Need reasons why a satellite network would not work

Question

My story takes place on a hot desert planet that is a colony. At some point people are out in a very hot and inhospitable area of the desert. Dust storms, high heat, constant wind, etc.

Characters have tech that allows them to access the planetary network via satellite. But I'd like them to be out there and get isolated without access - to be truly disconnected.

I assume that a heavy storm with blowing sand and lots of dust in the air would affect things, but what about on a normal day with no severe storm?

I had thought about having this part of the planet have some natural way to interfere. Possibly a magnetic field or something.

I'm not sure if that would work, looking for ideas.

Answer 1

I can give you 2 technical reasons why there could be no reception in your designated desert.

1) Low population, concentrated in few areas.

This variant leads to GPS and communications being available only in relatively small areas where people actually live.

Did you know that Japan has it's own GPS-equivalent? It's made of just 4 satellites (planned total of 7). It's designed to service Japan, system working for any nearby regions is a bonus, but not a design requirement.

Image shows path drawn by geosynchronous satellites, overlaid on map of region over earth.

The primary purpose of QZSS is to increase the availability of GPS in Japan's numerous urban canyons, where only satellites at very high elevation can be seen. A secondary function is performance enhancement, increasing the accuracy and reliability of GPS derived navigation solutions.

It is perfectly plausible that newly settled planet, with just a few cities near landing site and farmland concentrated around those cities would opt to deploy similar sized constellation for local needs instead of going all out on full constellation of 30-40 satellites.

2) Planetary magnetic field insufficient to shield satellites above Low Earth Orbit equivalent.

This variant leads to lack of space based positioning or communication systems.

Local star being active or possessing strong stellar windis going to be detrimental to longevity of satellites, especially those outside of planetary magnetosphere. If planetary magnetosphere does not extend to planet-synchronous orbit (Earth's magnetosphere is large enough to cover Geosynchronous orbit), then deploying satellite network might be effectively unfeasible for new colony. Any GPS-equivalent or communications network relying on Low Planetary Orbit (Low Earth Orbit equivalent) would require constellations measuring in thousands to provide global reach. Any GPS-equivalent relying on synchronous orbits outside of magnetosphere would have to have satellites especially hardened against radiation, mandating larger electronics (physically larger transistors are less susceptible to damage by charged particles), more error robust correction (bit flipping due to high-energy charged particles is even more serious concern), heavier radiative shielding, sturdier and larger antennae (for better noise-to-signal ratio) and so on. All of those increase weight, which is very non-trivial, assuming spaceflight isn't casual in your world, potentially leading to decision of ditching space based solutions entirely, in favour for old-school radio and radio beacons, with some mobile networks and high-speed intercity cables mixed in.

Answer 2

Forget interference knocking out your GPS system - see below for the reasoning.

If your navigation equipment doesn't work, then it is for something more mundane.

• Crewman "Butterfingers" McClutz dropped a box of heavy supplies on the GPS receivers and the spare batteries. Crushed them all, with a truly impressive bunch of sparks and fire as the lithium-based batteries self-destructed due to the mishandling.
• Crewman "Wrongway Feldmann" got lost in a sandstorm and was never found again - presumed dead and buried under a sand dune. Unfortunately, he was carrying the portable solar charging system. Once the batteries run out, you are down to navigating by the sun and the stars.
• Dockworker "Joe Don't Giveadamn" didn't bother loading the crate with your navigation gear before you started out because it was too heavy and he was due for a smoke break - but he did pencil whip the checklist so everyone thought the navigation equipment was on board.
• Your equipment was bought from the local equivalent of "Alibaba." It worked fine during testing, but in actual use you find that the batteries all quit working after only a couple of days - they have non-rechargeable primary cells instead of the rechargeable cells they were supposed to have.
• The local "camel" equivalent likes the flavor of the plastic used in the housings of your equipment, and ate it all one night - incidentally destroying the electronics.
• Straight up sabotage - somebody wants your group to die in the desert, and has done something to either destroy the navigation equipment or make it mislead you.

While we're at it, forget ideas like "the satellites have worked for millennia." The satellites have to be replaced and maintained in any usable system.

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What most folks don't realize is, is that GPS signals are extremely immune to interference. The reason the GPS data rate is so low is because of all the things done to ensure that you can receive a usable signal under really bad conditions - and these conditions include intentional jamming.

An open desert is just about the ideal place to use GPS - nothing blocks your view of the sky. You have a fairly decent signal all the time. GPS only really has trouble in craggy areas - be it real canyons or the so called "urban canyon" effect where the city buildings block the signal.

