AMICITAS FLIGHT THREE – MISSION DAY 49
ARES III SOL 52
TRANSCRIPT – WATER TELEGRAPH EXCHANGE, ESA BALTIMARE and ESA SHIP AMICITAS
AMICITAS: Amicitas calling Baltimare, use suit SG for responses, over.
ESA: Baltimare calling Amicitas, copy transmit via SG suit, over.
AMICITAS: DF – all crops planted. Alien wants to use ship radio to attempt to contact his people. Request second attempt Comm Alpha and Comm Gamma. Over.
ESA: Stand by, over.
ESA: Ready for Comm Gamma, over.
AMICITAS: DF – Initiating Comm Gamma, over.
AMICITAS: DF – Comm Gamma concluded. Negative response on radio. Over.
ESA: Confirm negative connection on radio, no signal received. Over.
AMICITAS: DF – standing by for Comm Alpha, over.
ESA: Comm Alpha result negative this end. We calculate insufficient magic on your end for connection, over.
AMICITAS: DF – copied. Any better ideas, over?
ESA: Please confirm report ample quantities of enchantable crystal, over?
AMICITAS: Confirm quartz and related crystals, plenty of them, over.
ESA: Prepare for long message tomorrow regarding modifications to telepresence array for replacement crystal for comms system.
AMICITAS: Copy long message tomorrow to modify comms. Twenty-five hours from now? Over.
ESA: Confirm twenty-five hours mark. Go for alien use of non-magic radio systems. Out.
MISSION LOG – SOL 55
Well, I just finished putting the pony radio back together for the last time. I’m pretty sure everything’s the way I found it, not that it matters.
It’s been a frustrating four sols. It began with a conversation with Dragonfly about their radio. The pony ship’s primary communications system used magic, and it’s offline, despite several attempts to fix it. (They’re going to make a replacement core for their magic radio, but that has to wait until Spitfire clears Starlight for more magic use. She’s gone nine days without so much as a spark from her horn.) But they did have a normal, electromagnetic radio for emergency use, and Dragonfly showed me the specs on it.
The pony radio uses frequency modulation and a combined transceiver antenna. The antenna was under the skin of the ship on top of the cockpit, so it wasn’t too difficult for me to get to after Fireball gave me a boost. So far, so good, right? I could loot the thing, hook it up to the Hab radio, and contact NASA via relay through one of the orbiting satellites overhead, right?
Well… no. The Hab radio isn’t broad-spectrum. It broadcasts X-band microwaves, and the pony antenna isn’t built for that. I tried it anyway, because what the hell. I tried about a dozen different adjustments, anything I could think of that wouldn’t result in breaking the Hab radio or frying the antenna. I even let it just sit in place for a day, hoping the Hab computers would make the connection, even briefly, to one of the orbiters. It never happened. The equipment mismatch is just too great. I’d have better luck building a new transmitter from scratch.
So I reinstalled the antenna on the pony ship and tried using their radio as it is. Unfortunately there are a couple of problems with that.
The first problem is that the pony radio is pure analog. It’s a backup for voice comms only, not for the ship’s computer to speak to ground computers. I actually opened up the radio assembly with Dragonfly’s help, and it was like I was looking at the innards of that radio Gilligan and his friends used to keep track of the outside world. No integrated circuits, no chips- just big old transistors and resistors and capacitors, all of which are colored and shaped similar to the Earth variety.
That doesn’t sound like an issue, but it is. It means the pony radio and the Hab systems are totally incompatible. All of the Ares III communications are digital. It has to be, because analog voice broadcasts, even in FM, require more power than the Hab can ever provide to get back to Earth. Digital signals are 1’s and 0’s- full strength on or completely off- so they’re easier to pick up.
Even with digital, getting a signal back and forth isn’t easy. One of the reasons the Hab had a large directional radio dish and an enormous antenna farm was to enable broadband data transmission to and from Earth. Even at closest Earth-Mars approach, the period when we’d be on the surface, the distance between the two planets would seriously weaken signal strength, and the weaker the signal is, the slower data transmission will be.
Continuous video feeds like you get from the space station were out of the question. Even recorded video messages eat a shitton of bandwidth, so NASA restricted those. Voice communications were reserved for flight operations that Mission Control would want to monitor, because even digitized sound is bandwidth-heavy. As much as possible we were encouraged to use text files like this log, because ASCII text is bandwidth-light.
