Questions tagged [vacuum]

Questions regarding the effects and conditions in a 'partial vacuum' or space with a gaseous pressure significantly smaller than atmospheric pressure.

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Does the Merlin vacuum engine on SpaceX's Falcon 9 gimbal?

SpaceX uses the Merlin Vacuum engine on the second stage of the Falcon 9 launch vehicle. Does the merlin vacuum engine gimbal or does the second stage uses only nitrogen cold gas thrusters for ...
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8 votes
1 answer
598 views

How do you test-fire vacuum engines in a vacuum chamber? Why doesn't it fill up almost instantly from the exhaust and spray (deluge) water?

How are vacuum optimized engines tested without disintegrating them? is an excellent question as it's attracted quite a number of informative and diverse answers. @Uwe's answer informs us that there ...
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2 votes
0 answers
75 views

How unusual is it to test vacuum engines at sea level?

How are vacuum optimized engines tested without disintegrating them? is an excellent question as it's attracted quite a number of informative and diverse answers. @Uwe's answer informs us that there ...
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7 votes
4 answers
2k views

How are vacuum optimized engines tested without disintegrating them?

SpaceX recently test fired vacuum optimized raptor engines of starship. Doesn't vacuum optimized engines disintegrate when operated in atmosphere? If yes, what additional modifications are made to the ...
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10 votes
1 answer
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How do the roll-rings at the ISS work?

I get that on the ISS they need to keep the solar panels constantly rotating to keep them looking towards the sun. To transmit the electricity and data to and from the Solar panels truss structure ...
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37 votes
4 answers
12k views

If an astronaut threw a cup of coffee into space, would it freeze, or boil off into gas?

If an astronaut threw a cup of coffee into space somehow, would it freeze into a block, or boil off into gas due to the zero pressure?
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4 votes
4 answers
2k views

Would a spaceplane be able to softly land on an airless planet?

Assuming the spaceplane has no vertical (hover)engines, is there a possibility to land a spaceplane on a celestial body without atmosphere in a horizontal way as if it had one? One could lower the ...
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-2 votes
2 answers
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What happens if the inner door of a depressurised airlock fails?

What are the consequences of the INNER door of a spaceship airlock system suddenly failing (for whatever reason) when the airlock itself is depressurised? (The ship itself is in space/vacuum and not ...
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5 votes
0 answers
136 views

What are these white garbage-like things on Falcon 9 vacuum engine? [duplicate]

On recent launch I noticed, that some white things jumping on vacuum engine in space. Something like garbage or condensate. See video at right at times when Earth is at left: ...
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4 votes
1 answer
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How rover landing is achieved on planets with very low atmospheric pressure?

I would like to understand how safe landing of a rover is achieved on mars or any other planet where the pressure is very low. Is it achieved by releasing gas from high pressure to low pressure. I ...
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6 votes
1 answer
206 views

Are galvanised steel parts safe to use in space?

Are galvanised steel parts safe to use in space (high-vacuum environment), e.g. washers, fasteners, nuts? I've heard that zinc can sublimate at low pressures.
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3 votes
0 answers
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Why use nozzle extensions for ULA's Vulcan; why not make them this long in the first place?

This answer to What is the difference between the Vulcan 562 configuration and the Vulcan 5H2 ("Heavy") configuration? explains that the 2nd stage nozzles were modified by extending them, ...
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5 votes
1 answer
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Purpose of foil on Merlin Vacuum Engines of SpaceX

I want to know what is the purpose of this silvery foil situated above the bell in Merlin Vacuum Engines, and what purpose does it fulfill exactly?
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1 vote
1 answer
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What would happen if you jumped out of a moving spacecraft?

I've watched a film where one of the characters claimed to have rapidly disembarked a moving spacecraft during a 5g burn (?!) and immediately wondered how he survived. For example, you're on a ...
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4 votes
0 answers
185 views

Do vacuum-grade oils and greases trivially solve the "lubricants don't work in space, cold welding happens" problem (for short to moderate duration)?

(Related: How is the unwanted cold welding prevented in space?) I've often seen talk about fairly simple mechanical devices (hand tools, simple handheld power tools, firearms, etc) being unlikely to ...
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30 votes
3 answers
12k views

Was the ship decompression scene in the movie Aliens realistic?

