Sean Penn is leaving movies behind and making his way to TV.
The Mars-themed drama follows the first human mission to Mars and will follow the trials and tribulations as everyone tries to make sure the trip goes off without a hitch.
In a surprising move, the series will not solely be set in Space.
It will follow the families of the group sent to the elusive planet and the ground team back on Earth who will be on tap with support for the group as they press on with the most important mission of their careers.
“I have such deep admiration for Sean’s immense talent and extraordinary body of work,” said Willimon in a statement about the exciting casting news.
“I feel very lucky to be collaborating with an artist of his caliber.”
Penn has previously appeared on comedies such as Ellen, Two and a Half Men and Friends. He also stars as President Andrew Jackson in HBO miniseries American Lion.
Hulu handed out straight-to-series order earlier this year, and it is scheduled to launch in 2018.
The streaming giant is looking to capitalize on the success of The Handmaid's Tale, which became the first series from a streaming service to win an Emmy for Outstanding Drama Series.
This recognition will likely propel the streaming giant to find new and groundbreaking programming to drive up subscriptions to put it up there with Netflix.
Hulu has two high-profile drama series launches on tap for later this year. Future Man will star Josh Hutcherson, Eliza Coupe, Derek Wilson, Haley Joel Osment, Keith David, Glenne Headly and Ed Begley Jr.
It will focus on a man who is employed by a random group of visitors to travel through time to prevent the extinction of humanity.
It launches Tuesday, November 14 and will consist of 13 episodes.
Meanwhile, Marvel's Runaways boasts a cast that includes the likes of Rhenzy Feliz, Lyrica Okano, Virginia Gardner, Ariela Barer, Gregg Sulkin, Allegra Acosta, Annie Wersching, Ryan Sands, Angel Parker, Ever Carradine, James Marsters, Kevin Weisman, Brigid Brannagh, James Yaegashi, Brittany Ishibashi, and Kip Pardue.
It centers on a group of teenagers who find themselves on the outs, but unite to take down a common enemy: Their parents.
Over to you, TV Fanatic. What do you think of this casting news? What are your thoughts on the show? Sound off below!
Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.