little blue satchel” of mementos that includes “three or four little trinkets” from family and friends.

But during the flight, he intends to stay focused on looking back at planet Earth.

“I plan to be looking out the window with my nose pressed against the window,” he said during a chat last week with Blue Origin employees, clips of which the company posted on Twitter.

He then added, “The only thing I don’t want to see is a little gremlin looking back at me. Are you sure that’s not going to happen?”

Joey Roulette contributed reporting.

Fortunately for all three, none will be wearing a red Starfleet uniform during the flight.

Dr. Boshuizen or Mr. de Vries are the second and third paying passengers to fly on a Blue Origin flight. The first was Oliver Daemen, an 18-year-old man from the Netherlands. The company has not said how much any of these customers paid for their seats on the flights.

As ticket-purchasing customers, they are something like early investors in an industry executives hope will one day be cheap enough for a broader swath of the public to take advantage of.

Ms. Powers all but flew to space on New Shepard in April, when she and three other company executives were “stand-in astronauts” for Blue Origin’s 15th flight of the New Shepard rocket. She and her colleagues essentially performed a dress rehearsal for the missions with astronauts aboard. The executives went through all the motions of getting ready for a launch — climbing up the rocket tower, boarding the capsule, closing its hatch and testing out its communications system — until about 15 minutes before liftoff when they exited the capsule and left the pad.