It's the near future, and Bob goes for a spacewalk outside the International Space Station or Space Shuttle or some similar type of realistic space craft. Suddenly, and unfortunately, Bob goes space-crazy.
So, Bob is outside the craft, armed with a standard toolbox and a EVA kit. How much damage can Bob cause? Can Bob kill everyone on board? Can the guys on the space craft reasonably stop Bob without going out of the craft to fight him themselves?
First of all, this question depends on the contents of the toolbox. Answer for yourself:
Now, how to counter?! That depends on the ship/station:
Bob can certainly damage virtually any spacecraft, since they are complex objects with multiple weak points. Damaging solar cells, electrical connectors, protective tiles or even pulling off the thermal blankets covering sensitive equipment is going to disable most spacecraft.
OTOH, Bob isn't likely to do physical damage to the structure of the spacecraft itself, except in very limited circumstances. Due to the nature of its mission and the very narrow margins available with 1960 era technology, the LEM was built with some sections not much thicker than several layers of aluminum foil. Since the LEM was never designed for flight in the atmosphere or to operate in anything more than 1/6 g, this wasn't an issue (and NASA certainly didn't expect any of their highly trained and screened astronauts to "go space crazy" either).
More modern spacecraft have reasonably substantial structures. Even the Bigalow inflatable module is made of multiple layers of Kevlar, resembling a bulletproof vest more than a balloon. Certainly you are not going to push a screwdriver through the hull.
This brings up a point which seems to have been overlooked: how much damage could a person in EVA mode actually do? In order to do any sort of work at all, an astronaut needs to be solidly braced against the structure of the spacecraft, and special tools are needed which can cancel out torque and other forces which can unseat the astronaut. An astronaut who is unbraced and takes a swing at the spacecraft with a hammer or heavy object is likely to simply fly off the spacecraft instead. Bob will be dangling from the end of the tether rather than homicidally tearing big chunks from the spacecraft after the first whack.
Unless Bob is a trained space marine with special equipment like shaped charges, cutting charges, thermal lances or other tools specifically designed to cut through metal in a zero g environment, I have doubts that he's going to do more than some localized damage before he goes spinning off into space. While this is alarming for the crew, and potentially quite dangerous if unattended, another EVA can be done to bring Bob back inside and fix the damage.
He can damage the ammonium radiators, and if he can get enough leaks going then it's going to get very hot very quickly inside.
This could be done by removing the ammonia pump — this kind of thing happened by accident in 2010.
It depends on exactly which craft he's on, and just exactly what a "standard toolbox" contains.
If it's the ISS, with any sort of hammer he should be able to disable all of the solar cells simply by whacking on them. Concentrating on the end with the electrical connections would be a good place to start, since I expect the station arrays are configured as multiple parallel strings, and he would want to interrupt each string. With no solar power the station will go dark in fairly short order.
Something like the Shuttle is equally vulnerable, although in the slightly longer term. All Bob has to do is zip around whacking tiles. They are remarkably fragile wrt impact, and he should have no trouble doing enough damage to guarantee a Columbia repeat.
So we know how to damage a craft properly, but what can the guys inside do to defend?
Fresh from the Kerbal Space Program Field Study Institute I can offer some strategies for improvised space travel and short range transiting, containing something called the "most fuel efficient way to transit a kerbal from one craft to another". If done correctly, it can be used for self defense purposes against people in spacesuits going amok.
Usually includes a rope, good aim and lots of good luck: when attached to the station with some kind of rope (I think they have a specific name, but I can't recall) that should prevent EVAs from floating away, you can use this to apply force to whoever is at the other end of that rope. The centrifugal force will force the aggressor away as long as he is fixed. All you need to do is start spinning your station fast enough. Usually no EVA-suit has the thrust to nullify the forces applied this way. If you have some kind of rotation wheels (which is something I think is exclusive to ksp) you don't need to waste fuel on this, just electric charge.
As bonus, if you cut the rope in the very best moment you can send your aggressor in a predefined direction (like in front of the exhaust port of something that is about to accelerate). Or — more peacefully — this can be used to send EVAs at high speeds into a higher or lower orbit where they may rendezvous with another craft or station.
Of course, this may cause havoc inside your station if you have your staff and stuff floating around freely.
Works pretty similarly, but without the rope. You need a huge flat structure and the ability to rotate your station quickly enough. Big constructions might lack this ability, but smaller ones do excel with that.
Just wait until the aggressor is in front of said structure (solar panels might work, but usually are too fragile) and start spinning, slinging the aggressor away. It’s hard to aim with that technique (trust us, we tried), but you can easily push away stuff that starts to getting dangerous.
Sadly the aggressor might damage the surface used to do this, so use with caution.
