MISSION LOG – SOL 423
Seventy-one point seven five kilometers!
AND, this time, a full fucking tank of pirate-ninjas long before sunset!
We are celebrating, and honestly this time. I’ve broken open two of the meal packs and divided up bits here and there to give us all at least one flavor that isn’t alfatato.
(God, that’s a horrible thought; a genetically engineered spud that tastes like hay, or a bean that grows taters on the stalk. I hope I never live to see it. Of course, somebody will read this and think, “What a neat idea! And I’m sure Mark Watney will be honored to see the product of his genius in person!” Well, future reader, let me be clear: if you do make it, keep that shit the fuck away from me unless you want to wear it. I like to think of myself as a gentle and nonviolent person, but I have my breaking point, and that will be it. Fair warning.)
Okay, to explain the solution: hothouse roofs.
It’s a little more complicated than that, but not much.
On Sol 421 we went to the cave. Cherry drafted Spitfire to help her tend to the farm, including all the just sprouted new potato plants. The rest of us went and harvested the best remaining big chunks of rock crystal. These had to be absolutely clear, so sunlight could pass through. It wasn’t easy, since we already used the best crystals in the cave for the jumbo booster batteries, but eventually Starlight said she could use extra magic to alter the shape of the quartz to fit what we need.
Which she did next. We made thirty rather thick slices of crystal and laid them out in a large open spot at the back of the farm. (We only need twenty-eight, but spares.) A bit of magic later, Starlight had the thick chunks of crystal turned to really thin sheets, one meter wide by two meters long each. They’ll just barely fit through the cave airlock this way, but we had to do it here, because of the next step in the process.
The problem with crystal is, it can actually be more fragile than glass in certain ways. Cracks in glass propagate slowly, because the molecular structure is irregular. The whole definition of crystal is that it has a very regular structure, so if a crack finds one of its lines of cleavage, it’ll zip right down it, and all you have left is shards. And that’s a major concern, because these are thin sheets of crystal glass that will have to deal with every bump and jolt along the way, plus a daily temperature swing of between sixty and seventy degrees Celsius from hot to cold and back.
So we decided to add a lamination layer to our crystal panels to make them more resistant to breaking- and to make it easier to replace them when we have to.
That was Dragonfly’s job. She wasn’t happy about it, but she didn’t need much persuading. She cooked up a clear form of goop in her guts and spread it with surprising evenness across each of the slabs- surprising because the process involved projectile spitting the stuff from a few meters away, then wrapping the overflow around the edges of the slabs. She then nibbled off the excess gunk to recycle it.
Seriously, changelings are adorable, but they’re also gross as hell.
Anyway, we didn’t take the slices out to the rover immediately. There was no point in exposing them to the aforementioned temperature extremes until they were installed. And installation would require a bit of preparation. Besides, the laminate needed some time to cure properly.
Yesterday we took the full Whinnybago out almost to Site Epsilon. There we found a spot in the gully nearest to the mountain where someone standing on top of the bank could almost look straight down at the trailer. We then went to the cave, loaded the panels onto the roof (we’d removed the saddlebags for this operation) and carefully drove the things to the trailer. We then went back and fetched eight magic batteries, because what came next was going to take a lot of juice.
The frames of the solar panels are not designed to be opened up, at all, ever. In fact, they’re designed to hold together despite tremendous stresses, because they have to ride a resupply mission that launches at accelerations no human could tolerate and then land on Mars in a giant tumbler with air bags and everything. But there is a little lip sticking up from the surface of the actual panels, so that when they’re stacked you don’t actually have the panels rubbing against each other. That’s what we had to work with- that and a lot of pony magic.
Fireball and I spent nearly two hours and six batteries standing on thin air with nothing between us and broken everything except the willpower of a unicorn. We “stood” on either side of each panel as, one by one, the laminated crystal sheets were levitated down to us so we could carefully and precisely seat them in the lip of the frame. Thankfully, they were a perfect fit. We were very careful, both for the sheets and for the integrity of our spacesuit gloves. But the thick layer of clear laminate around the edges protected us. We got through all twenty-eight without a hitch.
