‘Nasa’s Curiosity rover has already proved a bunch of stuff I wrote is wrong!’

but I’m not going to teach Nasa or SpaceX anything they didn’t know.”

Given the huge success of his debut, it was “frustrating” that the follow-up, Artemis, featuring the first city on the Moon and a young Muslim woman, Jazz, as its heroine, didn’t take off in quite the same way.

“I feel like if I’d made Artemis in a vacuum, people would have maybe been able to enjoy it a bit more,” says Weir, who based Watney and Jazz on aspects of his own personality. “Watney is all of the bits I like with none of my flaws. In Artemis, I wanted to make a flawed character, but I think I went too far and made her so flawed people had a hard time rooting for her. I think I made Jazz an unlikeable character.” But he isn’t making the same mistake with his new hero, Ryland Grace. “This time my protagonist is a very likeable guy, his flaws are things people can empathise with, he’s scared,” says Weir. “He’s kind of innocent, he’s a bit goody two shoes. We learn he’s a coward more or less, ruled by his fear.”

If Grace is Watney-like, Project Hail Mary is also closer to The Martian than Artemis in theme and tone. But the inspiration for all three came about in a similar manner.

“Both of my other books started off with me speculating. Thinking about how we

SPACEMAN: Andy with former Apollo 11 astronaut Buzz Aldrin MARS ROVER: Matt Damon played Mark Watney in the film version of The Martian

could do a human to Mars mission in the real world led to me coming up with the idea for The Martian,” he says.

With Project Hail Mary,Weir was wondering what the most efficient rocket fuel might be. “Theoretically it would be something that turns matter into light and shines it out of the back of your ship. Light has momentum.When you turn on your torch, it actually has a little bit of kick, not that you’d feel it.”

His musings led him to create a fictional organism he calls “astrophage” – “a thing that eats stars” in Greek – an interstellar lifeform that lives and breeds on the surface of stars by consuming their energy. He explains:

“My original plan was astrophage exists and we get hold of it and it’s about the scientific advancements we get from it.And I thought, ‘We’d have to be real careful not to let that get into our sun, that would be disastrous’, and then I was like, ‘Wait a minute, disaster is where stories come from…’”

Thus the new novel, cannibalised in part from an unpublished work, Zhek, begins with Grace waking up with amnesia on board a spacecraft, the Hail Mary, the sole survivor of an interstellar mission to see what humanity can learn from Tau Ceti, a star in another system that appears unaffected by the organism. Despite being endlessly inventive, Grace will only survive if he can beat his fears. His creator’s engaging optimism extends to real life, even the coronavirus pandemic.

“I would say it’s a huge tragedy but, as a species, our response to it has been pretty darn impressive. Over the course of basically one year we developed a vaccine. And not just a vaccine but an entirely new technology of vaccine – mRNA vaccines – and those are a game changer. With mRNA vaccines you can hand the lab a virus and it can hand back a vaccine in three weeks.”

In an “insanely optimistic claim” (his words), he says: “I think Covid-19 is going to be the last pandemic in human history, because now we have the technology to stop one in its tracks.”

In recent weeks, needless to say, Weir has been watching with interest as Nasa’s Curiosity rover explores Mars. “It already proved a bunch of stuff I wrote wrong,” he laughs. “For instance, there’s an enormous amount of water ice in the Martian soil so all that stuff Mark Watney did to make water, he wouldn’t have needed to do that.”

HUGE success appears to have changed Weir little. With his money from The Martian, he splashed out $10,000 on a genuine Martian meteorite the size of a walnut – one of only a few hundred to have been found on Earth.

“Mars gets hit by meteors and has a thin atmosphere, so sometimes it gets hit so hard it kicks rocks out of Mars’s gravity well and they wander around the solar system for a while and some fall to Earth.”

As for humanity’s interstellar ambitions, he isn’t convinced we’ll get to Mars in his lifetime. Nor does he worry about private companies run by billionaires like Musk, Jeff Bezos of Amazon or even Richard Branson being gatekeepers to the stars.

“These people are all ultimately guided by a desire to do a for-profit industry and they’re in competition with each other,” he says. “If a government is the gatekeeper on whether or not you can get to space it becomes political stuff that decides whether or not they’ll let you. If a company is in charge it’s whether or not you can afford the ticket, it’s democratised.”

But would Weir, who famously hates even flying, pay to go into space? “No, no, no… I would not go into space even if it were free.”

So what if someone offered you a flight? He laughs: “I’d say, ‘Thank you, I really appreciate it, and good luck, but no thank

you…’”

●●Project Hail Mary by Andy Weir (Del Rey, £20) is out now. For free UK delivery, call Express Bookshop on 01872 562310 or order via www. expressbookshop.co.uk