"No," Fireball insisted, "the hard part will be putting everything back in the right order."
Dragonfly, unable to deny the point, crawled into another lower cabinet and began loosening another bolt.
After lunch, Dragonfly returned to the ship, this time with Mark. With Starlight's and Fireball's help, one airlock load at a time, they got the carefully cut slices of rover insulation foam into the ship. Of course, this left practically no room for human or changeling to get through the jumble of meal packs, hay bales, medicine, and other things that absolutely had to travel in the Whinnybago's trailer.
Dragonfly felt more grateful than usual when she set up the mana battery for field projection and switched the power on. Inside the mostly bare metal walls of the hab deck, the rainbow sparks that rose from the aerials occasionally lashed out to strike the unpainted portions of metal.
"Okay," Mark said. "Rover foam for the ceiling, especially to cover up the docking port. We're not going to use that any time soon. What's left of the ship insulation in the spots where the cabinets go. When we run out of ship insulation, Hab canvas. Use the ship insulation on the outer bulkheads, the canvas for the wall between habitat and bridge. You up for a lot of spot-gluing? I noticed you had a huge lunch."
"Just a moment." Dragonfly grinned a fang-filled grin, and then she shifted.
Mark's expression was everything Dragonfly had hoped it would be. "Um," he said carefully, "can't you pick another form? That one makes me really uncomfortable."
"I'm used to this shape," Dragonfly said, doing her best imitation of Beth Johanssen's voice to match the blue-jumpsuited body she was imitating. "And it's easier for me to work around the cabinets as a biped. Besides," she added, "I could change into you, but it takes a lot more energy to change mass."
Mark did his best to not look at her. "Really, really uncomfortable."
"Think of it as building up a tolerance," Dragonfly said, chuckling. "Or would this be better?" Another flash of green flame, and from the neck up she was still Johanssen, but from the neck down she was a certain actress famous for a role where she wore cutoff jeans for seven years. And instead of the blue astronaut jump suit, she wore those cutoff jeans and a string bikini top.
Mark's efforts not to look increased. "Really not helping," he said as firmly as he could manage. "Not helping in so many ways."
"Relax, Mark," Dragonfly giggled, now throwing a southern accent into her voice. "I'm not like Starlight or Spitfire. I don't kick. Much."
"This conduct is contributing to a hostile work environment!"
Dragonfly's giggle became a full-out laugh, and with another flash of green she went back to plain, jump-suited Johanssen. "All right, all right," Dragonfly said. "Just messing with you, Mark. And it feels good to be able to shift." She paused for full effect before continuing, "Although lust is a nice delicious treat... and I could really go for some empty calories right-"
"OH LOOK!" Mark said loudly. "I think that's a spot that needs some insulation right there!" He pointed up at a random spot near the ladder leading to the dorsal docking port.
"Some joker you are," Dragonfly muttered. "Okay, let me climb up so you can hand me some of the foam."
"Like that?" Mark asked. "Are you going to be able to... you know... make glue... in Johanssen's body?"
Dragonfly felt a blush coming on. Darnit, sometimes the disguise had a mind of its own. "Well, yes," she said, "but you probably don't want to watch. Not this soon after your own lunch, anyway."
MISSION LOG — SOL 405
Quick note for the record: changelings are gross. Really, really gross.
I haven't missed alcohol so much since the day we lifted off from Canaveral...
Author's Notes:
Ten and a half hours of driving, I got home tired and uninspired. So today you get Dragonfly being cruel to Mark.
The difference between Dragonfly and Chrysalis being, Chryssy wouldn't have let it drop...
... that, and Chryssy wouldn't have settled for Johanssen. She'd use Lewis's form instead, because commander.
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Sol 407
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MISSION LOG — SOL 407
Well, we didn't have to start weaving insulation out of hay, so that's good.
The combination of the RTG in the habitat deck and shutting down all air flow to Rover 2 and the bridge, plus the ugly-ass insulation job we did on the walls of that compartment, kept the room warm enough during the early part of the evening and only a little chilly by just before dawn. That'll have to do, because we can't really afford to run heaters, and we don't have anything else to use for insulation except hay, which has problems.
We decided one other thing: when we leave, we're going to line the floor of the habitat deck with the mattress pads from the Hab bunks. They're only a few inches thick— they were made to be thrown across a string base to save launch weight— but they're better than nothing.