How serious is this constraint? Well, Curiosity didn’t have the big dish or antenna farm- it just had three small antennae and an occasional connection to satellites overhead. And its direct data transfer rate to Earth was at best 32 kbps- not even good enough for streaming audio. At maximum separation, that drops to 0.5 kbps. That’s why Curiosity mostly talked to its orbiters, which had more power and better transmitters. But even then, if you were trying to watch Twitch by that connection you’d spend more time buffering than watching.
Anyway, the satellites orbiting Mars are also all digital. They wouldn’t know what to do with an analog signal if they detected one.
All of that is Problem One. Problem Two is a more fundamental one: the pony radio is hard-wired to a range of five frequencies, all between 86 MHz and 109 MHz. In other words, it transmits right into the teeth of nine-tenths of the commercial FM radio on Earth. Unless the radio telescopes NASA uses are all dialed in to the exact spot on Mars to hear it, the signal would be swamped by local broadcasting.
I tried to fix this. I disassembled the radio, looked carefully at its wiring chart (which didn’t help- the equipment looks the same, but the diagrams are nothing like Earth wiring charts apart from lines), and tried like hell to think of some way of rewiring the radio that wouldn’t risk permanent damage. But in the end, I came up empty.
So, now everything’s back where it belongs. I’m pretty sure the pony radio works, up to a point. But it’s not useful to me unless I can get in contact with NASA and get some help from the other end on making it work as a backup connection.
Open the safe with the key you will find inside.
Long story short: I can’t build a working radio that will contact any of the orbiters, much less Earth, with the materials I have at hand. The only way I’ll be able to communicate with Earth is if I go out and buy a new radio.
… wait a minute, that’s actually not as stupid an idea as it sounds.
Let me look at a map. The ponies will have to wait for their language lesson a few more minutes.
Yay Pathfinder time! Wonder if he will take any of the equestrians with him.
500 baud from a napkin transmitter accross the entire interior solar system?
You dont know how good you got it. Ship0s Morse was a couple baud and my first hard line net access was a 300 baud modem on a machine that had less power than a Poundland TV remote control.
Which could save and load images, slowly, over an analog, tape storage. Which you could acoustically couple to the phone line. badly.
Now I have to go read up on Software Defined Radio Pi and Arduino, and FM synthesis modulation on Paula.
Still, always fun to try and reverse engineer 20 plus year old tech given how quickly they like to drop it to save a tiny fraction of a percent.
But its the reception that he has the problem with. They have backup transmitters on the satts. Beat frequency between the bitstreams modulated onto each. Its been demonstrated to be possible to transmit analog signals detectable by TV Yagi, by using a fixed laser and a modulated laser, the nonlinearity of the antenna doing the mix and downconversion.
Lets see what happens next.
Hello, Pathfinder!
I'm a bit surprised he didn't go the "just in case they're watching" route and set up the radio to transmit a message on loop until it got a response. Maybe even set his Morse Code rocks to say "Listen to 86 mHz FM". As for a response, even digital systems can transmit a tone to be picked up by analog systems so a broadcast to him could be re-routed through the local satellites for better reception. Essentially, he could talk to Earth (after they know to listen with a radio telescope) but he'd have to listen to their response in Morse Code. It would, of course, be complicated with the several minute delay and inability to transmit and listen at the same time.
Yah its rover salvage time
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I know, I kept waiting for it come into play. Should be interesting for those back on Earth, its camera will finally give them a good look at Mark's guests and open another line of communications from mars to another planet.
One of my favorite quotes from Cyanide "The freaking Mars Curiosity Rover gets better Ping then I do!" During a laggy game in counter strike.
Though now I'm starting to think he might've been exaggerating didn't know how bad the WIFI was on Mars.
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Trust me, the ping is even worse than the bandwidth.
It should be noted that digital transmitters do not transmit "Digital signals [of] 1’s and 0’s [at] full strength on or completely off" and it is certainly not be "so they’re easier to pick up" if they did. Transmitting hard 1s and 0s actually degrades far faster than analog sound-to-electrical-wave analog signals. This is why Analog Current (AC) is transmitted along electrical cables over long distance rather than Direct Current (DC), because the "discrete jumps" in voltage degrade far more quickly over distance (whether in cables/space etc.)
