Sol 485
“Well, Bruce,” Venkat said, looking across the desk at the chief of JPL, “what have you brought to show me? The final MAV modification procedures, I hope?”
“I figured now was a good time,” Bruce said. “We finalized them six days ago, but the storm thing came up. By the way,” he added, “I was somewhere over New Mexico during the comms window with Hermes. What’s the report?”
“Seventy-five kilometers today,” Venkat said, smiling. “Spitfire is resting, eating well, and recovering, though she reports still having headaches. Even better, they’re entering Meridiani Planitia; mostly flat, level, empty land. Between the clear skies and smooth terrain, they should make excellent progress over the next ten sols or so.”
“That’s good to hear,” Bruce said. “I’ve been looking at the satellite photos taken near the time of the event. It’s a shame that Hermes was at the wrong angle to see the flight. I doubt its video cameras could have picked up any details, but it would have been nice to try.”
“Believe me, the photos we have are still plenty,” Venkat said. “Not that the people demanding more would agree. We’re lucky we had satellites in place to monitor the Whinnybago’s usual drive time, and that they launched Spitfire during that window. But some of the people asking for more pictures act like NASA has a secret time machine that would let us go back and take more photos.” He shook his head. “The ones with doctorates, at least, ought to know better.”
“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.”
Stats
Page generated in 0.042 seconds
Total duration
825 users online
537,226 hits today, 2,314,256 yesterday
FIMFiction
My Little Pony: Friendship is Magic Fanfiction
Designed and coded by knighty & Xaquseg - © 2011-2024
Follow & Support Us
Support us
SubStar
Chat!
Discord
Follow us
Twitter
MLP: Friendship is Magic® - © 2024 Hasbro Inc.®
Fimfiction is in no way affiliated with or endorsed by Hasbro Inc.®
Here’s hoping Lord Luck’s on their side.
That is great news about Spitfire. I hope. If she is up and about with only headaches to show for her decompression sickness, she is one very lucky Wonderbolt.
1 per stage maybe? Or just an AE (author Error)
Good to hear the plans at last! And a nice way to cut away while still keeping us updated on Spitfire.
9156686 It said resting, eating well and recovering - no mention yet of being up and about; I presumed the implication was that she was doing all that within her improvised suit chamber, or at most from her bunk.
Funny thing? The Equestrians aren't as paranoid (yet) about backups, and might wonder why humans carry all this crap full time, while still limited to reaction engines.
OTOH if they manage to set up space trade, I can see human designed capsules and possibly their whole life support recycling systems if the mass works out better for Pony drive systems being a major deal for all space programs. When it comes to saving mass and long duration space flight humans have a huge wealth of experience.
We have good reason to be paranoid with our backups.
9156271
Yeah. I just heard about his passing this afternoon. Farewell Burt, may you keep doing your own stunts. TUT
9156703
That got me thinking about the potential of a spacecraft using combined human and pony technology, and a thought occurred to me: the pony life support systems destroy any complex molecules that pass through them, which makes them useless for food and fuel. So what happens to all the dust particles, microbes, and other microscopic things in the air and water that gets sent through the system?
When your only consolation is that "it could be worse", you know you're in trouble. Especially when the planet you're trying to escape from is sentient and actively trying to kill you. Good luck, Maretians, you're gonna need it.
9156271
Rip Bandit
Spitfires flights been Argosed so now its on to how bad the book couldve been?
Not sure if the SM or LM either stage had auxilary fuel pumps, none of the Stage 1 F1s did? And the translunar injection third stage of the Saturn only had a single engine, and not sure if the SM engine, designed for full land and liftoff and transfer back from the moon could easily handle a full Abort to Earth, or what its oribit was like?
9156733
I have in mind that's come up before, in either this or CSP - they all get destroyed, but there's such a small amount of them that the effects are not noticeable from a user's point of view.
Why the HELL would a two-stage rocket (plus capsule) have -one- auxiliary fuel pump?!
