43

Two major problems present themselves right away. As the human body is almost neutrally bouyant with water, one might think that there are no issues with the actual movement in water. But this is only partially true. Directional orientation in the water will be very difficult. On earth, when we swim, not only is our chest slightly more bouyant than our legs,...


28

More than anything, the reason for this were cumbersome EVA (Extravehicular Activity) suits used with the six Apollo program missions that landed on the Moon. They were basically a one-piece suit, each made to fit (custom tailored) each of the astronauts. There were two basic configurations of the space suits used to support Apollo Missions: An ...


27

First, I'll adopt terminology from Ringworld: "spinward" is in the direction of spin, and "antispinward" is opposite the direction of spin. And I'll say a bit about the Coriolis equation, but then go into qualitative effects. Basically, anything that involves "up", "down", spinward or antispinward motion (which captures the fraternity-party activities in ...


18

Why Is Ice Slippery? That's a surprisingly involved question. The main takeaways: The common explanations of "pressure melting" and "frictional heating" are indeed true to some degree, but they can't fully explain why ice is as slippery as it is. In addition, they only apply relatively close to the melting point of ice, which is far from the case in the ...


17

Let's first see what calculations we have available on the Internet, maybe from what could be considered relatively reliable sources: University of Arizona - Phoenix Mars Mission - Mars 101: Gravity on Mars is only about 38% of Earth's. So, if you weighed 100 pounds on Earth, you would only weigh about 38 pounds on Mars. And if you can jump one ...


14

Shortly after this question was asked, it was answered (in the case of the moon, not Mars) on XKCD's what-if. Summarizing that article, for most average people swimming would be the same, as the buoyancy effects are an order of magnitude more dominant than the gravitational effects. Extraordinarily skilled swimmers would notice small difference, but the ...


14

Human powered vehicles used within domed or cavern cities would seem to be extremely plausible. One way to look at it is a simple bicycle is less complex than a powered vehicle. The power source (aka a Human) is extremely complex and maintenance intensive, but given that we already have a functioning human and want to get that human to some other place, a ...


13

I think they did (page 120): The reference is a bit indirect, but the water storage was right next to the 'exercise ring' (storage lockers):


12

Basicly you have 2 Options (and a third hybrid one): Fastest: Do a sub-orbital hop with a reaction engine. It doesn't matter if this is a cold-gas thruster, a rocket engine, a anti-matter engine... you need a thrust/weight ratio above moon gravity, than the amount of deltaV defines how far you can travel. Keep in mind that you need half of your deltaV to ...


12

At that surface gravity, I don't see how it would be possible to ride a bicycle. The friction between the tires and the road is how the motion of the wheels is converted to motion of the bicycle and the rider. 0.3 milligee is practically no gravity at all. It would take 80 seconds to fall to the surface from a height of one meter - not so much a fall as a ...


12

TLDR Its much harder to swim fast, even though it might be easier to swim slowly. WHY Your main difference will be due to a reduced hull speed of the swimmer. As noted in the comments section, the phase velocity of a wave would be reduced. This forms a hard limit on the speed that one can swim whilst displacing water. As you swim, you generate a wave. If ...


12

Off the top of my head, two issues for free swimming (no breathing gear) I can think of: Absent a sense of "up" and "down", it would be very easy to become disoriented and lose track of where the nearest surface is to take a breath. Surface tension will become the dominant force governing water flow as you come up for breath. In particular, the water will ...


10

The EVA suits worn are big and bulky - leading to a odd distribution of weight - throwing off the balance. Aside from the bulk of the suit - when you're in a pressure-suit in a hard-vacuum environment, bending your arms/legs changes the volume of the suit somewhat. For a practical example, inflate a latex glove and try bending the fingers - they snap-back ...


9

Yes, with suitable modifications. The loop must be ferrous. Your bike needs strong magnets in the wheels. You will start out with low friction and have to pedal very gently but as you build up your speed your friction will increase. Arrange the loop so you can go round and round as many times as you want before leaving it. You could build up substantial ...


7

No dog was ever on the ISS. This is from an advert of a Japanese cell phone provider called SoftBank. Here's the full video: The ad is part of a series. This episode is called "父と交信" or (Communicating with Dad; 父/dad being the dogs name). I found no hint that the production was in any way extraordinary. It appears to be ...


