It may have taken Ridley Scott 30 years to come around to the idea of revisiting Alien, but he certainly seems to be focused on the task in hand. Earlier this week, at the Hero Complex festival in Los Angeles, Scott confirmed that he is planning two prequels to his 1979 slasher-in-space, with both most likely to be shot in 3D. And he talked a little more about the previously-revealed focus of the two films: the mysterious giant "space jockey", long since dead and wrapped in an ivory-like suit or exoskeleton, which the doomed crew of the Nostromo walk by as they are investigating the planetoid in the iconic first movie.

"I sat thinking about the franchise, which died on the road way back and was lying in the dust, and I thought, 'What I should do is go back,'" said Scott during an on-stage interview at the event. "In the first Alien, when John Hurt climbed up and over the top of the rise there was a massive giant lying in a chair. The chair was either a form of engine or some piece of technology, and I always thought: no one has ever asked 'Who was the space jockey?' Inside the suit is a being.

"What we're going to try to do is squeeze in two prequels … because if you explain who [the space jockey] was and where he came from, then you may want to … go to the place where his people came from."

All of which sounds suitably intriguing, particularly when coupled with suggestions that the prequels will focus on the terraforming of new worlds: was the space jockey on some sort of mission to transform the planetoid into a suitable environment for his people? And could the xenomorphs have been bred as the perfect killing machines designed to wipe out current occupants as part of this process? Scott has theorised previously that the crashed ship explored by the Nostromo crew might have been a weapons carrier capable of dropping Alien eggs onto a planet so that the Aliens could use the local life forms as hosts, which would tally.

Of course, there are a number of issues here. James Cameron has proved with Avatar that you don't have to use human protagonists to keep people interested in the motivations of your central characters. And yet the idea of making the space jockey race integral to the plot does seem tonally inappropriate. If the new films are to feel like Alien movies, they surely need to maintain the atmosphere of claustrophobic uncertainty and suspense that made the first two films such masterful works. Spinning off into a galaxy-wide saga to investigate the origin of various races feels more like Star Trek or Star Wars to my mind. Plus, the CGI work required to create the creatures and their world would be astronomical - the concept seems like a hugely ambitious venture that risks falling into the kind of territory George Lucas struggled with in the disappointing prequels to his trilogy. The technology may exist now for us to paint entirely new worlds on the big screen, but nine times out of 10 they end up looking pretty ropey.

On the other hand, if Scott were to use the humans who originally crash-landed on the planetoid as the basis of the storyline, he runs straight into the main obstacle of making a prequel: we already know what happens (everybody dies). The film-maker has said that the central figure in the first film will once again be human (and female): but how much fun will it be to watch a movie in which the Ripley character must inevitably end up getting slaughtered?

Right now, we have to trust Scott to do the right thing, and, at the very least, he's already been thinking hard about how to shoot in stereo without losing the dark visual tone of the original film (decent 3D is notoriously hard to achieve in low levels of light). Head on over to Ain't It Cool, who grabbed six minutes with the director after his Hero Complex appearance, for all the techy details – but suffice to say, Scott reckons he can darken the picture in post-production to create an appropriately gloomy visual experience.

According to the film-maker, the screenplay for the first Alien prequel is complete, and I'm most definitely intrigued to see what he and his team have come up with. I've already mentioned that the movie needs to look like an Alien film, but, on the other hand, it needs to avoid becoming a shallow retread of the original. One last thought before I leave you to your own speculation: HR Giger, the Oscar-winning Swiss artist who played such a huge part in the design of the original alien and its lair, is still alive, aged 70, although he apparently retired from painting a couple of years ago. For a truly spectacular reimagining, and a chance at adding some genuine originality to the new films, wouldn't it be worth Scott giving him a call?