I can't believe it took me this long to figure out...Cherry Berry's cutie mark. It's not saying her talent is eating cherries. It's appreciating them, to the point of her destiny being to grow the first cherry trees on Mars and giving them Groot. Who, I'm sure, is somehow going to save them. Not sure how yet, but it's going to happen.
9156683
Lord because ponies are matriarchal so we gender flip, or Lord because The Lady can be...capricious and you're trying something new?
9156818 Bit of column A, bit of column B.
Liked the nod to the book/movie launch. “You want to send him into space in a ragtop?”
9156755
I think the Saturn V was back when NASA went full Kerbal. Heck, they didn't add auxiliaries to life support until AFTER Apollo 13's near disaster. Extra engines? Not a chance.
Although if Stage 2 had a burnout on the center engine, it just had to burn a bit longer, as proved in the Apollo 13 launch and noted in the official operations report. If a side engine died, they'd have to shut down the opposite engine for balance purposes or possibly abort the mission (which was luckily never caused by Stage 2).
As for auxiliaries on the LM and SM, I know for a fact that the SM (at least up to 13) had 3 fuel cells for power, but I'm not sure about fuel pumps. The LM had to be as light and strong as possible, so I doubt it had extra equipment (Its launch stage had a single engine anyway, and I think the landing stage too).
Full speed ahead!
9156733
Reduced to molecular hydrogen, perhaps?
It's also possible that the system doesn't break up all bonds, just a large enough percentage that what remains isn't identifiable as its original composition. It could produce a slurry of miscellaneous, lighter elements in addition to exploding everything at the speed of microwave polarization.
Good luck tomorrow.
"We’re packing seven days of short rations in this time."
Immediate problem: They will be in their suits. There's no way to eat in them.
9156733
9156768
That....that actually means this has some SERIOUS applications I didn't think of when I first heard about this spell.
Humanity is exceptionally careful about sending microbes to space after the mess that happened during the Columbian exchange and the invasive species problems we have on earth. I suspect once Ponykind has access to that data they will LIKEWISE become really careful about that sort of thing.
(Also I suspect Fluttershy may PERSONALLY come to deal with some of the invasive species. Especially if she hears about some of the lengths we have used to control Invasive animals If her ability to talk and influence animals works on Earth [Even with the really REALLY low amount of magical energy life produces on Earth] she could save so many lives.)
But as the tardigrade proves, (as does the difficulty in maintaining a super clean room) actually purging all life from an area is REALLY hard. And their are other compounds you don't want in the air and water as well, and contaminants to metals and the likes.
With a little modification, Twilight Sparkle's spell could purify air and water for clean rooms, purge bacteria from any substance, and possibly if modified only to send through particular atoms, be used as the most powerful purifying tool known to mankind.
9156875
They won't gut the capsule as they did in the movie, so they can open their helmets to eat.
Because two would have increased the mass to the point that orbit wasn't possible, making the entire exercise in redundancy moot? There are times when you must accept that there will be a single point of failure in a system, be it due to mass, volume, complexity, expense, etc., and work like hell to make that point as reliable as possible. You already had Bruce answer your question: "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."
9156858
This would seem to be the best way to fuel a rocket engine IMO.
Two separate pairs of "life support" crystals; one piping elemental oxygen, one hydrogen.
Would such a thruster have infinite Isp?
9157056
If you could devise such a system, as long as its thrust were sufficient to overcome local gravity, then specific impulse woud be irrelevant, as you would not be bound by the Tchaikovsky Rocket Equation.
Your rocket's operating range would be effectively unlimited so long as you could maintain remote control and translocation of fuel.
9156686
Of course, if Spitfire was a REALLY lucky Wonderbolt, then the headache she now has might be an early sign that she's beginning to grow a horn.
9157122 Could be the lowered magic environment meant there wasn't enough magic to ascend her on the spot. Could be an exciting moment when she gets home.
9157124
"oof! Wait, what is.... You gotta be kidding me!"
9157209
Going cross-eyed looking at her horn, Spitfire opened her mouth, adjusted her throat for a proper parade-ground voice, and took a deep breath. "You have got to be %&$#%$ing kidding me?!"
