# Weapons for boarding spacecraft?

With today's technologies firing a gun inside a spacecraft could be catastrophic, although not certain it's widely agreed that firing weapons inside the space stations is very risky.

Assuming space travel was much more prevalent but technology not significantly far beyond ours I'm interested in the sort of weaponry and tactics police, army and other tactical organisations would use.

For example:

• A hostage situation onboard the ISS
• The armed response team want to save the hostages and the station itself

I assume

• Projectile weapons
• Explosives
• Tasers

Are all out for fear of damaging the station and killing everyone. How would they do it? What weapons would they use?

• A few well-chosen key word searches in Space Exploration's iss tag may also prove useful, although at the moment search is down. – a CVn Oct 13 '14 at 8:34
• Thanks guys, just rephrased a little to suggest that it's risky rather than catastrophic – Liath Oct 13 '14 at 8:35
• An EMP might be helpful to start things off. – overactor Oct 13 '14 at 8:41
• Also consider the getting to the spacecraft in the first place. IIRC actually docking with the ISS is a maneuver a few hours long, and that's between two cooperating spacecraft crews. A couple of nudges from the ISS thrusters to stay away would probably make it very difficult to dock at all! – a CVn Oct 13 '14 at 8:50
• Another related question: space.stackexchange.com/questions/2372/… – HDE 226868 Oct 13 '14 at 16:43

Space stations are confined spaces. Assuming that you can get in at all (this will be quite a dangerous struggle), consider gas weapons. Especially if you can find some plumbing on the outside to pump it in. A teargas canister will incapacitate the unprepared and not affect your suit-wearing boarding team.

But what if they are prepared in suits? This levels the field somewhat with your boarding team who have to wear suits. Try expanding foam: you can very quickly fill the area around someone. Within a confined space station, even an inflatable object made of tear-resistant material becomes a useful area denial weapon. Nets will also be good weapons, a concept dating from Roman gladiatorial times. You could have memory-wire or heatshrink technologically advanced netting that speeds up the process.

Another possibility is laser weapons for blinding rather than burning. One flash of a suitable laser onto a specular reflective surface and everyone nearby who isn't wearing the right filters is permanently blind. These are banned under the Geneva convention for this reason, but if ocular reconstruction technology is cheap and easy you could imagine them becoming un-banned.

However, any kind of "dead man's switch" on a bomb or critical systems would easily make it a Pyrric victory. The station is very easy to destroy if the occupiers want to prevent its capture.

The easiest thing to do is vent their atmosphere, forcing them into suits with limited air supply, and wait. The disadvantage of this is it takes time and will result in deaths of hostages.

• Vent the air, tell them you have air. Tell them that one hostage-taker will be allowed on board for each living hostage they bring with them. Wait for them to finish killing each other and bring on board the survivors :) – Tim B Oct 13 '14 at 11:18
• @TimB And then the hostage takers start disguising themselves as hostages and take over your ship. – Nzall Oct 13 '14 at 13:27
• @TimB, what if there are more hostages than hostage-takers? That seems like a pretty likely scenario, so 1 breathing hostage=1 breathing hostage-taker sounds like a bad trade. – Brian S Oct 13 '14 at 19:22
• Adjust the numbers to fit, it wasn't a serious suggestion anyway :P – Tim B Oct 13 '14 at 20:25

Well, if your space station is a military-type installation, or built anywhere near those standards, I can imagine that they would invest in bulkheads similar to what you'd see on a modern naval ship. Right now, the reason we have relatively fragile things in space is the cost of putting materials into orbit. If space travel has become prominent, then it can be assumed that we overcame that challenge.

So, that being said, if you build a space craft like a modern naval ship...the walls are tough enough to shrug off small arms fire. Low-velocity hollow rounds would probably be the safest...enough punch to go through a squishy human, but a steel wall would stop it cold, with little more than a dent to tell of the impact. It makes sense that a craft built with the potential of being boarded is going to be built in such a way that it can survive the first person to fire a gun onboard. Otherwise, boarders will hop aboard, breach your hull, then just sit back and wait.

Barring the idea that someone would build a space station such that a kid with a .22 wouldn't be able to breach the hull, or considering your specific scenario here are some other options that currently exist.

Sonic weaponry (you can use the right frequencies to reduce humans to nauseous puking messes on the floor), Infrared weaponry (so called 'heat rays' inflict debilitating pain on organics, but do practically nothing to anything non-organic), anything used for riot control (rubber bullets, beanbags, stingball grenades, gas, etc.).

Flashbang + melee is always good too, that is a very common means for close quarters combat, and is probably what would be used in a situation like the ISS. Perhaps not with your standard flashbang grenade, but the idea is sound: blind/disorient opponents, swarm in and take them down without firing a shot. And yes, this works in military applications as well; I have first hand accounts of someone who was onboard a ship when, during a training exercise, it was boarded and taken over without the boarding team firing a single 'shot'.

