"Well, when we work out the bugs, we'll let you know," Bruce said, smiling. His smile dropped as he pulled a bundle of printouts from his briefcase. "We've spent over half a year working on this," he said. "These procedures remove the most weight possible from the MAV without fatally compromising life support or the capacity for a Sparkle Drive direct abort to Earth."
"Should I be concerned?" Venkat asked.
"You will be, regardless," Bruce said. "Remember, the MAV at launch, minus its descent stage, weighs 12,600 kilograms plus the weight of its fuel and oxidizer. We sat down and did the math and figured out that, without the pony booster system, we'd have to find a way to add extra fuel and, at the same time, reduce the tare weight of the ship to 7,300 kilograms in order to achieve intercept velocity with Hermes."
Venkat blinked. "Forgive my imprecise math," he said, "but that's almost cutting the ship in half, Bruce. How on Earth did you expect to manage that?"
"By removing the parts of the pressure vessel Mark could access directly, using Hab canvas to seal the holes, and having the crew ride up in their space suits," Bruce said.
"You've got to be kidding me," Venkat said. "That's the most outrageous proposal I've ever heard."
"It would have been an act of desperation, yes," Bruce admitted. "Thankfully, we don't have to go there. But I want you to bear that in mind as we go down the list of everything we have to do to shed two and a half tons from a ship we already intended to be as light as possible. Just keep in mind it could be worse."
"Go on," Venkat said.
"First, bear in mind we'll be adding some weight to the ship," Bruce said. "The Sparkle Drive made by Starlight Glimmer on Mars will use up the entire five hundred kilogram weight allotment for surface samples. We're also allowing the crew fifty kilograms for personal effects. The MAV would normally carry only one day's rations for the crew, with rationing in case of the low orbit abort scenario. We're packing seven days of short rations in this time. And we're adding the surviving ship thrusters from Friendship. We considered just using them to replace the existing thrusters outright— they're lighter and they regenerate if there isn't too much shielding between them and the crew. But the headaches of adapting the existing controls to the new system were too much. They'll be backup in case the Direct Earth Abort scenario becomes necessary."
"How do you propose to use them, then?" Venkat asked.
"We'll use the control systems for the secondary and tertiary thrusters," Bruce said. "They're redundant for good reason, but they're still redundant. They go. Speaking of redundancies, we'll be dumping the backup comm systems. Life support, too, except for emergency tanks for Mark's suit. The pony suit life support systems will take up the slack except for heat, and that's not an issue, because we're sending up both the Ares III and Ares IV MAV's RTGs to extend the life of the MAV batteries. Which we're going to dump three of, plus the entire auxiliary power system. Also the copilot station and controls, plus every control panel that isn't absolutely required for on-board control."
"That's an interesting qualification," Venkat said. "Not that I'm suggesting this in any way, but why not throw out all the controls and have the computer fly the ship? Or Martinez, using the MAV satellite launch protocol?"
"Because we need a live pilot if the Direct Earth Abort becomes necessary," Bruce said. "We can't program a computer for any immediate responses required if and when the MAV makes it to Earth local space. There are just too many unknowns. That means there has to be one set of pilot controls on board. And if they're going to be there, it makes more sense to use them than to risk a computer glitch or a loss of signal on the ride up."
"Only if the pilot's qualified," Venkat pointed out. "Assuming Cherry Berry is going to be the pilot, we need to get her simulation time every sol from their arrival at the MAV until launch day. And only if she qualifies— and qualifies at least comparably to Martinez— do we give her the power to manually override the computer."
"No problem," Bruce agreed. "But anyway. Comms, life support, power system, controls... okay, yeah. No medical kit. No tools. All the suit interface gear except for Mark's, gone. We'll be swapping out the human flight couches for the couches the ponies rebuilt using parts from the MDV, again except for Mark's.
"And, finally, the two big issues. The auxiliary fuel pump, and one of the Stage One engines. Both are redundant, and both are heavy as hell."
Venkat had to stiffen his jaw to keep it from dropping. "You want to remove an engine," he said, keeping his voice level.
"Yeah," Bruce said. "We get more delta-V out of the ship without it. It's only there as a redundancy in case of breakdowns."
"Bruce," Venkat said carefully, "is there a single backup system on the MAV you aren't gutting?"
