Kate tried to remember the briefings about the Pheia she had attended while it was being built. Somewhere in her memory was something about the gas system. She had to admit, the briefings were really uninteresting to her. She only really cared about the biology and that part of the mission had been months away at the time. “Typical. I zone out in the one lecture that I really need right now. And where is Google when I need it?”
She tried to remember how the system worked. She knew it wasn’t an osmotic process. Several people had tried to build artificial gills, but down here there wasn’t that much dissolved oxygen and they had to support a big crew. The gills would be massive. “Just me now though,” she thought.
“Electrolysis.” She remembered. That was partly the reason for using the Russian reactor. It supplied a lot of electricity and a good piece of that was used in the gas extraction system. The principle was simple: apply a direct current voltage to a pair of non-reactive electrodes immersed in water and hydrogen appeared on one and oxygen on the other. All you had to do was collect the gas as it bubbled up off the electrodes.
So somewhere above her head the gas system was separating oxygen and hydrogen from the water and then dumping the hydrogen somewhere. Where was it going? Why hadn’t she seen bubbles outside? Perhaps the rate was too low. The oxygen consumption rate of the full crew wasn’t that great. Perhaps the hydrogen dissolved back into the water?
“I guess we’ll go and look then.”
Kate went over to her dive gear, unclipped the flashlight from her BC and turned it on. She shone it up at the ceiling where the ladder stopped at a hatch. The hatch was secured with bolts and she had no tools. She paused for a minute thinking. “Radiation?” she wondered.
“Well death by radiation is about the same as death from advanced HPNS, so I chose death.”
She went up the ladder until she was wedged against the ceiling and inspected the bolts. They were not very big but there were quite a few. The hatch looked like it was designed to keep the crew out not to keep anything exciting in.
“Let’s go diving.” She said aloud.
Ten minutes later she was in the moon pool room looking for tools. She was fairly sure there weren’t any in the storage area. She’d have seen them earlier. And it seemed crazy that there would be no tools. “There must be at least a few wrenches to work on the dive gear, to replace hoses or whatever.” She wasn’t sure that was really true. The expedition was relatively short and they had spare scuba sets. But it gave her a reason to search.
She found a small adjustable wrench in a Pelican case with Duncan’s name marked on it. It was his ‘save a dive kit’ and contained a few spare O-rings and other items.
Kate took the wrench and headed back up to the ops room.
Back on top of the ladder she set the wrench on one of the bolts and adjusted so it was tight. She didn’t need it to slip and round off the bolt head. She held the ladder with one hand and pushed on the wrench with the other. To her delight, the bolt moved easily. She rotated it a full turn with the wrench until it was loose and then put the wrench in her teeth while she removed the bolt with her hand. She dropped the bolt in her pocket and started on the next one.
It took a few minutes, but she removed all the bolts except two on opposite sides of the hatch. These two she loosened but left in place. She banged on the hatch cover and it dropped down slightly until it was resting on the two bolts. The next bit was tricky because she needed to hold the ladder with one hand and work the bolts with the other. She stepped up one more rung and wedged her shoulder against the steel plate. It moved up enough to take the pressure off the bolts and she removed one of them with her free hand. Then she let the plate down slightly and rotated it on the other bolt until it was out of the way.
The room above was dark but full of noises. Kate pulled her dive light out of her pocket and shone it up into the space. On the wall was a light switch. She flipped it up and the room filled with light.
There were two ladder rungs welded to the wall above the hatch and Kate used these to get herself up into the machinery space. It was a bit cramped but she could stand up if she stooped a bit and was careful how she moved.
It was easy to find the oxygen generator because it had a sign on it saying “Oxygen Generator.” Next to it was another, much larger unit with a “Desalination” label on it. But Kate found the rest of it to be less obvious. There were several pipes coming into the unit.
Everything was painted white but two of the pipes had colored bands on them. One was red and one was green. Kate traced one of the white pipes to the desalination machine and from there to a water filter. The filter was connected to a flange on the wall where there was a shutoff valve. “Must be the water inlet,” she said to herself.
The pipe with the green bands on it led to a unit with fins on one end and an electric motor on the other. Kate guessed this was a compressor. And the green probably meant oxygen. “Aren’t oxygen cylinders green?” If that was the oxygen then the pipe with the red bands might be the hydrogen. That pipe went into another unit and from there through a valve to another fitting on the wall. There were several attachments to the pipes with wires coming out of them. “I guess those are the pressure or flow sensors.”
Kate looked at the whole assembly and shone her dive light over it to make sure she’d gotten a good look at everything. “OK, so now what?”
She thought about that for a minute and decided to ask for help from above. They hadn’t been much help so far, but it would be stupid not to ask.
She climbed back down to the ops room and composed a message to Williams: “I have found the hydrogen/oxygen separator. Is it possible to direct the hydrogen into the hab?”
While she waited for a response, Kate thought she had better see what other tools she could find. If Williams’ people had any ideas, she was sure she’d need some tools, although what exactly she was going to look for she had no idea. She was sure that it would take a while for them to respond to her message and she might as well keep busy.
Kate checked her scuba gear. She still had plenty of gas in the tank she’d been using. She was very relaxed in the water and breathed a lot less gas than other people. Her buoyancy control was excellent and her movements always very efficient. She really just liked being in the water. The situation in the Pheia was a little different from a recreational dive but she had found that once she was submerged it felt much the same — from a diving point of view.
Kate suited up and put on the scuba gear. She ran through the checklist on the wall and realized she had left her dive light in her pants pocket. “Crap.”
She had to pull the scuba gear off and unzip the suit. Even then it was awkward to fish the light out of her pocket.
When she was ready again, she looked at her hands. They were still steady. Forgetting about the light was a simple oversight but she was getting a bit paranoid about the gas mix in the hab and how that might affect her. “At least the mix in the tank is good,” she thought.
As she dropped down into the moon pool room, Kate decided to go through the tunnel and search the storage room again. She was pretty sure she wouldn’t find anything but not looking was a sure way to not find something that might be lurking there. And in any case, the last time she was in there she wasn’t looking for tools, so she might have just not noticed them. She tried to think through what she was looking for. “Tools, pipe, valves, gizmos, emergency tank of hydrogen, cheese sandwich.”
In the storage room, Kate scanned the piles of stuff she had rummaged through before. It was everywhere. Some of the ones she hadn’t opened floated up at the ceiling. A few floating items were trapped in the shelves and the rest was either still on a shelf or on the floor.