Her solar panels are getting 72 W now, and it's still rising. She's not going to be able to refill her suit battery even if she sits here all day, but every additional hour of being plugged in buys her another hour of active work (she's only net getting maybe 50 Wh in an hour now that she's running the air and basic monitoring and climate control, even if it's not needing to do any cooling for her yet.)

...She can walk far enough with the power armor still plugged into charge to peek into the tent. It's 38° C in there, and the pot inside her makeshift still now has half a centimeter of clear desalinated water at the bottom. 

...She'll make another still in a pit. She can do that without moving much, she barely even has to dig, just remove the broken rocks and gravel from one spot and pile them up in rings around that spot until she has an inverted cone. Line it with more of her precious waterproof plastic, put her eating bowl in there to catch drips... The most annoying part is carefully transferring over five liters of the now-bath-temperature seawater inside the tent, because there's no way it's worth going down the cliff again, she brought up like 10L of it and there's no way she's turning all of that into freshwater this afternoon. 

And then, apparently, Merrin is going to lie down, still wearing her power armor which is still tethered to the solar panel unit, and take a nap. She has been awake for around 19 hours at this point, and they were busy hours. 

Merrin wakes up after five hours to find her primary suit battery up to 480 Wh of charge (she has more like 600 Wh total, the auxiliary battery isn't fully drained). A glance over the analytics confirms that the solar power output peaked at 91 W, and is now descending but slowly. It looks like she will hit 1000 Wh today, albeit just barely. 

And she has work to do. 

The thing about surviving on a hostile exoplanet while completely alone, is that there is an approximately infinite queue of Tasks that will need to be Dealt With and the consequences if they are not Dealt With are lethal. 

A lot of them aren't that urgent! Many she's completely blocked on for now and can't even think about productively! But in any individual moment, there's almost always something. 

Merrin conserves suit power - no more exploration, she'll do setup at her NEW CAMP in the PERFECT CAVE tomorrow - but she is not at any point bored during the rest of that day; she has math to do, and documenting all of her thoughts and observations and plans on actual paper.

She plugs her main battery into the solar output to charge, and the 265 Wh generated over the remaining eleven hours of the day get its total charge up to almost 2800 Wh. Plus, of course, she's got the two random auxiliary batteries with awkward half-charges each, because she has NOT been organized about that so far.

Also, she has two and a half liters of water from her stills – rather, that's what's left after she drinks half a liter, after having finished all of the stored water she arrived with. This is all she's got until - realistically it's not "tomorrow morning" it's "sometime tomorrow afternoon." There are a lot of efficiency improvements on the basic design; she'll work on that once she has a permanent campsite that doesn't drop to -30° C inside at night. 

Her suit O2 reservoir is down to 60L, which would at her going rate last her five or six hours and run out while she's asleep. She ends up draining both of the half-charged backup cells entirely, plus about 100 Wh from the main battery, in order to run the oxygen concentrator and compressor and directly fill her main suit reservoir all the way to 500L. 

It's a pleasant 12° C outside – today definitely ran a little bit warmer than yesterday, though of course it takes more than one day to call whether that's a fluke or a trend. 

The tent is still a sauna inside – hot enough that her still is probably still working, in fact. And Merrin isn't desperately exhausted yet, after her noon nap. She seals the tent flap behind her to keep the heat in, because she will be glad of it at - ugh, she needs a time system for this stupid planet - at Minus Ten Hours In The Morning. 

She carefully writes down the exact time-since-dawn in hours and minutes for sunset and her best guess at the end of astronomical twilight – "dawn" is the most approximate number here, really, she was going off "the light woke her" which is later than astronomical dawn and earlier than actual sunrise, which she missed due to hiding. She'll try to catch it today, because "moment of sunrise until moment of sunset" is the single least-subject-to-measurement-error metric she can track for whether the days are getting longer or shorter, and if the sun-arc measurements point in the same direction after a couple more days, she'll be pretty confident of her result. 