Then Starlight put us back on solid ground so she could finish the job. She snugged up the lips of all twenty-eight panels to hold the new panels firmly in place, using the wrapped-around laminate as a sort of rubber gasket. And then she stretched the crystal. She didn’t make two big meter-square pyramids per panel, as I’d suggested. She had a better idea. She made a bunch of little pyramids- fifty of them, twenty centimeters on a side, per panel, with rounded and reinforced edges and peaks. As she pointed out, the smaller each pyramid is, the less distance the sides will wobble on each bump, and the less likely they are to crack or break. It’s a damn good idea, and I give her full credit for having it.
In addition to turning the roof into a giant cheese grater, she laid a very simple zero-power refraction enchantment on the panels; any light, from any direction, that hits the glass gets transmitted through and directed straight down on whatever part of the panel is directly below.
Let me tell you, it makes the panels look freaky as hell. They’re not totally black, because a lot of light gets reflected off the original solar panels, and much of that escapes back out the pyramids normally. But any light coming, for example, from the sky or from landmarks behind the pyramids gets sucked down inside them. So when you look at ‘em, all you see is a distorted reflection of the solar cells, plus a little bit of glare reflected off those cells. And that glare is never anyplace you’d expect to see glare, like on the tops or edges of the pyramids. Very Uncanny Valley of the Kings.
Then we drove back to the Hab. On the way back one of the crystals broke, and we had to replace it with a spare, using the last of the batteries we got from the cave. After seeing the damage, Starlight says she might be able to repair them en route, and if they can’t be repaired, we’ll bring enough crystal on the Schiaparelli trip to replace about one-third of them. But for now, we wanted to go with all original installation for the test.
Now, why are we going to all this trouble? Simple. Before, each solar panel had two square meters of surface area. With the new crystal bubbles, they have a surface area of 2.8 square meters each.
Now, it’s not perfect. At early and late hours of the day you’re still dealing with a shallow angle of attack on the solar panels which reduces their effectiveness. But the slightly higher profile of the pyramids catches more of that light, sooner and later, than before… and from about 0930 to 1500 hours Mars time, when the sun is shining down on the entire surface of the pyramids all at once, we’ll get as much as a forty percent boost to our recharge power- in theory.
Today we tested the theory. Net result, averaging out recharge rates over the day: a power gain on the altered panels of 20%, in round numbers, over what we had. Hence seventy-one and a bit kilometers, plus full batteries long before sunset.
It’s not all clear gain. Power consumption per kilometer is up, because we added about a ton and a half of material to the top of the trailer. Even stretched thin, quartz weighs a LOT. But we still have a significant power surplus now. With this boost we could technically start a little later, drive a bit longer, and still have a full battery. And if we get into serious trouble, we might need that. But I’d prefer to stick with seventy or seventy-one kilometers per day and just enjoy having more power than we need. With that in mind, we’re still going to pre-bake all our potatoes and keep an eye on power consumption.
Margins are nice to have. In the time we’ve been stuck here on Mars, we’ve had margins and not had margins, and it’s a lot more fun to not have to worry quite so much about everything going to shit and all of us dying because we just had to have one fresh baked potato.
MISSION LOG – SOL 424
Back at the Hab. None of the pyramids broke on the two-day shakedown.
The next time we take out the Whinnybago, it’ll be when we leave the Hab for the last time. Testing is done. All that’s left is to load this puppy up, cross our fingers, and hope nothing goes wrong.
Meanwhile, Mindy is likely freaking the hell out, if she can determine that Mark is actually floating off the ground from satellite images.