I was directed here from Sci-Fi SE to pose this question. Towards the end of the Aliens (1986) movie, Ripley is forced to override the clearly marked "outer door" control having already ...
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6 votes
0 answers
130 views

Why do spacesuits have air in the body? [duplicate]

Wouldn’t it be easier to make a space suit that only maintains air around the head, and just has a “tight” insulated and shielded suit around the body? It seems to me the reasons we need a space ...
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1 vote
2 answers
211 views

Can we create a vacuum inside an EVA suit when the outside is pressurized, will it implode?

EVA suits are specially designed spacecrafts for astronauts during spacewalks. I can say for sure, it can handle the following cases of pressurization of the system: Pressurized inside, but vacuum ...
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-3 votes
1 answer
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A question about the feasibility of the Casimir propulsion system [closed]

There is a connection between vacuum energy density and the Casimir effect , see : https://arxiv.org/abs/quant-ph/0204125 Another reference can be found here: https://aapt.scitation.org/doi/10.1119/...
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5 votes
1 answer
136 views

Why were some early interplanetary probes pressurized?

Mariners 2 through 9, and the Soviet spacecraft of that era, sometimes suffered from leaks that impaired or disabled parts of their scientific payloads. What kinds of sensors couldn't work in vacuum? ...
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2 votes
1 answer
138 views

Was there a measurable effect on gas concentration on the Moon during the Apollo missions?

Gas was released by the Apollo Lunar Modules during depressurization of the cabin in preparation to an EVA. Did this release of oxygen had a measurable effect despite the small amount of gas and the ...
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0 votes
1 answer
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Exit pressure value for vacuum nozzle [duplicate]

What value of exit pressure should I use in the design equations for a small liquid rocket engine nozzle for 200km-500km operating conditions? Since using zero as a value is not possible or else ...
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0 votes
1 answer
257 views

Ambient pressure for vaccum nozzle design

How do I find out the ambient pressure for designing a vaccum rocket engine? I am using the propellant combustion charts from the braeunig website. But I cannot figure out the ambient pressure for ...
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-1 votes
1 answer
152 views

What is the vapor pressure limit of liquid metals in space?

Would liquid metal be stable in space unlike most other liquids like water? Are there any metals that has a high vapor pressure limit? Side question: Can liquid metal be given an electromagnetic ...
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3 votes
1 answer
127 views

Spacesuit needed for 1 psi 100% methane atmosphere - 60 Fahrenheit?

What sort of spacesuit would an astronaut need if she were to walk on a planet with a 1 psi (0.07 ATM) 100% methane atmosphere and -60°F (-50°C) temperatures?
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3 votes
0 answers
208 views

Can I freshen my clothes on the ISS with a clothes line?

There are a number of questions about washing clothes on the ISS, the short answer is that they do NOT wash them. Nudism in space: Why wear clothes anyway? Washing clothes in space: are there any ...
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3 votes
0 answers
123 views

What is currently known as the thinnest combination of material to hold 1 atm in space?

What is currently known as the thinnest combination of material to hold 1 atm in space? Note: must define what the composing materials are.
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1 vote
0 answers
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Nozzle skirt in the second stage of Rocketlab's Electron [duplicate]

As we can see, in the first stage of Rocketlab's Electron the nozzles have small nozzle exit area. Source (all) But for second stage why are they using nozzle skirt/ extension with huge exit area?
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3 votes
0 answers
168 views

How far/much time could an appendage extend outside of the ISS before succumbing to severe damage?

I was reading the question asked here in regards the Alexander Gerst's patching of a small (5mm) hole with his thumb temporarily. This got me wondering, if his thumb was only fine because the majority ...
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6 votes
3 answers
4k views

How come we don’t put a huge windmill-like machine in space? [closed]

I am new to this sight, but since space being a vacuum there is little to no air resistance at all making a windmill spin forever. There is no wind in space however, if you spin it once, it should ...
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5 votes
0 answers
183 views

Pool on the Moon?

Hypothetical scenario: There is a dome on the moon containing an Olympic-size swimming pool. Our intrepid hero is receiving a scuba diving lesson at the bottom of the pool (3m) when a hull breach ...
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1 vote
1 answer
352 views

Cooking in Space

Someone in the Worldbuilding SE asked How to Build a BBQ for the ISS. My first through was: Why not just stick it in a sealed container out in direct sunlight for a bit? It'll get plenty cooked ...
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3 votes
2 answers
802 views

In the absolute vacuum of Space, will an electric dynamo still work? [duplicate]

In the absolute vacuum of Space, will an electric dynamo still work? Can it produce an electric current if it is not inside (or being affected by) a magnetic field (like earth's magnetosphere)?
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5 votes
1 answer
1k views

What type of electrical wiring provides the longest life in space?