And then she lies on her back on the rocky plane and stargazes. ...Actually, the simplest way to identify celestial north is to switch on the suit camera and review the footage to get the star trails. It's been off because she mostly doesn't keep it on for solo work in sims, and it's not like anyone except her will be able to use the footage, which the suit can only store six hours of anyway, video is much less compressible than biometrics and navigation vectors. 

(She has a separate miniaturized camera, packed with the medical diagnostic equipment, but it's a separate piece of electronics that she would have to power on, and besides, it's packed away in a box all the way over there.) 

Camera on. Lying still, looking at the sky. Four hours should hopefully be enough data to use later. 

It's beautiful. 

Merrin is not going to dwell on the overall depressingness of her situation. She's not. She has high baseline wellbeing, that's always been true, it's not just because her life was really great in every way and she did not appreciate how great it was until she DIED and ended up on a planet that really appears to have been optimized to kill her slowly so she can spend longer afraid of it. 

She doesn't understand the broader situation, but has she ever understood a broader situation in her life, really? She didn't understand Civilization. There was too much of it, too many people with vastly more thinkoomph than her. Really, she's never understood all the pieces of the important things, and - that's not actually what she's upset about, anyway. 

She's upset about obvious, concrete things. Never sleeping in her nice apartment in Default again. She liked her apartment. Never going on a date again! Ever! Or if she somehow does it'll be with ALIENS and then she'll be offended about how romance with aliens is a really stupid trope according to her, there's no reason for that to be workable.

She's never going to talk to her mom again. 

And she's not going to dwell on it all night and make herself miserable. She'll allow herself five minutes to notice that she's upset for incredibly reasonable reasons, and then she's going to look at the stars, and then eventually sleep. 

The strapwrack, it turns out, hardens as it dries into whatever shape it was left in, and has quite a lot of flex but snaps back to its hardened shape when released. 

Merrin isn't sure of this first thing in the morning, of course. At that point any moisture left in it is frozen solid, and she's not going to touch it and damage it while it's brittle. 

She's well-rested at dawn. She went to sleep maybe four hours into the night, slept for nine hours despite being in her armor in the sleeping bag, was awake for...a lot of hours, but at least a few of them were quite mentally productive, and she does seem to be getting used to the endless nights and was able to pass some number of those hours pleasantly in a sort of free-associating narrative-dream-logic state, thinking about fiction she likes...and at some point she slept some more, and eventually woke up and it turned out to be an hour before projected dawn. 

...Which ends up being almost fifteen minutes earlier than she was expecting. Could be her shitty approximate math from yesterday, or could be that the days really are getting longer and her near-term power generation situation is going to end up pretty good. Unless it's rainy here in spring. That would be bad. She really needs to figure out how to heat her cave by burning local biomass rather than running her power armor all the time. 

Merrin's suit is actually recharged to 1500 Wh; she left it charging from the main battery after its internal battery ran low, and fell asleep like that, and apparently had at some point set it to "charge to 3/4 and then pause". The main battery is down to 1020 Wh. 

She has 110L of oxygen left in the suit tanks - which, now that she's turned the percentage down to 17.5%, will probably last 7 hours even at higher exertion-related O2 consumption - and presumably still the last untransferable 40L or so in the medical canister. 

She sets up the solar panels - she'll carry them to the new site last, tonight, right before sunset when they're no longer generating anything to speak of - and then plans her move. 

First: packing up. Merrin had unpacked more than she'd realized; getting all the miscellaneous objects into the correct spots, and then dismantling the personal-pod tent and stowing the poles and guylines and tarp, takes two hours. 

It's about 650m from her current position to the surprisingly optimal (!!!!) sinkhole cave. The most direct route from it to the top of the riverbank might be closer to 550m.

The ground is flat enough that it's probably more suit-power-efficient overall to load herself up with the maximum four-box arrangement and make two trips rather than four. 