Today we're going to make sure everything's in its proper place. Then tomorrow, Sirius 7, the dress rehearsal.
Fingers crossed...
(I need to ask Starlight what the pony version of that is.)
Author's Notes:
Sorry, but two things happened today. (1) I committed to helping a friend in Dallas, whose apartment lease is up and can't afford the new higher rent, get her crap out before the landlords lock her out and shitcan all her worldly possessions. And (2) I found a problem for our heroes, but not yet the solution, and I just spent an hour and a half verifying that the problem is, if anything, worse than I thought.
So this is all I had time for today, what with unloading the van and filling it with boxes and paper for moving stuff. And since tomorrow involves about twelve hours of driving plus five hours or so of moving house, I won't have any time for writing tomorrow.
Hopefully two chapters on Thursday to make up for missing a day.
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Sol 409
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MISSION LOG — SOL 409
There may be a problem.
We began Sirius 7 with the Whinnybago loaded as it would be, more or less, for the final trip:
ROVER 2 (empty, with extra hydrogen cells) — 3.7 tons
FRIENDSHIP TRAILER (empty) — 14.5 tons
FOOD (110 days supply) — 0.65 tons
BOOSTER SYSTEM (substitute equivalent weight of rocks) — 4.5 tons
SPARKLE DRIVE plus 7 batteries to power it — 0.5 tons
OTHER MAGIC BATTERIES — 0.84 tons
FRIENDSHIP THRUSTER PACKS — 0.12 tons
TOOLS, SCRAP, AIR TANKS FOR SPACE SUIT AND MAV, ETC. — 0.5 tons
CREW, SPACE SUITS, AND PERSONAL EFFECTS — 0.7 tons
14 SOLAR PANELS (NOT COUNTING THOSE INSTALLED ON TRAILER) — 0.1 TON
TOTAL ESTIMATED MASS: 26.11 TONS
To be specific, the trailer's total loaded mass is a little more than seventeen tons, with Rover 2 carrying the balance.
This load was propelled on ten wheels, eight of which are powered, two of which have the clutch disengaged so they rotate freely. (All the rover wheels have their own built-in electrical motors, rated at roughly fifty watt-hours per kilometer of travel on a normal load. This is more than double the normal load rating, with Rover 2 almost at maximum emergency load and the trailer miles beyond that..) The two rover batteries plus four Hab hydrogen storage cells add up to fifty-four pirate-ninjas to power all of this.
Bear with me. I'm laying all of this out so I can think.
We got a bit of a late start, so the sun was already up before we began rolling. We drove for about three hours, until the battery readouts showed 10% power remaining. (The rover computer is smart and can detect the extra, unauthorized power storage and monitor its charge level. Which is good, for reasons which will become obvious in a moment.) This got us 69.66 kilometers away from the Hab. All well and good, right?
We stopped, unloaded the fourteen extra solar cells from their stacks on top of Rover 2, and set them out for recharging the system. With a clear sky each panel provides 120 watts at peak power. The ongoing cirrus cloud coverage knocked that back a little, but with forty-two out of the Hab's fifty-four panels with us, we figured we had power to spare. Also, we have the 100 watts provided by the RTG, which isn't much, but it's 24/7.
So we retired to the trailer for the rest of the day, gathering in the habitat deck when the sun went down and it began to get uncomfortable in the bridge. I set the alarm for first light, about an hour before dawn, expecting to get up to find a full power system and an easy drive back the way we came to return to the Hab.
Nice theory. Too bad it didn't quite pan out.
We got up when my alarm went off. I suited up, went outside, picked up the solar panels in the Martian pre-dawn, and got into Rover 2 for the drive home. And that's when I discovered that the batteries were only recharged up to 70%.
Remember, it took 90% of the batteries to drive seventy kilometers yesterday. And since 70% is less than 90%, we definitely weren't going to get seventy kilometers today. But, since this was a test, we pushed on anyway. 90% got us seventy klicks, so 60% should get us two-thirds as far, right? Forty-six and two-thirds kilometers, no problem, yeah?
Nope. Barely forty kilometers. And that's where we are now, as I type this; thirty kilometers from the Hab, and temporarily out of contact with Earth.
I've got a lot of questions I need to find answers to. Where did my recharge go? Why is my driving performance fourteen percent less efficient on the second day? And, assuming I find answers, what can I do about it?