It sound like standard electrical wire as you would use in earth bound transportation would have a significantly shorter life in the vacuum of space. (See related Do plasticizers evaporate in space?) ...
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4 votes
1 answer
219 views

Do plasticizers evaporate in space?

A recent statement in an answer got me wondering. I looked and could not find an answer on space.se Polymers (think plastic cladding on wires) has "plasticizers", which make it elastic instead of ...
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9 votes
1 answer
1k views

Mars Vacuum-blimp Feasability

There's an article published by NASA in which they discuss the practicality of using an evacuated blimp or airship on Mars. Their main points are that since the exterior pressure is so much lower, ...
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10 votes
2 answers
2k views

Could there be any use with importing vacuum from space to Earth?

Space exploration pessimists say that there's nothing to import from space to Earth. So why not begin with doing exactly that?! :-) It's commonly claimed that the vacuum of space is harder (emptier) ...
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4 votes
1 answer
190 views

Flight Suit Pressurization

I'm curious about the pressurization of a full pressure flight suit (such as). For example, the linked suit has an operating pressure of 3.5 psi, but my assumption would be that during normal flight ...
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3 votes
4 answers
1k views

near space vacuum balloon

OK we know that due to air pressure a vacuum balloon would not be possible on earth. But would it be possible to create one that floated near space with almost no air pressure? If so how much ...
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4 votes
0 answers
86 views

How are electrical and other utilities interfaces added to an operating pressurised spacecraft?

How are extra utility lines and pipes, like data, electrical, ?or gasses and fluids, added to a manned, pressurised and operating vehicle or habitat, in space? A spacecraft may be launched with, ...
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8 votes
1 answer
3k views

What is the ring at the bottom of the Merlin vacuum engine?

When watching SpaceX launches, around 2-3 seconds after the Merlin Vacuum ignition a ring can be seen breaking in 2 from the bottom of the nozzle and then falling away from the second stage. My ...
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6 votes
6 answers
3k views

Do electronics and mechanical components work in a vacuum or require a sealed controlled atmosphere?

I'm curious about the electronics and other instruments on Voyager and similar spacecraft. Are the electronic components kept in open vacuum or in a sealed atmosphere? I imagine cooling gets tricky ...
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37 votes
1 answer
6k views

Why does there appear to be a 180-degree stereo microphone array outside the ISS?

I was watching a feed on the latest footage of Hurricane Matthew as seen from the ISS just now, relayed from NASA TV. Suddenly, I spotted something poking out of the ISS hull in the footage that ...
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6 votes
5 answers
5k views

Has any living thing been directly exposed to the vacuum of space

In our several decades of spaceflight have we ever exposed any living organism to space? I'm pretty sure this hasn't happened to Humans, but have we jettisoned some lab rats into space ("for science") ...
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7 votes
2 answers
897 views

What happens to a body, that has been exposed to vacuum, once brought back onboard?

You are on a ship in the cold vacuum of space. You find a body of an astronaut exposed to vacuum (for this instance just assume human, but you never know). The body was essentially freeze dried and ...
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4 votes
1 answer
892 views

What is the air pressure threshold for cold welding?

Cold welding is a problem in vacuum of space - where two metal parts come into contact, they may weld accidentally to each other. As I understand, even a little air or other substance prevents it. My ...
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2 votes
2 answers
761 views

How much efficiency is lost from a fixed De Laval nozzle when modified for atmospheric use?

Fixed nozzles designed for vacuum are larger/broader than those designed for atmospheric or combined air/space use, which have less flanged nozzles due to the drag a larger flange would incur in the ...
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21 votes
2 answers
8k views

Is it real to patch an opening to the vacuum with plastic tarp and duct tape as in Martian?

In the Martian movie Watney patched a broken door to the martian surface with plastic tarp and duct tape. The pressure on Mars is 0.5 kPa, which is 200 times smaller, that on Earth (100 kPa), i.e. it ...
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  • 723
3 votes
1 answer
3k views

Could you hear the sound of your own body in the vacuum of space?

I think the answer to this question probably lies more in biology than astrophysics. If you were in space with an oxygen mask on (ignoring the fact that you will get quite cold for the moment) you ...
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  • 311
-1 votes
3 answers
454 views

What is space made of, and what is nothing? [closed]

We get told "there is nothing in space except planets etc.." (saying there is no air etc) but is there "nothing"? If there is it must be a strong vacuum and how strong will it be? could we use it for ...
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