She takes it slow, doing as much as she can with muscle power. She's going to have to get stronger, so that once she's acclimatized to the lower oxygen, she can do the required ongoing physical labor during the tolerable-temperature windows of the day, without a suit. It'll burn more calories, but that's exactly why she needs to do as much as she can unaided, and save the power armor for the aquatic work needed to find something on this stupid planet that she can eat. ...Eat and also digest and metabolize, technically she can eat whatever she feels like but those parts are pretty important. 

Two hours later, though, everything but the solar panels is stowed in the cave. She walks back up the slope and can see the solar panels glinting in the sun, safe on the bank. The wind is slight and there's no megafauna here to disturb them. 

The tarp shelter kit comes with six standard configurations, but none of them are precisely designed to turn a sinkhole cave into an actual shelter. She'll have to improvise. 

Fortunately, the kit is also optimized to be friendly to improvisation. It might come up! With Merrin specifically it will and has come up a lot, actually! 

Merrin did a whole bunch of mental design while lying in her sleeping bag last night, and now it's time to find out how well it works!

(In the long run, she's actually mulling on replacing as much as possible of her dath ilani shelter kit with whatever she can find locally to use as building material. It'll be less optimized and less durable, but her shelter gear is not, actually specced for multiple months of intense UV exposure, and if the local materials break down quickly, well, she can just go get more. No way to get more fancy Exception Handling tarps.) 

Merrin's brilliant middle-of-the-night idea was that she doesn't need to switch which way the tarp is facing twice a day. She doesn't actually need the entire cave to be toggle-able between "day mode" and "night mode", because she's going to be spending the too-cold-to-be-out-of-her-sleeping-bag portion of the night sleeping. But she does need a larger work area that will stay a vaguely tolerable temperature for as wide a window as possible, during daylight, and it's going to become more and more true that the problem in daylight is heat and not cold. 

So: tarp facing shiny side out, in something midway between canopy and lean-to mode, joining with the hollowed-out arch to form the other half of a flattened hemisphere with the tent-flap as a "door" in the middle. This is a nonstandard pole arrangement and is actually really annoying to set up the geometry for; she totally screwed it up when working purely with visualization, and the forces were in the wrong place and the part at the top kept wanting to pull away from the lip of the overhang and gape. She doesn't want the tarp to be hanging from the arch, she would have to drill stakes into the arch for attachment points and it looks pretty stable but she has no desire to stress it more than she has to. She does another sketch on paper and eventually figures out a structure where the super-grippy rubber-gecko-foot-like swappable pole tips are actively pressed against the rock by the weight of the rest. 

Merrin really wishes she had some way of ever seeing a human being from dath ilan again, specifically whichever Exception Handling team designed her reconfigurable shelter tarp with sufficient adaptability that she was able to turn it into an exterior wall around a weirdly shaped sinkhole cave. So she could give them a HUG about it. It only took her like three hours! 

Six hours into the day. The temperature has already climbed by twenty degrees! ...Unfortunately, that does still leave it at a current temperature of -20° C. 

High tide appears to have arrived, and turned, a couple of hours ago. 

...Whoops, Merrin was deeply focused and also below-grade in the sinkhole and totally missed that. She needs a TIDAL GRAPH. Ideally a GIANT POSTER ON HER WALL but that's a little difficult when she can't just order one printed and delivered to her house. Maybe the hyperpigmented UV-resistant lichen can be turned into ink and she can paint her cave like a prehistoric hominid. That would be really cool, actually. Also not a today priority. 

Her next today-priority is the rest of her brilliant convertible-day-night-cave idea: a separate sleeping capsule, all the way at the back, lined with all of her emergency medical blankets this time with the reflective side facing inward. She can make it even smaller than the personal capsule tent, since she won't also need to cram, like, an oxygen concentrator and a battery and a pee-bucket and a collapsible tub full of evaporating saltwater into it; the larger cave is for daytime work, the capsule is only for sleep (and lying in the sleeping bag for eight hours in between her nighttime sleep blocks, until the summer nights get warm enough that it's still comfortable to work ten hours after nightfall and also she's solved the artificial lighting problem). Small means her body heat alone will go further toward keeping it warm inside, but if the rest of the cave stays cooler than the daytime high, it won't be starting out so hot that she can't fall asleep. 

