Friday, May 31, 2013

Humans to Mars

Rand asks for, "What We Need To Get To Mars" with reference to two articles.

"How We’ll Fix That" so we can send colonists to mars is the subject of the first article covered (similar to my three steps to mars) by the following subjects:
  • But how real is it?
  • Getting Off the Earth
  • Fuel Storage
  • Advanced Propulsion
  • Landing on Mars
  • Keeping the Crew Healthy
  • Living Off the Land
  • Protecting Ourselves and the Planet
  • Dealing with Dust
  • Making the Plan
But how real is it?
NASA has annual funding so the assumption is that NASA will do the job... someday. But government does not spend money efficiently (or wisely.) Private companies, being in competition with other companies, have to spend wisely in order to survive. NASA also has no driving reason to do this where private entities do: settlement.

But this section doesn't really discuss this fundamental point about funding being the main road block other than to say it would be expensive leaving it to the last section to talk about hundreds of billions of dollars for a NASA mission. Instead focusing on technology:
We currently lack the technology to get people to Mars and back ... there’s nothing technologically impossible about a manned Mars mission.
Getting back is a major part of the problem because NASA is not going to colonize. Private companies will; not just at a tenth the cost but perhaps even at a hundredth ($2b vs. $200b.)

Getting Off the Earth
The NASA way: NASA’s Exploration Missions and Systems Office, estimated it would take 70 or 80 launches to assemble a Mars mission spacecraft. This would be on the SLS which is another example of the government spending unwisely to send one massive ship to mars.

The commercial way: 9 launches for just $1.32b all using the least expensive trajectories and dual ship redundancy on the 6 mo. voyage. Supplies would be waiting on the surface of mars for an additional $195m for every 2500 kg. we choose to send. The more we send the greater the mission success probability. Sending four would bring the mission cost to about $2 billion.

But that's not really an apples to apples comparison. NASA proposes sending four while I propose sending twelve. Sending only four the commercial way only requires four launches (one lander in mars orbit, one modified Sundancer in earth orbit, one fueling mission, one crew to Sundancer) costing only $545 million (not billion.) Extra supplies would still be $195m/2500kg but we would not need to send as many. However, having many small launches is likely to be the greatest factor in bringing costs down.

Fuel Storage
Doing it the NASA way fuel storage is a big issue. Doing it the commercial way it isn't. Even NASA knows they could be doing things in a better way. In all cases, zero-g fuel transfer is required.

Advanced Propulsion
Is not required. It's in the nice to have category.

Landing on Mars
NASA is doing all sorts of research (producing lots of paper.) SpaceX is bending metal, preparing a modification of its Dragon (that has proved itself) that Mars One plans to use by 2016. They will need to land within a reasonably sized landing ellipse. They prepare for that by supply landings near the edge of that ellipse surrounding one close to the center. None of these landings need be more precise than those we've already done. They just need to be within reach. When the colonists land, after the supplies, they should have with them an electric tow vehicle and light trailer (both together no more than 250 kg) with a range that can be extended with solar panels they will also have with them. Fully charged they should have no problem reaching supplies. They would have enough supplies with them to last two weeks to make this less than two hour journey. The vehicle would have a safe top speed of 20 kph. They would have one of these vehicles for each four crew. Later they could use parts from these vehicles for other purposes.

Keeping the Crew Healthy
Radiation is not a showstopper. We can mitigate but even if we did nothing sending non smokers would balance the 5% greater lifetime risk of cancer. As Elon points out, for solar radiation we only need a column (not massive shielding surrounding your ship) which means orienting the ships during the voyage. Apollo did nothing to mitigate cosmic radiation. With informed consent we could try that. Once on mars radiation mitigation is almost a non issue. Zero-g during the trip and psychological factors? Not showstoppers even if we did absolutely nothing to mitigate.

Update: Prepare to be scared!
...just the trip to and from the red planet could expose travelers to an accumulated dose of radiation that would approach – and in some cases exceed – the maximum allowable career limits for a NASA astronaut.
So if they only go one way that would be about half that right? So what is that career limit? It's 3% lifetime risk of fatal cancer. Why don't they give it to us in numbers (mSv) we can compare?

The real number: 1.8 mSv per day or 657 mSv per year. Anything less than 100 mSv in a year has no measurable cancer risk. 657 mSv all at once would not kill and might not even show radiation poisoning symptoms (which may start to be seen with as little as 400 mSv if exposed to it all at once.)

Living Off the Land
For the first 5 dozen (my proposal for the first two missions: 12+48) we could completely supply them if needed but it would require 36 annual missions at $195m per mission. However, we have learned that water will be easy to get from mars so that reduces the requirement to only 9 annual missions. Growing their own food with many possible options (Zubrin's 50m hobby farms at 10psi being my favorite) eliminates the need for any resupply missions except for non essentials. Industry on mars is possible because all the essentials are already there but one... people with the right skills and knowledge. We send chemists and machinists. Perhaps young marines? Scientist can wait until we've made them a nice safe cushy place to live.

Protecting Ourselves and the Planet
These guys can go sit in a corner and play with themselves.

Dealing with Dust
Even assuming the very worst about mars dust it is easily mitigated. It does require awareness and precautions but not alarm. Solutions are known and easy to implement. Put this in the same category as worrying about a B movie monster eating them.

Making the Plan
In the grand scheme of things, engineering challenges are easy.
Finally, some wisdom I can completely and absolutely agree with. This in no way means belittling the challenges; Just an acknowledgement that humans are good at this (when not prevented.)
The plan would also have to be flexible.
Hey, we're starting to hit them out of the park.
The U.S. is not going beyond low-Earth orbit without international partners.
...and then they fall flat on their faces. By U.S. I think we can safely assume they mean NASA. International partners being counterparts in other countries. Yes, people from all countries should be able to go and Mars One takes the lead here with their plan (which has its own problems.)

If you want flexibility, colonists need to be individuals** with their own resources and not employees. If you want solutions to living on mars issues, you need people with experience dealing with those issues. Not planners. You can plan all you want, but experience trumps planning. No plan survives the first battle. Plan, by all means, but not paralysis by analysis. For any problem we should NOT come up with a solution; We should come up with ten potential solutions and include them all. For example, we send a wide variety of plant seeds (seeds are made for space travel) and a bag of live soil. This soil isn't enough for farms and most of the seeds may never get planted anywhere, but we include them anyway. Don't make the mistake of trying to protect the seeds more than we do the crew. I can just see us destroying all the seeds from secondary radiation because we decided to protect them in some radiation box.

We are talking about settling a new world. Does anybody get this?

Update: Somebody gets it right: progress is opportunistic, not deterministic. Also see Elon's 'forcing function.' "It is not a given that things improve."

**Think family farmers. If you don't know any I recommend finding one that will allow you to live with them for a few weeks if not longer. It will be a real eye opener in regard to self sufficiency. Especially if something breaks down while you are there and you see that they don't call anybody in to fix it. They fix it themselves (like the axle I broke on a friends tractor.)

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