56 votes
Accepted

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

This was tested nearly sixty years ago. Using a very large cup filled with 95 tons of water. An empty second stage of a Saturn I under test was used. Only the first stage should be tested but with ...
Uwe's user avatar
  • 49k
55 votes

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

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 ...
Organic Marble's user avatar
36 votes

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

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 ...
Martin's user avatar
  • 1,831
36 votes
Accepted

Was the ship decompression scene in the movie Aliens realistic?

I did a quick extrapolation from Organic Marble's data (1.5" diameter hole = lose 1500 lbs of air per hour from 14.7 psi; flowrate proportional to the square root of the pressure differential) and my ...
Russell Borogove's user avatar
31 votes

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

It would not freeze into a block. It would quickly expand and boil, but not in a rolling boil. Without pressure, bubbles would form throughout the coffee and expand rapidly, causing it to spray out of ...
Mark Foskey's user avatar
30 votes

What stages of distress occur to a person when there is a small hull breach in space?

To understand subjective symptoms of a hull breach, it is important to remember that respiratory drive (the sensation of shortness of breath) is driven by blood CO2 level, not blood O2 level. As long ...
Woody's user avatar
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27 votes
Accepted

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

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 ...
DarkDust's user avatar
  • 12.5k
25 votes
Accepted

How are vacuum optimized engines tested without disintegrating them?

Flow separation can occur in a rocket nozzle that is overexpanded. This can cause quite severe turbulence and thus buffeting of the rocket nozzle. The SSME used a special rocket nozzle shape to ...
CuteKItty_pleaseStopBArking's user avatar
24 votes

Was the ship decompression scene in the movie Aliens realistic?

As much as I love this movie, it's not very realistic. Here are some cabin leak numbers for the shuttle Orbiter. At an initial 14.7 psi cabin atmosphere, a 1.5 inch diameter round hole was projected ...
Organic Marble's user avatar
17 votes

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

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 ...
Russell Borogove's user avatar
16 votes
Accepted

How do the roll-rings at the ISS work?

The ISS Utility Transfer Assemblies (UTAs) are located in the center of the Solar Alpha Rotary Joints (SARJs) - the continuously rotating interface between the outer truss segments that support the ...
Organic Marble's user avatar
14 votes
Accepted

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

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 ...
geoffc's user avatar
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13 votes

How are vacuum optimized engines tested without disintegrating them?

There are several test stands with altitude capability of up to 100 K ft (30.5 km or 8 Torr) for engine firings using the steam ejector system and up to 250 K ft (76 km) non-firing capability with ...
Uwe's user avatar
  • 49k
13 votes

What stages of distress occur to a person when there is a small hull breach in space?

Supplementary answer For your timeline, it's important to note that the pressure drop is not even remotely linear. The flow through the leak is large at first because the differential pressure is ...
Organic Marble's user avatar
12 votes

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

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 ...
user's user avatar
  • 7,310
12 votes

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

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 ...
Organic Marble's user avatar
12 votes
Accepted

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

Yes But... This only works if your craft can generate enough thrust to reduce orbital velocity to zero quickly enough that acceleration due to gravity does not produce a crash landing, since you are ...
GremlinWranger's user avatar
12 votes
Accepted

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

According to the Falcon Payload User's Guide posted on the SpaceX website, the 2nd stage engine gimbals. (Emphasis mine)
Organic Marble's user avatar
10 votes

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

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. ...
fred_dot_u's user avatar
  • 1,935
10 votes
Accepted

Are galvanised steel parts safe to use in space?

It's not just zinc. Pure tin coatings and cadmium coatings are also prohibited, at least in the vicinity of electronics. See the Prohibited Materials Section of the NASA Parts Selection List (NPSL). ...
David Hammen's user avatar
  • 74.8k
10 votes

Lorentz force space propulsion

The linked paper looks very bogus. Electromagnetic propulsion by itself is nothing unusual. Pushing against the Earth's magnetic field or similar can very well be used to generate some mild thrust. ...
SE - stop firing the good guys's user avatar
9 votes

near space vacuum balloon

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 ...
Dan Pichelman's user avatar
9 votes
Accepted

Mars Vacuum-blimp Feasability

For the sake of this answer I'm going to use the numbers I get from NASA and Wolfram Alpha. These are: ...
bendl's user avatar
  • 294
9 votes
Accepted

Why were some early interplanetary probes pressurized?

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 ...
Hobbes's user avatar
  • 128k
9 votes
Accepted

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?

I got a book from 1963, "Wie funktioniert das?", how things work: Translation: ...
Uwe's user avatar
  • 49k
7 votes

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

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 ...
Johnny Robinson's user avatar
7 votes

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

In 1996 in a vacuum chamber space suit test Jim le Blanc had his air hose detach and he was exposed to a virtual vacuum at 0.1 psi. It was 87 seconds before the chamber was returned to normal air ...
Johnny Robinson's user avatar
7 votes

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

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 ...
Andrew is gone's user avatar
7 votes

Was the ship decompression scene in the movie Aliens realistic?

The outer door of the airlock should open inwards against the air pressure. But opening the door against the huge force of the pressure to the large area of the door is impossible. If the door is ...
Uwe's user avatar
  • 49k
7 votes

Lorentz force space propulsion

The same theory they use to predict the effect has been mathematically proven to conserve energy and momentum. In short, no correct application of electromagnetic theory can result in prediction of a ...
Christopher James Huff's user avatar

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