Questions tagged [microgravity]

Questions regarding the absence of significant gravitational force.

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Could Apollo astronauts stand up if they fell on the moon?

I was watching old Apollo footage and noted how astronauts on the moon had a very particular gait most likely due to the poor flexibility of the EVA suits, low gravity, and need for safety. I was ...
RoboKaren's user avatar
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49 votes
6 answers
11k views

Can/should you swim in zero G?

Inspired by Are there types of animals that can't make the trip to space? (physiologically) and related to but not a duplicate of Can you swim in space? Swimming on the Moon / in low gravity looks ...
Baldrickk's user avatar
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43 votes
2 answers
19k views

Can fish really live in microgravity without water?

Yes, you read that title correctly. I saw the claim in "Colonies in Space", hosted on the NSS site. In a weightless space farm, it may be possible to raise fish without water. On Earth, when a ...
AlanSE's user avatar
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36 votes
4 answers
9k views

Can't astronauts use ball point pens in space?

Is it true that astronauts can't use ballpoint pens in space? The mechanical contact of a ballpoint with the paper should make the ink show up on paper but I'm not sure if it's true. Any clarification ...
Harish Chandra Rajpoot's user avatar
34 votes
3 answers
5k views

What causes microgravity (i.e. non-zero gravity) in orbit?

NASA and others seem careful to talk about microgravity instead of zero gravity. Why is for example the ISS not in zero gravity? Is it because of movements onboard? Because of variations in center of ...
LocalFluff's user avatar
29 votes
1 answer
3k views

What are the "unpleasant effects" of having a cold in microgravity?

I went to Technik Museum Speyer's space exhibition, which presented an excellent overview of the Apollo missions in a series of posters. The poster describing the Apollo 7 mission (an Earth orbit test ...
Anko's user avatar
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27 votes
3 answers
13k views

How do astronauts turn in space?

A recent question back in Physics asks whether there is a way for an astronaut to rotate when in microgravity and without touching anything else, while still conserving angular momentum. One way to ...
E.P.'s user avatar
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24 votes
4 answers
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Is there a self-rounding celestial body from which an Olympian could jump into space?

Is there a self-rounding object in our solar system whose mass is insufficient to prevent the highest jumping human from escaping its gravity?
Hal's user avatar
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24 votes
0 answers
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Why is artificial gravity not included on space stations? [duplicate]

I'm wondering why artificial gravity is not included on the ISS, or on the currently planned OPSEK. There are long-term health effects of weightlessness, which would be avoided, using artificial ...
Iter Ator's user avatar
  • 821
22 votes
1 answer
3k views

How are hair and beard lengths maintained in space?

From the question What are the regulations governing (against) beards in space? we know that hair and beard length are not regulated on the ISS. For the most part pictures indicate both men and women ...
James Jenkins's user avatar
21 votes
5 answers
6k views

Why is dust such a problem in microgravity? Wouldn't proper air circulation and filtration take care of it?

Dust and small particles in microgravity environments are generally regarded as bad, and items prone to generating these tend to be discouraged: Bread should be prepared quite differently, so that it ...
Vikki's user avatar
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21 votes
2 answers
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How was "Space Ram" (instant ramen noodles) prepared and eaten on the Space Shuttle?

The BBC Witness Podcast The Invention of Instant Noodles mentions that "Space Ram" (ramen noodles for space) was developed for eating on the Space Shuttle. After about ...
uhoh's user avatar
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20 votes
4 answers
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How do iPads on the ISS know which way is "up" for their users?

The question What makes smartphones tilt-sensitive? Will they retain this ability in zero-gravity conditions? brought to mind the video of astronaut Steven Swanson's detailed tour of the ISS, in which ...
uhoh's user avatar
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2 answers
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How well would a broken bone heal in zero gravity?

We know that being in space has negative effects on bones. If you had a broken bone is space would it heal ok? Has there ever been a broken bone healed in space? Other then Spaceflight osteopenia ...
James Jenkins's user avatar
20 votes
1 answer
590 views

Would the blast clearing technique used in snorkeling work in an EVA situation?

Luca Parmitano wrote about his experience with water filling his helmet during EVA on the International Space Station. It's a harrowing account and he explains part of his thought process: I force ...
Jon Ericson's user avatar
20 votes
1 answer
790 views

Mining in microgravity: are there sound studies?

I was wondering whether there are any sound studies on mining in microgravity. For example, smelting iron (out of ore) in weightlessness has been described and (in theory) solved. Also, there are ...
s-m-e's user avatar
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18 votes
6 answers
10k views

How can astronauts float in space without being affected by the gravitational force of nearby objects?

According to the Newton's law of universal gravitation: Any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely ...
Ayyappan's user avatar
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17 votes
6 answers
4k views

Would a higher air pressure on the ISS or elsewhere make it easier to "swim" in microgravity?

