Yeah, already did that, after we woke up this morning and found we'd only managed to recharge up to 71% of total battery capacity. It didn't help worth a damn. We still only managed 51.8 kilometers today.
If we'd made a proper full sol of driving, we would have had to turn east or west to get around Crommelin crater today. We'll probably just barely reach it tomorrow. After that we have to make some hard decisions.
Before we put out the solar panels today, we tried running on magic power. The ship has a magic-to-electricity converter in the bridge controls, where the emergency magic batteries normally connect. We hooked one magic battery into the system today and began driving on it. After about a minute and a half Starlight called a halt to the experiment, because she could watch the charge readout dropping as we rolled. We were burning through mana that fast.
After we set out the solar panels (now operating at a measly 59% of peak), we checked the levels in the battery we used and the distance we traveled in a minute and a half (accelerating most of the way, admittedly). Then we did the math and worked this out.
In very rough, round numbers, the Whinnybago burns twenty kilowatts per hour driving at top speed. That's a kilowatt every three minutes.
In the minute and a half we spent driving on magic power, we only hit top speed for about half that time. It takes the Whinnybago a long run-up to get started. So we only traveled about half a kilometer, burning (again, very rough, round numbers) five hundred watts in that time.
In that time, the battery went from fully charged to 95% charged.
Put another way: the battery would get us ten kilometers before it pooped out. It would only run for a bit more than twenty minutes. It's effectively the equivalent of a battery with a watt-hours rating of about ten kilowatt-hours.
Give it its due— that's more efficient for a lot less weight than the rover batteries, and it competes with the lighter weight but much bulkier Hab batteries. But considering I've seen Starlight do things with fractions of magic battery power that would rate in megawatts or possibly gigawatts if they could be done at all electrically, I've got to say that the magic-to-electricity converter is really fucking inefficient.
But that's not really the problem. The problem is recharge time.
If not for the dust storm, we'd have a little over 70 pirate-ninjas of recharge power every sol, of which we can only store 54 pirate-ninjas. Every sol we'd start out with another seventy kilometers or so of driving in the tank.
If we hooked all twenty-one of the small magic batteries up to the rover power system and used it only for driving, we'd get two hundred and ten kilometers out of it. The batteries are currently recharging at a rate of one point four percent per sol... which means a full recharge from zero would take sixty-seven sols.
Sixty. Seven. Sols.
During which time we could do nothing, absolutely nothing, involving magic.
During which time the jumbo batteries would be losing charge at the rate of 0.5% of a regular battery per day... each.
During which time Dragonfly begins drifting back towards physical collapse.
We would have to be really fucking desperate to take that option. And we would also have to be a lot closer to the Hab or Schiaparelli than we currently are. As it is, we are now slightly closer to the MAV than to the Hab or the cave farm. If two hundred kilometers got us to safety, it might be worth it. Otherwise, better to save the magic for a better idea.
Let's just hope we find one before we lose all light completely.
By the way, if you say, "Why not just use the magic batteries to drive the distance they recharge by?" All twenty-one batteries gain about 1.4% of their capacity each sol. That adds up, combined, to the equivalent of 29.4% of the charge of a single battery, or just under three kilometers. Under the current conditions (technical definition: "fucked nine ways from Sunday") it's not worth it.
Better to keep the changeling, dragon, and ponies healthy with that power... while we can.
AMICITAS FLIGHT THREE — MISSION DAY 490
ARES III SOL 481
The wind didn't howl outside the Whinnybago. The dust didn't hiss as it hit the bare ship hull. The only electricity came from the flickering glow that appeared occasionally on the tungsten discharge points attached to outer hull mounts around the former Amicitas, some of which were visible through the bridge windows.
But the dusty haze of the prior few sols had become a fog, a cloud of dust motes drifting past on the weak Martian wind. The afternoon sun shone dimly outside, providing a light more similar to what the ponies thought of as moonlight than anything associated with a star. The storm had them firmly in its grip.
And considering that they'd only driven thirty-six kilometers before running out of power, and that the solar panels which produced that power provided only forty-two percent of what they should have produced, everyone in the Whinnybago recognized that grip was tightening.