I do know one thing: forty kilometers a day is not going to do it. That's over eighty days— more than half our safety margin for modifying the MAV gone.
So we're cancelling today's read-along. No D&D. All of us are doing math and brainstorming solutions to this issue. I'm keeping this log open and using it for, well, kind of the minutes of the meeting. If we come up with good ideas, this will help us remember.
Okay, going forward.
Dragonfly asks how much power each solar cell produces. On Earth, with its almost circular orbit, sunlight adds about 1400 watts of heat energy per square meter of surface. Mars is a lot farther out, and its orbit is a lot more elliptical. Raw solar energy ranges from 500 to 700 watts per square meter. The solar cells turn that energy into electricity we can use at a 10.2 efficiency rate. That means, on a clear, day, each 2 sq. m. solar panel should have a peak power of about 120 watts.
Of course, we aren't having clear days lately. Cirrus clouds let in most of the sunlight, but not all of it. Also, the northern hemisphere's summer corresponds almost perfectly with the Martian apisol— that means farthest point from the sun in orbit. Mars is gradually getting closer to the sun, but this hemisphere is tilting away from the sun as we approach the equinox, so it's kind of a wash, energy-wise.
Fireball points out that estimates aren't the same as actual testing. Okay, so thing to do: connect one of the power meters in my tool kit to a solar panel and monitor its performance. That will give us an exact measurement.
Starlight Glimmer does some math and works out that, assuming twelve hours of good sunlight, our forty-two solar panels ought to produce a total of 60,480 watt-hours, or more than enough to fill up the batteries without the RTG. Nice idea, except that fourteen of the solar panels aren't producing while we're driving. We can't start driving until there's at least enough twilight for the ponies to see beyond the range of their suit helmet lights, so some recharge time during the day will be lost to driving.
Fireball asks: doesn't that mean that the batteries are charging from the twenty-eight solar panels on Friendship while we drive? Good point... come to think of it, damn good point. Let's think about that for a moment.
It takes at least half an hour after sunrise for the sun to be high enough off the horizon for the solar cells to get a decent current going. Before then the angle is too low and the panels are catching more photons reflected from the atmosphere than direct from the sun. But after that, the current is close enough to peak as makes little difference. And yesterday— and in the prior power test, come to think of it— we started driving at or after that point. That means that, in addition to burning what was in the batteries, we were also using 100 watts from the RTG and as much as 3,360 watts from the solar cells every hour. In three hours, that comes up to maybe 10,380 watt-hours.
I think we just found that fourteen percent efficiency loss. We didn't lose any efficiency. We were just burning more juice than we thought we were.
This morning we got rolling long before dawn and ran out of juice in a bit less than two hours of driving. The solar cells were putting out negligible amounts of current for about two-thirds of our drive time today, so we didn't get the benefit of their juice.
Doing the math again. With a normal load, the rover wheel motors are rated for fifty watts per kilometer per wheel, or (with eight drive wheels running) four hundred watts per kilometer, total. But more weight requires more juice. Yesterday's performance was (I thought) sixty-nine kilometers on 49.6 pirate-ninjas, or in round numbers about 720 watt-hours per kilometer. But it turns out we were probably closer to 60 pirate-ninjas, or roughly 870 watt-hours per kilometer.
More than twice as much energy consumption, for more than twice the rated load. There are a lot of reasons why this could have been different— lack of air resistance, rolling load, Mars gravity, all sorts of other shit— so I never bothered to run this calculation before. But...
... eight hundred seventy watt-hours per kilometer, at seventy kilometers, requires 60,900 watt-hours— call it sixty-one pirate-ninjas. We can only store fifty-four pirate-ninjas at a time, and an all-day recharge cycle gets us not more than 60.5 pirate-ninjas per sol. That's not sustainable. Either we find a way to use less power in motion, or else we accept a maximum theoretical range of (fifty pirate-ninjas divided by 0.87 pirate-ninjas per klick) fifty-seven kilometers per day.
The obvious answer is to lighten the load. The problem is, that's impossible. The ship is stripped down to the absolute minimum systems. We need all the magic batteries for emergencies, for magic rations to keep Dragonfly from crawling back into a cocoon, to top off the jumbo batteries for launch day, etc. We'll have to think of something else.
