Project Hail Mary author Andy Weir had no idea what alien creature Rocky was going to look like until he saw the puppet

Over a decade after Ridley Scott turned Andy Weir's 2011 novel The Martian into an Oscar-nominated film starring Matt Damon, another of the popular author's bestsellers has been adapted into a big-budget movie.

This time, it's Ryan Gosling who takes the lead in the extremely likeable adventure Project Hail Mary, with directing duo Phil Lord and Christopher Miller at the helm. There have already been some very early whisperings that we could see more Oscar nods – with the film opening to rave reviews from critics – while it also looks a safe bet for box office success.

One aspect of the film which seems certain to contribute to it becoming a popular favourite is the existence of an adorable, rock-based alien named Rocky, who Gosling's character Ryland Grace meets and bonds with while conducting an extremely important outer-space mission.

Of course, given he's won all sorts of acclaim for the vivid science fiction worlds he's created on the page, you'd probably imagine Weir had a fairly good idea of what he wanted Rocky to look like on the big screen – but according to the man himself, the opposite is in fact true.

"In this case, I have sort of an advantage in that I don't have a very visual imagination," he told Radio Times in an exclusive interview ahead of release. "When I'm writing, characters are just sort of blobs and concepts really – more than deeply visual items."

Weir added that while he had a good idea of the characters basic morphology – "I knew he was like a thorax with like five legs" – he had by no means meticulously planned the more specific details of the characters.

"I couldn't have told you if his legs were thin or fat, or if they were lumpy or smooth," he explained. "I didn't define any of that. Or it's not a matter of defining, it's just I didn't see it in my head.

"So once I saw the Rocky puppet when I went to the model shop, and the puppeteers workshop, and I saw it, I was like, 'Oh, great. Now I finally know what Rocky looks like!'"

For their part, directors Lord and Miller – whose previous films include 21 Jump Street, The Lego Movie and producer credits on the Spider-Verse movies – admitted that working out exactly how Rocky would be brought to life was a "scary" challenge.
"It was a long process," Miller revealed, explaining that it had taken about a year while they were working with special effects artist Neil Scanlan at the Creature Shop in London.

"He's such a great partner," he added. "The team there is really, really smart. And we did a bunch of variations on the shapes, but keeping it to what was described in the book: that it was a rock-like carapace, with five legs, three fingers on each leg, no face, no eyes, no mouth.

"It speaks through sort of whale song, and we found proportions that we felt were appealing.

"And then we had to work on, 'How do we make this a real character?" he continued.

"And so each facet of his carapace had a different sort of rock-like shape that wasn't a face, but you could project an attitude onto. And then we put carvings on him that would give him cultural history, like a wedding band, a family tartan, a patch, engineering equipment, all that type of stuff.

"We just gave ourselves a lot of tools to make him interesting from every angle. And then James [Ortiz] and the puppet team, and then Aslan [Almukhambetov] and animation team really elevated him through movement."

Project Hail Mary is now showing in cinemas.

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