Would a spacecraft carry arc welding supplies?

Question

Okay, I'm researching for a scene in my science fiction story. A character is in a spacecraft and needing to open a locked hatchway. It's locked electronically by an unknown code. All methods of forcing it open are failing, and there's limited time. So...I was thinking it might be plausible for the character to use an arc welder to just burn away the lock (holding the stick away from the metal so that it's essentially a torch). But then...I'm not sure if a spacecraft would keep an arc welder onboard. I've heard of arc welding experiments done in space before, but is that considered dangerous/antiquated?

Note: The spacecraft is a step above modern...it's futuristic, but I'd just like to stay a little grounded in reality. Any expert ideas are appreciated!

Answer 1

Seems like Mast may have already alluded to it but I doubt modern spacecraft contain much weldable metal. I would be surprised if there is much or any steel left on spacecraft and I'm sure most of the aluminum is being replaced with carbon fiber if it hasn't already. I can't imagine there would be much use for a welder.

Additionally you have described a stick welder (which is a form of arc welding, but so are almost all forms of welding) which is probably the least likely form of welder you would find on a spacecraft. Stick welders have a really hard time welding thin materials and an even harder time welding aluminum. They also make extremely dirty welds and discharge a lot of shielding gasses. I think unless your world has some sort of propulsion system that makes weight a non-factor it would be extremely unlikely your ship would contain any steel or cast iron thick enough to be welded by a stick welder.

The ship would almost certainly want a TIG welder which can weld metal virtually as thin as metal can be and is perfect for welding aluminum. That being said most TIG machines are actually combo machines that can also stick weld, but I would think an organization making advanced spacecraft would be able to create a bespoke dedicated machine with the absolute bare minimum in order to save weight.

The issue: Stick welders can be used as a rudimentary cutting implement, but TIG and MIG welders can't really be used for that. (or not easily anyway) Additionally, in order to cut with a stick welder you need a welding rod that is oversized for the metal you are cutting, this would mean the ship just so happened to be carrying welding rods that it didn't really have a use for.

My suggestion: A sawzall or sawzall-like saw. A good demolition blade on a sawzall will cut through just about any material I expect you would find on a space craft like butter, and they are useful enough for so many tasks that it wouldn't be completely unreasonable to include one in a mission.

Additionally, depending on what the door's purpose is it probably wouldn't be unreasonable for it to not be very strong. If it just separates one part of the ship from another it probably wouldn't need to be that strong and therefore it may just be a door frame with a thin aluminum skin on it to save weight. You would be able to cut through a door like that with a steak knife.

Answer 2

The equipment will depend on the mission. In particular, the length of the mission, the size of the crew, the total weight of the ship, and very strongly on the exact nature of what they are going to be doing.

Imagine a mission that is intended to be almost entirely observational. Go out to Jupiter, for example, and carefully look around. No landing on anything. No obtaining physical samples. The equipment for this is likely to be oriented towards keeping electronics and optics working. So they would have lots of equipment for that. Such a mission might be quite limited in mass. They might consider that, if they needed a huge industrial arc welder, they are probably already dead. Because they might think the only thing they could want to weld would be the ship's hull.

Turn it up a notch to landing on one or more of the Jovian moons and collect samples. Now you have physical equipment that may need to be patched up. Or adjusted due to last-second changes in schedule and plans. Oh, we can't possibly use this equipment module because the chemicals we have detected, from orbit, would utterly prevent its operation on this moon. So having it in the lander is a complete waste. Let's get it out of there fast so we can complete the mission. An arc welder might be the required tool. Or not, I'm not any kind of mechanic. But a lander could easily have a minor accident like bending a landing strut or scraping something. Or some equipment gets caught in a small little shift of rock. In the hands of a skilled tech an arc welder can do lots of cool things.

Turn it up yet another notch. It's a colonization mission. In this case, you would have many hard to predict tasks. Fix this, patch that, build the other. I once watched my uncle deal with a nut that had been "painted on" to a bolt. He got his arc welder and just sort of flicked it over the paint. The paint was gone and both the nut and bolt were fine. Not even warm.

So basically, the longer the mission, the more hands-on and heavy equipment oriented the mission, the more likely you will need an arc welder.

On the other hand, the more likely you will need any given chunk of equipment also. So the bigger the mission, the more likely you will be bringing various manufacturing equipment. It may not be very far in the future that an arc welder might be produced in a 3-D printer. There are 3-D printers now that will print in a variety of materials, which can then be cured using heat or microwaves etc., to achieve a variety of densities and hardness. It shouldn't be that big a deal to print most of the parts of an arc welder, then add the wires from non-specific supplies of wire. Possibly a few metal parts might need to be fashioned using other tools. And there you are, one arc welder. Overall, depending on the weight and room requirements on the ship, it might be preferable to take the data to run a 3-D printer, and tanks of printer material, than to try to take every possible tool you might need.

