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66 votes
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Why can't we use the same radiation shielding in Mars that we used when going to the moon?

Radiation exposure is a cumulative risk. The more radiation you receive, the more likely you are to develop cancers. The Apollo missions took no more than two weeks to complete; the astronauts ...
Russell Borogove's user avatar
66 votes

Why can't we use the same radiation shielding in Mars that we used when going to the moon?

In addition to what Russell Borogove says about cumulative risk you're operating under a false assumption--that there was shielding on the Apollo capsules. Not only did the Apollo capsules not have ...
Loren Pechtel's user avatar
54 votes
Accepted

Could a space colony 1g from the sun work?

Interesting but no, it wouldn't work for the same reason that astronauts in the International Space Station, other space stations, or orbiting shuttles or capsules do not "feel" gravity with respect ...
uhoh's user avatar
  • 149k
53 votes

Before we build a Mars colony, why don't we build a 100% self-sustainable test colony in the Antarctic?

The colonization sites under consideration would be in the mid latitudes or equatorial, and would be more like Arizona than Antarctica in terms of sunlight, with a near 24 hour day/night period and ...
Christopher James Huff's user avatar
47 votes
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When will we send floating probes to Venus?

When will we send? We already did. In 1985 and 1986 the Soviet Union sent two Vega probes to Venus. Both included a robotic balloon (usually called aerobots). The two balloon aerobots were ...
Ginasius's user avatar
  • 920
35 votes

Flung debris in lunar landing

Great question. The exhaust velocity from typical landing engines is about 3 km/s. You can imagine good-sized particles being accelerated to a significant fraction of that, say 1 km/s, which is the ...
Mark Adler's user avatar
  • 58.2k
35 votes

When will we send floating probes to Venus?

Why are people so fascinated about Mars and not about Venus at all? The trivial answer - Mars is moderate place. A human could easily get around with a spacesuit, and it is trivial for robots and ...
Fattie's user avatar
  • 1,621
35 votes

What are the advantages of building a human colony on Mars vs the moon?

There are three big advantages to Mars over the Moon for a longer term settlement. There is a thin atmosphere. The days are approximately 24 hours The gravity is about twice as high. Let's break ...
PearsonArtPhoto's user avatar
  • 121k
31 votes
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Why are tunnels not popular considerations for Lunar or Mars colonies?

One of the important factors in regard to not considering tunnels as a first colonization step: Our modern boring technology stack uses a great deal of water. A liquid water. This requires having the ...
fraxinus's user avatar
  • 2,519
31 votes

Before we build a Mars colony, why don't we build a 100% self-sustainable test colony in the Antarctic?

One reason for not starting a new one is that we have already built several: Flashline Arctic Devon Island Utah Dessert Sealed 500 day missions Hawaii Underwater And the actual antarctic stations, one ...
GremlinWranger's user avatar
25 votes

If colonists burrowed far enough under the ice on Ganymede or Europa, would the ice provide adequate protection for them from Jupiter's radiation?

Yes, it absolutely would! The radiation on Europa is about 5.4 Sv (540 rem) of radiation per day. Looking at this guide, and assuming you want to meet OSHA standards of 5 rem per year, you would need ...
PearsonArtPhoto's user avatar
  • 121k
24 votes
Accepted

Mars versus the poles of Mercury WRT colonization

Your delta-v analysis doesn't account for the landing delta-v. On Mars, only a fraction of a km/s has to be done propulsively, on Mercury the entire landing will be propulsive. You also don't account ...
Christopher James Huff's user avatar
20 votes

How would a violin or trumpet degrade over time on Mars?

Generally the first question is: What causes instruments to degrade over time here on Earth? Multiple factors play into it: Temperature and humidity variations: Temperature change causes materials to ...
Dragongeek's user avatar
  • 19.2k
18 votes
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If we got to Mars right now and landed at the poles (where there is a lot of water ice) how long would we be able to stay there?

There's really no limiting factor on how long we could stay there if we brought enough supplies with us and we had regular resupplies. Humans really only need food, water, and oxygen to survive. Via ...
David Morris's user avatar
  • 1,339
18 votes

Is a dome really the most efficient way to contain gas in a vacuum?

