Piracy in Space is Possible Part I: Dastardly DeltaV and Stealth Steamers

Space Piracy is a common science fiction trope. It has been continuously derided in Hard Science Fiction as silly and a holdover of the 'Space is an Ocean' analogy. 

But is it really that unrealistic to have space pirates? Let's find out.
What is piracy?

A chinese Junk, by Wayne Haag

Piracy is a specific type of theft. Goods, crew or the vehicle itself are stolen, ransomed or captured by pirates while in transit.

Piracy functions under the rules which make theft worthwhile:
-The value of the reward is worth the cost and risk of a pirate attack
-The reward can be liquidated reliably
-The pirates are safe from prosecution after an attack

By artist Geoff Hunt.

These are rather straightforward rules. 
Pirates want to gain something from the attack worth their time and the risk they take. Unless the reward is cash, they need to convert their gains into money. They then want to spend and enjoy that money without having to be constantly on the run from police authorities. 

One prominent modern example of how critical these rules are to piracy is the situation off the coast of Somalia between 1986 and 2013. 

In 1986, a devastating civil war started following the brutal crackdown of an aging tyrant on his population. Government institutions ceased to function, rebel and gangs organized themselves into armed groups and the Somalian Navy disbanded.

Fishermen felt the toll of illegal dumping and pollution of their fishing waters and saw their livelihoods at risk of disappearing too.

Together, this situation allowed for numerous men equipped with AK-47s and RPGs to get a hand on fleets of small boats and fishing trawlers and have free reign of the seas... the very same seas that saw a constant, rich stream of ships laden with cargo containers entering or leaving the Indian Ocean through the Suez canal.

These men attacked those ships.

Now pirates, they had practically no opposition either at sea or on land. Shipping companies paid ransoms on their crews and whatever the tiny bounty their boats could carry back was traded with unscrupulous merchants. This money was then shared between the pirate crew, the pirates' patrons, bribes for officials, the cost of fuel and new boats, and with the fishermen and their families. Often the Somalian pirates were seen as benefactors of the fishing villages.

The pirates were earning millions, at little cost and with no real risk. Their rewards arrived directly in bank accounts or in cash from jewellery, mobile phones and other high-value items stolen while on-board the cargo containers: these are easily sold. Finally, there was no real police or government authority to enforce any sort of law on the pirates. All the requirements for piracy were met.

The situation changed by 2011. 

Barkhad Abdi from the Captain Phillips movie.

The pirates had grown to attack thousands of ships a year, and were demanding ransoms measured in the millions per ship. The world's navies were given permission to violate Somalia's waters as needed in the pursuit of pirates. US warships now patrolled the waters, along with contributions from more than twenty nations, including Japan and New Zealand. The cargo ships were equipped with water cannons, safe rooms and armed guards. Somalian anti-piracy initiatives raided pirate hideouts, confiscated weapons and created Maritime Police Forces.     

US Navy destroyers looking for pirates.

The risks increased considerably. Failed attacks now could lead to pirates being shot by US Marines or detained and trialled in foreign countries. These stories scared many and forced the rest to travel further and further in search of unprotected prey, so costs increased too. Shipping companies became less inclined to pay millions to recover their crews and instead called in the warships to handle the situation. Satellites trained on the region could follow even fleeing pirates, to be plucked out of the water by helicopter or to be intercepted upon their return to the shore.

Rates of Piracy.

The requirements for piracy were no longer being met. And thus, there have been no successful attacks on cargo ships off the Horn of Africa since 2012. 

The end of an era.

Numerous examples throughout history can be analysed in light of these requirements to understand why piracy was prevalent or not. The most famous examples, such as the Pirates of the Caribbean, the Barbary Pirates and the Qing Pirates, were all the result of situations that met these requirements. 

Southeast Asia is the new piracy hotspot.

Piracy... in Space!

One of the most iconic 'Space Pirates'. 

Pirates have attacked horse carriages, trucks, trains, ships and planes. Space is an entirely different environment and presents new challenges for meeting the requirements for piracy.

We will assume for now that we are considering piracy in our Solar System, where most solid bodies are inhabited by permanent populations of various sizes that trade significant volumes of goods across interplanetary distances. 

Travel between the planets is cheap enough for bulk goods to be worthwhile (large quantities of raw material), yet the cost of propellant is not negligible and is an important variable in the profitability of shipping companies. 

