Last week it was quietly reported that Sandra Bullock has indeed signed on to star in Alfonso Cuarón’s Gravity, a film that has struggled for months to land an actress for its pivotal lead role.

Robert Downey Jr. signed on for Gravity earlier this year as well, but he may no longer be up for playing Bullock’s fast-talking copilot in the big-budget, sci-fi venture due to his increasingly jam-packed schedule.

Gravity was originally scheduled to begin filming in London this past summer, which would’ve allowed Downey to complete his work on the project before he departed for Sherlock Holmes 2. Downey has both The Avengers and Iron Man 3 to tackle after shooting wraps on Guy Ritchie’s sequel, which will make it difficult for him to find time for Cuarón’s space-set thriller. The hard-working actor is far from officially out at this point – not to mention that both Warner Bros. officials and Bullock are reportedly pushing for Downey to stay attached to Gravity as well.

Bullock will be the big player in Gravity as her character – an astronaut determined to return to her daughter on Earth after the space station she is working on is destroyed by debris from an exploded asteroid – will be the only individual onscreen for most of the film. Downey’s space veteran does survive the destruction of the station, but the fellow is away on another space ship while Bullock’s heroine struggles to survive and make her way home.

Tom Hanks was shipwrecked on an island in ‘Castaway’.

Bullock’s role in Gravity has been compared to that of Tom Hanks’ in the man vs. nature survival tale, Castaway. Cuarón’s project will be not only far more fast-paced and action-driven than the Hanks vehicle, but the cost will also be significantly higher as Gravity is expected to be upwards of 60% CGI, a la Avatar. The Children of Men filmmaker also has plans for his new sci-vi venture to open with a 20-minute long tracking shot – ambitious, to say the least.

While we always appreciate it when Robert Downey Jr. shows up in a film, Gravity won’t be hurt too badly if he has to quit the project. The success of the movie will depend heavily on what Bullock brings to the table and whether she can make for a truly compelling and engaging lead.

If Downey can spare three weeks to work on Gravity, then we’ll all be much obliged, of course.

Source: Deadline