It all depends on the material. A dome/balloon is mechanically same thing as an arch, just loaded in the opposite way. The material of a balloon is all under tension, the material of a masonry arch is ...
TooTea's user avatar
  • 1,765
17 votes
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How many plants would be needed to produce oxygen enough for 20 humans?

This article addresses much the same question. The quick summary is about 300 to 500 typical domestic houseplants per person, with significant caveats, more like 700 to be safe. So 6-14 thousand such ...
Steve Linton's user avatar
  • 19.6k
17 votes

Is there dirt or its structural equivalent on Mars?

The fine regolith on Mars is regarded as being the closest equivalent to an Earth like soil. It contains sand and dust. Clay deposits have been found. The two could be mixed to produce a more graded ...
Fred's user avatar
  • 13.1k
16 votes

When will we send floating probes to Venus?

No, there is no space race to Mars. The original space race was to orbit, for entirely military reasons. Sputnik was simply a demonstration of "we can drop a nuke anywhere we want, any time". The ...
Graham's user avatar
  • 1,930
16 votes
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Could ozone be used in a biodome on Mars?

If we have $O_2$ lighted with UV, we have actually many reactions working together: $O_2 + \gamma \rightarrow 2O$ $O_2 + O \rightarrow O_3$ $O_3 + \gamma \rightarrow O_2 + O$ $O + O_3 \rightarrow 2 ...
peterh's user avatar
  • 3,298
16 votes

Could a space colony 1g from the sun work?

Have the object tidally locked into its orbit around the sun This way we would get the 1g gravity from the sun on the opposite side of the asteroid Interesting idea, but you missed something in your ...
Peter Cordes's user avatar
15 votes
Accepted

How deep a valley or trench would be needed on Mars to provide the same atmospheric pressure as 6 km above sea level on Earth?

Mars' atmosphere scale height is, depending on who you ask, 10.8 to 11.1 km. Pressure at the bottom of Hellas Planitia: 1.16 kPa Earth sea level: 101.3 kPa Earth 6km altitude: ~50 kPa. So we need ...
Russell Borogove's user avatar
14 votes
Accepted

How long is a day on the Moon?

This may belong to Astronomy SE, but the $29.5$ Earth day figure, or more accurately the time in the third reference, is what you should be planning on when you or at least your instruments go to the ...
Oscar Lanzi's user avatar
  • 8,525
13 votes

Flung debris in lunar landing

Damage to existing equipment from exhaust plumes is indeed an issue for lunar outpost planning. The best information currently available about this is from the Apollo 12 mission that landed close (...
OliverS's user avatar
  • 131
13 votes
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Why would humans travel to Mars before machines have built a colony?

One reason is that we don't have robots as versatile as humans. We have machines capable of high speed, high precision, reliability and endurance not possible for a human, but no robot is good enough ...
SF.'s user avatar
  • 55k
13 votes

What is the deepest place on Mars? Do humans need pressurized suits there?

Is there any particular deep areas of Mars in which a person could survive with only an oxygen supply without a pressurized suit? No. Hellas Planitia is the lowest point on Mars, the basin floor is ...
Rob's user avatar
  • 3,276
12 votes
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Would the one million people on Mars be killed by an impact equivalent to an Extinction Level Event on Earth

I would guess no. What makes the extinction level events so dangerous for us isn't the impact or the shockwave. A shockwave on Mars won't do much damage since the atmosphere is very thin anyway, and ...
Innovine's user avatar
  • 4,625
12 votes

Use of carbon monoxide as propellant on Mars

Yes, it could be. The ISP for CO/ O2 is about 200. Compare that to Methane, with a specific impulse of 299, and you can see it's really not that great. Of some related interest is a hot Carbon ...
PearsonArtPhoto's user avatar
  • 121k
12 votes

Titan vs Mars for colonization

The biggest obstacle of living on Titan is bound to be it's insane cold. People say space is cold, but space is a vacuum. A thermos bottle uses a vacuum as insulation. So wearing a space suit in a ...
Johnny Robinson's user avatar

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