Hermes had run out of hopeful news. Their report today had been grim; center of storm one hundred forty kilometers east-northeast. Storm almost stationary, no longer widening but getting thicker at the core. At the storm's center, they estimated, only about ten percent of the sun's light reached the Martian surface... ten percent and still dropping. If the storm remained at current strength and intensity, it would take over a month to pass over Crommelin crater, which the broken ground outside suggested was now very close by the Whinnybago.
"So here's the situation," Mark said, as the six of them gathered in the bridge to discuss options. "We have three options. We can hunker down and hope the storm passes more quickly than expected. Anybody want to talk about how likely that is?"
Not a word. Everyone knew this storm had their names on it.
"Yeah, me neither. Option two; turn east-southeast and begin making for Schiaparelli at whatever speed we can. That takes us closer to the heart of the storm, but it also runs against the direction the storm's currently moving, so it's just possible that we get out from under it sooner. We can run life support off the RTG and your ship's system, so we should be able to at least crawl a little each sol."
"Maybe we could pull the ship behind us," Cherry Berry suggested. "Like when it was salvaged."
Fireball slammed a fist into the deck. "No!" he shouted. "Tying ropes around our space suits? The way they are? Look at us!" He pointed to the patches on his own suit, the elbow and knees on Cherry and Spitfire, the large gash of black gunk of Starlight Glimmer's right foreleg. "They blow out quick. Kill wearer. No rescue. Suicide. Dumb idea. I know what I'm talking about."
"I could make harnesses-" Dragonfly suggested.
"NO!" Fireball took a deep breath, held up a palm to stop anyone from speaking, and thought carefully. "Even harness make different pressure on some parts of suit than others," he said. "Different pressure puts more pressure on patches. Can't avoid. Can't fix. Trying that will kill somebody. Listen to me."
Dragonfly nodded. "I hear you, Fireball," she said, "but if it comes down to the choice-"
"If it's choice, then ask Mark for medicine," Fireball snarled. "You want a choice of how to kill yourself, he find something a lot less trouble than losing all your air outside."
"Okay," Mark said after nobody followed up Fireball's declaration. "Anybody like that option? My main problem with it is, if my navigation is right, we're still about thirteen hundred kilometers from the entrance to Schiaparelli, plus maybe another four hundred kilometers after that to get to the MAV. Seventeen hundred kilometers. If we traveled at the rate we did today, we'd reach there on Sol 530— but we all know the storm would get a lot worse. My math says, we'd miss the launch date and run out of food first."
Again, no argument.
"Option three. Go around Crommelin to the southeast. We have another hundred and fifty kilometers of southward travel before Pythagoras becomes our enemy— sorry, cultural reference, I meant before we start getting farther away from Schiaparelli instead of closer. So long as the storm doesn't turn south and cross the equator— which it's not supposed to be able to do, but who knows what this fucking planet will do next— we'd begin to get out from under the shadow.
"The problem is, we don't know how far south we'd have to go. The dust cloud extends a long way south of the equator— maybe eight hundred kilometers. If we go that route we'd have to take the backup route into Schiaparelli on the southwest side, which requires crossing a lot of uneven, rugged terrain. It'll take a long time, and there's no guarantee we'd reach the MAV before our food runs out."
"There's a fourth option," Starlight said quietly. "I've been thinking about it for the last two sols."
"What is it?"
Starlight shuffled her forehooves on the deck. "Remember the booster system test?" she asked. "It cleared the skies instantly. We had weeks of clear weather and unseasonably warm temperatures. We could do it again."
"Hey, yeah," Dragonfly said, grinning. "That is a great idea! We don't need as big a mass this time! Or as much speed, either! All we need is a big rock from the surface, a little booster target, a booster crystal, and some battery power!"
"We've got half a ton of clean crystal," Starlight said. "I think we only need twenty-five kilos of it to make the booster and its target."
"We still have the data from the test," Dragonfly said. "We can use that to keep the power use to a minimum. Maybe only one battery would do it!"
"Yes!" Starlight grinned even wider than Dragonfly now. "I can't think of any reason this might go wrong!"
"I can," Fireball grumbled. "How do we know the last test didn't cause this storm now?"