Due to the danger a accident a collision poses at interplanetary velocities, either to the spaceships or to space stations, either directly or through the debris created, omnipresent surveillance and tracking of all objects larger than a centimeter is the norm throughout the Solar System. The implication is that all spaceships are weapons of mass destruction while in operation and are treated as such.

The Kronos 1 by MacRebisz

We will consider how changing these assumptions will affect piracy in space, but for now we will work with a realistic, 'near-future' setting. 

Finding a target

This is not a trivial task, and it is a crucial step to making piracy happen at all.

Pirates are parasites on any economy, and so prolific piracy requires a large host. The consequence is that for every pirate operation, there are hundreds, thousands or more, legitimate traders and businesses running transport ships between across the Solar System.

Due to the significant delay between a cargo being ordered and it reaching its destination, measured in weeks, months to years, it is only possible to make a profit upon arrival by correctly predicting the market conditions weeks, months to years ahead: the timing of these deliveries is crucial. This is exacerbated by the fact that the cheapest shipping involves infrequent deliveries of massive quantities of goods all at once, with a significant 'dumping' effect on the markets at the destination. 

The dangers inherent in space travel require that every spaceship declare its flight plan and time of departure ahead of time. This prevents a nasty collision between spaceships that leads to a shower of debris hosing down densely-occupied orbits and littering busy trajectories between planets. 

As merchants are unable to hide their timings, they will insist on privacy on the nature and quantity of good being shipped. A competitor with that sort of information would be able to short sell the markets, undercut prices or place well-timed buy orders that steal profits away from the shipping company.  

By SMPritchard.

A delivery of iron or platinum would look pretty identical from the transport ship's outside, and it becomes impossible to distinguish the goods being transported at long distances, through a telescope for example. 

Pirates would need to glean this information from three sources: the transport authority's inspection reports, spying operations or from the internal communications between the shipping company's agents.  

Piracy cannot happen in space without this sort of detailed information. It is too expensive in terms of time, effort, propellant and simple risk to intercept potential targets blindly. 

Therefore, it is required to make piracy work that there is some possibility of hacking, bribery, infiltration and other information collection methods being both effective and undetectable.

Intercepting the target

The next challenge is to actually get to the target once it is in flight and outside of the safe haven of the port or space-station it departed from. 

The Spitzer space telescope.

The major problem is the ubiquitous tracking of spaceships.

If every ship is under observation, any pirate attack will be witnessed by everyone. Any spaceship deviating from its planned trajectory would be flagged as a potential threat to everyone around them and to anything in their path. This is similar to how aircraft are tracked today when flying over North America or Western Europe.

If the pirates conduct an attack, they will be recorded in the act and watched intensely wherever they go. A military spaceship might be sent after them, or they will be greeted by the police once they dock at a space station or other port.

In space, every increase or decrease in velocity, or change in trajectory, requires propellant. Matching a trajectory with a target usually involves accelerating towards the target, and then slowing down until the relative velocity reaches zero. As a consequence, pirate spaceships must have a higher deltaV capacity than their target in the best of cases.

The target will notice a spaceship speeding towards it due to the previous fact, usually from millions of kilometers away. It will start to accelerate to try and 
escape.

For every meter of second gained by the target, the pirates will need 1m/s to catch up and another 1m/s to slow down after the attack. The pirates will need more than twice the deltaV of any target they attempt to run down. 

For example, if a target travelling at 20km/s has a 25km/s deltaV reserve to slow down at its destination and maneuver, and is equipped with a rocket engine that has an exhaust velocity of 30km/s (Isp 3058s), then its mass ratio started off at 4.48 and is now 2.3. For every kilogram of dry mass, the target spaceship is carrying 3.48 to 1.3kg of propellant. 

Expendable propellant tanks helps achieve high mass ratios.

A pirate spaceship attempting to catch this spaceship must first reach the 20km/s the target is travelling at, run down its 25km/s deltaV reserve, then slow down from 45km/s to stop. If it has similar engines as its target, it must start with a mass ratio of 20. For every kilogram of dry mass, it must bring along 19kg of propellant: it is over 95% just a stack of propellant tanks! 
   
Due to how the Rocket Equation works, doubling the deltaV capacity of a spaceship requires that the mass ratio be SQUARED. 

There might be a slight chance to stage an 'accidental intercept' and catch the target in without having to ride around on propellant balloons, but it will only work once, and for a very short period of time. 

There is a solution to this critical problem with space piracy: Stealth.

Screenshot from The Expanse.

