AMICITAS FLIGHT THREE – MISSION DAY 369
ARES III SOL 363
[08:13] WATNEY: Good morning. I have a problem I want to bounce off the back rooms back at JSC.
Two sols ago Starlight Glimmer added the launch boost enchantment to the jumbo batteries. If all goes well, the jumbos will throw three pieces of specially enchanted quartz, and anything attached to them, completely off this planet. This should provide more than enough thrust, when added to the lighter load you’ll give the MAV and the existing engines, to reach Hermes with a substantial fuel reserve in the second ascent stage.
There’s just one hitch. The geniuses back in Ponyland who thought this system up (after Starlight gave them the idea) want it tested. And NASA being NASA, you want it tested too, because nothing makes a NASA engineer clench his buttocks tighter than the thought of sending a human being, never mind six people, up on a launch system that’s absolutely never flown before.
We spent all day yesterday talking about how we could do it. The enchantments are specific and can’t be re-tuned to a new target. If we use the enchantments Starlight made sol before yesterday, we lose those targets. Also, we aren’t completely sure how quickly the jumbo batteries recharge, but we think it’s slower than the regular batteries, so we don’t want to use them for anything again until escape day.
So we decided, in a few days, that Starlight would enchant some new crystals and three new targets. We’ll hook the new crystals up to the existing batteries and use them to launch something as a test. We considered rigging things to make the targets retrievable for future tests, but there’s too much danger of dropping the whole test vehicle on top of our heads. We absolutely want to reach escape velocity. Ideally we want to launch at a time where the expected launch trajectory has the maximum chance of going straight up, leaving Mars’s sphere of influence, and then dropping straight into the sun.
We’ve chosen to launch one of the pony ship’s three engines. We won’t be using them for anything, and we know the mass to within ten kilograms, so the data we get from the launch should be good. Future archaeologists will have to make do with the other two engines when we return to this site.
Our main problem with all of this is tracking. I’m sure we can pick a launch date and time when several Mars orbiters will be in view to watch the show, but cameras aren’t as good as radio tracking. Right now the only thing we have that can broadcast beyond atmosphere is Pathfinder, and we’re not launching that. Its ancient systems wouldn’t survive launch vibrations anyway.
But we have two good remote weather stations and one half-operational one. They all have short-range radio transmitters. I could fuck up one of them so it sends a constant signal, and I could attach a heavier battery to provide extra current. Could we send extra juice through the transmitter to allow the orbiters to track the test vehicle for, oh, five minutes? If it burns out after that we don’t care, but we really want accurate tracking for the first five minutes after launch.
We’ve still got plenty of time. The rover mods are essentially done, and we have about a month before we’d need to do serious testing and final prep for the drive to Schiaparelli. Get back to me when you’ve got some solid answers.
[08:39] HERMES: Ooooh, Mark, cosmic litterbug! Between this and how you’re completely trashing Mars, Greenpeace is going to picket your apartment when you get home.
[08:46] JPL: Those are some good ideas, Mark. We’ll get some systems engineers to work testing how much voltage the weather station transmitters can handle and if there are any other ways you can increase the gain using tools on site. In the meantime, I’ll put the problem of tracking your launch in the hands of our very finest SatCom technician.
Mindy Park didn’t notice she had a visitor until the mellifluous voice of her five-and-a-half-management-levels-up boss spoke from over her shoulder. “Good morning, Mindy. And how’s my favorite satellite herder today?”
Mindy sighed, sitting up from her terminal and swiveling her chair around to face Dr. Kapoor. “About to get a whole lot busier,” she said. “Am I right?”
They have a method and a how, but they don't know if it would kill them. Here's to hoping that everyone makes it out okay. We must hug the bug!
Another major magical discharge on Mars. There's no way this can go wrong :)
And then the engine, being exposed to the magic batteries and the reactionless drive attached to it, fires and rains all hell onto the intrepid martians.
More testing data is always a good thing. Here's hoping it goes off without a hitch.
Anyone besides me ever see Space: 1999?
Because this is how you get a Breakaway scenario.
You know, as magic as the system is, it kinda sounds like a potato gun. And I'm sure Mark has one or two he could spare. For science, of course.
Good news: The test of the repulsorlift boost technique works well within acceptable safety parameters.
Bad news: The test package, along with Deimos, are now on a trajectory that may intercept Hermes. No. We don’t know how that happened to Deimos.
9059043
Considering what happened the last time they did this, with their luck. Olympus Mons will pitch a fit and deliver one hell of a show.
Also two days until Mark has officially spent an entire Earth year on Mars.
Marsnado.
If they can do an overdrive and reduce before burnout of the transmitter, then a dish like the Old Man can follow it from Mars to the Sun. the 250 foot Lovell Radio Telescope at Jodrell Bank that picked up Sputnik and was used to relay, or intercept, the images from the first Soviet Lunar Orbiter.? By the time of this story its roughly 90 years old? But even currently its supposed to have the sensitivity to be able to pick up a Cell Phone on Mars. With the correct alignments.
Hopefully the batteries boost crystals wont suffer some form of resonant behaviour especially if the Martian atmospphere spins up and dumps a full Lightning strike into them as well.
