Donald Trump’s declaration that space represents “the next warfighting domain” comes at a time when nervous superpowers are taking an idea that once belonged to the realms of fiction increasingly seriously.

US military briefings leading to Trump’s formal announcement of a new, separate space command argued that “an emergent China and a resurgent Russia” have eroded what Washington traditionally believed was an arena it could dominate.

At its heart are concerns about the safety and security of satellites, a fear that critical civil and military communications and navigation systems – such as GPS – could be knocked out by a rival power in a future conflict.

Lurid slides even show how space war technology might develop: satellites armed with lasers, radio frequency jammers, chemical sprays and even robot arms to rip apart other extraterrestrial equipment, although none are yet known to exist.

As things stand, the only proven method of waging such as space war is by firing a missile from the ground to smash a target in space: a “hit to kill” technique first tested by China in 2007 and subsequently by the US, Russia and, this March, by India.

Last year, France’s defence minister, Florence Parly, accused Russia of conducting espionage using a satellite with “big ears”. It was not absolutely certain what the Olymp-K, or Luch, was capable of, but it was not the first time the military satellite had manoeuvred itself close to its western counterparts.

Britain has already been drawn in as the new battle lines emerge. Last month, Penny Mordaunt, when still defence secretary, announced plans to join the then obscure US mission Operation Olympic Defender. “This will be an international coalition formed to strengthen deterrence against hostile actors in space,” the then cabinet minister said, without offering much detail as to what the operation would involve in practice.

It may not amount to anything resembling Star Wars, but even simply smashing up rival satellites is fraught with risk. One fear is that it could lead to a nightmare scenario called the Kessler syndrome, named after astrophysicist Donald Kessler. The American scientist warned against the consequences of an unrestricted build-up of space debris, choking important orbits to the point where they become unusable. China’s 2007 demolition, for instance, produced 3,000 trackable particles.

Historically, the 1967 Outer Space Treaty was supposed to prevent the militarisation of space by banning the use of nuclear weapons in orbit. But the combination of a simpler technology and nationalistic governments are combining to make the final frontier a zone of conflict half a century on.