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Zubrin Critiques Elon's Mars Plan


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Zubrin’s suggestions include

  • the SpaceX Interplanetary Transport System should have 3, rather than the proposed 2, stages. This would allow the 2nd stage, with its massive engines, which are much larger than needed for launching from Mars to return to Earth, to quickly return to Earth orbit. The Interplanetary Spacecraft part of the ITS, which is currently its 2nd stage, but with Zubrin’s change, would be a 3rd, would have much less massive engines, so much more – he suggests 10 times – passenger and cargo payload.
  • Rather than the current single-piece vehicle, the large, passenger and cargo-carying part should be detachable, and be used as a pre-manufactured Martian building. Only a small part carrying flight crew and a few return passengers and scientific payload will lift from Mars and return to Earth. This would reduce the amount of fuel that would need to be manufactured on Mars by about 75%. The 2nd stage would return to Earth within a couple of weeks of launch, rather than the current ITS plan of a few years.
  • To reduce the per-passenger cost, the travel time to Mars should be longer than the current proposal for the ITS.
I’ve not checked Zubrin’s suggestions for feasibility, but he’s a well-educated engineer with decades of experience in planning spaceflight missions, so I have high confidence in them.

 

Though a very smart and inspiring person, this video revealed Zubrin to be no better a US national political prognosticator than most of us, as he assumes that Hillary Clinton will win the 2016 presidential election.

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Thanks Craig, great summary and I finally get it. I guess the first few flights should absolutely have an ITS that lands a fully fitted out habitat. But once there are say 500 to 1000 people on Mars, we can revisit the ITS plan to try and get the ticket price down by having the Mars base build their own habitats. The reason is cost. It's the old problem of the cost of a plane flight if the passengers are buying the plane outright for one flight. So the first 5 to 10 trips should definitely land habitats fully fitted and ready to live in and extend! But at some point the goal would be to bring the passenger price down. They would build out new habitats from local materials and industry, and be constantly manufacturing fuel to launch whatever they needed. Would this mean the ITS is purely space bound, and not landing on Mars for fuel efficiency? How soon could we build a space-elevator on Mars — I understand this is feasible with today's materials on Mars due to the lower gravity? Or would a series of shuttles ferry passengers down from the ITS?

 

So, I think we're agreed that in establishing the first serious Mars colony, we need to land huge habitats.

At some point the colony takes over building habitats.

Then the ITS can be a huge tethered rotating spacebound habitat that carries a hundred or so passengers spun-up for gravity, and landed on Mars via elevator or ferries.

Your thoughts?

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I said Zubrin smashed it. This was the reply to my post on another forum. I think I'm changing my mind!

 

No, he doesn't. He's a smart guy, but he's also dogmatic. He can't get past his Mars (Semi) Direct plan. His criticisms of ITS read like a blow for blow list of differences from Mars Direct.

Mars Direct has its merits if you want an Apollo style mission. It makes no sense for this context.

Why increase the fuel burden on the Mars base just to haul a potential Mars habitat all the way back to Earth?

 

 

SpaceX wants to build an interplanetary railroad. That requires bringing launch costs down, which requires reusablity. (Fuel costs far less than building safe, dependable, human rated, rocket ships.) If you make the ships more expensive because they're less reusable, then fewer people will be able to go to Mars. If fewer people can go, then you defeat the benefit of leaving extra habitats on the surface.

Being able to send more people is a good problem, and it's progress. Being able to send some few people that housing isn't an issue? Well, we already have that problem.

Instead, the ITS should be able to leave the huge 100 person habitat on Mars as the beginnings of the Mars city, and just fire a smaller rocket & cabin back to Earth.

 

 

  1. Elon Musk already said he expects the first mission or two to Mars might just use the ITS ships as surface habitats. The ITS being designed for usability doesn't preclude its use as a Martian habitat.
  2. If the ITS crewed ship were redesigned so the habitat portion stays behind, what are the next round of people supposed to come in? Construction of new cabin sections would be a rate limiter on colonists heading to Mars.
  3. Dedicating structures designed for space travel as ground habitats is a waste of resources, even on Mars. The cabin sections of crewed ships would be vastly over engineered for ground living.
  4. The high numbers Musk gives for ITS crew complement is partly due to its use of internal space assuming weightlessness. Without that assumption, a lot of internal accommodation changes need to be made. If the ITS crew ships were designed to be primary surface habitats, they would need many more floors to make the open spaces usable in gravity and the crew accommodations would have to be redesigned with gravity in mind. That all means fewer people.
  5. Longterm Martian habitats will probably need to be underground. How do you expect people to move a ship underground it they can't even build a habitat with local materials? You're supposing habitat construction is impossible, but the solution you're supporting is also made impossible by that supposition. Using ships as a habitation shortcut is moot. We need to be able to do construction from the moment we land on Mars, so repurposed ships solve nothing. A ship is only useful as a stopgap habitat if you want to build a colony.
A new one will be required for every trip. But isn't a home on Mars kind of important?