...The alarm she preset in the suit controls is warning her that at current consumption rate she's down to two hours of supplementary O2 in the tanks. So actually her next priority is to turn 60% of the remaining charge in the main battery into a full suit oxygen tank. 

Down to 380 Wh, from 5000 to start. Her suit has 1150 Wh, though, and even at moderate activity levels (but with lower heating needs than the last-six-hours average, she's been pretty out in the open working) that should last her, like, 22 hours, which brings her to sunset. At which point she should have another 1000 Wh to pick up in the backup batteries currently with the solar panels, and that's...about what she needed for last night, isn't it. 

Not sustainable.

But decent shelter will cut tonight's power needs a whole bunch. 

...And there's the point that she's been here for more than five dath ilani days, when you actually add up the hours, and her body will be busy acclimatizing; she already suspected yesterday that she's no longer meaningfully cognitively impaired while breathing ambient air, just exertion-impaired. But once it's a comfortable temperature in her shelter, she might be able to sit inside doing low-exertion work all afternoon and not use any battery power at all. And if that goes fine and she's not feeling like soggy toilet paper after eight hours, it's probably also safe to sleep without oxygen. She'll still need supplementary O2 for intense exertion for a while longer, but...less, as time goes on. 

For now, the suit power is heavily being spent on heating and it'll actually spend less on that if Merrin is working out. 

Still sitting with the oxygen concentrator and compressor running and plugged into her suit (inefficiently in the cold, but she put emergency blankets over them to help a bit), she'll starts digging - well, rock-collecting-and-shifting - a new pit for her relocated still. She can make it more efficient later by, instead of waiting for the vapor to saturate the (hot) air and condense onto the (also hot) plastic, she can send it through a bunch of tubing that cools it and also traps all of it rather than letting droplets fall right back into the salty water. The obvious cooler location is underground. More digging. She can probably get to it today even if she needs an afternoon nap again, she has 22 hours. 

About 90 minutes later the suit tanks is full and Merrin puts the equipment away again. She has a snack break, and a water break (rationed sips of her remaining exactly 1.2L of water; she'll have more "soon" but "soon could be twelve hours away.) 

She finishes the pit to the depth she wants - she's going for wide and shallow, this time, for more effective evaporation and since she doesn't need to do the weight-it-with-a-rock plastic drip method if she's going to cannibalize a bunch of IV tubing instead. She lines it with previously used plastic sheeting (dirty side down), and builds a little rim-wall of nicely stacked interlocked rocks that naturally cracked into conveniently brick-ish shapes and sizes.

And then it's 9 after dawn and the temperature is up to 0° C and she might as well go haul a whole lot of seawater over, she won't get much evaporation for hours yet but it's not going to freeze. 

...That took longer than expected, with the 650m hike back very carefully carrying her collapsible tub with like 50L of water in it. (It has a lid but Merrin does not trust the seal if dropped, it's meant for stationary use and not necessarily specced to be watertight even under rough handling.) 

And now for Merrin's master plan!

Merrin is going to determine if dried and stiffened strapwrack fronds will soften again if dunked in the 30L of water left after she filled her evaporation basin to a reasonable depth. If so, she can take what she already harvested, soften it for manipulation, weave the wet fronds and arrange them over her storage crates, and once they re-dry in the baking afternoon sun, she'll have a frame to wrap in emergency blankets and use as a sleeping capsule tonight.

It's a hackish first try, but if it works as well as she hopes, she can harvest more! And do it again, better! The one single nice thing about being a solo human on an exoplanet is that there's no way she's going to drive strapwrack extinct by over-harvesting it.