Edit: Also, thinking of Mindy, I was wondering: in the book, Mark had to essentially make his way to the Crater blindly; using an incredibly simplified map of Mars, the stars, Mars' moons, and the sun to find longitude and latitude, and deal with terrain obstacles as he came across them.
Since Pathfinder is still functioning, is it possible for NASA to use their satellite network to essentially plot out the best course for him ahead of time? It would depend on how detailed of information the satellites can get on the topographical features (depth, size, etc.), and I honestly don't know how sophisticated those satellite cameras can get.
At the very least, NASA should have access to exactly the kind of map they sent with Ares III, and can therefore help Mark by giving him approximate (if not exact) positions of craters and other obstacles that aren't shown on that map well in advance, saving them both time (since they wouldn't have to turn around and find a way around a surprise crater) and ultimately making the trip safer all around. At least until they enter the Crater.
Pick one. Light being reflected back up from the solar panel hits the glass.
"Hope nothing goes wrong"? Are you insane, Mark? Or do you just like a challenge? You of all people should know, don't tempt fate the universe the author.
oh, this made me think of Mulch, the dwarf, in the Artemis Foul books. he tunnels under the ground by eating rocks and dirt, can fart himself into the air, and lots of other weird tricks...
When they leave the Hab for Schiaparelli, Mark better remember to deflate the thing. After all it's done for them, giving it the "final honors" of a mission close is the least they can do.
But for this chapter, magic and science mesh together in freaky cool ways. Now, if only they could use that sun-catching enchantment (from the cave) to MAKE solar panels, that'd be crazier. It might not work, though, but a variant could be thought up.
Margins are definitely a good thing to have, especially when lives depend on things working. Of course, I have no illusions that the trip will go smoothly, especially with that planet-wide dust storm still impending. That is still a thing, right? Has Mark given any thought to how that will affect their recharge rate and travel time?
9111180
In the book, he was well into the storm before he even became aware of it. With Pathfinder still working (for now), he'll learn of it well in advance.
MISSION LOG – SOL 425
...things went wrong.
or alternitavly
why did I open my big mouth?
9111199
How is this increasing efficiency anyways? The same number of Lumen hit that panel as before, bit now it needs to travel to more quarts and laminate. Wouldn't that reduce efficiency? If it was this easy we would be doing it here on this planet.
9111155 Already being done. Mindy is working on the best course, which will be transmitted to Hermes for the crew there (mostly Johanssen) to sysop Mark through using the orbiters around Mars for more detailed shots.
9111165 One-way glass enchantment. What hits on top gets pulled down. What hits from underneath may or may not escape, depending on whether or not it would normally.
9111211 More surface area + more angles of interception + no reflection off glass from outside = more lumens.
9111211
I'm not certain, but I think the idea is that by building a pyramid that refracts light down onto the solar panel, the cells are able to be "Facing the sun directly" for significantly longer periods of time. Since these panels are going to be laying flat on top of the Winnybago, they're almost never receiving direct sunlight, and therefore not charging as efficiently. By having a larger surface area at a more direct angle of absorption, they're able to collect more energy over a longer period of time, increasing their daily power collection. I assume don't do this on earth because we can just build panels that face the ideal angle no matter the time of day.
9111128
so no magical fresnel lens invisibly hovering over the crystal?
Instead? The crystal top side has a complex geometric shape with loads of sides to create a large of total surface area?
The enchantment uses magic to virtually unfold all the geometric faces of the solar collector topside into a flat virtual plane of connected shapes centered around the crystal, just as a cube can be virtually unfolded into into six flat squares centered on the original cube?
Any photons that passes thru the virtual plane of unfolded geometric faces floating above the crystal has its spacetime path bent so that every photon that passes thru a given segment of the virtual unfolded geometry then hits the corresponding geometric face on the physical collector crystal?
Am I the only one who sees Mark Watney portrayed as Matt Damon from the movie?
I now imagine Mark using Dragonfly like a glue gun.
