Actress Natalie Portman is gearing up to lead space drama Pale Blue Dot as a replacement for Reese Witherspoon.

The Legally Blonde beauty had originally signed up to star in and produce the project in 2015, but filming was postponed until early 2018 due to screenwriter-turned-director Noah Hawley's busy schedule.

However, Reese withdrew from Pale Blue Dot's cast in November (17) so she would be available to shoot another season of her hit miniseries Big Little Lies, which has since been confirmed to start production this spring (18).

Witherspoon remains onboard the Hawley film as co-producer, alongside Bruna Papandrea, but now Portman is in talks to fill the main role, reports

If she signs on, the Black Swan star will play a successful astronaut who struggles to adapt to life on Earth after returning from a mission in space.

Casting for the male lead is still underway, but Hawley is expected to get cameras rolling on the Fox Searchlight film, written by Brian C Brown and Elliott DiGuiseppi, in the coming months.

Meanwhile, Reese will juggle her work behind the scenes on Pale Blue Dot with filming and producing commitments for Big Little Lies' second season, as well as her new TV morning show series with Jennifer Aniston.

The as-yet-untitled project was picked up for two seasons by Apple bosses, as one of the tech firm's new original scripted series. Reese and Jennifer, who previously played sisters on Friends, will also serve as executive producers.