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Mars colonization
Alain Fournier wrote:
SpaceX plans on building Starship to transport Mars colonist and equipment for a Mars colony. But they mostly expect other companies and organizations to handle the actual establishment of a base on Mars : habitats, greenhouses... Starship seems to be advancing well, but I haven't heard much about others working on the necessities for living on Mars. Have any of you heard about others having such plans? Alain Fournier Hello. I have been surfing a bit about basic facts about the planets and Mars. Overall, I am thinking that a post nuclear war world where the U.S. has 30,000 nuclear weapons like it did at its peak in the middle 1960s and the Soviet Union with its 50,000 nuclear weapons like it did in the 1980s, all aimed at all the word's cities at an even spread throughout the world for maximum kill - is much more livable than even the most hospitable of other planets in this solar system. It is not a matter however of supporting a small handful of persons on Earth, but each individual out of billions and billions, and infinitely reproducing hoards controlled by their lust to reproduce more and more humans without end. Getting to space, however, reading about the ice caps of Mars I am very intrigued. Basic questions - How does the dry ice at the poles of Mars accumulate in the Martian winter? Does it snow or freeze onto the surface? To what extent is it mixed with water ice when it happens? If one were to drop it into an enclosed area and let it sublimate upon heating, would it have less embedded carbon monoxide in it than the atmosphere of Mars in general? How easily could it be accumulated to aggregate onto heating coils to act as a first step to be sent to lighted lake-vats or air-caverns to be converted into oxygen and condensed carbon/food through photosynthesis? Where is the Nitrogen on Mars? If you remember, four fifth's of the Earth's atmosphere is Nitrogen. So if four fifth's of it were on Mars that would be a lot of Nitrogen that is not in the atmosphere of Mars. Did it escape into space a long time ago or is it embedded in the rocks or the interior of Mars? People on Earth have wandered across the Earth's surface looking for precious rocks and minerals since ancient times. On the other plants, moons, and asteroids and comets, there is no free oxygen ready to combine with fossil fuels to act as an energy source. This means - solar for places near the Sun like Mercury - or nuclear - meaning you would likely want to purify better grade uranium and thorium ores as a starting point for all other energy sources - from smelting of metals to heating materials to make them in the right temperature range for humans if humans are wanted. How much 'prospecting' of the planets can be done of the Moon, planets, or asteroids using satellites? In other words, understanding where on or in the planet or asteroid it would be most likely to get the best ores? How much water is there on the poles of the Moon? Is it a very dispersed and extremely rare aggregate of hydrates mixed in with a vast amount of rock by Earth standards, or could it realistically be called 'ice' by any practical Earth standards when we would see ice on a glacier on Earth? How do the poles of Mercury compare? How about Ceres or some of the other major Mars-Jupiter belt objects? I am intrigued by how much mass there is in the interior of a 20km diameter asteroid. There are a lot more of these objects between Mars and Jupiter than just Ceres and Vesta although there is a lot of matter in Ceres and Vesta. Furthermore, with a lesser amount of gravity it might be possible to mine into the interior with a greater extent with less hazard from cave ins. On Earth, humans have not even drilled to the mantle yet, much less the inner or outer cores. It takes a lesser delta g to get on and off asteroids in the Mars to Jupiter belt and they have rock, metals, and volatiles, however they have lesser solar energy than Mercury or Mars. Floating above Venus at an altitude high enough to have one Earth atmospheric pressure using oxygen as a lift gas might be an interesting concept, but I wouldn't want to fall from the balloon. Of course, practical fusion energy would be a major change for the feasibility of various endeavors in space, but it would also have significant effects on Earth. Of course people have been trying to do that for some time. When it comes to Mars, however, are there any new polar missions planned? I am thinking that the only successful one so far died before the most interesting time period, between the dry ice freezes and dry ice thaws during the dark winter at the pole. |
#22
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Mars colonization
On Mar/16/2021 at 14:17, JF Mezei wrote :
On 2021-03-12 10:36, Alain Fournier wrote: Mars' orbit. You just need to time your departure so you arrive at aphelion when Mars happens to be at that same spot. Thanks. I hadn't considred elliptical orbit around the sun. So if you time departure from earth timed so your high point is close enough to be grabbed by Mars, how do you not get grabbed by Mars if you need to abort landing and return to Earth? Fire retrograde so you let Mars move ahead and you drop altitude above sun? Fire towards the sun to reduce the fancy name for apogee so you don't get high enough to get grabbed by Mars? Mars will not gravitationally "grab" you. If you want to land on Mars, you need to slow down deep in Mars' gravity well, either by firing rockets or more likely by hitting the Martian atmosphere. You will need to make a trajectory correction when you get near Mars. Either you correct the trajectory to hit Mars' atmosphere at a quite precise angle, or you correct the trajectory to not hit the atmosphere and return to Earth (see below). If you don't abort and go for a Mars landing, you have to hit the atmosphere steep enough so you don't just go through and continue away from Mars and shallow enough so you don't burn in the atmosphere or don't do a "lithobreaking" (lithobreaking means to stop by hitting rocks, in other words a crash). And more importantly, if you timed departure from Earth so Mars ends up being in the right location to grab you and you abort that and continue on your elliptical orbit, will Earth be there to grab you when you reach the fancy word for perigee? While you were traveling "up" to Mars, wouldn't Earth have sped up relative to you and be much further ahead by the time you drop back down to fancy for perigee? Or is it a case that for such long durations, the Earth may have circled back and be just behind you? No Earth will not have circled back, that would be too long. I have explained this in my previous post. If instead of having aphelion near Mars you give a little stronger push when leaving Earth and have a theoretical aphelion at just the right distance from the Sun, somewhere in the asteroid belt, then if you chose that aphelion just right, you will have on average the same angular speed as Earth around the Sun on the Earth to Mars leg of your trip. But if you timed your departure just right, you won't reach that aphelion because Mars will be on your path. Once again, when close to Mars you have a decision to make, do you adjust your trajectory to hit the atmosphere at just the right place to land safely. Or do you do another fine adjustment to not hit the atmosphere but instead to have Mars' gravity bend your trajectory just right to send you back to Earth. If you had the same angular speed as Earth on your way to Mars, after having Mars bending your trajectory, you will have the same speed as on the way to Mars and you will be on a solar orbit similar to the one you had going to Mars. Only instead of being on the part of the orbit moving away from the Sun, you will be on the part of the orbit moving closer to the Sun. And on that leg of the trip you will still have the same average angular speed as Earth around the Sun, and therefore will get back to Earth. Note that if you had not encountered Mars, as you would have went nearer to aphelion your orbital speed would have slowed down and you would then slip behind Earth, with no chance of getting back to Earth for many years. If all you want to do on Mars is to plant the Canadian flag and come back, the trip with the Hohmann transfer orbits takes you 26 months. But the minute you get grabbed by Mars and land, isn't your orbit around the sun circularized, and a return to Earth requires megafuel because you have to recreate that elliptical orbit from scratch? Yes. If you land on Mars you can't have a free return. Alain Fournier |
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