9111246
Mark Watney is best Jason Borne
9111229
9111220
So the idea is that by adding these pyramids one gets more sun to hit the panels. Using nothing but the power of refraction.
Doesn't work, at all. If it did work like that, solar farms would look very differently. The Mars rovers would look differently.
Solar cars would be completely different.
So not light from any direction is refracted back to the solar panels. Just like light coming in from the outside. Pitty, that could actually work with magic.
How badly did Mark have to resist doing either the Superman pose or a surfer pose while riding the panels?
9111287
I suspect the enchantments works by decreasing the minimum angle required for total internal reflection to near zero degrees with the normal, and also adds some ability to dynamically warp the space-time layout inside the crystal so the reflected ray always goes vertically down towards the panel
9111339
The angle light hits a solar panel at has no effect on efficiency as far as I am aware.
With the bump in efficiency in the solar panels, I wonder if that makes it more likely or less likely that on the way to Schiaparelli they'll go too far into a dust storm than they can recover and backtrack to escape.
I have no idea how the math on that would work, so it could be possible that they'd just barrel through and come out the other side. Of course, they look to be in contact NASA all through the trip so the chances of wandering into a dust storm are nil. On the other hand, their repulsor lift system test has altered the starting conditions to such a degree that if there is a dust storm it may be completely unavoidable, even with direction from NASA.
9111351 It's about the target profile of the solar panel compared to the available light source(s). A solar panel turned at an angle to a light source is less efficient than a solar panel turned directly to the light source because the target area looks wider. This is why a lot of large solar farms have motors on their panels to make them turn automatically to follow the sun.
9111351
I'm fairly certain that the angle does effect efficiency. https://www.solarpaneltilt.com/ Hence why all of our solar panels here on earth are tilted whenever it is practical.
9109384 He could have been a truly great President if he could have only let go of his paranoia and obsession with scheming.
I've known people like that. They can't resist making up ploys and/or think people are plotting all around them. It's exceedingly frustrating dealing with them, because even when I briefly break through with common sense, they quickly revert back to the old pattern. They all also tend to otherwise be of fairly high intelligence... I wonder if it's a much milder cousin of schizophrenia.
Besides which, they should realize that I'm the only one important enough for everyone to be plotting against! Well, me and Neil Breen.
I'm getting shades of Thunderf00t and EEVBlog solar snake-oil debunking videos here.
A given insolation cross section only has a fixed amount of energy in it (ie. a fixed number of photons pass through it per unit of time). The only question is what percentage of them you're capturing.
When the rays of the sun are directly perpendicular to a flat panel, you're already at maximum efficiency because you're presenting minimal opportunity for losses in the system.
Ignoring losses to atmospheric effects, in the morning and evening, when the rays of the sun are at an angle to the panel, the same amount of solar radiation is being spread out across a larger area, so you get lower efficiency because most of the radiation is no longer hitting the panel. (ie. The panel is getting a smaller sub-region of what it would at noon, spread out across its entire surface.)
Now, sure, putting the pyramids onto them will have an effect equivalent to a tracking motor, making the panels capable of capturing some photons that would otherwise whizz by... but the pyramids on the most sunward side will cast shadows on the less sunward panels, so you'll only get overall improvements equivalent to making the panels frameless plus angling the panels farthest from the sunward edge so the rear edge is raised up to the height of the pyramids. That's why they don't pack tracking solar panels very densely in solar farms.
The increased proportion of photons being captured won't be very large compared to the overall surface area, the vast majority of the gains will decrease around noon as the pyramids' abilities to cast shadows on panel frames are reduced, and I strongly doubt that it'll gain you more than you spend on the motors to move that extra weight. (Same problem as with the "spinning solar" idea, which proposed using spinning, conical solar arrays under lenses.)
Here's Thunderf00t's video on it:
You HAD to say it Mark. How many times is this now? Murphy is more than happy to tag team with Mars to ruin your day. I foresee Sod hopping in there while their at it.