Grins vanished. The others looked meaningfully at one another.
Cherry Berry finally spoke up. "So maybe we have a storm during launch day," she said. "We'll deal with that then. But if we don't try something, this storm right now will keep us from even having a launch day." She looked at Starlight. "Do it," she said. "We'll launch your cloudbuster tomorrow morning."
Author's Notes:
Going to be busy the rest of the day, so here's what I wrote last night.
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Sol 482
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AMICITAS FLIGHT THREE — MISSION DAY 491
ARES III SOL 482
The rock sat on other rocks, as rocks sometimes do.
To differentiate it from other rocks, it sat with its ends supported by two carefully constructed rock cairns, lifting its middle up and away from the ground. On its underside a small bit of clear quartz had been carefully attached, pointed straight down towards where a slightly larger bit of quartz lay. That second crystal chunk was connected by a series of cables to a much larger, metal-wrapped chunk some twenty meters away, which in turn was connected to a switch, which itself was connected by ten meters of changeling-made rope to the hand of a figure in a somewhat worn-looking space suit.
The rock didn't know it yet, but it was about to go for a ride.
Spitfire, having retired inside the Whinnybago after helping gather the rocks for the launch cairn, stared through a cockpit window and allowed herself to feel jealous of a rock. Your life sucks, she thought to herself, when a rock gets to fly and you don't.
"If my calculations hold up," Starlight Glimmer was saying over the comms, "the missile should reach two hundred fifty meters per second at about one thousand meters altitude. The shockwave should begin to form there, clearing out the skies without sending the missile on an escape trajectory."
"If you say so," Mark said. "Fireball, is the camera rolling?"
"No," Fireball said, sounding confused. "Camera in my hand. You want me to roll the camera?"
"I meant, is it recording?" Mark asked.
"Ooooooooooooh," Fireball replied. "Is it recording? That different. Recording now."
"You did that on purpose," Mark said. "I'm proud of you."
"Back on task, everyone," Cherry Berry said, standing near Spitfire and watching through a different window. "All go for launch in ten. Nine. Eight. Seven."
Dragonfly, also inside and safe, paced the small open area of the bridge.
"Six. Five. Four."
Spitfire put one forehoof on the bulkhead next to the window, watching the dust-blurred figures, a hundred meters away, leaning towards the ship as they prepared to run like hell from the launch zone.
"Three. Two. One!"
A hundred yards across the rubble-strewn surface of Mars, Mark yanked the rope that triggered the switch and began half-bouncing, half-running for the rover.
Unlike the first time they'd done this, with a much larger and heavier projectile, Spitfire could follow the ascent of the rock with her eyes. It got faster in a hurry, and in a couple of seconds it left the limited visual range of the porthole, but it had definitely been slow by comparison to the original booster system test.
"Tracking missile drifting west," Fireball said. "Not gonna drop on our heads."
"I'm back at the ladder," Starlight panted. "Climbing up now."
"And I'm right behind," Mark said. "I don't see any shockwave, though."
"Lost target," Fireball said. "No shockwave. All I see is a kind of swirl in the dust." Pause. "Got a breeze."
"Shoot!" Cherry Berry snapped. "Why didn't it work? Not fast enough?"
"It'll get faster as it gets higher," Starlight said. "And most of the dust is upper-level atmosphere. Give it time."
Spitfire continued staring out the porthole. She could see dust, the thicker, grittier dust that the weak dust storm couldn't pick up, dancing in little clouds and gusts from the surface. A roller-wave of the stuff rippled across the slope towards the launch point. Another one rolled away from the rover towards the launch point.
And the haze seemed to dance and twist around the launch point... almost as if...
Updraft.
Updraft plus heat from friction, as the rock continued to accelerate past the speed of sound.
"Commander," she said in Equestrian, "I strongly urge we get the others in at once. Leave the equipment outside."
Cherry Berry turned to look Spitfire in the eye. She stared for just a moment, then turned back to the window. "Emergency abort," she said in English. "Everyone back in right now."
"What for? Just a little breeze," Fireball said.
"Not for long," Spitfire said, this time in English. "Dust devil forming. Tornado. Get inside right now!"