• Melee at Zero G? – T. Sar Mar 21 '16 at 18:02
• @ThalesPereira You'd need special training, but sure...grappling still works, you just need to learn to compensate for zero-g. And if you can have a way to secure yourself in place by bracing or use of mag-boots, then you can even hit people without knocking yourself around. – guildsbounty Mar 21 '16 at 19:45

There are a variety of weapons that are designed to be non-lethal for riot control.

Rubber and plastic bullets (which need to be fired from special guns) don't penetrate people, so I would tend to think the spacecraft should be okay.

There are specialized versions of rubber and plastic bullets called pepper rounds which are used for home defense. In addition to the non-lethal stopping power, they also leave a trail of pepper dust which can irritate eyes, skin etc... Of course, there are a whole host of agents both lethal and non which can be used in its place.

Sponge grenades and bean bag rounds are larger rounds, but also could be effective.

There are also varieties of lower powered bullets like .22 shorts. These are largely used for target practice and hunting little creatures. They do not penetrate as deeply. Occasionally they are made of compressed metal dust, common at target ranges, which essentially disintegrate on impact.

But the holy grail in this case is probably a bullet like the Glaser Safety Slug which is the ammo of choice for Sky Marshals in the US. The Glaser is a hollow bullet filled with bird shot which disintegrates on impact with any surface that is harder than it. They theoretically cannot pierce an aircraft's hull, they don't ricochet, but they'll still take down those space pirates.

• Sort of amusing, but sometimes these weapons are referred to as "less than lethal" instead of non-lethal. The things we choose to care about when shooting someone... – MadPink Oct 13 '14 at 13:17

The power of a single hole to suck things through it has been overstated in a lot of fiction.

Having said that holing of a space station/space craft is something you would generally try to avoid. In Babylon 5 that was actually one of the reasons they gave for the energy weapons they use - they don't do serious damage to ship hulls etc.

Tasers would be safe enough to use - the amount of charge they deliver would be dissipated harmlessly if they struck a wall/floor/ceiling. If they directly struck sensitive electronics they may burn out those electrics but that would just involve replacing a few components or circuit boards to repair. They wouldn't work very well against people in space suits though.

Explosives might actually be a very effective weapon in a military operation not involving hostages or if some or all of the kidnappers are in a separately airtight area of the base. The attackers would be wearing combat-reinforced space suits. If they deliberately blow a large hull breach then everyone inside would be sucked out and/or killed by the explosive decompression then you can clear up, repair the breach and refill the atmosphere. If repairing and refilling are not practical and you want to keep the space station/craft then obviously explosives are not a good idea.

Projectiles as mentioned in the comments would risk some damage so would be best avoided, if they were used then low caliber and low power rounds would probably be preferred. One good option would be riot guns and beanbag rounds. They would be unlikely to damage the station but be very effective at subduing the people inside it.

• "If they deliberately blow a large hull breach then everyone inside would be sucked out and/or killed by the explosive decompression" I for one wouldn't want to be part of the hostage in that case! – a CVn Oct 13 '14 at 8:48
• @MichaelKjörling Yes, good point. I've clarified my meaning on that point :) – Tim B Oct 13 '14 at 8:50

Given that AFAIK the ISS gets all its energy from solar power, I guess a good strategy would be to block the sunlight from the solar cells, and then wait until the hostage-takers give up.

That's of course assuming they are not the suicide-terrorist type. But if they are, I doubt much can be done anyway.

The hard sci-fi RPG Diaspora mentions the possibility of a boarding party using old-fashioned bladed weapons, like swords and daggers, for this very reason. However, to use swords effectively requires enough open room to swing them, so if space is cramped, that might be an issue.

• Swinging a blade in a near-zero-gravity environment won't do you much good, because it'll just swing you the other way. Which is touched on in this (long) answer as well. Daggers maybe, but it'd probably take a good amount of practice to use them effectively as the moment they hit something and you keep pushing forward, you will also be pushing yourself in the opposite direction. I haven't checked out Diaspora but this doesn't seem very hard-scifi to me. – a CVn Oct 14 '14 at 8:42
• Agree - swords, bad. In space you'd want propulsed weapons, jet-axes that swing themselves on button-press (and backwards, too). Harry Harrison in One Step from Earth had a short story about space boarding, the attackers carried such axes and counter-rotating drills with propulsion. – gbjbaanb Oct 14 '14 at 9:59
• Well, there is a separate "MicroG" skill for effectively moving/fighting in low- to no- gravity conditions, and if a ship isn't accelerating or rotating sufficiently, this skill must be used instead of the usual combat skill (except for weapons that are specially marked as "low recoil" weapons). There's no magic gravity generators, which is more than most soft space-opera sci-fi settings assume. – Caleb Hines Oct 14 '14 at 13:16

If we ever get to the point of having "space marshals", they will probably carry frangible bullets(safety bullets made of polymer packed with bird shot so they fragment on impact rather than pierce) just like air marshals used to. While the little pellets would cause their own problems in zero G, it shouldn't be too hard to believably work around or hand wave away low penetration round with no details on how it works. Perhaps bean bags like some less lethal weapons fire.