Honestly Mark...
9111287
It isn't normal refraction. With normal refraction, changing the angle in will change the angle out. What GlimGlam did was to change all angles in to a fixed angle out. As Mark noted in the text, it would appear black except for the reflected light off the panels escaping. All the 'normal' background refractions are missing, producing the "Uncanny Valley of the Kings" effect. Not only are they increasing the effective generating time from direct sunlight, they are also collecting a significant amount of ambient light energy and turning it into directed energy.
9111425
Given that the crystal got turned into a bunch of little pyramids, I would have thought
the magic Swiss Army KnifeGlimGlam would skip hunting down yet another super crystal for a large flawless sheet and instead make a bunch of smaller pieces from multiple smaller (but much easier to find) crystals.I also worry for the rover chassis. It was already overloaded before adding another ton to the top of the already topheavy load...
9111170
like suction cup pores!
Yay power!
9111484
Can't help but hear this as if spoken by Thunderf00t Lol
9111527
And then enchant each individually? And fidn a way to hold them together?
Lot of small pyramids are trickier in some cases.
9111512
It has an effect that can be achieved with normal refraction.
But who cares, the effect is not effective at achieving the states goal: Moar power.
You know what would limit unnecessary refraction? Not putting a useless lens in front of it.
9111429
Well, if you let more light hit a solar panel more power comes out. Duh. But that is because more light is hitting the panel, not the angle the light is hitting at.
Hothouse might be the operative word, extra layer of insulation on the top, greatest radiation cooling effect, and th panels warm up more with increased irradiation meaning the roof warms up faster in the morning and stays warmer longer, reducing power needs for heating?
Hope it doesnt get so hot that someone tries opening the window.
Hmm, non image forming concentrators. Tried running a patent application back in 97 on a variation of those, gave up as not worth it when they started wanting thousands of dollars in payments, and the design could be mass produced cheaply but only by large companies. Which at the time had lots of cheap oil to play with. That and the rest of housing design etc didnt have room for integrated storage like Victorean Terraces did. The coal storage area.
Really worried about that break on the easy run the very first trip. Thats making it the first moving rock they go over that causes a pot hole drop and so much is going to break all at once, never mind the Crater slope where they just dont have anough rope, mountings, anchors, or giant elephant sled to make it safely.
"Myself" is one word, not "my self".
9111173
Did Mark deflate it in the book/movie? I thought he just shut everything down/off and left it there for future visitors.
9111246
No, I'm pretty sure most of us are imagining Matt Damon as Mark while reading this. Why wouldn't we?
9111484
9111220
While this video contains relevant information, it is not particularly dense with it.
The most relevant bits are the ones where they compare solar cross sections.
Would small glass pyramids increase the bago's silhouette? Not significantly.
9111762
You're obsessed with finding errors in reality with a system made of changeling goo, crystals and magic. What's the point?
9111762
*nod* I remember there being one with some more directly relevant info, but I can't specifically remember which one it was. (It could have been one of the solar roadways ones, or the one about the Fontus self-filling water bottle, or one of Dave's solar-related videos over on EEVBlog, etc.)
9111785
First, because they're blips of overriding the physical laws in a universe that is primarily The Martian.
Second, the story has already established that magic can't simply make an energy conversion more than 100% efficient. If it could, then they could make an "over-unity battery charger" and their problems would be solved. (wire some LEDs into a solar panel, point the LEDs at the panel with such a magic efficiency-booster in between, use a flashlight or the sun to jump-start the system, and then siphon off the power produced above and beyond what goes to the LEDs to charge batteries and do whatever else is necessary.
The closest step I can imagine would be of there were some way to do black hole-esque bending of light rays passing through the space above the panels, which would give the equivalent of a very tall sun-tracking mount for all the panels... at the expense of that area of spacetime looking somewhat lovecraftian.