Latests news. 100 nanometer glass beads in a circular polarised laser beam, can spin a Billion times a second. thats the same speed as natural rotation of a hydrogen Molecule, 21cm, just over 1 Ghz.
I hope someones watching out for the acceleration, because they only need Ten seconds at 30 g for it to go all the way?
9059091
Since a Sol is roughly 39.5 minutes longer than a terrestrial day, the 1 earth-year mark was back around Sol 355 or 356.
So what is this level of magical discharge going to do to Mars' weather...
Leaving Mars is relatively easy: 5km/s deltav, escaping it: 7km/s, but throwing something into the Sun from the Mars surface needs 20-24km/s, that is Huge!
You need to sustain 30g acceleration for 80 seconds, which is very much possible for the "repulsorlift" if you throw a light "spacecraft", but seems quite overkill.
(number were rounded up and are slightly bigger if you can only throw straight up)
I continue to fear for a Macross moment when they try to lift the entire ship using relatively tiny target crystals.
Don't forget that Mars has an allergic reaction to magic experiments.
"YOU MUST CONSTRUCT ADDITIONAL PYLONS!"
... we hope.
Couldn't they use Dragonfly's pet robot for the transmitter?
9059101 Receiving the signal is one thing: accurately tracking velocity and trajectory is another. You don't want to depend on Earth for that, not when Earth is 2.5 astronomical units away.
9059151 I welcome anybody who wants to calculate the shot. In my mind the best launch time would be just before sunset- enough light for the orbiters to see the launch, and a vector opposite to the orbital motion of Mars for maximum reverse-Oberth effect.
9059278 ... you do realize you just suggested they throw Sojourner into the sun?
River Babble, KwirkyJ, and I just read this chapter together on voice chat! It was fun taking turns for each paragraph!
9059278
DON'T YOU DARE! She's a pretty rover, yes she is!
I'm looking forward to the guys at NASA collectively passing enough masonry to build a castle when they confirm the launch data.
This can only end well.
9057575
Like I said, they suck, big time.
Aim for the Tesla! Aim for the Tesla!
The ESA is letting people name their new Mars rover. Let's all suggest "Amicatas".
Edit: seems that only people who live in Europe can enter. So all of you Europeans, we're counting on you.
9059339
Plus sojourner has a range of only like a quarter mile.
9059310
I don't need to calculate anything to know that they just can't do that.
They don't have that accuracy to actually hit that tiny sun, even if it was directly overhead.
The sun never will be directly overhead at their location.
If you actually wanted to hit the sun, you'd fire retrograde compared to Mars orbit. With a Delta v of exactly Mars orbital velocity + escape velocity + gravity losses. But how would they rotate Mars to make it point in that direction? And if you have a pocket alicorn to rotate the planet, how do you plan to get the launch accurate to the exact speed required? A few m/s off target and you get an orbiting engine instead. Sun = focal point of any orbit.
9059030
No need, they know where Dragonfly is.
Dragonfly has to give her all love to others, then she will survive the trip.
Martian Pumkin Chuckin test is a go!
9059310
In rough numbers the test vehicle is going to accelerate in somewhere between 30 sec to 1 min 30 sec and reach orbital velocity to escape velocity. (Just because it reaches orbital velocity, it is not going to be in orbit, but it is at least not going to hit the hab when it comes back down.)
9059539
If you release full "lift MAV" power on the test vehicle, then the weight difference is enough to give it enough speed to hit the sun. (Warning for extremely high Gs if tested.)
You are right in that they do not have the accuracy to hit the sun, but to come close enough to burn/smelt the test vehicle is much easier.
Good thing you keep Mindy a bit busy too.
But what is Cathy Warner and her "Watney and friends" program up to these days?
Mellifluous is a wonderful word
9059690
9059310
From their location even that is impossible.
What they could maybe do is launch a pykrite block, They have the spare hay. Or a concrete block, They have the spell now.
And if they add some of the sunlight collection crystal on the vessel, It may save the cave.
9059120
I meant going by days
9059065
Only if they set off the Sparkle Drive on Mars which we know has a rather fuzzy rule set on what constitutes the "ship" to move. On the other hand, this booster system should provide some entertainment for a bunch of very, very bored Mars colonists. Reminds me of model rocketry in my stupid-teen years, launching stuff just to see it go up and not really care where it lands.
A very powerful bit of magical technology if you think about it. A launch system that is almost self-charging (assuming Earth has the same ambient magic field as Equestria), far cheaper than anything capable of orbital launch, and if you discount the quartz you just threw into space, no waste-byproducts or environmental impact. It would revolutionize the space race, assuming we could get more than the one unicorn in the entire human universe to stick around.
The ending of this story where Earth meets Equis, which I hope happens, would have history-altering impacts on both worlds as technologies are exchanged and blend. For humanity's sake, they really do need an eternal Princess to guide them before they blow themselves up with these new "toys"...
p.s. Build more pylons!
9059539 Even granted that precision is not on the menu for this launch, Mars does rotate by itself. And launching at high noon wouldn't get a Sun strike, because the launch would take nothing off Mars's orbital velocity except, possibly, its rotational velocity.
