On Space Warfare With Unconventional Weapons
Every single day, every single hour, every single minute, thousands of satellites orbit us: silently serving us in many different ways. Multiple networks of satellites run our world, they tell us how the wind blows, where road traffic flows, they talk of harvest good and bad, they monitor threats of nature and nurture. These humble machines are critical to our modern lives as we know them and they are only becoming more and more useful by the day.
Most space based satellites are also dual-use, meaning that they have both civilian and military uses. Conventionally, the 'other' use of satellites has been as strategic assets for intelligence, reconnaissance, and surveillance (ISR) activities or as communication/geolocation nodes for ground-based assets. But change is the law of nature and our world is changing fast. There is yet another set of wars in the Middle East, war in Eastern Europe, war in Northeastern Africa, tensions and escalations in South and South-East Asia. There are many motives, but the outcomes are always similar; as Sartre (or Shinoda, your choice of philosopher may vary) put it, 'when the rich wage war, it's the poor who die'. Humans have tried and humans have failed time and again, generation after generation, in preventing war in all its forms, and in a world where monkeys have been killing monkeys over pieces of the ground for times immemorial there is no other form of survival except being prepared for what comes next, when (and not if) it comes.
While known dual-use for space assets is usually deterrence (ISR) and/or support (communication), there have been attempts and calls to weaponize space-based assets in the past (read: Project Excalibur). The rules of engagement that bind the chastity of the earth's orbits and the rest of outer space (and Antarctica for that matter) are only as sacred as the ethical framework of the powerful nations that pen and enforce them. A new space race has begun and if all goes according to plan, humans will be back on the moon in less than 5 years, more nations than one this time. Mars is next. Competition brings the best and worst out of nations and if the trends over the last ten years are to be considered a sign, if not already done, space is about to be weaponized very soon. And while we should be concerned, I will leave that responsibility to the people who are experts in the setting of such rules.
Because my primary audience here is my very own self, the focus of this essay is on figuring out what the most egregious way of conducting space warfare would be. The contraption that I have come up with (with some useful inputs from friends) is the Spacecraft Harassment And Reconnaissance Termination SATellite, affectionately known as the SHART-SAT. My primary motivation for coming up with the SHART-SAT was a scene from the now-cancelled Netflix show, Space Force, where an adversarial asset with a robotic arm flies by the target satellite and chops its solar panels with a robotic arm. I wanted to think of something that was even more diabolical and here we are. Also, no large language models were used in the creation of this essay, my brain is perfectly capable of coming up with this weapon of ass destruction on my own.
But before we begin, a disclaimer to colleagues and friends in the space industry who may be reading this; more importantly to those who tirelessly regulate space activities, making it safe for all: THIS IS A JOKE. I PROMISE TO NEVER EVER DO THIS (unless the powers that be deem such activity as legal and socially acceptable).
So, SHART-SAT.
Objective: To build a very low-cost small-satellite that can ruin other satellites by spraying a sort of sticky ink on lenses of cameras, star-trackers, and other optical instruments, thereby ruining a multi-million dollar space asset.
Key Requirements and Observations:
- REQ-01: The satellite shall be capable of operating in lower earth orbit (LEO) between altitudes of 350 km and 700 km.
Anything lower and we enter VLEO territory, which is expensive to build for in fuel terms. Anything higher and we enter longer life + higher radiation territory, which is also very expensive to build for. Given that a majority of LEO satellites are in this range, it is safe to consider it enough for the purposes of this thought experiment.
- REQ-02: The satellite shall survive in space environment at the orbit specified in REQ-01 for at least 18 months.
This is a reasonable expectation for a mission where the SHART-SAT is expected to maneuver to the target satellite that allows us to size the solar panels and batteries. Most components here will be COTS, so this won't be too expensive.
- REQ-03: The satellite shall have propulsion capabilities with a fuel budget that allow it to:
- Perform altitude maintenance and corrections to the tune of ±15 km throughout the course of its life.
- Perform ±2.5 degrees worth of out-of-plane (inclination-change) maneuvers over the course of its lifetime.
- Perform both high-thrust (escape), low-thrust (approach) and precision (very fine control) maneuvers.
The idea here is to ensure that the satellite can perform one or maybe two (depending on the target's orbital parameters) total shart attacks over the course of its lifetime. Out-of-plane maneuvers are more expensive in fuel and thrust requirement than in-plane maneuvers, so we have to be judicious with how we use the satellite's fuel budget. SHART-SAT is not a dormant long-life sleeper-agent that is ready to strike in space, it is to be treated as a use-and-throw, ready-to-launch-whenever-you-want satellite, which can fit on ride-share missions (that are generally in SSO or 45 degree inclination orbits between 400 km and 550 km). So ±15 km and ±10 degrees of inclination change seem reasonable. If there is more money to build and launch, a bigger prop system can also be thought of. The central idea here is that a comparatively cheaper satellite can take out targets that take years to build and are worth tens and hundreds of millions.