You are right that it would be useless to try to use an analog transceiver like the ponies have though. The pony radio would need to be hooked up to a modulator to convert the 1s/0s they wish to transmit into frequency-divided Fourier transforms which would be received and interpreted by the PHY layer of the digital receiver on the satellite. That would be impossible for a human (or any non-machine) to do.
mHz = milliHertz. You meant MHz.
Also, FM takes much more power than AM or SSB.
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AC = Alternating Current, not Analog Current. And power transmission isn’t really going for high fidelity...
Funny to think that, considering how much attention they're getting from earth, it would have worked. Not well, and basically for Morse, but it would.
Making earth flip out when they find out the aliens are little ponies is worth every second, though.
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The ping for a something on Mars is something like between 480.000 and 2.880.000... so that's REALLY bad to play with ^^;;
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Hmm AC is used on long distance transfer only because you can go to HIGH voltage easily. And with higher voltage you can transfer more energy with lower current, and lower current equals smaller size conductors. AC is fundamentally going from most positive voltage to most negative voltage fifty or sixty times per second [depending on where you live]. Digital transmission tends to have a sudden transition from clear to complete garbage, analog ones tend to degrade more gracefully. That said the analog transmission use much more bandwidth in the sense of range of frequency, an analog channel in FM is covering a broader range of frequency than a digital FM channel.
Actually, that's not true. While 56kbps may be what a phone line has, they allocated that for audio based on the use of archaic analog companding technology. Modern codecs which support low-latency narrowband (voice-call) applications like Opus, Speex, and the the AMR-family codecs go much lower and the Wikipedia page for the AMR codecs says they can give quality comparable to an analog telephone line in as little as 7.4 kbps and can operate at bitrates as low as 4.75kbps. (comparison chart)
Opus will give you super-wideband bordering on fullband (ie. music) audio comparable to a 64kbps MP3 at 32kbps... I've actually got some MP3s of Vivaldi's Four Seasons that are only 80kbps that I downloaded from some university website over a decade ago and you'd be surprised how good they sound.
(For most of the cases where you hear garbage on the web, what you're actually hearing is either a bad MP3/AAC/etc. encoder, a bad master recording, or the audio equivalent to JPEG-compressing solid-color regions. I haven't done any ABX testing, but I don't notice any difference between my 80kbps Vivaldi and what everyone listens to off YouTube these days.)
It also compresses well, which means you might be able to shrink it to 50% of its original size, for a net size reduction even after padding out the compressed data with forward error-correction. (FEC is what allows you to tear off the corner of a QR code or slap a logo in the middle and still be able to scan it. NASA makes heavy use of it.)
RAR archives actually have built-in support for this "compress, then FEC" pattern under the name "recovery records". (Though the amount of FEC applied is lighter than what NASA would probably use because it was intended to hedge against failing floppy disks rather than transient interference over astronomical distances.)
Had a grim thought: He should focus on training Fireball and Dragonfly how to survive on their own, since they are the only ones not at risk of starvation.
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I dunno if Fireball can sustain Dragonfly on his own. Also Dragonfly and Fireball alone for extended period of time = HAB becoming 200 foot pillar of flames.
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Good point. I wonder if Dragonfly could shift into dragon form and supplement love with quartz.
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As noted earlier, AC=Alternating Current. The positive and negative sides of the line switch (in the US they do so at 60 Hz, don't know about other parts of the world). The reason it transmits better over long distances is because AC is much easier to step up to high voltages for transmission (and back down again at the point-of-use). The higher the voltage, the fewer losses you will see over the transmission distance. At normal use (120-240v) levels, a generating station putting out DC has about a 30 mile effective range. With AC, you can step up the voltage and get a couple hundred miles out of the same effort. Basically, it has nothing to do with the difference between analog and digital signals.
The difference between analog and digital signals is exactly how it's described in the story. Digital is "either on or off" while analog has a full spectrum of the waveform. While this might seem like a benefit (coloring with a full palette instead of monochrome) it actually makes the signal much more susceptible to interference and data loss. That's why dial-up is so much slower than DSL even though they both use the same phone line. The problem Watney is facing is that a digital receiver doesn't know how to deal with an analog signal. Conversely, an analog receiver can pick up a digital signal, but all you will hear is the classic "duck choking on a kazoo" sound.