Despite incidents of bad "solar weather" since the system went into service, GPS hasn't had any large scale, long lasting drop outs over large areas.

So, forget about bad reception in the desert. Ain't a problem if your future engineers are half as good as the guys back in the 1960s and 1970s who designed and built our current system. The design goal back then was 100 meter accuracy for civilian use and 10 meter accuracy for military use - and then they delivered 10 meter accuracy for civilian and 1 meter accuracy for military use. And then to top it off, other engineers added further processing to make it possible to use GPS receivers for surveying with accuracy down to single centimeters.

Answer 3

Poor software design, and choices that you later regret.

We have real examples. Remember the Y2K bug? Did you know GPS has a mini-version of that bug, that affected lots of devices in April 6, 2019?

That's because GPS satellites uses ten bits to represent datetimes in their broadcasts. They can only represent timespans of about 1,024 weeks. So starting from whatever date and time they consider zero, they can count up to nineteen years and a few months. For comparison, modern softwares like nowadays browsers use 64 bits to represent date and time. Most of Microsoft's software can handle dates from 00:00:00 in January 1, gregorian year 1 to 23:59:59.9999999 UTC, December 31, gregorian year 9999.

GPS was designed to use only ten bits for dates and times because it is cretaciously old, for computer standards - it was released in 1973. And the system has been working well enough, and devices get obsolete fast enough that people would rather reset the "datetime zero" every nineteen years rather than fix this "flaw". They've had plenty of opportunity - the oldest GPS satellite in operation was launched in 1997. It would be pretty easy to add more bits to the datetime - each bit doubles the span of dates that can be represented. But no one wants to fix what is not broken.

Prior to April 6, 2019, the "date zero" for GPS was August 21, 1999. On April 6, 2019, all devices that could not update their software started thinking they were receiving satellite broadcasts from that "date zero". And broadcasts from April 7, 2019 were processed as being from August 22, 1999. April 8, 2019 was understood as August 23, 1999 and so on. At best the affected devices would show wrong dates in their user interface, but mostly they ignored the GPS broadcasts after comparing the broadcast date with their own internal clock. Ignoring all GPS broadcasts means you cannot get a reading so you won't know where you are.

And you know what kind of devices could not be updated? Think TomTom and Garmin handheld GPS devices that have no Wifi connectivity and no USB port, and which some people love to use when doing tourism because they won't learn how to use an Android or iPhone.

Devices like this:

And even when they do have the port or connectivity to update, the company will force users to buy new hardware or be left without updates. This happened in 2018.

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Now imagine your characters in the desert planet. The planet has a satellite network that worked fine for some period - maybe millenia, maybe even longer eras. It just happens that the satellites have hit the maximum date they will hold in their memory. At the next tick, they will reset to their date zero and start counting from there.

Worse, their date zero is out of the range your characters' devices can use. And they don't have access to the satellites control system, or maybe updating their dates will cause something else to fail. And the only place where you can buy new hardware is a few star systems away. Your characters may develop some hatred towards IT professionals from the past.

Don't want to get too technical with programming and binary code? Just say some bug happened that is causing issues.

Or use something else to make the satellites dysfunctional. Maybe they require a password that you don't have. Maybe a prank went wrong and the satellites have been trying to calculate the last digit of Pi for millenia. Maybe the poles of the planet shifted and the compasses on the satellites aren't handling it well, so they are pointing their dish antennae to the wrong hemisphere.

Answer 4

This is going to be the most mundane solution to the problem that you're going to get, but it could be as simple as static electricity.

Deserts are hot dry environments across which winds can whip up quite easily. These conditions actually make them ideal static electricity generators and it's said that dust storms are strengthened in the desert because of it.

Of course, static electricity can also damage your electronic devices so put the two together and you have a perfectly plausible reason for why your crew were cut off in the middle of the desert; their devices failed because of a static electricity event.

I've never used a smartphone or other device in a desert, but I'd imagine that's not the only issue you might face. Sand in the charging port would be problematic as well, and if you have it out at the right time I really don't know how even minor sand blasting impacts a AMOLED screen but I'm guessing it can't be good for the device.

Important safety tip when you get right down to it; if you're navigating by GPS in the desert, always remember to properly earth your camel.