"A couple," Bruce said. "But only a couple. Every kilogram we save means a little fuel we can save in the second ascent stage for maneuvering or, if necessary, for Earth orbital insertion. And dumping this weight gives us a margin if some of the pony booster pylons fail. As it is, we predict that if the pylons all work properly, the MAV can achieve orbit on the first stage alone, with this payload."
"No backups, Bruce," Venkat insisted. "What's the estimated odds of failure with this setup?"
Bruce shook his head. "Impossible to say," he said. "The repulsor launch system and the Sparkle Drive are too unfamiliar for us to judge. And if they both fail, Mark and his friends are stuck in Mars orbit if they're lucky."
"Jesus Christ," Venkat moaned.
"Yeah," Bruce said. "Just keep reminding yourself, it could have been worse."
Author's Notes:
Bleargh. Spent all day with a mild headache. Meant to cook today, but didn't have the energy. And the stress test and ultrasound are tomorrow, which means I have to get up at 6 AM for the almost two hour drive to where it's being done.
Fun, fun, fun.
All the named stuff coming off the ship, by the way, is listed— and then some— in the original novel. Don't ask me why a two-stage rocket plus capsule has -one— auxiliary fuel pump...
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Sol 489
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AMICITAS FLIGHT THREE — MISSION DAY 498
ARES III SOL 489
Dragonfly watched as Sojourner navigated the walkways between Amicitas's flight couches. The little rover crept along at a snail-like pace, navigating based on orders given by her laptop and relayed via wireless network to Rover 2's computer and out through its radio to Sojourner's receiver. Every two minutes it paused, slowly rose up to take stereograms with its forward cameras, then rocked forward to do the same with the aft-mounted color camera.
"C'mon, bug, put Robo-Bug away." Spitfire, still wearing Starlight Glimmer's space suit, walked out of the habitat deck. The helmet made her voice sound very muffled to Dragonfly without the suit comms to transmit it. "And help me off with this thing. I gotta hit the head."
"Good morning, Spitfire," Dragonfly said. "How are you feeling today?"
"I'm going stir crazy," the pegasus said. "I want out of this suit full time. I want to stretch and start doing exercises again. I've got a lot of work to get back in flying trim."
"Uh huh. Now try that with symptoms added."
"Ugh." Spitfire turned her head away, as much as the suit helmet would let her. "All right. I still have a headache, there's still pins stuck in my fetlocks, my new feathers itch horribly, and I can't put three words of English together. But it's all better than yesterday."
"It must be," Dragonfly agreed. "After all, you couldn't put three words of English together before."
"Fuck you."
"Two, however, you manage just fine."
"Look, if this was your suit I wouldn't mind, but I don't want to fill Starlight's suit full of roadapples when I don't have an undergarment anymore. Y'wanna help me out of this?"
"Sure, Spitfire," Dragonfly said, rearing up to grip the helmet between her forehooves. "But once you're done in the head, you go back in the suit and lie right back down. You've got two days of treatment to go, and treatment is high pressure, oxygen, and lying down. No exercise."
"But I'm feeling better-"
"How does it feel to swap places with Starlight Glimmer, by the way?" Dragonfly asked pointedly.
When the helmet came off, Spitfire's ears slumped in shame. "Yeah, all right," she said. "You made your point. I'll be good."
"That's our hero."
"And don't you forget it," Spitfire muttered, wiggling out as Dragonfly helped unseal the rest of the suit. "I may be flying a desk after this, but at least I have one record Rainbow Dash is never going to beat."
Dragonfly looked at Spitfire's wings. They were in tatters. Another couple of primaries had come out overnight. The Feather-Fix potion had begun growing replacements for all the feathers they'd had to chop up to get the gunk-lined suit wings off her, but it came a lot more slowly than it would have done at home. The new feathers were barely barbs. A lot hadn't even broken the skin yet.
Spitfire noticed Dragonfly examining her wings. She looked the changeling straight in the eyes and said, "Worth it." Stepping free from her suit, she walked to the head, wobbling only a little as the deck underneath them rocked gently. The morning was young, and the Whinnybago was rolling along at top speed through an uncommonly smooth stretch of Martian terrain.