 

 

Mars colonization will depend on people being able to build habitats on Mars with local resources. With that being true, why design ITS to primarily be a leave behind architecture? It would quickly become obsolete.

Maybe once there is a native Martian population building new accomodations it will be cheaper to just front up the fuel and shoot the whole accomodation module back to Earth for re-use.

 

 

You seem to be under the assumption that fuel costs (per kg) more than spacecraft. You are mistaken.

But until there is a sizable industry on Mars, I can't see how the earlier colonists are meant to colonise without a base. It's not like you can just put a habitat module in your suitcase!

 

 

  1. Why is an uncrewed presupply mission which drops off habitation hardware so unconceivable for you? If you want to increase the number of ships built so they can be used as Martian habitats, why not just build the habitats directly? Reusable ships as cheap as Elon Musk claims would be able to run a constant supply chain of habitation hardware if people wanted. Unreusable ships wouldn't.
  2. You're assuming habitats built on Mars are not an option for the foreseeable future. This also is a bad assumption. For example, NASA had been holding a very public contest for a '3D printed' Mars habitats that can use as few Earth based resources as possible.
Edited by Eclipse Now
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  • 6 months later...

I agree, not so much for the vacation purpose, but for the experience. When you want to start hiking you wouldn't want to start out on Mt. Everest. You would find somewhere easier where you could check the comfort of your boots, see how your tent holds up, and determine how much water and supplies you must bring or gather on your own once you are there.

 

The moon is the perfect training site to test our equipment and people for long distance habitation. The other benefit of it is during this trial run help can be there much more quickly if something doesn't go how we have envisioned it.

 

Mars is another planet and getting there is a tantalizing objective for our race, but it must be done intelligently. Throwing hail Mary's at it will just invite disaster and put a further drag on our space program. A program that has moved somewhat directionless and slow for the last 40yrs or so.  

Edited by Deepwater6
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Never thought about this but you make a good point, just like the hiking example, arctic equipment is tested amongst other in Hardangervidda (a high plateau between OSlo and Bergen, Norway) because you get the conditions (-30C and snowstorm) but are still close to civilisation.

I mean also everything which goes on a rocket is tested soo much that it is old school tech by the time it reaches space, why should it not be the same for planets? First test it on the moon then take it to mars.

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In either body, you are going to have to live underground to protect yourself from the cumulative effects of radiation for any long term stays. The main difference between the Moon and Mars is gravity and the length of the day. Mars has a more Earth like day, but if you are going to live underground most of the time, it doesn't matter. The habitation of the Moon or Mars looks pretty much the same, the technologies that keep you alive looks the same too. A Mars spacesuit can be used on the Moon, as their is not much difference between 0.7% of Earth's atmospheric pressure and a vacuum. Mars also has twice as much gravity, so you are going an enormous difference in order to have not as much bounce in your step as the Apollo Astronauts. Mars is more scientifically interesting, there is the possibility of life and evidence that liquid water once flowed on its surface, the Moon on the other hand is just a rock with craters and ancient lava flows, but it is much closer to potential markets. I think the first thing we need to do in order to have lunar tourism is to build a resort underground. This resort will resemble a hotel in a cave.

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Honestly, I think all of this is premature Mars should be terraformed first before people go to this planet. I say we make use of our nuclear arsenal and set off nuclear warheads in the core of mars to reheat the outer core back to a higher temperature liquid state able to produce a stronger magnetic field to allow the atmosphere to be kept on the planet along with protection from solar radiation. The radiation from the nuclear warheads would be contained by the mantle not effecting the crust of mars. This would take thousands of ivy mike class warheads at 13.5 megatons, but 13.5 Gigaton to 25 Gigaton gain of energy would do it. restarting the dynamo that generated its magnetic field millions and billions of years ago when mars had water. The US and the Russians have 20 or so thousand just sitting there from the cold war better than dismantling them. They did cost 2 to 3 million dollars per warhead to build seems like wasted resources to just break them down.