What if the atmospheric pressure onboard the ISS was 5 atm, 5 times the pressure on Earth and currently on the ISS, while maintaining the breathable oxygen level, e.g. if the additional atmosphere ...
LoveForChrist's user avatar
17 votes
3 answers
2k views

Can plants grow in microgravity?

If a manned mission to another far-off planet were to take place, the crew probably would need something more sustainable than tubes for a food resource - plants would probably be the best option. ...
user avatar
17 votes
1 answer
2k views

Can you have birthday cake in space?

In zero (or micro) gravity there are lots of problems for a birthday cake. Cakes "rise", and flames "burn up", without gravity how could any of this happen? Will my cake fail to rise? Will my ...
James Jenkins's user avatar
16 votes
1 answer
3k views

How do astronauts battle loss in blood volume in microgravity?

Past manned space missions teach us that the loss in gravity gradient has an adverse effect on the blood volume of astronauts. Our bodies are simply built to expect pressure gradient and in gravity, ...
TildalWave's user avatar
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15 votes
4 answers
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How is lower/no gravity simulated on a planet with gravity, without leaving the surface?

I have seen videos of simulated lower gravity (possibly for training astronauts). I am curious what methods/techniques can be used to simulate lower gravity like environments without leaving the ...
DaveIdito's user avatar
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15 votes
6 answers
4k views

How do you weigh things in a micro-gravity environment?

Obviously a balance scale is not going to add value to the task in free-fall. Weight in space is more accurately described as mass, but the need to define it still exists. Regardless of if you're ...
James Jenkins's user avatar
15 votes
4 answers
3k views

Was this printer shown the ISS in 2015 built specially to work in microgravity?

The question Printer on board of the ISS? was answered in the affirmative. This seems to be a printer with a special paper cassette on "top" to feed the paper, since gravity feed is not going to work. ...
uhoh's user avatar
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1 answer
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How do they conduct electrolysis in zero gravity?

I'm building an electrolysis cell myself, and got to wondering. On Earth, there is a significant force pushing bubbles of hydrogen and oxygen upward, so your electrodes still contact mainly water. ...
BWG's user avatar
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15 votes
2 answers
2k views

If I lived in space, could I have a dolphin for a pet?

Inspired by the question Can fish really live in microgravity without water? I got wondering. If I lived in zero G, could I have a dolphin for a pet? Dolphins (and whales) breath normal air just ...
James Jenkins's user avatar
14 votes
9 answers
3k views

Tiny emergency propulsive device if stuck floating in a large volume in microgravity

The questions here in SXSE Can you swim in space? and in Physics SE How to escape the center of a room without gravity? [closed] both address aspects of how to move if stuck floating in the center of ...
uhoh's user avatar
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14 votes
2 answers
7k views

What is the context of this seemingly "zero-gravity" photo on Earth?

A man appears to be in zero gravity in a room which doesn't look like it could possibly be inside of an aircraft. If so, that's one gigantic aircraft, entirely unlike all the other photos of the "...
Giann S.'s user avatar
  • 183
14 votes
4 answers
2k views

Do humans need less calories and water in microgravity?

Astronauts in microgravity don't use their legs much. This has negative health effects in the long run. But I wonder if it doesn't have the good side of lowering human need for food and water and thus ...
LocalFluff's user avatar
14 votes
3 answers
2k views

How many seconds of near-zero gravity are practical with a Reduced Gravity Aircraft?

When I saw "50 seconds of weightlessness" (see quote below) I made a very rough estimate based on 45 degrees nose-up to 45 degrees nose-down Reduced Gravity Flight centered at about 35,000 feet where ...
uhoh's user avatar
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14 votes
1 answer
5k views

Healing of bruises and internal bleeding in 0g

I heard an unsourced claim about wounds, bruises and internal bleeding healing much worse in 0g conditions than in normal gravity. Is it true? And if so - could you provide a quantitative comparison, ...
SF.'s user avatar
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14 votes
1 answer
1k views

Do the majority of astronauts experience space sickness while adapting to micro-gravitational conditions?

Do the majority of astronauts (and cosmonauts) experience nausea, or symptoms of space sickness while adapting to micro-gravitational conditions? How severe are their symptoms and how much they vary ...
user avatar
13 votes
1 answer
4k views

Why did a shuttle astronaut have an open book during ascent?

In the top right of the video of a shuttle launch an astronaut has an open book resting on (attached to?) the left thigh. What was the purpose of this book? The astronaut then seems to take a pen or ...
Bob516's user avatar
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13 votes
3 answers
743 views

How steady is the atmospheric drag force experienced by the ISS?