For very fine control AND for low-thrust operations, multiple small FEEP thrusters are perfect and they can comfortably fit a 8U - 16U cubesat. For high-thrust operations, a chemical propulsion system makes more sense and tank size of the propulsion system will be a big constraint, because SHART-SAT needs to have a high thrust-to-weight ratio for escape maneuvers. Chemical propulsion is also a sensible choice because a small satellite won't have a lot of power for high-thrust maneuvers that a hall-effect system would require. While stealth for a low-cost asset should be optional, the very thought of a multi-million dollar ding-dong-ditch in space is too crazy to ignore.
- REQ-04: The satellite should follow the cubesat standard and not be larger than a 16U cubesat, compatible with both ride-share and OTV options.
Launch flexibility and the capability to work with standard deployers is important.
- REQ-05: The satellite ink should be a vacuum-stable UV-curing polymer that is stable in extreme temperatures consistent with environment of the satellite in SHART-02.
Finding the right ink is definitely a huge challenge. Maybe something like this in some sort of a zero-G solution could work out. Storing it in a way that does not contaminate the SHART-SAT itself would be an even bigger challenge. I like black ink particularly because when sprayed on star-trackers or sun-sensors, it will just confuse the hell out of the poor target satellite as it tries to search the star-field or the sun to determine its attitude in space.
- REQ-06: The storage tank and spray mechanism shall be compatible with the ink specified in SHART-05. The tank pressure and spray keep-out zone should be such that it does not damage the SHART-SAT.
If finding the ink is tricky, figuring out how to store and disperse the ink without damaging SHART-SAT is trickier. The nozzle and valve of the spray and tank mechanism need to ensure that they can handle the viscosity of the ink in REQ-05, but they also need to be leak-proof at the same time. They angle and spread of the spray should at all times ensure that it does not damage SHART-SAT. Perhaps a deployable spraying arm (with no degrees of freedom, for financial reasons) makes sense. The tank pressure can't be too much because the torque that it will impart to SHART-SAT will have to be corrected by the low-thrust propulsion on the satellite.
- REQ-07: The spray and nozzle shall be capable of meeting a spray distance of anything between 5 to 20 meters with a pointing accuracy (3σ) of 0.1 degrees.
An approach of 20 meters is a reasonable expectation from SHART-SAT given the low-thrust propulsion on the system. 0.1 degrees of pointing accuracy gives it a error radius of less than 40 mm from 20 m, which is good enough to handle most star trackers and optical payloads.
- REQ-08: The satellite shall have two on-board navigation cameras capable of imaging and resolving objects at a distance of 5 m - 500 m and 500 m - 5000 m from the satellite respectively.
Honestly, both the cameras could be simple digital cameras with different lenses and a university student grade computer vision algorithm in the background that is working to identify different parts of the satellite and look for the optics. For the long-distance navigation camera, a simple digital camera with adjustable focus is more than enough. TLE's are good enough to follow the target to a couple kilometers until the on-board cameras can spot it.
While these would be some of the critical requirements, all other requirements would be supporting elements for this mission. The satellite power-budget (and therefore battery and solar panel sizing) needs to account for long FEEP operations. There will be requirements on the attitude and orbit control system that ensure pointing accuracy and maneuver requirements are met. The communication system can be a S-band transceiver (5 Mbps or so seems enough) that is capable of receiving tele-command and sending down imagery so that operations of the on-board cameras can be verified. Then there will be security requirements to ensure that SHART-SAT does not harm an asset other than its target.
Conclusion: Overall, I think SHART-SAT can be as cheap as $600K - $750K including costs associated with vibration and thermo-vacuum testing of the satellite and its spray mechanism. Prima facie, I can see that there is a room for a 20%-25% reduction when the manufacturing is at scale (more than 15 units). These numbers are obviously my personal estimates so they are not very exact. It is definitely possible, but building the ink-spray mechanism would be the key to making this a success. Recent docking experiments in space have shown that approach itself is a solved problem in small-satellites, so an approach of 5 m - 20 m is definitely solvable.
If you have any thoughts and opinions on the topic, or any corrections that you would like to make, please feel free to share them with me on my email. I'm slow at responding, but I'll try my best.
Thanks for reading. Next time, I'll introduce my other contraption, the space-bidet. Or maybe not.
July 28, 2025
Update: While this is a joke satellite, a major shout-out friends and colleagues who have read this and given some very valuable feedback.
A few changes I've made and some additional recommended reading:
The original expectation of ±10 degrees of inclination change would have shot up the delta-V requirement by a lot, so this has been corrected to a ±2.5 degrees of inclination change.
Russia's Nivelir program is doing a lot of what the SHART-SAT plans to and beyond (including projectiles).
[Link 1] [Link 2]While my preference was to use a UV light along with the payload to cure the ink on the optics; suggestions to using ink that is charged seem interesting. Iodine based thrusters as both sources of ink and propulsion is another interesting thread to tug on some other day, some other time.
As the golden dome redefines what space-based security means, significant startup investment that has gone into satellite companies and there is more to come.
[Link 1] [Link 2] [Link 3] [Link 4] [Link 5]