We are under space attack. It's time for dozens of crew members to run up and down interlocking corridors frantically waving communications devices. We're not really under attack. But the London press junket for Rogue One does feel a little like one of those scenes from the Star Wars series. You could run a new Death Star with the numbers Walt Disney have sent to this groaning West End hotel. Stand by for buffeting.

It requires only a few strokes of the calculator to confirm why this operation is worth mounting. Wealth distribution among Hollywood movies has never been more unequal. In 2015, just five films took 62 per cent of the world’s box office.

And Star Wars movies are more unequal than others. When Star Wars: The Force Awakens was released this time last year, a few rubes suggested it was sure to become the most successful film ever at the world box office. That was never likely. Somehow or other, despite subsequently slipping from every brain, Avatar is so far ahead of rivals – it took an eye-watering $2.8 billion – that it may not be caught in any of our lifetimes. But The Force Awakens managed the number three spot and, in a year of unprecedented bounty, it easily took the 2015 title. It joins Avatar and Titanic as one of only three films to take more than $2 billion.

Walt Disney, which now owns the rights to the franchise, was, in this zero-sum economic climate, always likely to fill every available corner of the calendar with Star Wars action. We will get an "official" film on every odd-numbered year. In each Ryder Cup year we will get an addition to the Star Wars Anthology.

Telling stories adjacent to the main strand, the Anthology episodes will work in much the same ways as spin-off novels used to. In two years time, we get a Han Solo film. The zippy, uncomplicated Rogue One tells us how the rebels secured the information that eventually helped Luke Skywalker to destroy the Death Star in the film we are now urged to call Star Wars Episode IV: A New Hope (that's Star Wars to you and me).

When I last met Gareth Edwards, a charming Warwickshire man with no apparent pretensions, he was managing acclaim for his ingenious low-budget non-monster monster movie Monsters (it was really a romance that happened to take place near monsters). That got him a job directing a reboot of Godzilla. Now, well, he's doing this.

“Yeah, it’s all been downhill from there,” he laughs.

Let’s talk about the vulgar subject of money. There’s no point pretending he and his team won’t be thinking about the opening weekend. Reputations are made and lost on such tabulations.

"That's actually an interesting question," he says. "How do you measure the success of Star Wars? It's going to do well no matter what – in theory. If any film can make its money back it's Star Wars. So if any film should be able to take a risk, it's these movies. Because it's a standalone movie we were given licence to go out on a bit of a limb.

But Force Awakens did such crazy business. It did three times the business of any opening December weekend ever. As a result, there really aren't any expectations on us. Nobody is putting a number on it."

What was it Hitchcock said to Ms Bergman when she was fretting over a line? “Ingrid, it’s only a movie.”

Each Star Wars film is just that. But each episode also engages with the collective childhood memories of a generation (and a half). There are people in their early 40s still angry with George Lucas, the series' creator, for doing what he did to The Phantom Menace in 1999. I wonder if Edwards was wary of taking on the responsibility. If Rogue One goes wrong, the internet may very well explode.

"Yeah, it was kind of like checkmate," he muses. "My initial reaction was: I don't know if they should make this film. Star Wars is like sacred ground to me. And we're making a film that connects directly to it. Part of me thought this was sacrilegious. You shouldn't make this movie. Then I thought, if I turn it down I'll eventually have to walk past buildings with billboards of it. It was your dream project and you didn't do it because you were scared. I was trapped in a good way. You can't say no to Star Wars."

Negative gossip

It looks as if Edwards and his team have got away with it. During production there was some negative gossip about the apparent need for extensive reshoots. But the reviews have been positive and the atmosphere in Disney's Death Star by the Embankment is convincingly positive. The film's biggest selling point is a charming lead performance by Felicity Jones. The English actor, a recent Oscar nominee for The Theory of Everything, plays a rebellious space cowgirl who becomes the bravest member of the picture's core rebel posse.

Jones also shot the Dan Brown adaptation Inferno in the past two years, but surely nothing can prepare a person for the attention that comes the way of a Star Wars lead. She has already had the experience of attending the Comic Con jamboree in San Diego. That is where nerd Gods and Goddesses are declared.

"It is the closest that any of us will get to feeling like rock stars," she tells me. "But that's a wonderful way to watch Star Wars. When you watch it with the true fans, they all cheer when Darth Vader comes on. There is such joy around it."

It is nearly 40 years since Star Wars was released. Felicity Jones has never known a world without it. Like Edwards, she must feel she is shouldering a burden of responsibility.

“I think we all felt we had an enormous sense of responsibility,” she agrees. “Particularly because those films registered with so many people’s lives. We would look at those films and think what makes them so good and how do we keep that essence in the film.”

So, did they find an answer to that question?

"The spirit of it was trying to keep a sense of spontaneity. Sometimes blockbusters can lose a bit of life and they become a bit stilted. We had that handheld camera from the beginning. That helped us be in the characters' heads. Star Wars wouldn't be Star Wars without the humour. But there is also a serious undertone to it."

No spanners have lodged in the machine's mighty clanking works. The Star Wars entity continues to power through cinemaspace and may do so for another 40 years. It pays well. But the creative team seem genuinely committed to its aesthetic.

"To me, the success of Star Wars isn't this weekend," Gareth Edwards says. "If, 20 years from now, I see a kid with a tee-shirt featuring our K2 robot or a Death Trooper I'll be like: 'Yeah, we did it!'"

- Rogue One is out now

Those Official ‘Star Wars’ films ranked

8. The Phantom Menace (1999)
What was, at the time, the "most eagerly awaited movie ever" turned out to be a dull plodding disappointment.

7. Attack of the Clones (2002)
That was the one with a pugilistic Yoda. Right? Less tedious lore. A bit more action. Much less Jar Jar Binks. Tolerable.

6. Revenge of the Sith (2005)
Maybe we were just relieved the whole sorry prequel business was over, but the conclusion actually felt like a proper film.

5. Rogue One (2016)
Very exciting. Excellent lead in Felicity Jones. The lugubrious K-2SO is among the best droids. But it feels a little like a superior TV episode, rather than a fully fleshed out feature.

4. Return of the Jedi (1983)
Bores like to argue the film was let down by the Ewoks. In fact, the Ewoks are the best thing in it. After all, these films are aimed mainly at children.

3. The Force Awakens (2015)
It's essentially a reprise of themes from the first film, but it is carried off with such élan there is no real reason to complain.

2. The Empire Strikes Back (1980)
One of Hollywood's better sequels, the second film made delicious use of a variety of terrains and a vast array of strangely headed beasts.

1. Star Wars (1977)
Love it or, well, not love it quite so much, Star Wars is among a handful of films (The Jazz Singer and Gone With the Wind are others) that changed the way Hollywood does business.