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#151 2022-03-09 08:59:09

RGClark
Member
From: Philadelphia, PA
Registered: 2006-07-05
Posts: 692
Website

Re: Terraforming Mars, and connecting it functions to the other planemos

Void wrote:

This is likely of insterest per Starship as Moon/Mars bases.

Quote:

New update on how SpaceX will use Starships to build Moon and Mars bases.

https://www.bing.com/videos/search?q=Ne … &FORM=VIRE
And this is sort of an update about the notion of a "Stretch Starship".
Quote:

SpaceX's crazy new Starship upgrade will change everything! Seriously, though.

https://www.youtube.com/watch?v=3YpcrY5gTkM
So, I am liking the drift of things per these articles.
It is probably good to start strong, not wimpy, as long as forward planning for what is likely to be possible to make come is done periodically.
Per the 2nd article, SSTO is mentioned for "Stretch", but I am even more interested in the Starship itself perhaps becoming a 1st stage, and perhaps not needing as much heat shielding.  A wish would be to not need tiles at all, but that may likely be unattainable.  I am not sure what the heating would be if it were to have a travel profile more like the Superheavy will.  In my thinking, a Superheavy/2nd stage
use would allow more launch sites to be used, which may reduce congestion.  I am not sure if this would have fairings attached to the Starship that would open up, or just to have a blunter point on the Starship and mount a 2nd stage on that.  Maybe none of the above, but I am interested.
Perhaps such a 2-stage device could work for the Moon and Mars as well.  Don't know.
Done.


You know I like the SSTO discussion wink, but on a less controversial issue giving the Starship three more engines, bringing its engines to 9(nice homage to the Falcon 9 that started it all), means it could launch from the ground. This brings up a very important point. By making the Starship ground launchable, then it could also launch its own upper stage. This harkens back to a very obvious point, and I'm surprised that Elon and SpaceX can't see it. Every transport system going back to even the horse-and-buggy days, came in different sizes. This one-size-fits all approach SpaceX had been promoting for SuperHeavy+Starship won't make sense economically.

So producing a third stage, which could also be used as an upper stage for just the Starship, gives you lots of options for your launch systems. Quite key is the 3-stage version could launch a manned lunar mission in just a single launch. The current idea of using 8 to 16 launches just for refueling is simply untenable.

See discussion here:

Starhopper+Starship as a heavy-lift launcher. Triple-cored Starship for super-heavy lift. 2nd UPDATE, 9/2/2019: Starhopper as a lunar lander.
https://exoscientist.blogspot.com/2019/ … -lift.html

Additionally, its possible, I think likely, the Starship could also in itself be SSTO. Coming up with the new third stage, means you might also be able to get an even smaller SSTO. This would be important to opening up the launch market for private owners who could afford the smaller reusable launcher.

  Robert Clark

Last edited by RGClark (2022-03-10 01:00:14)


Old Space rule of acquisition (with a nod to Star Trek - the Next Generation):

      “Anything worth doing is worth doing for a billion dollars.”

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#152 2022-03-09 12:05:34

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,335

Re: Terraforming Mars, and connecting it functions to the other planemos

Some sort of launch assist, boosting the Starship to at least Mach 1 at takeoff, would greatly reduce gravity losses and boost payload.  There are a number of technological options for achieving this and it makes the idea of an SSTO far more achievable.  The decision over staging is about trying to increase payload fraction at the expense of added complexity.  A tiny payload fraction would be an economic failure, even for an SSTO.  A balanced solution tries to reach the best compromise between development, capital and economic costs.  So the question becomes, can we use launch assist to do away with the lower stage in a way that reduces total cost per kg payload?  A complicated question to answer.


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#153 2022-03-09 12:06:29

Void
Member
Registered: 2011-12-29
Posts: 6,934

Re: Terraforming Mars, and connecting it functions to the other planemos

RGClark,

It does seem like fun stuff.  I think that we are going to continue to get closer to a possibility of a SSTO for Earth, that may have some economic value.  I don't think we are in reach yet, but eventually, perhaps with some "RGClark Tech", it might happen smile Maybe Nano structured walls of some kind, someday might help.

But a cousin to your 2019 post, in your blog, may be much closer.  I would intend to entangle parts of SpaceX technology, and parts of the Rocket Lab Neutron methods, and also "Nesting", in order to get something of potential value.  A 2-stage affair, 1st stage based on Starship, 2nd Stage, based on the 2nd stage of Neutron, but sized up.