Suppose one wanted to modulate the power of a hypothetical, powerful ion thruster on the ISS to continuously compensate the atmospheric drag force in order to achieve near-perfect free-fall conditions ...
uhoh's user avatar
  • 149k
13 votes
2 answers
362 views

How are the symptoms of long-term exposure to microgravity similar to those of bedridden patients?

A large number of symptoms of long duration stays in microgravity seem to be associated with the headward shift of organs and blood. I've always wondered, couldn't these symptoms also happen in ...
AlanSE's user avatar
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13 votes
1 answer
2k views

Would human "superpowers" in low gravity fade away through reduced muscle mass?

If suddenly put in a low gravity as on the Moon or on Mars, humans should feel very strong, easily breaking some olympic records for example. Apollo astronauts have said that they did not get tired ...
LocalFluff's user avatar
12 votes
7 answers
6k views

Why do people experience weightlessness on the way up in parabolic flight?

To experience "weightlessness" without actually traveling into space, and orbiting the earth, a parabolic flight is used. See the flight path of Mercury, as shown in this link: https://en....
Niranjan's user avatar
  • 3,758
12 votes
2 answers
961 views

How do people drink from cups in Space?

How do people drink from cups (an activity which heavily relies on the presence of gravity) in space? I know they could try to wait for the liquid to 'split up' and try to catch a chunk, but is there ...
Chandough's user avatar
  • 1,127
12 votes
3 answers
2k views

3D modeling software for zero gravity

I think that many 3D modeling software packages like Blender and Rhino-3D assume the presence of gravity acting downwards. What would a person use to model a structure in microgravity (more ...
Kevin Ford The Submariner's user avatar
12 votes
3 answers
1k views

How would a zero gravity cat litter box work?

In fiction cats are often chosen as the optimal zero/micro gravity pet. Clearly there is some rational for this, all existing answers at How do astronauts turn in space? include cats in them. ...
James Jenkins's user avatar
12 votes
1 answer
384 views

Does atmospheric drag or reboosting maneouvers affect the integrity of microgravity experiments aboard ISS?

ISS is in low Earth orbit, and as such, its orbital progress is gradually slowed by atmospheric drag and consequently requires occasional reboosts. It also has to be occasionally maneouvered to avoid ...
Anthony X's user avatar
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12 votes
1 answer
834 views

Growing food in space

I can't find info on NASA site, but saw a picture of romaine on ISS and am wondering how it maintains its shape in zero-gravity- why doesn't it spread out, what makes it grow up...?
BVV's user avatar
  • 121
12 votes
2 answers
417 views

Least artificial gravity needed to maintain health on a one year space trip?

What is the least gravity needed for human health on a one year space trip?
D. M. Barrett's user avatar
12 votes
2 answers
304 views

How firmly does Rosetta rest on 67P/Churyumov-Gerasimenko?

Now, since Rosetta touched down on "Tschurri", as the comet is called in the german speaking world, I am asking myself how firmly does Rosetta sit on its comet? Since on the comet very little gravity ...
Dohn Joe's user avatar
  • 976
11 votes
2 answers
2k views

Using a fidget spinner to rotate in outer space

There is a question How do astronauts turn in space?, and related questions here and on physics.stackexchange, that detail how astronauts might maneuver by spinning their upper and lower body ...
StefanH's user avatar
  • 213
11 votes
2 answers
618 views

Is there any research or recommendations for a diet in microgravity?

The Dietary Reference Intake (aka RDA) is formulated for humans operating at one Earth gravity. Is there a similar reference or any research supporting specific recommendations for a human in ...
James Jenkins's user avatar
11 votes
1 answer
2k views

Could a harpoon-like gun be used by an astronaut to stop drifting away from a ship?

I saw the movie Gravity. Spoiler alert, hover with your mouse over the yellow bar below to reveal a part of the movie's plot: Why can't they have a gun kind-of thing with a string/rope? One end of ...
Ravi's user avatar
  • 253
11 votes
2 answers
532 views

Would the life support systems on the ISS and STS work well also in 1g?

Changing gravity level can be a problem for flows of fluids, gasses, heat and for structural loads. Much equipment designed for Earth gravity fail in microgravity (even light bulbs and ballpoint pens)....
LocalFluff's user avatar
11 votes
2 answers
1k views

How big are the tidal accelerations within the ISS?

This question asks about placing an object at rest in the International Space Station. But the ISS is a large object, large enough that gravity will vary across it and cause tidal forces that can ...
Bob Jacobsen's user avatar
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11 votes
1 answer
670 views

Can (human) gas propel someone in a contained space station?

I am NOT trying to be lewd, but I had a student ask this. Yes, she may have been tongue-in-cheek, but I promised to answer her. And yes, I am trying to keep this as practical as possible. If and ...
Mikey's user avatar
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