Answer 5

I once stood at the middle of Uyuni salt flat, which is a 10,000 km2 flat surface 3 km above sea level. It was daytime and I had just replaced the batteries for my Garmin hand GPS (this was in 2011). I hold it still for a few minutes and then check the screen. It has a message that reads more or less like this: "Satellite signal is too weak, please go to open space." I look around, see the salt flat extending dozens of kilometers in every direction. I look up, not a single cloud in the sky. I reply to the device: "Bitch, we are at the openest space in the world!"

A few years later, attending to a workshop in INPE, I am told that South America is the only place in the world that has what could be translated as "ionic atmospheric poket", which are atmospheric phenomenon that jams electromagnetic signals from GPS. Googling it today, I could not find that particular name the lecturer used, but I found about the South Atlantic Anomaly, and this article about its role creating above mentioned ionic pockets.

Having lived there most of my life, I can say GPS signal at South America is much less reliable than in the rest of the world, but it is nothing like a complete jamming of all signals, and my particular problem at Uyuni resolved itself after a few minutes.

That said, its is totally conceivable a planet where such atmospheric anomalies, fueled by the interaction between planetary magnetic field and spatial radiation, would be able to completely block GPS signal over some parts of the planet.

Answer 6

Due to the uneven mass concentration of the planet, there are no stable orbits in which satellites can be placed which will always be "visible" from the location of your colony.

A stable orbit where the satellite does not require constant station-keeping is called a frozen orbit. Due to the various mascons, the gravitational field of Earth's moon is uneven - this means that most "Low Lunar Orbits" are inherently unstable, and in fact only 4 viable orbits have been identified.

On your planet, there are 2 satellite "blind spots" (on opposite sides of the planet from each other) which result from there being no stable orbit that comes close enough for regular satellite connectivity. There are small periods of time when one or other satellite may creep over the horizon - but outside of these, you are effectively cut off

Answer 7

Satellite signals are purposefully jammed in this area by the owners of the satellites.

The desert is territory which is politically hostile to the owners of the satellite system. To prevent persons living in the desert from taking advantage of the satellites (and possibly using their tech against the owners), signals are purposefully jammed by a geostationary satellite over the desert. It is possible to jam GPS signals, and so presumably everything else can be jammed as well.

https://www.economist.com/international/2013/07/27/out-of-sight

Or maybe the desert is remote enough that satellites can cease signalling while traversing them then turn back on to serve their home countries.

The one signal your characters can receive is a Voice of America propaganda signal. The rest is squeaky white noise.

Answer 8

Solar Storm

A solar storm can take out satellites as well as disrupt satellite communication.

It could run from a few hours to a few weeks or even destroy the satellite. The 1859 Carrington Event caused the telegraph system to shock operators and even continue running after the power was disconnected. The same event today would take out the power grid and block communication.

Answer 9

You say that even if there are no sandstorms in a "good" day, the desert is always windy.

The answer to your loss of connectivity could be the following:

1. The desert is made of a sand very rich in metallic/conductive compounds.

2. The sand is so fine that when it is raised by winds it keeps floating around for a very long while.

3. There are high-altitude winds that keep a constant veil of sand suspended in air at high altitude.

Therefore, even in a sunny day you have a thin layer of sand floating very high in the sky. Let's call it, for dramatic effect, "the Veil"!

The Veil doesn't affect heat radiation from the sun appreciably, but creates all sorts of scattering effects on incoming electromagnetic waves at the frequencies of the satellite signals, disrupting transmissions severely.

Moreover, since winds are constantly changing, the Veil has constantly changing characteristics. That makes even military grade comm equipment unable to compensate for the scattering. It's not that you are not receiving the signal from the satellites, but it is so garbled from multipath distortion that no portable equipment has the complexity needed to filter out the signal.

In more "urban" areas, where sand is not so abundant (more rocky terrain), the always present Veil is less disruptive, and ground equipment has more computation power to compensate for the distortion using complex computer algorithms. But in that nasty Valley of Death where your characters are stuck, even a small sandstorm could raise so much sand to reinforce the Veil for days in that area!

Moreover, and dunes in that area are big as hills and they are made of conductive sand, so the scattering effects are also worsened by that additional factor. Even if your crew climbs on a tall dune to transmit, the scattering from the "valleys" below will reach their equipment, rendering the tactic not so effective. Not to mention that dunes move with the desert wind, so constantly trying to stay on high ground is a huge effort.

BTW, I just found an article about sand storms disrupting communications in southern Lybia. Even if sand is not rich in metallic elements, like in our hypothetical desert, it affects propagation and scattering of EM waves, so it seems my scenario is quite plausible.

