One of the highlights of 2019 will be celebrations of the 50th anniversary of the moment in July 1969 when the human race held its collective breath to watch its first members set foot on another celestial body. In retrospect, the Apollo moon landings were a triumph of engineering and right-stuff piloting but in exploration terms a frenzied dash up a blind alley. By taking stupendous risks with human lives the US was able to beat the Soviet Union's cold war challenge in space. However once the stunt had been achieved, there was nowhere else for astronauts to go and the technology was not available to exploit where they had been.
The very impracticability of exploiting the 1960s space race for military or commercial purposes left an important legacy. It allowed both superpowers to put on a high-minded front about exploration for the benefit of science and humanity: 'We came in peace for all mankind', as the lunar plaque signed by President Richard Nixon put it. An important consequence of this spirit was the 1967 Outer Space Treaty, supported by both then superpowers and unanimously endorsed by the UN General Assembly. It has since been ratified by 62 states.
Article I of the treaty provides that: '… exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind'. Specifically it prevents the placing of weapons of mass destruction in orbit or on the moon or other celestial bodies. The treaty also rules that outer space is not subject to 'national appropriation'.
In the spirit of the 1960s, these were easy enough rules to sign up to (though with an element of humbug: both superpowers were running covert programmes to find ways of exploiting the military's new high ground). Half a century on, reality has changed. Whether we like it or not, space is now militarised. More to the point for international law-making, it is increasingly a commercial proposition. Hence we see a growing chorus of calls for reform in international law to protect commercial activities, including clarifying that awkward ban on 'appropriation'.
Reformers will face an uphill struggle, however, simply because - unlike in the 1960s - commercial exploitation of outer space is no longer in the realm of science fiction. While space tourism will probably prove a flash (perhaps literally) in the pan once a few billionaires have had a ride, the commercial potential of small, cheap, low-orbit satellites is immense. Meanwhile, advances in artificial intelligence and robotics make the remote exploitation of the resources of the moon and asteroids a plausible possibility. A harbinger may be this week's impressive Chinese landing on the far side of the moon.
Experience shows that, the higher the commercial stakes, the more difficult it will be to draft new international laws. Legislating for reality is a lot harder than sanctimonious posturing. And business can also expect counter-lobbies calling for the protection of celestial environments: after all Apollo 11 may have come in peace, but the litter it strewed on the moon is still there, 50 years on.
Rather as the high seas were once de facto governed by English law, outer space will be regulated by whichever nation emerges as the dominant space power. That may well be neither of the contenders in the moon race.