Sean Penn has signed on to star in Beau Willimon’s upcoming Hulu series “The First,” Variety has learned.

“The First” is set in the near future and follows the first human mission to Mars. The series explores the challenges of taking the first steps toward interplanetary colonization. Hulu gave the show a straight-to-series order in May. The exact details of Penn’s role are being kept under wraps.

Penn has appeared on various television shows throughout his career, but this marks his first regular role on a series. He has previously appeared on shows such as “Ellen,” “The Larry Sanders Show,” “Two and a Half Men,” and “Friends.”

Penn is one of the most accomplished film actors of his generation, having been nominated for five Academy Awards throughout his career. He was nominated for Best Actor for “Dead Man Walking,” “Sweet and Lowdown,” and “I Am Sam” before winning his first Oscar in 2003 for his role in Clint Eastwood’s “Mystic River.” His second win as Best Actor came in 2009 for Gus Van Sant’s “Milk.”

He is repped by CAA.

“I have such deep admiration for Sean’s immense talent and extraordinary body of work,” Willimon said. “I feel very lucky to be collaborating with an artist of his caliber.”

Westward Productions, an independent film and television studio founded by Willimon and his producing partner Jordan Tappis, will own and produce “The First.” The series, commissioned by Channel 4 and Hulu, will be co-financed by Hulu, Channel 4, IMG and AG Studios. “The First” will premiere on Hulu in the US and on Channel 4 in the UK and Ireland. IMG will handle all international rights.

The series will go into production this year and is slated to premiere on Hulu and Channel 4 in 2018. Executive producers are Willimon and Tappis for Westward. The series was commissioned for Channel 4 by Simon Maxwell, head of international drama, and Beth Willis, head of drama. For Hulu the series was commissioned by Craig Erwich, senior vice president of content, and Beatrice Springborn, vice president of content development.

The news of Penn’s casting comes after Hulu made an impressive showing at this year’s Emmy Awards. The streaming service picked up 10 awards in total this year, with “The Handmaid’s Tale” winning eight, including Outstanding Lead Actress in a Drama Series (Elisabeth Moss) and Outstanding Drama Series, making it the first streaming series to win in the latter category.