 

internal-structure-of-mars.jpg

nuke_it_by_craigh937.jpg

 

 

There is a second stage to this then we release genetically engineered Bacteria on to the planet once the temperature rises and magnetic field stabilizes this will generate oxygen via photosynthesis being a class of Cyanobacteria. Mars being high in CO2. The Genetic engineering would be the addition of a cold shock resistance genes or over-expressed one from psychophillic bacteria such as Chryseobacterium greenlandensis

which survive in temperatures as low as -37 C. The current temperature of mars being around -55 C, so you will have to do this after nuclear reheating unless methods to over-express the genes were taken. It would be easy to splice Cynobacteria and Chryseobacterium greenlandensis species into a hybrid bacteria species for survival on mars via somatic hybridization after that they will evolve and adapt to mars over many reproduction cycles. They did not evolve 4 billion years to be stopped by a ice age, life will find a way. It just need a little intelligent design to get started on this fridge wasteland. Plus think about it we play a vital role in creation of new species on another planet which could possibly gain self awareness in 4 billion years long after our extinction.
 
tree-of-life_2000.jpg
 
We started something like this on a scorching wasteland 4 billion years ago whether it be via Aliens or Natural events, but in this case it would definitely be humans playing the role of God. Although, they may be more worried about the Sun's expansion rate then whom created them as the sun begins to red giant after 105,120,000,000,000 Generations past our original bacteria. That being said I do think this should be done not only for the reason of making humans a second home but for the evolution of mankind as a species.

 

.  

 

Instead of a terraform taking 500 to 1000 years, I think this would terraform this planet in 20 to 50 years thanks to former weapons of mass destruction. The wars of mankind had meaning to think through the path of destruction we found this it added to our evolution not the regression of it.

 

new_life.jpg

Edited by Vmedvil
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Honestly, I think all of this is premature Mars should be terraformed first before people go to this planet. I say we make use of our nuclear arsenal and set off nuclear warheads in the core of mars to reheat the outer core back to a higher temperature liquid state able to produce a stronger magnetic field to allow the atmosphere to be kept on the planet along with protection from solar radiation. The radiation from the nuclear warheads would be contained by the mantle not effecting the crust of mars. This would take thousands of ivy mike class warheads at 13.5 megatons, but 13.5 Gigaton to 25 Gigaton gain of energy would do it. restarting the dynamo that generated its magnetic field millions and billions of years ago when mars had water. The US and the Russians have 20 or so thousand just sitting there from the cold war better than dismantling them. They did cost 2 to 3 million dollars per warhead to build seems like wasted resources to just break them down.

 

internal-structure-of-mars.jpg

nuke_it_by_craigh937.jpg

 

 

There is a second stage to this then we release genetically engineered Bacteria on to the planet once the temperature rises and magnetic field stabilizes this will generate oxygen via photosynthesis being a class of Cyanobacteria. Mars being high in CO2. The Genetic engineering would be the addition of a cold shock resistance genes or over-expressed one from psychophillic bacteria such as Chryseobacterium greenlandensis

which survive in temperatures as low as -37 C. The current temperature of mars being around -55 C, so you will have to do this after nuclear reheating unless methods to over-express the genes were taken. It would be easy to splice Cynobacteria and Chryseobacterium greenlandensis species into a hybrid bacteria species for survival on mars via somatic hybridization after that they will evolve and adapt to mars over many reproduction cycles. They did not evolve 4 billion years to be stopped by a ice age, life will find a way. It just need a little intelligent design to get started on this fridge wasteland. Plus think about it we play a vital role in creation of new species on another planet which could possibly gain self awareness in 4 billion years long after our extinction.
 
tree-of-life_2000.jpg
 
We started something like this on a scorching wasteland 4 billion years ago whether it be via Aliens or Natural events, but in this case it would definitely be humans playing the role of God. Although, they may be more worried about the Sun's expansion rate then whom created them as the sun begins to red giant. That being said I do think this should be done not only for the reason of making humans a second home but for the evolution of mankind as a species.

 

.  

 

Instead of a terraform taking 500 to 1000 years, I think this would terraform this planet in 20 to 50 years thanks to former weapons of mass destruction. The wars of mankind had meaning to think through the path of destruction we found this it added to our evolution not the regression of it.

 

new_life.jpg

 

Honestly, its easier to dig a cave than to terraform a planet, we could settle Venus without digging a cave. Venus has more in common with Earth bulkwise. Mars is mostly geologically dead, its volcanos are billions of years old, Venus on the other hand is geologically active, it has volcanos erupting now, the reason it doesn't have a magnetic field is because it doesn't spin fast enough, but the nearest Earthlike planet is Venus, there is just that little detail of what's on its surface, but if you go much below the surface of Venus, its interior is similar to Earth's

 

Venus doesn't need a magnetic field, its thick atmosphere will do the job all by itself. the main problem with Venus is threefold, it spins too slowly, it lacks hydrogen to make an ocean, and it receives too much sunlight. Two of these problems are related, Venus' slow rotation provides a very long day, if we were to build a shade around Venus, we can have whatever day length we want and can therefore assign it a 24-hour day with an artificial light source on the inside of the shade. If we can wrap something around Venus, we can gather enough energy from the Sun to generate a planet sized magnetic field if we desire. All that's left is to import hydrogen from Uranus to make Venus' oceans.

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