Även om inte berättelsen du strävar efter finns en liknande uppsättning osannolika omständigheter i Iain M. Banks " Hydrogen Sonata ". En liten måne har avvecklats och fallit i en underyta omlopp (!) Runt en något större planet
So Fzan-Juym had been appropriately refitted, refurbished and improved, towed to Eshri, slung into a low orbit around it and then carefully lowered still further – kilometre by kilometre, metre by metre, eventually millimetre by millimetre, speeding up all the time – until its orbit now lay a kilometre beneath the planet’s surface, darting along one of the widest and deepest canyons of all in a blur of planet-girdling movement, its course held steady by a network of hermetically isolated AIs and multiply redundant thruster systems dedicated to doing nothing else.
Its own engines had done almost all the work at every stage, though various other craft had helped and been there to step in had anything started to go wrong, but a modest degree of seeming helplessness was deemed to be useful in providing a sort of camouflage of its own.
Fzan-Juym, headquarters of the Socialist-Republican People’s Liberation Regiment #14, had been in sub-surface equatorial orbit of Eshri ever since, zipping along like a super-fast bullet in a slab-sided groove open to the pitch-black sky, orbiting the planet in less than an hour and covering over two hundred million kilometres every year – nearly half a trillion altogether by now – while never coming closer than fifteen hundred metres to either the flat canyon floor or its sheer, polished sides.