Belying its austere reputation for pure science and the search for fact, the European Space Agency (ESA) is branching out -- into fantasy film-making.

ESA has released a six-and-a-half-minute work, complete with a TV star, Oscar-nominated director and dramatic digital effects, that turns the spotlight on its historic mission to explore a comet.

Called Ambition, the short film features Irish actor Aiden Gillen -- a star in TV's Game of Thrones -- as a mind master in a world where humans have the powers of demi-gods.

He oversees an apprentice, Aisling Franciosi, in using mental powers to assemble asteroids and planets, drawing on the pioneering experience of Rosetta to understand how life is formed.

The film -- which can be seen on http://www.esa.int/spaceinvideos/Videos/2014/10/Ambition_the_film -- is directed by Poland's Tomek Baginski, nominated for an Oscar for a short movie, Katedra, in 2003.

Filmed in Iceland and digitally enhanced, it was released last Friday at a festival in London.

Launched in 2004, Rosetta is an unmanned probe that has taken more than a decade and more than six billion kilometres (3.75 billion miles) to reach its target, Comet 67P/Churyumov-Gerasimenko.

Rosetta is now in close orbit around the comet at a distance of around 400 million kilometres from the Sun.

The scout will send down a robot lander, Philae, on November 12 to carry out on-the-spot scientific tests.

Comets are believed by astrophysicists to be made of ancient ice and dust left from the building of the Solar System.

Experts see them as time capsules of primeval material that may give insights into how the planets formed after the Sun flared into light.

Some also believe that, by bombarding the infant Earth with water and organic molecules, they provided our planet with the building blocks of life -- a theory called pan-spermia.