Indeed, on certain types of mission, you might be able to obtain the raw materials to make "3-D printer ink" rather than transport it. Maybe you only transport stuff you are not confident you can obtain locally. On the moon, for example, there is not much hydrogen available. So maybe you must transport tanks of hydrogen, possibly as water. Then you count on getting nearly everything else you need once you get there.

Answer 3

The cosmonauts of the Soyuz 6 mission (1969), Georgi Shonin and Valeri Kubasov, actually did test arc welding in space.

During the test, Kubasov almost burned through the hull of the Soyuz 6’s living compartment, a mistake that would have hurled the pair into space without spacesuits to face the final 30 seconds of their lives. Fortunately, the hull remained intact, but with a warning about the harshness and complexity of welding in space. (James A. Wilkey "Welding in Space", American Welding Society, 22 July 2015)

The answer is yes: the Russians have tested it and it works.

Answer 4

Arc welding in an atmosphere on a spacecraft sounds undesirable. You're generating some really unpleasant fumes and potentially releasing reasonable volumes of shielding gasses (bad news in confined spaces, also inconvenient if your atmosphere reprocessing life support can't keep up) and some potentially quite dangerous sparks and small metal fragments (conductive dust in microgravity is going to play havoc with electrical and electronic systems that aren't thoroughly sealed).

If you're not in an atmosphere, you should be using something more intrinsically awesome that takes advantage of the environment, such as electron beam welding, but that doesn't necessarily help in your specific situation.

As the author, you are of course free to handwave some arc welding devices. Have a look at the ones in Aliens, for example... general purpose compact utility tools, perhaps more justifiable than a proper welding rig.

Answer 5

One of the problems with arc welding is you need to generate an actual arc. In atmosphere, this isn't a problem because the electricity is arcing through the gasses to complete the circuit.

In a vacuum, like outside of a spaceship, this is going to be a problem. No gas to arc across, no arc. No way to complete the circuit. So this depends on which side of the door your character is on and what he has to hand. Break down the problems one at a time.

You could simply handwave an arc welder aboard as emergency equipment. That's the easy out. Justification could be that gas-based welding (I imagine) would be way more dangerous aboard a spacecraft. While current based welding systems do not share the same dangers, they have their own set of problems.

If you don't want to give a narrative excuse for having a welding rig on board, you could have your character MacGuyver it. A welder isn't really all that complex from an electrical standpoint. I don't have an electrical background but I found this paper on what it takes. I have a welder that can run off the same circuit as our clothes dryer so I imagine the ship will be able to supply an adequate amount of power. So your guy breaks down some non-survival-based equipment like a microwave oven, adds the extra stuff he needs and he builds a welding rig.

If your guy has to go outside the ship he might need some sort of medium that will stick to a surface and allow electricity to arc through. I think the gel depicted in the show "Firefly" would be an imaginative way to start

Answer 6

In a large space habitats (say, 50+ people), arc welding (esp. argon or co2 - using varieties) will be probably quite common. Argon and co2 are not toxic, can be recycled out of the atmosphere (that's how we get argon on earth and any space habitat is expected to recycle co2 anyway). These welding methods (TIG/MIG/MAG) are applicable to iron and aluminium alloys and probably a lot more, generally don't depend on gravity and produce little to no byproducts in gaseous or dust form.

A lot of modern welding inverters come with an plasma-cutting option that use compressed air (the air is released back to the atmosphere with an ozone scent, but otherwise unchanged).

MMA welding (stick welding) is probably not really useful in space setup.

Answer 7

In a post modern spacecraft as you specify, I'd imagine having an arc welder similar to those found in many home workshops around the world today is quite unlikely.

However, depending on the mission profile having some form of equipment to weld a patch onto the hull or repair equipment is definitely plausible, though I'd guess it would be more likely a gasless MIG or TIG welder for improved weld quality and versatility. Both of which could be fairly quickly modified to melt something metallic and exposed.

Which brings me on to the next point, all you need to bodge together an arc welder is a current source and the right electrodes. I've personally done a bit of very basic welding with a 24V truck battery, jumper cables and a spare weld rod that was rolling around the bottom of the boat, it wasn't pretty but it held. Depending on the lock, if it's anything like the form of a padlock running current through the shackle until it glows then hit it with a hammer and you're in.

Answer 8

Any rational spaceship will have a manual override behind a locked cover on every door or hatch, that cover lock can be picked in a few minutes by young MacGyver, TheLocksmitingLawyer or smashed in moments by detective Spooner.

The only door with no easy override would be the brig. This will require additional plot manipulation.

To do the welding will require a gouging rod and an un-fused connection to a power bus. A gouging rod is typically a copper plated carbon rod by the copper is a convenience to allow holding from the end. Any carbon rod from some experiment, or some carbon fibre / nano-tube reinforced material could serve the same purpose, perhaps an artificial limb component made for this purpose.