Space, as Star Trek fans are reminded at the start of each episode, is the final frontier. But while it is a place that few will ever visit, that does not mean it should be allowed to become a wild west.

An international coalition of lawyers, scientists, government representatives and academics has recently started to draft the first legal manual of space warfare. Establishing the legal parameters for the military uses of outer space, the manual will provide guidance on issues such as the legality of attacking satellites and firing lasers from space during war, and the future rules of engagement.

The document will also consider what constitutes a war crime in space, examining, for example, whether it is a crime to alter satellite images to suggest civilian objects are military targets and whether military astronauts should be governed by the same laws as terrestrial combatants.

Designed to be “future proof” to take into account developments in space exploration and travel, the manual will also examine who has responsibility for cleaning up space debris after military action, and whether the Geneva conventions on the treatment of prisoners of war should apply in space.

Many will consider such a document long overdue. Ever since Nasa put a man on the moon in 1969, space has become increasingly militarised.

In 1983, US president Ronald Reagan outlined a plan for a Strategic Defence Initiative, popularly known as “star wars”, that included a network of space-based lasers to shoot down incoming Soviet missiles. The plan was never realised but many defence experts saw it as evidence of things to come.

Two years ago, the UN general assembly observed that the current legal regime was no guarantee that an arms race would be prevented in outer space and that there was a need to examine further means to prevent a “grave danger to international peace and security”.

But existing space law treaties adopted at the peak of the cold war focus predominantly on the peacetime exploration of outer space. These include the 1967 treaty on the principles governing the activities of states exploring and using outer space, and the 1968 agreement on the rescue and return of astronauts.

“At the moment, the rules of space law found in international treaties focus almost exclusively on the peaceful uses of outer space,” said Dr Kubo Mačák of the University of Exeter law school, which is one of the institutions tasked with drafting the manual.

“But to what extent are states constrained by the law when it comes to their military activities in space? For example, what type of interference with a satellite in orbit amounts to an ‘armed attack’ which would trigger the right of the victim state to use force in self-defence against the attacker?”

Those helping to draft the document, known as Milamos – the manual on international law applicable to military uses of outer space – hope it will eliminate the legal uncertainty. The aim is to produce an authoritative statement of the law on the military uses of outer space and define the scope of responsible behaviour even in times of conflict.

Mačák admitted that the project raised some difficult questions. “Imagine that two states are already engaged in an armed conflict and want to target each other’s space assets in order to achieve a permissible military advantage. In that case, how much, if any, collateral damage does the law permit in space, where any explosion necessarily creates debris that may stay in orbit for decades or even centuries?

“For now, we have more questions than answers. However, the participation of legal and technical experts from around the world gives hope that the solutions we identify will gain global credibility and thus shape the policy and behaviour of space-faring states in the foreseeable future.”

The project is the latest attempt to clarify the application of the law to the changing nature of armed conflict. The 2017 Tallinn Manual 2.0 on the international law applicable to cyber operations is now regarded as having widespread recognition and authority.

Professor Michael N Schmitt, the general editor of the Tallinn Manual, will serve as Exeter’s representative on the management board of the Milamos project. Other institutions involved in the drafting of the new document include McGill University and the University of Adelaide.

SPACE CRIMES

War crimes Images taken by satellite are hacked to suggest civilian objects are military targets. A number of civilians are killed in subsequent military strikes. Is the hacking of the satellite a war crime?

Space debris

This is created after a missile strike takes out the satellite of an enemy nation. Who is responsible for cleaning up the debris?

Does Geneva apply?

Military astronauts are held after their space station is boarded by a hostile power. Are these prisoners still subject to the Geneva conventions?

Permissible targets

Is a civilian-owned communications satellite that contains some transponders used exclusively by the military a permissible military target in time of armed conflict?

Self-defence?

If a country jams data transmission from a satellite that is gathering information on it, does this constitute an armed attack that would permit the state gathering information to use force in self-defence?