As a result of all this, they had lost water that could not be completely recovered; they had a broken pipe section, therefore a broken main reactor cooling system; and the temporary loss of both cooling systems had caused the reactor rod pool temperature to redline, and parts of it to begin shutting down. Now the backup cooling system was functioning, so it wasn’t an immediate emergency, but the damage to the main cooling was serious. They needed to get a new pipe made and installed as quickly as possible, and some of them were going to have to do some really expert waldo work to get the melted section of pipe cut out and a new section installed in its place. When all that was repaired, they would have to open the main cooling system’s fill cock and refill it with water from their reservoir. Possibly some of the lost water could be filtered out of the air and later returned to the reservoir, but some was likely to stay dispersed throughout the spine, adhering to its inner surfaces and sticking by way of corrosion.
That night, back in their apartment, Devi said, “We’re breaking down, and running low on consumables, and filling up with unconsumables. This old crate is clapped out, that’s all there is to it.”
The telescopes housed in the bowsprit of the ship were extremely powerful, and now as they crossed Tau Ceti’s planetary orbits, they could look at the planets more closely. Planet E and its Earth-sized moon remained the principal objects of interest, with Planet F and its second moon also getting long looks.
Planets A, B, C, and D all orbited very close to Tau Ceti, close enough to be tidally locked. They glowed with heat on their sunward side, and the sunny side of Planet A was a sea of lava.
The low metallicity of Tau Ceti, and thus all its planets, was discussed endlessly by the ship’s little astrophysics group, who were finding that what metals the system contained were concentrated most heavily in Planets C, D, E, and F, which was useful for their purposes.
The telescopes shifted from one target to the next as they drifted downsystem. By far the greatest part of their viewing was now given to E’s moon. It was ocean-covered for the most part, with four small continents or large islands, and many archipelagos. It was tidally locked to Planet E, and had .83 Earth’s gravity. Its atmosphere averaged 732 millibars of pressure at sea level, the air mostly nitrogen, with 16 percent oxygen, and about 300 ppm of CO2. There were two small polar caps of water ice. On the Nguyen Earth-analog scale it scored .86, one of the highest scores yet found, and by far the highest found within 40 light-years of Earth.
The probes that had passed quickly through the Tau Ceti system in 2476 had found that the oxygen present in the atmosphere was abiotic in origin, by using the Shiva Oxygen Diagnostic, which analyzed for an array of biologic marker gases like CH4 and H2S. If these were found in an atmosphere along with oxygen, it indicated the O2 was almost certainly biological in origin. Atmospheric O2 found without the other gases also present indicated the oxygen had been produced by sunlight splitting surface water molecules into hydrogen and oxygen, with the much lighter hydrogen later escaping to space. E’s moon’s oxygen had scored very strongly to the abiologic end of the rubric’s scale, and the moon’s remaining ocean, combined with its nine-day periods of intense sunlight, gave this finding a solid physical explanation. In essence, part of the ocean had been knocked by sunlight into the atmosphere.
On their way in to E, they inspected Planet F’s second moon, a so-called Mars analog, also of interest to them. Its surface g was 1.23 g, and it was almost without H2O, being entirely rocky. It was speculated that an early collision with F had created this moon, in much the way Luna had been created by the early collision of Neith and Terra. F’s second moon would have Planet F bulking hugely in its sky, being only 124,000 kilometers away. Planet F’s first moon was quite small, and ice-clad, probably a captured asteroid. It could conceivably serve as a water supply for the second moon. So the F system was considered to be a viable secondary option for inhabitation.
But first they flew to E’s moon, which was now being called Aurora.
Approaching Planet E they decelerated until they were so close they had to decide whether to orbit E or Aurora, or position themselves at E’s Lagrange 2 point. Ship would not have to expend much fuel to get into any of these orbital configurations. After consultations the executive council chose to orbit Aurora. People became more and more excited as ship closed on the watery moon.
Except in Nova Scotia, where it was known that Devi was becoming quite ill. The result was a confusion of spirits. It was exciting to reach their destination at last, and yet it was precisely in this unprecedented situation when they might most need their chief engineer, now nearly legendary for her diagnostic power and ingenious solutions. How would they fare on Aurora, if she were not there? And didn’t she deserve more than anyone to see this new world, to experience the dawn of their time there? These were the things people in Nova Scotia said.
Devi herself did not say anything remotely like that. If visitors spoke such sentiments to her, which in itself indicated they did not know her very well, she would dismiss them with a wave. “Don’t worry about that stuff,” she said. “One world at a time.”
Many nights Devi and the ship had long conversations. This had been going on since Devi was Freya’s age or younger; thus, some twenty-eight years. From the beginning of these talks, when young Devi had referred to her ship interface as Pauline (which name she abandoned in year 161, reason unknown), she had seemed to presume that the ship contained a strong artificial intelligence, capable not just of Turing test and Winograd Schema challenge, but many other qualities not usually associated with machine intelligence, including some version of consciousness. She spoke as if ship were conscious.
Through the years many subjects got discussed, but by far the majority of the discussions concerned the biophysical and ecological functioning of the ship. Devi had devoted a good portion of her waking life (at least 34,901 hours, judging by direct observation) to improving the functional power of the ship’s data retrieval and analytic and synthesizing abilities, always in the hope of increasing the robustness of the ship’s ecological systems. Measurable progress had been made in this project, although Devi would have been the first to add to this statement the observation that life is complex; and ecology beyond strong modeling; and metabolic rifts inevitable in all closed system; and all systems were closed; and therefore a biologically closed life-support system the size of the ship was physically impossible to maintain; and thus the work of such maintenance was “a rearguard battle” against entropy and dysfunction. All that being admitted as axiomatic, part of the laws of thermodynamics, it is certainly also true that Devi’s efforts in collaboration with the ship had improved the system, and slowed the processes of malfunction, apparently long enough to achieve the design goal of arrival in the Tau Ceti system with human passengers still alive. In short: success.