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52

That is a UHF antenna. It was well placed on the Lab to get in the way of robotics ops during space station assembly. This is a picture of a different UHF antenna unit (this one is on the P1 truss segment) but it's clearly the same device. Fortunately this is from a credible source, NASA's ISS Flight Systems brochure (warning, pdf). I can't quite figure ...


33

There are multiple problems with this idea. The first and most obvious problem is that the sealed container which has a perfect vacuum inside (seller claims so at least) is not of much use until you can put something inside (experiment, material, ...). And when you do that, you unavoidably get some gas inside with it, which ruins your perfect vacuum. You ...


27

As far as I understand you want the "windmill" to drive a dynamo. Have you ever tried turning a dynamo? It takes some force to do so, and that force is then (partially) turned into electricity. So the dynamo is braking your windmill and unless there is some power input to the windmill (wind), it will eventually come to stop. But there is no wind so your ...


23

The material used for the seal is silicone rubber. Example materials considered for NDS iLIDS are: Parker S0383-70 (as part of Gask-O-Seal product) Esterline ELA-SA-401 Silicone rubber is the only class of space flight-qualified elastomeric seal material that functions across the expected temperature range. NASA Glenn has tested three silicone ...


22

For the most part, satellites are opened loosely to space. The components are designed to work in a vacuum, and in fact, are tested to work in a vacuum on the ground. However, there's a few things of some note along with this: There are typically a few components which must be sealed in. The most common is propulsion tanks, also, some Reaction Wheels are ...


20

The fix as show in the movie wouldn't work. To seal off the atmosphere in a more permanent manner, one would need to have something much stronger than Duct tape, or any tape. That wouldn't hold a seal. The book mentions a resin that they had to patch the hab. I suspect the tape was shown in the movie because it looked more jury-rigged, but in reality, they ...


19

"Rusting", or more chemically correct "oxidation", is a reaction with oxygen in the atmosphere. Iron reacts with oxygen and turns into iron oxide, the reddish-brown substance commonly referred to as "rust". In space there is no atmosphere with any oxygen to react with, so any iron in space would not rust. This, however, assumes that there is really no ...


19

On planet earth, food spoils for several reasons: Oxidation Dehydration Microorganisms Oxidation is a reaction with the oxygen in the atmosphere. You can witness this when you cut an apple in half and leave it. It will only take minutes until the cuts become brown. Oxidation is usually harmless, but often gives the food an unpleasant texture, look and/or ...


16

Yes, it would explode. Most hand grenades are nowadays triggered chemically, electrically or contain a fuze enclosed within the assembly, so they don't require atmospheric oxygen to ignite, are watertight and otherwise more reliably go off at a preset time since activation. You would however create a large number of dangerous debris that would float forever,...


16

According to WP, at the upper end of Earth thermosphere -- that's LEO, somewhere above the orbit of ISS -- the pressure goes to around $1 \times 10^{-7}$ Pa. This level of vacuum is regularly achieved on Earth, with MBE chambers going down to around $1 \times 10^{-10}$ Pa. To get a better vacuum you'd need to get quite a bit farther from Earth. In any ...


15

Generally open to space. Maintaining a perfect seal a long time is hard. If your equipment needs non-vacuum to operate, and you expect it to last, then it is pretty likely it will leak over time, so might as well design to operate in a vacuum. One benefit of an atmosphere inside would be better cooling. But since there is no difference between hot/cold ...


12

Generally speaking, all "air-tight" containers leak to some small degree. On Earth this manifests itself as an inability to maintain a vacuum indefinitely; in space, it manifests itself as an inability to maintain an atmosphere indefinitely without a source of replenishment gases (which themselves are going to leak over time, so you are really only delaying ...


12

The nozzle of the Merlin Vacuum is very large, to help get better expansion ratios since it only ever fires in a vacuum, unlike the 9 sea level optimized Merlins that have smaller nozzles. This is very obvious when you realize the Falcon 9 first and second stage are the exact same diameter, but on the first stage with normal Merlin engines, 9 engines and ...


12

Consider the windmill as a system. If there is no wind blowing on the windmill, there is no energy being input into the system. If you pull power out of the windmill, energy is being output from the system. With an output and no input, whatever energy is in the system will be drained and not renewed.


11

The effect of the void of space is not so much cold, rather it is an insulator. Though heat radiates away, there is no convection nor conduction. Many spacecraft take precautions not to overheat in space, very few spacecraft have a too-cold condition. Even the Spitzer space telescope has since warmed up since the coolant ran out. Additionally, the void of ...


