Hot answers tagged

28

You don't care about transporting H₂O. You want to transport hydrogen and oxygen atoms, and if that includes a few other atoms as baggage, that's no big deal. One easily available atom is carbon, as it can be extracted from CO₂. So you need two pipelines. Hydrogen has the nasty property of escaping pipelines, so you need to bind it to carbon to produce CH₄. ...


26

The diagram you show would work only for specific instances. A few things that it relies on: Gravity is required for this to work, or else all of the liquid will escape. The diagram you show works because of pressure differential, basically the pressure due to gravity counteracts the pressure from the air. Without gravity, the air would simply push the ...


22

There are no technological barriers, provided one is not too ideological about biospheres. In a comment on the question it is remarked that self-sustaining biodomes have not yet been successful on Earth. This is somewhat besides the point. These exercises on Earth have generally been about creating a self-contained biosphere within a dome, independent of ...


21

I kept wondering where this 72 km/s maximum is coming from, and I figured it out! This is the calculation: Why? Firstly, it's obvious that the Earth is traveling at 30 km/s in its orbit. But what possible directions can the asteroid hit from? The most logical approach is to hit it moving the exactly opposite direction. That means we demand an asteroid ...


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 ...


18

No, it couldn't. The Curiosity rover is 2.9 meters by 2.7 meters by 2.2 meters. It's tiny little scoop is 7 centimeters by 4.5 centimeters by 2 centimeters (or so; I can't find a reference on the last dimension). Assuming that the burrow is at least four times the volume of the object, this means more the robotic arm needs to make a million scoops with that ...


17

Probably not. A good measure of comfort is how much external body pressure is induced from laying on a hard surface. Earth gravity is enough to cause an adult considerable discomfort when lying on a hard surface. Paresthesia, or the sensation of having arms and limbs falling asleep, would be a good standard to measure against to answer this question. The ...


11

Canals? It's too cold on Mars for water to be liquid, so canals are not going to work. Pipes? ...would need to be constantly heated, so they would require quite a lot of energy. Hydrogen balloons? The atmosphere on Mars is very thin. Hydrogen zeppelins would work in theory, but they would generate even less excess lifting force compared to their ...


10

Yes, eventually, but we would first have to establish structural stability of any such rocks, get a sense of Martian subsurface seismic activity, seasonal changes to its thermal characteristics, how fast would aeolian processes block access to it, amount of volatiles embedded within the rock that could collapse it during drilling or with higher temperatures ...


10

How could a probe detect and map voids? Are there techniques for this? Ground-penetrating radar? Radar, either GPR (Ground-Penetrating Radar) or SIR (Subsurface Interface Radar) would seem the obvious solution. However, the shortcomings of those techniques (as pointed out in @FraserOfSmeg's answer) may mean that they are of limited use for finding deeper ...


8

Assuming you could extract all the water from the soil, which apparently has roughly 2% of it by weight (by the way, that's really dry and even the driest of desert sands contain more), then you'd need at least 189.27 kg (417.27 lb) of Martian soil to produce one gallon (≈ 3.79 liters) of water. This would be extremely difficult to do though and would ...


8

It probably could, but with its wheels, not with the drill on its robotic arm. But why would it do that? The Curiosity rover has independent drive on all six of its wheels so technically all it would have to do is find a soft enough ground, lock the rest of its wheels and dig a hole with one or two of its front or rear wheels that also have individual ...


8

Expedition 1 in 2000 was the first long duration stay on the International Space Station, but in 1998 the construction of the station began, with several spacewalks and using Space Station Remote Manipulator System (SSRMS) installed on the Space Shuttle used to assemble and prepare for operation first three ISS modules, Russian Zarya and and Zvezda, and ...


8

What is missing from your timeline in when Zvezda, the Service Module arrived. It was launched July 12, 2000 and docked on July 26, 2000. The actual living quarters in the station, initially were all in Zvezda. Zarya could maintain orbital control, provide minimal power, and life support, but it is Zvezda that is really the main module of the station, at ...


7

With the right google search you can find just about anything. This link has details about the leak from each module and the volume of each module. You can average the values or find whichever you think is most appropriate for your purpose. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110012997.pdf It's just a shame this question is over a year ...