Until now the aggressor usually could maintain the ability to fly back if his EVA suit did contain some sort of propellant in high quantities. So what to do with troublemakers that keep coming back?
Well, if your station owns a robotic manipulation device (well, some shafts with a clamp at the away end) you can try to grab the aggressor. What is done next is up to you. Hold him? Throw him away? Smack him into something else? bbq him in front of your main thruster? Well, use your imagination. If you are having your evil day you can try to squeeze his EAV so it will break and let the air out, but that’s way too cruelsome.
If your station owns some kind of emergeny-capsule, maybe you can just start this thing when the aggressor is right behind it. Its mass will be too much to counter with his EVA's monopropellant, and with a bit of luck he will getting stucked at it somehow.
Anyway, you will get him away, and in some cases he will stay there until the capsule enters the atmosphere again. Than he isn't of any problem for you any more.
Big fragile structures disqualify themselves for that tactic, but if you do have a big maneuver thruster you can just kick start your engine and fly away. Bets are that your ∆v is way bigger than his!
Just don't forget to stabilize your orbit once out of reach, or you will either do a surprise reentry or find yourself on a escape trajectory from your home planet.
So maybe your EVA does have a remote control that cannot be switched off... well, do we need to say more?
At the other side, most space suits own a communicator that is either impossible to turn off or at least pretty hard. So threaten the aggressor start singing the Russian national anthem (just applies if not a Russian patriot) or a freely choosen Justin Bieber song will make him reconsider. You could ask ground control to force 10 hours of nyan cat into his channel.
Sadly this may backfire, so take good care.
Well, Bob was out on a space walk with a box of standard tools and an EVA kit, so I'm guessing the answer is probably yes, he can do a fair bit of damage to the station. I am less exactly sure what your standard toolbox contains, and trying to be flexible in regards to your shuttle or station, so assumptions are as follows:
a) he was supposed to be fixing something before he went "space crazy",
b) he could have fixed that something with the toolbox,
c) the toolbox therefore has the tools (duh) to fix that something and any other standard somethings (to go with the standard toolbox),
d) the tools are therefore capable of affecting or changing things outside, while on space walk,
e) they're probably important or they wouldn't have needed fixing while spacewalking,
f) he can therefore probably un-fix, or rather break, the things he can access or alter.
I would guess, if the somethings he was supposed to repair, or that the toolbox can give access to for repair purposes, are sufficiently immediate, he can indeed kill the other astronauts, or cripple the shuttle/space station, or wreak general havoc - other answers have some good ideas of exactly how. If there's a bit more redundancies in the systems, the crew might be able to hang on long enough to repair his un-fixing (with, of course, the same standard toolbox) and/or get supplies from other stations or earth (depending on what's available), for whatever has been broken or irretrievably tossed into space.
What can the shuttle do to stop him? Well, that will depend on the exact scenario. If he has a tether or something, he could maybe be reeled in like a fish, struggling the whole time, and subdued inside the station. If he's tethered to something outside, not just at the airlock, someone will have to creep to the tether point, remove the local tether and use a tether to the airlock to drag him in (best wait until he's in the middle of moving, so that he can't tether himself down again). As long as Bob is not tied down anywhere else, keep the pressure on the tether linking him to the ship, and he will eventually lose his grip, run out of fuel, and can be reeled in from there. If Bob cuts it - well his problems are bigger, he's lost quite a safety net. This might also be the time to draw on Confused Merlin's strategies.
If they think Bob can be cured, another step might be to try and deprive him of the toolbox, since clawing at the station/shuttle (or other astronauts) with his suited hands is likely to be much less effective in destroying things - there's a reason we have tools, after all. knocking them out of his hands will probably do a lot, especially if the contents can be spilled or scattered (it will be hard to find them after just a few moments, and will be quite a distraction). This will probably require someone going out there to achieve this, though.
If he can't be cured, or your crew doesn't have time to try, one of them can armor up, and try to get Bob first - cut the tether, breach the suit, etc. Depending on the specific tools and spacesuit weaknesses, he may not have an immediate advantage in fighting - especially if the crew rigs up counters to the worst possibilities (cover over tool access so he can't undo things, reinforce or double tether so he can't cut, use tape and glue and spare packaging, it will be harder to get your person out of the suit afterwards, but also harder for Bob to do so in battle).
If all else fails, distract away - Bob has limited time and fuel, and the surroundings are decidedly hostile. He will run out of air with exertion, run out of fuel dodging and maneuvering, and every moment you're annoying him is one more moment he's not breaking anything else. Your crew has time, resources, help, and a lot more tools than Bob's standard toolbox, so let them use those resources if they don't want to fight Bob directly.
