Jake McDorman, Colin O'Donoghue and Aaron Staton are among the actors signing on to play the Mercury astronauts in the adaptation of Tom Wolfe's book.

National Geographic's The Right Stuff has recruited the rest of its Mercury astronauts to star in the series adaptation of Tom Wolfe's book.

Jake McDorman (Murphy Brown, What We Do in the Shadows), Colin O'Donoghue (Once Upon a Time), Aaron Staton (Castle Rock, Mad Men), Michael Trotter (Underground), Micah Stock (Escape at Dannemora) and James Lafferty (The Haunting of Hill House, One Tree Hill) have joined the series alongside the previously cast Patrick J. Adams.

The actors will play the Mercury Seven, the test pilots who became the first group of astronauts for the United States.

The series will use Wolfe's best-selling book about the early days of the space race as a starting point; subsequent seasons will follow the U.S. space program through the Apollo missions and beyond.

The Right Stuff opens in the height of the Cold War, following the Soviet Union's successful launch of the Sputnik satellite into orbit. NASA's Project Mercury makes instant celebrities of the seven test pilots tapped to be future astronauts, portrayed as heroes before they actually do anything heroic.

Adams is playing John Glenn, who was already well-known before Project Mercury and develops a rivalry with Alan Shepard (McDorman), who's furiously competitive and one of the Navy's best test pilots; both want to be the first man in space.

O'Donoghue plays Gordon Cooper, the youngest of the seven and a surprise selection. Game of Thrones alum Joe Dempsie was originally cast as Cooper but had to leave the project due to visa issues. Staton will play Wally Schirra, a competitive pilot and prankster. Lafferty plays Scott Carpenter, nicknamed "The Poet" by the rest of the group. Stock plays Deke Slayton, a taciturn but talented pilot and engineer, and Trotter plays Gus Grissom, who will eventually become the second man in space.

The Right Stuff, which was previously adapted as an Oscar-winning 1983 film, comes from Appian Way and Warner Horizon Scripted Television. Mark Lafferty (Castle Rock, Halt and Catch Fire) is the showrunner and executive produces with Appian Way's Leonardo DiCaprio and Jennifer Davisson and Will Staples. Michael Hampton shepherded the project for Appian Way.

The series is set to begin production in Florida in the fall for a 2020 premiere. Nat Geo's other scripted shows include limited series The Hot Zone and anthology series Genius.

Aug. 19, 10:25 a.m. Updated with Colin O'Donoghue replacing Joe Dempsie.