In other news, this chapter prompted me to read up on the various Mars rover projects. This year marks the 20th anniversary of Sojourner's landing. Also, MER-B (Opportunity) is well into it's seventh Martian year (just over 14 Earth years) of it's 90 sol mission and still tooling around up there. Holy. Crap.
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The world is split between 60Hz (places that got their infrastructure from U.S. suppliers) and 50Hz (places that got their infrastructure from European suppliers). Japan is actually half-and-half because the south and north sourced differently and they have conversion stations at the boundary. That caused problems after the Tsunami because the capacity to convert power was less than the available supply in the unaffected areas.
Technically, the reason AC power is good for distances does have something to do with radio signals... it's just not obvious. AC is easier to step up and down because the oscillating current is what enables a transformer to work. (It's the constantly varying current in one coil which is key to inducing current in the other.)
(And, sure enough, for runs long enough for AC inefficiencies to dwarf the cost of conversion equipment, high-voltage DC is preferred.)
Radio transmissions encode data onto a carrier wave for the same reason. Some form of constant change is necessary to induce detectable levels of current in the antenna and encoding methods which don't use carriers (eg. spread-spectrum) require much smarter electronics to extract the signal from the raw antenna impulses.
Nice! I've never heard it described like that. :)
That said, I think you're describing the modem handshake process... which is quite different from what it sounds like when data actually starts flowing. Rather, it's the two modems using the most primitive protocol they know to communicate each others' capabilities and probe the line to assess the signal quality. Once they've agreed upon an encoding and identified the limits of the channel, digital data flowing is just a constant hiss because that's what it sounds like when the channel bandwidth is being used as efficiently as possible.
See this infographic for a breakdown of what those tones actually are. (I don't remember that second block of scrambled-mode data because that transition was when my modem would go silent. Also, here's a video someone made mapping the audio to the poster.)
I'm already dreaming of the next chapter!
*Insert brilliant pun here*
I wonder what Mark's sojourners will say when he tells them all about the path he found ( ͡° ͜ʖ ͡°)
I forgot it was Pathfinder they went for rather than Curiosity (until I read the comments), so now I have Rarity singing 'Curiosity!' in my head to the tune of her Manehattan song.
Now, let's just hope none of the others do anything stupid to the rover. Or Mark, for that matter...
Also, seems like Baltimare found a way to use the suits to respond, thus addressing the whole "flood the hab with overlong messages" issue.
Getting pathfinder is a much harder decision with the aliens as part of the equation. If he went off on his own, he'd have to pilfer a bunch of solar panels despite the load being higher on the Hab, and let the aliens have free reign in it while he is away. Or bring them with him, which is pretty much a non-starter due to how difficult it was with only carrying resources for a single person.
Leaving them in charge of the Hab while he is away could be dangerous, for various reasons. Only he has training on how to repair the Hab should it rupture for any reason. If he left, then returned with the rover, almost a month would have passed with the aliens on their own. Who knows what kind of state he'd return to?
8712219 Baltimare can't initiate contact using the suits except in dire emergency, because loose water in a spacesuit while it's being worn is a major no-no. But if the castaways initiate contact, they can designate a suit not currently in use for response and monitor that. It takes careful watching, though- the difference between water pulses through a straw and through a firehose.
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Taking the ponies with him isn't as crazy as it sounds, although he originally went stir crazy being stuck in the rover by himself. It'll be even more cramped with the others in there.
However, a lot of his concerns on the trip to Pathfinder was survival issues like power efficiency, oxygen, and water. I don't recall weight being too much of a concern, and the ponies space suits make oxygen and water a non-issue. Really, once he takes care of heating (and 5 more warm bodies might tip the equation in his favour this time around), then he should be able to pilfer the solar panels, leave the hab in pretty much the same state as the book, and he might take a drop in distance per charge this time around from the extra weight of passengers, but it should still be doable.
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That would provide a rather morbid explanation for why no unicorn ever showed up on Earth after experimenting with a teleport spell.
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Oh... Oh dear.
Sol is 40 minutes longer than normal Earth day, and yet I never catch a new chapter during the day. In 40+ sols, we should have gone at least one circle.
Kris, you are seriously disturbing my sleep schedule with this stories updates. But still I love you(no homo) for writing this.
