A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Space Science » Policy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Mars colonization



 
 
Thread Tools Display Modes
  #21  
Old March 12th 21, 06:01 PM posted to sci.space.policy
Trolidous
external usenet poster
 
Posts: 1
Default 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  
Old March 17th 21, 01:34 AM posted to sci.space.policy
Alain Fournier[_3_]
external usenet poster
 
Posts: 548
Default 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
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The 2016 Spacex Mars Colonization plan has been published online [email protected] Policy 0 June 15th 17 05:26 PM
Space colonization essay ! TheBeerjunkie Astronomy Misc 26 December 23rd 11 06:31 AM
Mars colonization versus Stanford Torus G. L. Bradford Policy 191 June 3rd 06 12:56 AM
Mars colonization versus Stanford Torus Mike Combs Policy 12 April 28th 06 08:25 PM
Mars Colonization Remy Villeneuve Policy 36 January 3rd 04 01:07 AM


All times are GMT +1. The time now is 12:10 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.