If the watchful eyes of police and military sensors cannot detect the pirate ship, then it is free to do whatever it pleases. It can approach its targets unannounced, attack them in complete secrecy, and return to the base of operations without being tracked or followed.

Stealth in Space was covered in a four-part series earlier in the blog. The gist of it is that detection in space happens when a spaceship reflects sunlight, has a thermal signature or bounces radio waves off its hull. Sensors available even today can track even the smallest amount of reflected light, the lowest temperatures and the faintest radar returns over extreme distances. So, the avoid detection, a spaceship must be perfectly non-reflective, have an undetectable heat signature and have no radar return.

Vantablack.

Each requirement is met in turn by a Vantablack non-reflective coating, a system of heat pumps and liquid hydrogen heat sinks that cool down the hull exterior to the cosmic background temperature, and an insulating sheath around any metallic component.

A pirate spaceship that incorporates these elements into its design can achieve 'hard' stealth: it would be physically impossible to detect unless it is on top of its targets.

Spaceship using mass driver for propulsion.

Maneuvering while 'running cold' is accomplished through any sort of thruster that expels very low temperature exhaust. Cold gas thrusters are one example, mass drivers are another. Curved nozzles with extreme expansion ratios can be fitted to a conventional 'hot' thruster to expand the exhaust until it cools down into untraceable gases.   

Stealth has another benefit: if the target does not know that the pirates are coming, they will not know to run away until it is too late. It will not have the opportunity to expend all of its deltaV, and so the pirate ship's deltaV requirements fall to those of typical transport ships. 

This undetectable spaceship design, called the Hydrogen Steamer for its use of boiling liquid hydrogen, does have drawbacks. It requires very large amounts of liquid hydrogen, which is not very dense. This makes even the lowest endurance Hydrogen Steamers very massive. For example, handling 10kW of room-temperature waste heat requires that 2.3 grams per second of liquid hydrogen be boiled off. If the spaceship attempts to hide for six months, it will require a reserve of 36 tons, which has a volume of 517m^3. This is a cylinder 3m wide and 73m long!

Covering this large volume in carbon nanotubes might be a very expensive affair, depending on the level of manufacturing technology the pirates have access to. Cryogenic heat pumps that can operate at 20 Kelvin and lower might not be readily accessible at kilowatt power levels either. Preventing the hydrogen over long periods of time from escaping is no easy task either. 

Furthermore, the low temperature exhaust requirement imposes a performance penalty on the spaceship's propulsion. Covertly matching the trajectory a target spaceship will require boiling away huge amounts of liquid hydrogen to cover the increased waste heat production from using propulsion systems.

The difficulty or ease with which stealth is achieved depends on what the pirates expect to get away with.

If the pirates are under a total surveillance and must evade the concerted efforts of every nation's military forces, they will need complete end-to-end stealth. A dedicated 'Hydrogen Steamer' design is required.

If the pirates operate out of locations with less stringent surveillance, sparse military forces and traffic control that doesn't ask questions about the pirate vessel's suspicious features, they can choose to use stealth only intermittently. Accelerating into a trajectory that takes them somewhere near their target can be done in plain sight, using normal propulsion. Liquid hydrogen is consumed only to hide the pirates as they fine-tune using 'cold' propulsion an intercept with their target to conduct the attack, after which they return to regular traffic as if nothing had happened. 

Port Royal was a pirate haven. 

Depending on how long the pirates need to maintain stealth, the spaceship they need might only need to carry small amounts of liquid hydrogen - small enough that they look like regular propellant tanks. The pirate vessel can then pass off as a merchant ship or fast transport and transit high-surveillance zone without worry. 

Making money - Types of attack

So the pirate ship catches its target. At the intercept, it may still be hundreds to thousands of kilometers distant from its target, and pirates' victims remain completely unaware of the situation.

From Disney's Pirates of the Caribbean.

How does this intercept become a pirate attack?
In fact, it heavily depends on how the pirates hope to make money. 

The easiest way to make money is to ransom a crew.

The vast majority of private entities will feel obligated to pay for the safe return of their employees if they wish to maintain their reputation - those that don't will quickly see themselves out of business. Ransoming a crew in space doesn't require boarding parties: all is required is that the pirates have a means of putting the crew's life at risk. This can be as simply as threatening to punch a few holes in the hull, or shining a laser on the radiators. Pirates might sit a few hundred kilometers away from the target and demonstrate their ability to do damage. They then establish a communication channel with the shipping company and start negotiations. 