Answer 10

weird location + past war.

say your desert is at some high or low latitude where there just generally aren't a lot of people. the satellite communication network flies at mid to low inclinations where all the people live, but your remote desert colony is out of the way and no/few satellites fly overhead. They COULD pay for a comm sat with a higher inclination orbit, but if they are a poor colony that may not be in the cards for many years.

GEO sats kind of ruin that answer... maybe there's a lot of debris in orbit from a war in the past that make GEO orbits a mess, and all current comm sats are in LEO. Count MEO in this category too for you Molniya fans, all that junk will smash those too. The debris and space junk in the lower orbit all fell back (takes 20 years or less for lower orbits due to atmospheric drag) but the higher altitude orbits are basically unusable. In that scenario the answer above works to isolate your desert colony.

Answer 11

Geosynchronous satellites use high gain transmitting antennas. And their beams are typically focused to maximize the return on investment. It could be possible the explorers have wandered beyond the boundary of the signal footprint.

Many satellite ground stations use receiving dishes, and it is possible to mount the dish to a frame that is then ballasted with cinder block. You can look-up non penetrating roof mount, see one here.

The mount does not have to be on the roof, but on the ground where it would be easier to daily pick up, move, and emplace. The storm could be coming up, the workers get out of the storm before the ballast is fully installed and the wind gust blows over the dish and mount, bending it into crumpled ball. Or a gust higher than designed.

Generally the dish uses a very narrow angle to 'see' the satellite, both horizontal, or vertical. Some will include audible signal strength feedback to tell if the dish is on track or not. If the dish is not tightened down well, it is possible for wind to push the dish off beam. Or an inexperienced explorer misaligned the dish, and the next time they do better. You can think of a laser beam between the transmitter and receiver. Many things could occlude the beam, e.g. distant rain, a mountain, (the explorers descend into the Grand Canon,) or someone parks next to the dish in a motor home

Answer 12

You've got the tech, but have you got the cash?

Some satellite based system such as satellite phones charge you by use. Your colonists may have ran out of data.

The catch-22 is that extra gigabytes or satellite time can only be bought online, so they won't be able to browse for a while.

They'll be good to go when their internet plan renews - as long as the satellite company is able to charge their credit card successfully.

Answer 13

The dust and sand of your dry world could create powerful discharges of static electricity that would generate bursts of RF that effectively jam the satellites uplink or downlink or both

The interference would be similar to a spark gap transmitter.

Answer 14

A nearby twin neutron stars solar system, gravity field and gravitational waves were not kept into account when computing GPS localization of satellites, and compensation systems for localization of satellitare and direct laser communication could not intercept satellites correctly and establish communication. This also prevent laser signals redshift in frequency to be compensated correctly

Answer 15

The satellites refuse to serve that area for some geopolitical reason

The satellites are being disabled while overflying that area owing to

• rebel activity in the area,
• due to a past war (and nobody bothered to turn it back on again because nobody cares about that region), or
• the sat network provides many civic services beneficial to governments and people but not really billable for, and the government of that area refuses to pay their fair share of the costs of the sat network. (compensation works that way in this economy). Perhaps they are billed based on their considerable land area, but have a tiny economy (likely because of the inhospitable conditions).

If this is a constellation of moving satellites, they are turning off services while transiting the area. If these are GEO satellites, oh, they hear you, but they have determined your position and are discarding your signal because of it.

The planet can't have satellites

A natural or artificial Kessler Syndrome has rendered the planet incapable of having a functioning satellite system.

Answer 16

Very simple suggestion:

Is their gear rated for use in that type of desert? Ruggedized gear comes in several ratings for various environments. The gear supplied could just not be suited for desert use, or use in a desert with a dust particles that small or that hot, and simply get clogged up or overheat and die in a very short space of time.

Like seconds after they get out of the vehicle due to all the dust it kicked up.

Environmental factors have always been an issue for gear life. Dust, cold, heat, water, etc... can all kill electronic devices very quickly when the device is operating outside it's ratings.

Answer 17

Here's a simple solution. The satellite(s) covering this particular area are missing, damaged or both (if more than one satellite).

While not a problem for aircraft (assuming there ARE aircraft), since these can "observe" other satellites from higher up, for anyone on the ground in that area you're getting too few signals to get a reliable position.

The problem with this solution, however, is that smart enough engineers should have known about this beforehand, so it's unlikely to be a surprise to anyone, unless the satellites get blasted / damaged during your story or your characters find themselves in the troublesome area by accident. Otherwise they'd know they're walking into a "blind spot" or notice the signal getting weaker and weaker.