Dragonfly returned her attention to Sojourner. The little probe would have to scoot back to its corner in a while; it didn't get a lot of sunlight through the cockpit windows to recharge its batteries. But learning the commands to make the little rover go gave her something to take her mind off of other things, like the hunger she imagined she could feel building up after days of almost no magic.
It had to be imaginary. A daily two minutes had to beat out twenty minutes every seventeen days. But... well, she felt weaker, she felt hungrier, and she couldn't stop feeling that way.
She hadn't mentioned it to the others, though she knew they would want her to. It just didn't seem to be helpful. There were very good reasons why magic time had been cut back so drastically.
The batteries recharged at 1.4 percent each per sol— they'd triple-checked the rate— for a total mana recharge of 29.4% of a single battery's capacity. 7.5% of that went to top off the jumbo batteries to compensate for their slow bleed. Two minutes of magic field, the new daily ration, ate up another 5.6%. That left just over 16% per day to recharge the eleven batteries they'd used defeating the Great Black Spot, as NASA was calling it.
At noon of Sol 483, they'd had ten full batteries and eleven empty ones. By tonight, assuming no emergencies, they'd have eleven full batteries and ten empty ones, or the equivalent. According to Mark's travel estimate, they might be able to recharge four more batteries before they reached Schiaparelli. After that work on modifying the MAV would eat more power— who knew how much. And at the end of the process— with recharging the jumbos, with MAV mods, with daily magic doses, with emergencies if more cropped up— they had to have at least seven full batteries, minimum, for installation with the Sparkle Drive.
Bottom line: recharging the batteries against future emergencies took absolute top priority— even if it meant pushing the edge of magic starvation again.
The Great Black Spot had totally bucked Spitfire— but to be fair, she'd got the last kick in. But it was still bucking Dragonfly over, too, and it wasn't around for the changeling to get her own kicks in. And it didn't help that she had entirely too much time to work all of that out, especially with Starlight borrowing her suit and taking her place scouting alongside Cherry Berry.
Spitfire eventually came out of the head. "Okay," she said. "Help me back into the flour sack."
"Rarity would have a fit if she heard you call it that," Dragonfly chided.
"Would she?" Spitfire asked. "Oh dear. Did this suddenly become Ponyville instead of Mars while I was on the can? Sure fooled me!"
"You're getting better," Dragonfly muttered as she helped Spitfire shrug the borrowed suit back on. "It takes energy to be sarcastic. What do you want for breakfast?" Mark had dug out a few of the precious non-meat food packs, formerly reserved for use if they had to take the MAV straight to Earth, to give Spitfire more incentive to eat full meals.
It hadn't worked as well as Mark might have liked. "What's the entrйe?" Spitfire asked, not bothering to fake optimism.
"Cowboy beans and rice," Dragonfly said.
"Bring on the hay," Spitfire said, allowing Dragonfly to walk her back to the mattress-covered floor of the habitat deck.
Watching Spitfire eat breakfast (and getting a snuggle-snack for her trouble) occupied twenty minutes of her attention, but that was over once the helmet was back on the suit, the life support turned back on, and a computer left beside her so the pegasus could read one of the mystery novels Fireball had recommended from the NASA stash. To make things worse, Sojourner had completed its pre-programmed little dance, so Dragonfly didn't even have watching that to occupy her mind.
Well, the Whinnybago was still rolling, so there was at least the entertainment of watching the gently rolling terrain of Meridiani Planitia slowly passing by and behind the rear-facing cockpit windows. She dragged Sojourner back to its usual resting place, then trotted forward to the co-pilot seat.
The flight couch was occupied, however, by a potted plant.
"Hey, Fireball?" Dragonfly asked.
Fireball reached over to switch off his outgoing suit mike, then said, "Done playing with the mini-rover?"
"Why do you have Cherry's shrub in a flight couch?" Dragonfly asked.
"I've been helping take care of Groot," Fireball said. "I think he likes looking out the windows. Of course, we're at the wrong angle here for him to get much sun, but I think he likes the view."
Dragonfly had her mouth open to say something like It has no eyes, it can't see the view, or How do you know what a plant does or doesn't like, or, most probably, It's a bucking TREE, before her brain caught up and turned all of it to a meaningless, "Errr..." After all, how many times had she talked about her delusions of sensing what this or that thing felt about anything? Where did she have room to scoff at what saner people thought an inanimate object felt or thought?
Come to think of it...