7

A rock surface might or might not be comfortable, but certainly there are lighter and more compact alternatives to mattresses that would be comfortable in lunar gravity. In the Apollo Lunar Module they used lightweight hammocks, and astronauts made a point of reporting how much more pleasant they were to sleep in under lunar versus on the Earth: "We ran a ...


7

The strength of a magnetic field is proportional to $1/r^3$, so if you build magnets into the floor, there's a huge difference in field strength between your head and feet. So using a suit to provide an evenly distributed force on your body is almost impossible. Even if you only use boots with a metal plate in them, you get strange effects. When you lift ...


7

The only reason to have an airlock is to move through it: if you're not going to move through it, you'd just replace the whole thing with a steel plate. NaK is a total non-starter for this. It is extremely reactive so anything passing through it would need to be extremely well protected. It tends to catch fire when exposed to air, so the surfacing pool ...


7

In order for a liquid airlock to work, some points must be considered; they have been mentioned in some of the other answers, but I will try to combine them and suggest some new implementations. Gravity: As stated, there must be some gravity (or constant acceleration) present for this to work in principle. The required column height (see sketch in the ...


7

Were these all pipe dreams from the start? Some most certainly were. Some most likely were worse than pipe dreams; they were just schemes to part foolish investors from their monies. I won't name names. Only one of those early commercial space station proposals, Bigelow Aerospace, remains intact. It was and is mostly funded by the founder's profits from ...


6

Diamagnetic gravity would require absurdly strong magnetic fields. The field strength required is proportional to the product of the field strength and the rate of field strength change; in order to get a reasonably uniform force across a two-meter-tall human, the rate of change needs to be small. A back-of-the-envelope calculation says you're looking for ...


6

No. It can scoop up only 1 to 30 cubic centimeters of soil at a time. It has done so only few times during its two years on Mars. By locking some of the wheels while driving it can make some marks on the ground. It's not really a caterpillar.


6

According to the American Meteor Society, meteorites usually hit the Earth's atmosphere going around 160,000 MPH. Meteors enter the atmosphere at speeds ranging from 11 km/sec (25,000 mph), to 72 km/sec (160,000 mph!)... The 70~ish top figure is also repeated in this answers.com answer. Why such a big range, between 25k and 160k MPH? The wide range ...


6

For life as we know it, it is not likely it could exist ! Even bacteria need metal ions like $\text{K}^+$ and $\text{Mg}^{2+}$ in their cytoplasm, and these metals have not been detected in the atmosphere of Venus. For life as we do not know it, we just cannot answer the question !


6

Despite the obvious reason - a torus looks much more elegant than a barrel - I can come up with several points that favor a toroid: Rounded shapes can withstand the pressure difference between inside and outside much more easily. Large areas with sharp corners like at the end caps of the cylinder are difficult to make really tight. The parts of the ISS are ...


5

Problem 1: Material Strength Strong and Flexible generally means heavy. The material has to be strong enough to handle the stresses of both the internal pressure when inflated, but also the localized pressures during inflation. Problem 2: Inflation Sequencing As the Russians discovered, inflation sequencing can go awry. This can result in a variety of ...


5

Should be noted that Zvezda was planned to be launched soon after Zarya and Unity. It was delayed by Proton launch failure in 5 July 1999, and by another failure in 27 October 1999. https://en.wikipedia.org/wiki/List_of_Proton_launches_(1990%E2%80%9399) There was a requirement of at least 2 successful Proton launches before putting ISS components on it. I ...


5

Glasses can be manufactured such that they transmits the desired parts of the UV. Looking at the picture below (found here), together with a somewhat official definition of ultraviolet wavelength ranges: UVA: 400-315 nm UVB: 315-280 nm UVC: 280-100 nm it is clear that most ordinary glasses are mostly opaque to UVC, and start being partially transparent ...


5

Whether or not a decompression will be explosive depends on the size of the hole and the shape and material of the wall it's made in. In terms of human factors, 600 Pa is not very different from a vacuum. To give a comparison, it is equivalent to an altitude of about 34 km -- compare that with Mt. Everest's 8.8 km.


5

There's a few different definitions of circumstellar habitable zone (CHZ), and it goes by a few names, but in a nutshell, no, planets orbiting within this zone are not necessarily habitable for humans (Mars isn't, and it's within the CHZ), thus no "planning" to even visit, let alone colonize any specific ones yet either; What we mean with it is that these ...


Only top voted, non community-wiki answers of a minimum length are eligible