Twilight looked at Spitfire in surprise. "What does %&$#%$ing mean? It sounds like the human language."
"It means %&$#%$ in Equish," Spitfire said.
9156945
It could be the ship uses a nontraditional system with electric pumps for one or both stages (as Electron does). Maybe the plumbing is such that, in the same way as an extra engine for engine-out is installed, a backup pump for pump-failure is - was - present?
Well, from the Hab to the MAV so far, theyve been running Eastbound And Down.
Time to Cannonball Run.
9156686
All the talk about side effects and crippling/fatal results. We all know that's based on humans, right? This is an alien all the armchair physicians are talking about... An alien that flies and apparently normally coexists at high altitude in addition to regularly experiencing moderate accelerations and so forth.
Just something to think about...
9157365 Pegasus biology are probably the only reason Spitfire isn't worse off.
9157096
Might have the minor engineering problem of stopping atomic oxygen reacting with your rocket plumbing.
Definitely solvable. Plastics,rubbers, and other organics: bad. Oxide coatings: good.
Diatomic oxygen is much less reactive. But real rockets might already take these precautions? I don't know.
edit
Ignore the above. the pony life support crystals can't be breaking gasses down that far.
If they were breathing atomic oxygen they would all be dead.
My reaction to hearing how NASA plans on helping them escape Mars:
9156447
All right then. Thank you for telling me :D
They could always ask Starlight if they want more photos.
9157953
Then she can explain there isn't enough magic on Mars to do it then and there, and not enough magic in this universe to do it once she gets to Earth.
9157056 It's been experimented with. The biggest problem is that a few seconds of thrust is usually enough to destroy one or both crystals.
9157953 After her experiences, Starlight has zero intention of even hinting that time travel is possible. And I don't think any of the others know it's been done, Pillars aside.
Bruce, "It could be worse..."
Venkat, "How?! How on Earth could it possibly be worse!?" (vague reference is vague)
And then Mark and the crew are attacked by Space Nazis. (a subtle clue!)
9158140
One thing ponies lack that humans do not, is nuclear option :)
With some google-fu and math, one reactor used in nuclear submarines (I assume Hermes has reactor with output similar enough) should be able to electrolyse approximately 10kg/s of water, delivered via pony life support, into oxygen and hydrogen. This is not enough for continuous high-thrust propulsion, but it can fill, for example, S-IVB, third stage of Saturn V, in three hours, and spend it in 8 minutes of 1MN thrust.
Sorry, no chapter tonight; in addition to the usual long day, my desktop compy is acting up. Six BSODs in three days.
9158464
I can see why Kris didn't want to use this. I does make things too easy. I.e not a good story.
9158929
Yeah it's not something that would help them now. Just some future possibilities of space travel on both worlds, once NASA spends next decade learning magic and figuring out how-everything-can-go-horribly-wrong-and-make-sure-it-won't on new spaceship design. And same time ponies would be learning about nuclear physics, turning their heads towards Dragonfly who would just say "Told you it was Death Box"
Just ride on the bare rocket, you wusses.
9159787
No, no. basilicum. Saint Joseph's wort. Basil.
As I understand, basil thrives in the desert. Uh, the hot kind. Basil just loves heat.
9158464
Even if you can generate it, you then have to dump the heat somewhere. That is easier on a submarine. Here, it has to be radiated out into space. Think reverse solar panels. So that will be hard. This is where cool equestrian water could make all the difference. And after it's turned to steam by the reactor send it out a nozzle for extra trust.
Add to this, they still have the fuel for the ion engine on board. And an ion engine. I am guessing that it has a higher specific impulse and no weight added to the vehicle. So it's likely a better choice then hydrogen-oxygen hydrolisis.
9159944
Ah, but remember the whole point of this is to leave all the heavy/massive stuff like nuke, electrolysis system, etc.. back on a planet.
You don't have to carry your fuel with you. The actual Motile/Space-capable part of the ship could be as small as a fireworks rocket, since you are circumventing the rocket equation.