A manned spaceship usually means that the goods being transported need human attention or supervision: high-value items, confidential data ect. 

Spanish merchants returning from South America laden with gold were prime targets.

Pirates might have knowledge of these and demand that they be handed over: in addition to a ransom, they commit theft (or take hostages). 

Theft in space is more complicated. The pirates must physically interact with their victims, and need the cooperation of the crew to some degree. Depending on how well the pirates threaten their victims, they can convince the crew that handing over the precious cargo is of less dire consequence than resisting the pirates. 

Release a cargo container or we will shoot!
By Luke Berliner. 

If it is impossible to guarantee the crew's cooperation over the radio, then the pirates might escalate to dealing damage to their target, or even attempting a boarding action. 

Hacking the airlock, by ThDark.

A distinction must be made between 'boarding' that forces a docking, but can be foiled indefinitely with a burst of the maneuvering thrusters, 'boarding' that destructively creates another point of entry into the target's hull, which puts the victims at considerable risk and might convince them to fight back, and non-penetrative 'boarding' that involves latching onto a spaceship's exterior and interacting with it from the outside. The latter method is the safest for both parties involved and of greatest interest if for example the victims' spaceship has a depressurized cargo bay that can be accessed and stolen from without touching the habitation sections. 

Another valuable prize for the pirates is any passengers onboard the target spaceship.

Passengers can be taken hostage and ransomed back to their families or employers. These ransom negotiations can take place along different channels than those for between the spaceship crew and the shipping company. It is in the pirates' interest that they keep their hostages safe and unharmed - this maintains their value during negotiations. 

Luxury space 'yachts' transporting VIPs must be vigilant.

However, pirates might decide to take their hostages onboard their own vessel so that they can escape under stealth before the authorities arrive without having to abandon their prize.

Pirates might try to make money off the target spaceship itself. It might be the only option if the pirates intercept an unmanned transport that does not carry any valuables or passengers. While it is unlikely that the spaceship can be carried away and sold whole (unless it is modular), there are valuable components and parts that can be sold on the black market: rocket engines, nuclear fuel or navigational computers, for example.

Finally, if pirates can intercept and even board a target, it might not be much more difficult to take control of the spaceship. This is hijacking.

Hijacking a spaceship allows pirates to make money even if their target was unmanned, carried no valuables or passengers and was made up of only parts with no re-sale value. 

There are three things that pirates can do with a hijacked spaceship: re-route, disable or turn into a weapon.

Re-routing a spaceship ensures that it arrives at a different destination (such as a dock where corrupt porters will steal its cargo), or takes much longer to arrive at its intention. A delay in shipping can create market movements that financially savvy pirates can exploit: it can reduce a company's stock value, force the payment of non-delivery fines, increase the price of a good due to artificial scarcity or manipulate market options and bets to the pirates' benefit. 

Disabling a spaceship forces the shipping company to spend money (and huge amounts of propellant) to retrieve it before it goes too far or even leaves the Solar System. This is interesting if the pirates are working in conjunction with a corrupt recovery business, or if it is part of a ploy to increase the value of a ransom.  

As mentioned above, any spaceship travelling at interplanetary velocities is a weapon of mass destruction. A hijacked spaceship can be pointed at a space station or colony to cause a huge loss of life and materiel... or the pirates can be paid a huge amount of money proportionate to the 'savings' from having the spaceship returned to its original trajectory. Larger settlements are therefore likely to pay more. They are likely to have defenses to shoot down asteroids and rogue spaceships, but there is little they can do against an unmanned ship hauling thousands of tons of rocks or ices, especially if the pirates hide traces of the hijacking until the last possible moment. 

The Base

Pirates need a base of operations.

Lunar propellant depot by SMPritchard.

It is where the pirates service their vessels, offload their bounties and stage their attacks. This implies that the base is able to provide propellant and fuels, replacement parts and repairs, fresh crew and information gathering services, secure storage, a method of moving stolen goods to black markets (or has its own marketplace), and most important of all, protection from the authorities. The protection for the pirates can be accomplished through stealth (the entire base is undetectable), weaponry (the base is not worth assaulting) or some sort of immunity (the base is located somewhere the authorities are unable to exercise their power).

Whether it takes the form of a pirate haven, a hidden space station or a reliance on their own infrastructure depends on the technological assumptions.

