The laser was an American Star Wars toy. Developed at Phillips Labs for the USAF, it was designed to be carried by a 747 aircraft, and used to shoot down short-range missiles. The technology was simple, light and robust, and no doubt inordinately expensive.

Still, the technology was remarkable. The laser was fuelled by hydrogen peroxide which was mixed with chlorine to produce oxygen atoms. At hypersonic speeds, the oxygen was forced with iodine into the lasing cavity, which was a container no bigger than a breadbox, with mirrors at either end. When the oxygen reacted with the iodine it emitted light which was bounced between the mirrors, before being released…

The power generated by this miniature contraption was more than a megawatt.

It had seemed absurd when Henry Meacher had requested this system. What was he expecting, dogfights with the Moonseed in orbit around the Moon? But now, it seemed, its true destiny was becoming clear.

It was a simple matter to fix the laser in place on the outer hull, with silver wire and tape, so that its blunt nozzle pointed ahead of the Soyuz. Arkady used his sextant to check its orientation; it must point directly along the axis of the craft.

When he closed the hatch and pressurized, he found the compartment filled with the sharp scent of space, the tang of scorched metal.

Next, he considered the nuclear weapon, the B61-11 bunker-buster, stowed here in the orbital compartment.

The laser could be controlled from a laptop computer, which he would have close to him during the landing. He ensured that the nuclear weapon could be triggered from the same device.

It was, thought Arkady, at heart a simple problem.

Henry insisted that his nuclear device, the bunker-buster, must be delivered to a precise point, at the very centre of the South Pole-Aitken Basin. But the nuclear device was in lunar orbit, on board Soyuz, and simply dropping it, at orbital speeds, would not suffice.

But to leave orbit and land took energy to remove the velocity with which a spacecraft circled the Moon. The two landers used in the mission had expended that energy in the form of rocket fuel.

Now there were no more landers available. And, just like the Apollo Command Module, Arkady’s Soyuz was not designed to land on the Moon.

Nevertheless, it had been decided, it would have to, in order to complete this new mission.

In the 1980s NASA had actually studied this mode of landing, if briefly. It opened up a new area of knowledge, tentatively called “harenodynamics’, which was a fancy Latin-derived term for “sliding’. Arkady had once attended a conference on lunar bases, industrialization and settlement, which had touched on the subject; when he raised it now with NASA’s Mission Control at Houston, it had not taken long for the back room people there to dig the material out of their archives.

And even less time to express their disbelief.