10

Sorry, no bulb-shaped exhaust plume, at least not in true vacuum. But you might see something similar to an incandescent light bulb shaped exhaust plume at high altitudes that first stages reach, up to about 135 km high (exact altitude depends on launch vehicle and its ascent profile) above sea-level where there is still some, albeit tenuous atmospheric ...


10

Space is not quite as empty as you might think, and your average jam jar is easily strong enough to hold atmospheric pressure against an internal vacuum. More to the point, there wouldn't be any need to go into space to create a jar full of nothing. Current technology can easily create a vacuum that would compare with that of "outer space". As for what your ...


10

Other then decay caused on earth by bacteria and such, other factors for decay in space; where decay = loss of pristine mummification of the original freeze dried corpse. A body in orbit around a sun would be impacted by the solar radiation. A quick search only found research on live tissue. Presumably this would cause some denigration of the mummified ...


10

It would seem that the ultra-cold vacuum would kill off most of the bacteria, etc in the body, as well as quickly boil off all of the water content. Here's a lovely description of the process from Focus magazine: In space we can assume that there would be no external organisms such as insects and fungi to break down the body, but we still carry plenty of ...


10

Unless the lubrication system fails in the dynamo that is in vacuum, electrical generation will work. Magnetic fields are unaffected by air or the lack of, at least at the level under consideration. Earth's magnetic field is too weak to have an effect on the generation of electricity by a dynamo. You can see how weak is the magnetic field of our planet by ...


9

Current iron and aluminium processes rely on gravity: Impurities (which are lighter than the metal being processed) are skimmed off the top of the molten metal. Molten metal can be relied on to stay at the bottom of the crucible, and not e.g. cling to the lid. Pouring under gravity is much easier than having to rely on pressure or somesuch to get the molten ...


9

Iron is generally used for steel and I will address iron in the question as referring to steel. You need a phenomenal amount of electricity to smelt aluminum in the most commonly used method here on Earth. Steel on the other hand requires careful management of additives to produce the correct strength and other characteristics. Steel with too much carbon ...


8

This was done to simplify thermal management. In a pressurized container, you can use air cooling. In a vacuum, you have to use heat pipes or liquid cooling to transfer heat to a radiator. This also explains the failures: as the air leaked out, heat transfer was impaired to the point were components would overheat. As the space race progressed, ...


7

Early Russian probes were pressurized. The reason was to give the equipment similar conditions which could be tested on Earth, and to simplify the thermal environment (making conduction/convection possible, not just radiation as in vakuum). They used nitrogen at 113 hectopascal, this source says: Andrew J. LePage at the space review http://thespacereview.com/...


7

But would it be possible to create one that floated near space with almost no air pressure? Possibly, depending on what material(s) you use to make the balloon. If so how much could it lift? what are its limits? That depends entirely on how big the balloon is and what material you use to create it. A regular balloon uses internal gas pressure (...


7

For the sake of this answer I'm going to use the numbers I get from NASA and Wolfram Alpha. These are: Density of Earth Atmosphere: 1.204 kg/m^3 Density of Martian Atmosphere: .020 kg/m^3 Density of Helium on Mars: .001458 kg/m^3 Density of Helium on Earth: .1663 kg/m^3 Volume of a 40m radius sphere: 268083 m^3 These assume 1 atm pressure and 20 degrees C ...


6

This is actually quite a serious issue, and one that has been solved in a variety of ways. The method I'm most familiar with is Reaction Wheels, and I'll try and cover some of the other key points as well. There are basically two kinds of reaction wheels. The first kind is those that are sealed up, done to make it easier to manage the lubrication. The ...


6

I'm pretty sure this hasn't happened to Humans... Depends on your definition of 'exposed'... Soyuz 11 suffered an accidental depressuriation when preparing for reentry, when a valve accidentaly opened; the crew were not wearing spacesuits and had no protection against depressuriation. The cabin was in vacuum for around ten minutes before it reentered the ...


6

In 1964 and 1965 at Holloman Air Force base in New Mexico a number of chimpanzees were exposed to a vacuum for 30 seconds. They were at 2 mm of mercury, which is 0.038 psi. They were revived with pure oxygen. Their ability to perform tasks were tested after they suffered rapid and total decompression for that time. They all did OK. When Stanley Kubrick first ...


6

This isn't quite as trivial a question as it first seems, since a self-excited dynamo needs an initial external magnetic field to start working. In principle, the Earth's magnetic field, weak as it is, could serve to kickstart the self-excitation. In practice, though, the initial field is normally supplied either by residual ferromagnetism of the stator ...


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