If the pirates cannot repair their own spaceship or obtain their own propellant, they will need a full-scale port that provides these services. If instead they can 3D-print most of the components they need and can scoop up propellant through In-Situ Resource Utilization, then they are much less beholden to any single location. 

Base embedded in a comet.

In practice, most pirates will need access to all three types of bases. Even the most self-sufficient pirates will need a way to sell stolen goods, and even the most dependant pirates can gather more propellant and parts, at the very least by stealing them off their victims' spaceships.  

Alternative pirates

So far, we have assumed that the pirates must travel in a vessel of their own, physically approaching a target and conducting an attack that they must then escape from under stealth. This is only a slight modification to the traditional sci-fi trope of Space Pirates, themselves a version of the romantic notion of Pirates of the High Seas converted to take place in Space. 

By that assumption, pirates are a group of space-going criminals skirting the law with specialized vessels. 

In reality, there are a broader range of options that match the true definition of 'piracy', which is any robbery or violence that targets ships in transit. 

Therefore, it is just as likely that we might have pirates that stay at home and try to remotely hack through the electronic defenses of their victims' spaceship. This sort of pirate is featured in Corsair by James L. Cambias. If they cannot get through these defenses, they can instead remotely control a drone ship to their target. This drone ship doesn't even have to be exciting: it can be a micro-satellite equipped with a radio, hooks and manipulators. 

Drone with manipulators

The drone can use its manipulators to access any exposed electronics, sensors or communications devices to bypass the electronic defenses and hijack the target. If even this is too difficult, the pirates can simply install a bomb on-board the drone and inform the crew that if they do not follow instructions, it will go off. 

This micro-satellite is much easier to hide using stealth than any large manned ship. It can flit around docked spaceships and latch itself onto a target's hull before it has even launched. Intercepting a target in deep space is also easier, as a micro-satellite does not need a big engine or huge amounts of propellant. 

Remotely or through these drone, the pirates can make money through most of the methods mentioned before with no risk to themselves. In fact, it is more realistic that 'pirates' are simply criminals that disperse dozens to hundreds of these miniature drones to multiply their chances of intercepting a rich target.

The other assumption, that the pirates are criminal groups, can be challenged as well.

The pirates might simply be contracted commerce raiders. This is a legitimate method of waging war, and pirates that fall under this definition have been known as privateers throughout history. Privateers act like pirates, but only against the enemies of the nation that is sponsoring them.

Privateering solves most of the complications that pirates in space have: they have a secure base of operations, they do not have to hide themselves in friendly territory and will not be hunted all the way base to their base of operations if caught. Captured spaceships can be diverted to the sponsor nation's ports to be sold whole or in pieces. 

German WWII U-Boats conducted commerce raiding expeditions throughout the war.

However, the number of potential targets is more limited than for true pirates Their sponsorship can be revoked if they do not follow the rules, or if the conflict ends. They will also be actively hunted as a military target and are unlikely to win fights against true warships. 

There is also a type of pirate that is a criminal, but has nothing to fear from the authorities: the corporate raider.

The East India Company practically had its own military, and its rule was law.

Corporation in space will compete at every level for control of the markets. This competition can spill over into illegal activities, such as attacking competitors' spaceships and raiding their commerce to ruin reputations or steal sensitive information. Between the enormity of space and the amount of money corporations have on hand to spend on bribes, a lot of these illegal activities can be hidden.

In short, these corporations can hire off-the-book crews to acts as pirates that attack only the spaceships of their competitors. They will be protected from the consequences if they follow these rules, but left to the authorities if they breach the terms of their contract. 

A competitor might be frustrated by police and military inaction, and might decide to take matters in its own hands by hiring its own pirates and pirate-hunters. There is even less of a chance that military forces intervene in 'red on red' conflict, even if it escalates into corporate warfare.

By Robbert Middelkoop.

The main difference between corporate warfare and true piracy is that the corporate pirates are unlikely to gain any money by ransoming their victims, as the corporations have nothing to lose from writing off their responsibilities, and are unlikely to target major settlements by using spaceships as WMDs, as this will draw in attention from the authorities that cannot be bribed away. 

Up next

So far, we have looked at what is needed in a setting to allow piracy to take place and even prosper. Pirates in space can be glamorous raiders that slip in and out using undetectable spaceships cooled to cryogenic temperatures, or mundane criminals working from home using remote-controlled drones.

Next, we will discuss the countermeasures that will be developed to combat piracy, and what effects this will have in terms of worldbuilding.