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The rocket exploded because it was a rush job that they didn't do any inspections on because Mark was about to starve.
8712996 They needed to explain those things in the movie. They had plenty of time. Many of the scenes dragged terribly and wasted too much narrative time on very little taking place, then sped through parts that needed more expansion and expository material. I notice this in quite a number of movies lately. I suppose the movie makers are trying to focus on 'mood', but they don't seem to know how to do it well. That was VERY apparent in the movie "A Ghost Story". Dear god, what a dull slog of nothing that movie was.
But even so, it's still just too many failures. Even Apollo 13 had just one failure. As did the Challenger explosion, as did the Columbia disintegration. I'm not a fan of lumping disasters together, it makes me think of the quintessential farce of disaster-type movies: "Airplane", where everything going wrong in a telegraphed fashion was part of the comedy.
8713133 Airplane was an almost scene-for-scene remake of an older, perfectly serious airplane disaster film. And system failures can snowball. Apollo in particular was designed in the expectation that as many as five THOUSAND parts would fail at some point during the mission. Having only two things fail in the case of Iris is perfectly reasonable.
8713152 Well, thing is, the various mini-disasters weren't in the same system. The supply rocket blowing up, for instance, and especially the timing of it, was telegraphed so heavily I counted down the seconds and it blew up just as I reached zero. That one was the last straw for me. Too many of the failures felt forced to me, just an excuse to have SOMETHING happening to try and create more tension because no one knew what to do with slow-burn drama.
Compare that with "Apollo 13" the movie, and even though we all knew the astronauts made it back safely, the tension was STILL strong even when nothing was exploding because each scene was set up and executed so flawlessly.
8711580 Talk about a bad connection to play World of Warcraft over. The raid would be done by the time you zoned in.
8713152 Zero Hour! The best of the worst movies of all time. They said when they were shooting Airplane, they had a tape of Zero Hour for reference so they'd have an example of how to light certain directly copied scenes. (And they bought the copyright, so no cries of plagiarism please)
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Well,
a) I doubt Kris included the size difference.
b) It was explained in the first chapter that Unicorns used a spell limited to three dimensions, but the spacecraft didn't. Besides, the spell checks for collisions.
Don't insult my state, that's fucking rude. (Only semi-serious)
And I live in western Kansas, and I've never met someone with dial-up...
I feel like X-band is a little low tech for a future Mars mission. If the point was to use a government band, wouldn’t Ka-band be a better choice for thoroughput?
Kapoor better go and get that new poster.
Get a space CB radio from some space truckers.
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Space Truckers!
...it's ASCII, which means that if Vogel would like to put one of these fancy umlauts in his messages, yea, he's out of luck. Also, no rich text, so you can forget about bold or italics. If I want to stress stuff I need to PUT IT IN CAPITAL LETTERS.
The horror!
Okay, no, I'm yankin' yer chain. We can use UTF-8, and as my logs so far have already shown, I've used italics too. The added headers to make rich text work are honestly pretty small, and UTF8 doesn't actually take more space on its own; it's plain ASCII unless you use a special character.
Ugh, why am I even explaining this? You guys got wikipedia; you can look this stuff up in seconds. Lucky bastards.
Oh, hah
Spell out in rocks "TUNE SAT TO 91.3 MHZ"!
And even if that works, NASA will probably end up only having some old radio-spectral analysis satellite to listen to it, and can't actually respond
But hey, at least Earth will get their daily Mars Survival Radio hour!
Mars Rover Recovery time!
I am still going with idea that Hermes is being a brand new ship. I know for a fact that the space technology is extremely old they literally can't afford high definition anything. There is a reason that the old 747 jets uses tape drives and floppy disks, and until the recent retirement people flying those forced to used old and dated equipment. So in theory in the future of 2035 SpaceX commander in chief would supply Starlink internet for Martian exploration.
Nothing is simple or easy... Lets hope for a boon or three since they need it badly...
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We know for a fact, since this story is a crossover with The Martian, that the Hermes is 6 years old, since its first mission was in 2029, and the current year is 2035
Somehow, that's a plausible place name. I googled it, and West Elbow doesn't exist.
The Mars Gift shop is under renovation, but maybe the Electronics shop is open for looting
I wonder if in my lifetime the Mars mission here described will happen. The space program seem to be ridiculous slow this days...