7

ISS expedition 53/54 crewmembers played badminton. Video:


7

Indeed Mars's gravity is about twice that of the moon, but getting around on your own two feet will probably be similar, at least when in an environmental suit. In my answer to the question about walking on Titan I discussed the situation with environmental suits: their stiffness makes a normal gait more effort than we're accustomed to. This led to the ...


7

There's one consideration probably neglected by most answers: with water viscosity unchanged, it will be much easier to remain on/above the surface through actively "pushing against the water" - unlike on Earth, where it takes a lot of (futile) effort to remain immersed any less than what your buoyancy gives you, a couple strokes will get you sliding along ...


6

The initial velocity assumption in TidalWave's answer is incorrect. The maximum initial velocity value is calculated from the accelerating force (muscle work) minus the decelerating force (gravity) over the time of the acceleration (time before leaving the ground). If the decelerating force (gravity) is smaller, the vector force is higher, the time before ...


6

Sure. Whatever the pressure-based limit is, they can dive proportionally deeper by the amount that the gravitational acceleration is less. For Enceladus, that would be 87 times deeper. The pressure is simply the weight of the water above you, and the weight is proportional to gravity. The pressure-based limit on Earth depends on what effect you are worrying ...


6

Depending on how close you are to the habitat's center of rotation, you'll feel anything from zero-g to the maximum the habitat is designed to offer - so while homes may be located in a one-gee zone, new opportunities arise closer to the spin axis. Zero-g manufacturing (for example: producing large crystals not possible in a gravity field; spinning extremely ...


6

Small automated flying probes have been considered for the exploration of lunar lava tubes. From Flying, Hopping Pit-Bots for Cave and Lava Tube Exploration on the Moon and Mars. by J. Thangavelautham et al: Fuel is non-cryogenic - RP1 and Hydrogen Peroxide. This feeds a single rocket used mainly for lift and hovering. For attitude control there are ...


6

Some informal lunar sports-adjacent activity occurred on Apollo 14: [Al] Shepard brought along a six iron golf club head which he could attach to the handle of a lunar excavation tool, and two golf balls, and took several one-handed swings (due to the limited flexibility of the EVA suit). He exuberantly exclaimed that the second ball went "miles and miles ...


6

That photo is a composite (links to here). Not only was the picture a combination of several Hasselblad shots, but the golf club, ball, the S-Band legs and some shadows were drawn in. The publishers of the book created the image because the existing real video images were too grainy to present in a book’s picture section. The golf shot was captured on ...


5

Sunita Williams ran the Boston Marathon in the ISS. Tim Peake ran the London Marathon in the ISS. source


5

Regarding safety, a bicycle designed for Martian conditions would quite likely use more than two tires for stability. Why? A regular bicycle with two tires is mostly stable, even in rough terrain, and there are no obvious reasons that is also the case on Mars (I personally use 1 or 2 tires). However, accidents happen. Most bicycle accidents are minor, and ...


5

Below this answer there is a discussion about driving a car (generalizable to any vehicle) around the inside of a rotating cylinder. If you drove fast relative to the cylinder in the retrograde direction, you would experience less and less artificial gravity until you came to rest in the inertial frame, at which point you would find your self with no ...


5

Moon Loping is a form of legged lunar locomotion performed by humans on the natural Earth satellite (the Moon) where the human propels itself through a space above the lunar surface along a ballistic trajectory with relatively long duration of the floating phase. Lunar gaits page gives the following description: Most of the astronauts on the later ...


5

To complement: There is the highest resolution photo of Europa surface by Galileo probe. Resolution is 6 meter per pixel. We can see the surface is no so flat, more suited for alpine skiing than ice skating. :) https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21431#:~:text=The%20topmost%20footprint%20is%20the,(6%20meters)%20per%20pixel.


5

Yes, but it would be tricky. First, I will assume from your question that this bike riding will happen indoors, in a shirt-sleeves environment that does not yet exist, such as a lunar station. Riding a bike during EVA would be a very different proposition, and I will not comment on it. Several lunar station proposals have included stationary bicycles as a ...


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