After appearing in various TV shows as a guest star, Sean Penn is to make his first proper foray into television for Channel 4 and Hulu's new space-exploration drama The First.
It will follow the first human mission to Mars, focusing on the first steps towards colonisation of another planet, as well as the astronauts' families left behind on Earth.
Most of the details of Penn's role are being kept secret, for now, but the newly released images depict Penn's character Tom Hagerty wearing a US Navy captain's uniform. McElhone, meanwhile, will play the "visionary aerospace magnate" Laz Ingram.
House of Cards' LisaGay Hamilton, Godless star Brian Lee Franklin and Generation Kill's James Ransone are also among the cast, while Australian actress Melissa George (Home and Away) and 22-year-old actress Anna Jacoby-Heron will appear as Diane and Denise Hagerty.
Penn has been Oscar nominated five times, most recently in 2009 for his performance in Milk.
The 57-year-old actor has appeared on several television shows during his career, including on Friends, Ellen and The Larry Sanders Show. But The First is set to be his first TV leading role.
In 2015 it was announced that Penn would star as US president Andrew Jackson in the HBO miniseries American Lion but director Phillip Noyce has since left the project and it's not yet known when, or if, the series will be completed.
The First is due to arrive on Channel 4 in the autumn.