We can try various things.  Reduced or absent heat Sheids where possible.  Neutron landing legs for 1st stage, or launch tower catch?

As for the 2nd stage, I would intend that to be lightweight and made much as the Rocket Lab 2nd stage of Neutron.  No heat shield, it needs a ride home from orbit inside of an orbital fully decked out Starship.

Really when we are talking rockets, we are talking "Noisy potential bombs".  The bigger, the noisier, and the bigger, the bigger explosion, should things go wrong.

I don't know how many places a 6 or 9 engine Starship 1st stage could take off from on land, but there may be some.  It may have favor over having to launch to and from seas.  And such launch/landing sites might be far enough away from major cities that they might be allowed.

But for the 2nd Stage to be brought back down with a full decked out Starship, then you also would need a sea-based landing place as well, I think????  Nearby, and a barge to take the 2nd stage back to land and so on.  Maybe a Helicopter/blimp?

Anyway, the 1st stage Starship, made of Stainless steel, may only need heat shielding like that of Super Heavy.

The reason to want to make the 2nd stage of composites would of course be weight.  Rocket Lab claims to have a "Quick Build" for this.  Perhaps it can be sized up?

As this "Side System" would likely not be for humans, it is possible that there can be landing/launch sites where the Superheavy/Starship and Starship/Neutron (Pseudo-2nd Stage), method might be allowed as it should be remote from sensitive areas such as major cities.

And then you might indeed consider a 3-stage method, in which case, I am guessing the 3rd stage is likely to be expendable or re-used somewhere other than LEO.

That is what I have for it so far.

Here is a link to the proposed Neutron rocket, for other readers: https://en.wikipedia.org/wiki/Rocket_La … y%20market.

Done.

Last edited by Void (2022-03-09 12:25:33)


Done.

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#154 2022-06-06 05:08:47

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,335

Re: Terraforming Mars, and connecting it functions to the other planemos

Interesting piece on the general impracticality of terraforming Mars.
https://www.science20.com/robert_walker … rts-240782

The resource requirements for terraforming are obscene.  The author recommends paraterraforming as a more practical approach.  A few things he doesn't pick up on:

1) If paraterraforming happens over a significant portion of Mars, there will be a surface warming effect that will result in substantial degassing, whether intended or wanted or not;

2) A doubling of atmospheric pressure would reduce surface radiation levels substantially, negating the need to build literally everything underground;

3) The present thin atmosphere is actually advantageous in some ways.  It allows, for example, electromagnetic launch of ships and materials from Mars surface.

4) Once we have the ability to produce cast iron on Mars, creating pressurised living space will be a simple matter of heaping loose soil and rubble over a repeating cross-braced cast iron frame.

Last edited by Calliban (2022-06-06 05:22:10)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#155 2022-06-06 09:24:16

Void
Member
Registered: 2011-12-29
Posts: 6,934

Re: Terraforming Mars, and connecting it functions to the other planemos

Calliban, I enjoyed your post and the reference to that article.  As I have always suffered from poor attention span, I have assimilated some parts of it.

I am happy that some items agree with what I think.  I agree also that it has some good but negative points.  I appreciate your evaluations also as to how to work with Mars.  They are not wrong, just different to some degree from mine.

I am going to approach this by confessing that I am one of those who would primarily consider Mars to be a "Mining World".  But of all the worlds that could be mined, it has very good conditions to adapt a agriculture and other human Earth patterns to.

Lesser worlds might be Ceres and Callisto, and others.  These all have a chemical distribution, and solar power available.

Mars has better energy and does actually have an atmosphere.  Ceres has better gravitation.  Callisto?  It is in the Jupiter gravity well.

So, then a half full glass.

In my opinion for Elon Musk, Mars is just a point "B" from his point "A".  He has said that his job is not to solve Mars itself, but to solve how to get sufficient materials and pattern replications to Mars, but it is for others to solve Mars itself.

If a further shift of perspective, we can "Bezos" or "O'Neil" many worlds in our solar system?  For me, if things can be done to "Improve" Mars, (From a human perspective), then that is potential gain.

I do think that using various tricks it may be possible to further inflate the Martian atmosphere.  You have indicated this helps for radiation, but possibly inhibits Mass Drivers.  I will say though that I expect that Mass Drivers could still work from high altitudes.

I am not in favor of nuclear flash bombs, but maybe they can do something of value even so.

I recall that if we could move the Earth as is to the orbit of Mars to replace Mars, there would still be some open ocean water.  Also, this very glacial world would have deep level habitats on the ocean floors, as water piled up to high areas.  So, the negative assessment of the article that you linked to.