In any case, failing a direct sundive, the goal should be a retrograde orbit, which will gradually decay into a sundive as gravitational interactions with other bodies slows it down.
As for launching other things, the primary concern is whether or not they hold together during launch. For example, a ton of ice (one cubic meter, not difficult for our heroes to put together) would be ideal- make your own comet!- except for sublimation on the ground and losses to atmospheric friction during ascent. Those losses would make the math questionable.
{Y O U M U S T C O N S T R U C T A D D I T I O N A L P Y L O N S INTENSIFIES}
9059884
Though it's still going to be nearly twice that before he will have been on Mars for a full Martian year.
Mars circles the sun once every 687 earth days.
9060017
Sublimation; a feature, not a bug.
Here are its advantages:
Mass-wise It is the equivalent of using fuel during your launch.
It is a build in mechanism to release heat build up during launch.
It creates a trail that allows for much easier tracking by Mindy, or, Mark aiming a gopro at it.
It allows for the creation of an aerodynamic shape. A tumbling engine with tumbling crystals are not necessarily equivalent, to one that is not tumbling. Assuming that the engine can even take the centripetal forces while subjected to atmospheric drag and crystal pressure(relative to the engine, in many different directions.). Max Q is a killer.
On the launch at high noon thing, that was intended as ‘rhetorical device’. I thought i had myself covered, by mentioning launching retrograde myself. Apologies for the confusion.
As mars only rotates around 1 axis, the closest angle you are going to get to sun-retrograde, assuming the launch goes smoothly, is 30° (hence pocket alicorn).
9060266 Sublimation is not a feature when you want to measure the steady thrust equivalent of a launch system. Nor is it a feature as regards surviving max-Q. Ice is brittle and prone to breaking apart in large chunks under stress.
9060277
Ice is not pykrete.
I am not aware of any significant relation between thrust and sublimation. Enlighten me.
9060318 If mass is not a constant, then you have to make an estimate of how much mass has been lost in order to get a measurement of thrust. For the most accurate measurement of thrust, you want a precise measurement of the mass being launched, and you want that mass to remain constant during the experiment. You don't want to simulate the fuel usage of an actual rocket launch, because the whole point of the exercise is to get as specific and accurate a number as possible to plug into the equations for a regular rocket launch later.
In short, the ideal experiment reduces variables as much as possible.
9058204
Justice, of course.
9060338
JPL is well versed in how to deal with changing mass in launched vehicles. That is the easy part of rocket science.
If you launch an 1000 kg aerodynamic comet, at the shortest route out of the atmosphere. i would be surprised if you lost more then 20 kg. But JPL would put a block of pykrete in a low pressure wind tunnel, and find the exact answer.
If you launch the non-aerodynamic engine, and have to start calculating how much you have lost to air resistance, and rotational energy, that's also a variable.
Another possibility would be the MAV 3 decent stage. Including its hydrazine engines and thrusters. Yes, it's a good bit of work, both electrical and aerodynamics, but it should have sensors and stuff to make it actually work. Steal what's missing from the MDV. It would give a lot more useful data. Assuming it can be outfitted with a helmet-radio-array.
Hm. Other than echoing 9059185 and suggesting that a test should maybe be done further from the Hab and Cave, I don't have chapter-centered comments. So here are a couple other thoughts.
I haven't read any Pratchett (something I should correct), and a good chunk of my knowledge of Discworld comes from FimFiction. (Not the majority; another chunk comes from watching an adaptation of "Going Postal.") So I'd like to hear more about Carrot as an Alicorn, starting with the birth/ascendance question.
And I can't imagine that Angel Eight was lost forever when we last saw it surrounded by friendly faces in (presumably) the first other universe Starlight visited. (Well, "can't imagine" isn't quite right. Disney's first "Jungle Book" never resolved the Pachyderm Brigade's mission to find Mowgli.) I'd very much like that to pay off in the story.
9060702
If you launch the "non-aerodynamic" engine with a known profile, at a known time and location, then those are not variables. If an "aerodynamic" block of ice loses around about two percent of both its mass and its volume, then those are both variables. And that doesn't even account for how much ice is lost while setting up the block for launch.
9060777
Its not ice. Sublimation is not a quick process. Just keep it out of direct sunlight. Also, volume is not a relevant variable.
Where do they get the profile for an engine tumbling through the atmosphere? They don't even have knowledge about how the mass is distributed, beyond the engine bell.
There also is the risk of activating it, and a tumbling engine running near Mars is a disaster in the making.
They are never going to get exact values from this test unless they launch an actual sensor array, or make it easy to track in another way. Its way to small for a relevant camera to track it.
9060869
Volume's relevant for the profile. The only way it doesn't change shape along with its changing mass is if the disappearance doesn't happen on the "outside"-- a region I cannot precisely describe (har de har), but which I believe mostly overlaps with the likeliest sites of disappearance.
9060869 No risk of an engine activation with no connected batteries. The repulsor target is not a battery and holds no mana charge, so it can't ignite the engine.
9061073
Holy wall of text...