9111785
Hmm, well, that's because stories that don't follow scientific models or at least internally consistent models of reality break my suspension of disbelief. I don't hunt for them, I notice them.
My expectation is raised exponentially when you create a work in a universe that is really good at following those scientific models. The Martian is one such universe.
9111785 The point is to construct as scientifically accurate (or, when magic is involved, as internally consistent) a story as possible.
Now, if I have to I'll just say that Starlight duplicated the light-sucking/amplifying spell on the cave solar collectors, but I really thought increasing the surface area via three-dimensional overlay and refraction would boost power, and thus I wouldn't need to. But the more I think about it, the more I'm coming around to Az's way of thinking; that the pyramids would only help for low-angle light and for indirect ambient light, which wouldn't do much to get more power.
Still thinking about this one.
And now we get to see what goes wrong.
Also, kudos on "Uncanny Valley of the Kings."
Quartz don't have cleavage planes.
i.pinimg.com/originals/4e/17/ee/4e17ee265edd8f3a0ce4ba5fa82b251e.jpg
Quartz also has insanely low temperature expansion coefficient.
9112015
Well, I'll give it to you that you've been remarkably science-consistent so far.
But with regards to the magic pyramids: when light hits the pyramid at an angle, it may miss the panel entirely. Especially keeping in mind that light doesn't just come from directly above, it bounces off absolutely everything. At any angle other than directly above, your light will begin missing the panel in some measure. Since the pyramid redirects light directly downwards regardless of direction, light which would otherwise miss the panel now hits the panel, meaning you overall get more photons passing through your panel to create the photoelectric effect. We aim solar panels at the sun to maximise the area of the panel that forms a cross section to the incident angle of the light, which you couldn't do before, but now the pyramids do so that the sun is perpendicular to the panels all the damn time. I would however note that that doesn't mean the panel is always at high noon, because light at any time of day has to pass through the atmosphere which decreases its brightness further away from noon. However, even so, that still means you're making the most of the light you have at any time of day, using the pyramids to sort of "aim" the panel at the sun without moving the panel.
In addition, the pyramid increases surface area. Say your panel is 4 square metres in surface area, and the total surface area of the pyramid is 6 metres. Light that hits the extra 2 square metres of surface area would now hit the panel instead, so you've effectively cheated and made the solar panel "bigger".
All in all, I still see no problem with the magic pyramids the way they are depicted.
9111987
Picture doesn't work.
9112026 The issue is target aspect. Extra surface area is nice for gathering ambient light, but light from a directed source only cares about the target profile. From directly overhead, the target profile would be the exact same. And although a higher profile helps catch light coming at a side angle, I've greatly inhibited that advantage by having Starlight make a lot of short pyramids instead of a few tall pyramids as a hedge against vibrational shattering.
I'm seriously rethinking this whole sequence, but I suspect time won't let me do more than the "same light absorbent spell as the cave uses" handwave.
Yeesh, I'm conflicted. On the one hoof, the spell already violates "conservation of étendue" (see https://what-if.xkcd.com/145/ ), so it might be fine.
But on the other hoof, arguments here along the lines of "angling solar panels right makes them more efficient!" misunderstand the principles. For instance, a flat 1m2 panel at a perfect 90o angle to the sun will "catch" the same amount of sunlight as a 2m2 panel at a 30o angle. The bigger panel will also catch more ambient light, but I don't know whether solar panels reflect light differently at different angles, so I can't actually figure when/whether the two panels will match in energy conversion.
9111758
Nah, I'm pretty sure he did, as does this quote:
"I performed the final shutdown today. The heaters, lighting, main computer, etc. All the components I didn't steal for the trip to Schiaparelli. I could have left them on. It's not like anyone would care. But the original procedure for Sol 31 (which was supposed to be the last day of the surface mission) was to completely shut down the Hab and deflate it." -Chapter 21, Sol 449