But it is vastly far away to think that Mars could have an atmosphere like Earth.  I feel that that is very far out of reach.  Not impossible, but not any time soon, I should think.

My notions of possible methods are very available from "Index» Terraformation» Worlds, and World Engine type terraform stuff.".

I regard them as evolving.

It is rather silly that we should want to Bezos Mars, and Musk the Moon smile

Real though, I think.

Done.

Last edited by Void (2022-06-06 09:50:26)


Done.

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#156 2023-04-13 14:08:58

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,335

Re: Terraforming Mars, and connecting it functions to the other planemos

Interesting exert on the use of CFCs for Martian terraforming.
https://en.m.wikipedia.org/wiki/Terraforming_of_Mars

Especially powerful greenhouse gases, such as sulfur hexafluoride, chlorofluorocarbons (CFCs), or perfluorocarbons (PFCs), have been suggested both as a means of initially warming Mars and of maintaining long-term climate stability.[19][20][49][32] These gases are proposed for introduction because they generate a greenhouse effect thousands of times stronger than that of CO2. Fluorine-based compounds such as sulphur hexafluoride and perfluorocarbons are preferable to chlorine-based ones as the latter destroys ozone. It has been estimated that approximately 0.3 microbars of CFCs would need to be introduced into Mars' atmosphere in order to sublimate the south polar CO2 glaciers.[49] This is equivalent to a mass of approximately 39 million tonnes, that is, about three times the amount of CFCs manufactured on Earth from 1972 to 1992 (when CFC production was banned by international treaty).[49] Maintaining the temperature would require continual production of such compounds as they are destroyed due to photolysis. It has been estimated that introducing 170 kilotons of optimal greenhouse compounds (CF3CF2CF3, CF3SCF2CF3, SF6, SF5CF3, SF4(CF3)2) annually would be sufficient to maintain a 70-K greenhouse effect given a terraformed atmosphere with earth-like pressure and composition.

Elon Musk suggests that launch costs using Starship may eventually decline to $20/kg.  Let us assume that we manufacture flourocarbons on Earth, launch them into LEO and then transport them to Mars using a tanker on a free return trajectory.  The tanker would not slow down upon reaching Mars, but would release its cargo before skimming the upper atmosphere and returning to Earth.  We need to drop 150KT of CFCs into the Martian atmosphere every year to achieve a 70K warming.  If it were to cost 5x as much to deliver the gas to the Martian atmosphere, then the cost of warming up Mars would be $17bn per year.  That is about $2/year for each Earth citizen, or $17/year for each rich world citizen.  That sounds like a bargain if the the prize to be had is a new world with human tolerable surface pressure and temperature.  Maybe this is something we could begin doing relatively soon.  It would turn the entire planet into habitable real estate within a century.  Once Musk has perfected Starship, serious planning could begin.

The implications for the habitability of the planet are very significant.

1. If surface pressure could be doubled or trippled to 2KPa, then surface radiation levels will be substantially reduced.
2. A 10KPa pressure would allow some plants to be grown in unpressurised greenhouses.  Humans could walk the surface in fairly minimal counter pressure suits, providing an additional 9KPa (1.3psi) skin pressure.  These would be relatively easy to make.
3. A 20KPa pressure would allow all plants to be grown in non-pressurised greenhouses.  Buildings would not need to be pressurised, just airtight with a slight positive pressure to prevent CO2 from seeping into structures.  This would allow buildings to be made from concrete and rammed soil.  Cities could be built in much the same way they are on Earth, but streets would need to be covered for pedestrian habitability.

Whilst colonisation could take place without terraforming, a warm surface with a 20KPa pressure would make it much easier for humans to live on the planet.  It eases many of the costs around growing food and creating living space.  If the population of Mars grows much beyond 1 million, then the benefits of warming the planet begin to justify its $17bn/year cost.

Last edited by Calliban (2023-04-13 14:44:08)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#157 2023-04-13 19:01:18

Void
Member
Registered: 2011-12-29
Posts: 6,934

Re: Terraforming Mars, and connecting it functions to the other planemos

That is an interesting vision Calliban.

I agree that a low price from Starship and others would open a reality options for Mars, Asteroids, and the Moon, at least.

In terraforming Mars however, the method you mention could very well be accompanied by other tricks, and so the magnitude of the materials to be delivered from Earth could be reduced, and perhaps the cost.

Done.


Done.

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