Free The Long Mars by Terry Pratchett, Stephen Baxter

lab, drone aircraft and even nanosat space launchers – and a bubble observatory, a particularly striking location from which the whole of the Armstrong could be seen, stem to stern.
    Such tours were a joy. Oh, there were plenty of small technical glitches to fix aboard each boat. But the engineering stuff was almost fun , compared with the issues with the flesh and blood passengers . . .
    Unlike the Franklin , with its relatively small and tight-knit Navy crew, on this trip Maggie had enough civilian academics aboard the two ships to man a small university, covering sciences such as geography, astronomy, ethnology, climatology, mineralogy, botany, ornithology, zoology, cosmology. And smarter people were always harder to command.
    Take the problem of the trolls, for instance.
    For five years now Maggie had kept her little family of trolls on board her vessels, because they were useful . Trolls had evolved out in the Long Earth. Through their ‘long call’ they were in touch with their kind throughout the stepwise worlds. They could even sense some breeds of danger coming well before most humans could respond, such as the imminence of Jokers – anomalous and often hostile worlds in the Long Earth chain. Plus trolls were good, and willing, at heavy-lift jobs of all kinds. Plus their very presence promoted an image of diversity and acceptance which Maggie thought was important to her wider mission of being a kind of ambassador of the central nation and its values to the far-flung Long Earth colonies. And plus , dammit, it was Maggie’s ship and what she said was the law.
    But that didn’t stop some crewmen from having problems. The trolls stank, they were noisy, they were dangerous animals loose inside the security cordon of the ship, and blah blah. Maggie had found ways to deal with this. Midshipman Jason Santorini had been with her a long time; he was no high-flyer but was a reservoir of common sense. She’d given him the task of organizing social events involving the trolls – noisy singalongs, for instance. He worked up briefing packages showing how useful the trolls had been aboard the Franklin . He’d even had the bright idea of restricting access to the trolls of an evening, when they preferred to huddle up in a corner of an observation lounge and sing, to winners of a prize in a performance-merit competition. Sailors and marines were competitive by nature; anything you had to work at to win had to be worth having, right?
    She knew she had a handle on the issue of the trolls when she came upon a mass choir of Navy and marines, joining in with the trolls in the observation lounge in singing a sweet, silly round about feeling good, feeling bad, feeling happy, feeling sad . . .
    But then there were the Chinese.
    A few days further into the flight, Chief Engineer Harry Ryan asked Maggie to come down to a particularly exotic engineering sub-department: Artificial Intelligence. Contained in vats of Black Corporation gel, enmeshed in fibre-optic cable, here were the dreaming artificial minds who oversaw most of the ship’s functions, but whose key role was to step the Armstrong across the new worlds – for only sapient minds could step. To Maggie, who had to scrub up to operating-theatre cleanliness standards before even being allowed in here, this was an eerie, somewhat frightening place. What were these manufactured minds thinking, all around her, right now? Were they aware of her presence? Did they resent their enslavement to her purposes?
    ‘Captain?’
    ‘Sorry, Harry.’ She tried to focus on her Chief Engineer. ‘You were telling me about—’
    ‘Bill Feng.’
    ‘Ah, yes.’
    ‘Look, the guy may have been a big cheese on board the Zheng He .’
    ‘More than that, surely. He was the co-designer of all this. The beefed-up stepper technology they’ve now given us to co-develop.’
    ‘Yeah, maybe. Big shot back home. And his English is good—’
    ‘Mother from Los Angeles. Which is why he’s called