August 31, 2011
Food Challenge For Mars Mission
Maya R. Cooper, a scientist in NASA's Space Food Systems Laboratory in Houston, says keeping astronauts fed during a 5 year mission to Mars poses big challenges.
Speaking at the 242nd National Meeting & Exposition of the American Chemical Society (ACS), Maya R. Cooper said that provisioning the astronauts with food stands as one of the greatest challenges in scripting the first manned mission to Mars.
If they took all their food with them they'd need 7,000 pounds per person for a 5 year mission. One immediately thinks: But why ship the food? Why not grow it there?
For flights on the space shuttles and the International Space Station, astronauts get 3.8 pounds of food per day. For a 5-year round-trip mission to Mars, that would mean almost 7,000 pounds of food per person.
It would be cheaper to send the food ahead of time on a slower but cheaper orbit. Anyone got a grasp on how to calculate the shipping costs for tons of goods to Mars orbit?
If all the food was sent in advance it would have to be packaged to last 5 years. Shipping the means to grow food would reduce the amount of food mass that would need to be sent. How much weight in food growing equipment would need to be sent to do this? How long does the mission have to last for Mars farming to become cost effective?
Whenever I read proposals for a Mars mission my reaction is we should work on enabling technologies first. Why go with lousy tech? Going to Mars is not just about the safety or speed or cost of the rockets and spaceship. It all gets much cheaper, easier, safer, and sustainable with advanced robotics and advanced bioengineering. Therefore going to Mars will get steadily easier in the 21st century.
Sufficiently advanced robots that include robot maintenance capabilities and very long lasting designs could go to Mars years before humans. Such bots could build up physical structures for humans to live in and operate farming equipment to grow and package enough food to assure astronauts of sufficient food once they reached Mars. even more important, sufficiently advanced bioengineering technologies will enable creation of plants suited for food, fiber, pharmaceuticals, and biomass fuel production. Bioengineering will make Mars farming far more productive and fruitful.
You do realize that those are hydrated weights? Quite obviously so. The weight of dehydrated food is perhaps a quarter or less of that.
"You do realize that those are hydrated weights? Quite obviously so. The weight of dehydrated food is perhaps a quarter or less of that."
But they still need water from somewhere to rehydrate the food, as well as for drinking.
Strikes me there's a conservation of mass problem here. Mass of material needed to grow food > mass of the food itself, and always will be. To what extent can we rely on Mars for the water and nutrients needed to grow food? To what degree are we successfully recycling water and other waste on the space station?
In my view the mission isn't worth it if we aren't extending the bounds of human technology, including in terms of food provision, but I still suspect they'll be needing regular supply dumps.
Yes, but water is one thing which is never in a shortage on spacecraft. Your food consists of "hydro" carbons, and carbo "hydrates", your metabolism generates a substantial amount of new water from the food you eat. Recycling piss and dehumidifying the air provides you with all the water you need. It's the easiest thing to recycle.
Granted, reconstituted dehydrated food wins no awards. But the numbers above are just put out for shock value, they're not realistic, you wouldn't stock a Mars mission at CostCo just before launch.
And while liquid water can only exist in rare places on Mars (it's a pressure thing), we've discovered that water is not so rare on Mars. It's not even all that rare on the Moon.
plus, i would think on mars you could extract oxygen from the co2 in the atmosphere, so all you would need is some relatively light hydrogen to combine with the extracted oxygen to form water
that should make up for any losses from trying to reclaim water from waste
You send the base to Mars FIRST, unmanned, in modules. Once all of the pieces are on the ground (including power sources, living quarters, food stores, emergency return capsule, machine shop with tools and equipment required to assemble everything, et cetera), THEN you send the astronauts.
Why not send fat astronauts?
Couldn't you dehydrate the astronauts?
I read in an old Air & Space magazine about how NASA developed edible materials that could be formed into interior components for space craft. It sounded like oatmeal that was heat pressed into forms such as handles, panels, etc.. and then sealed in a plastic wrap. It supposedly tasted terrible and had to be soaked and gnawed on for some time, but it was edible. heh heh - It was planned as emergency food in case folks were stuck up there without resupply, but the project was abandoned, if memory serves, as they figured folks would die for lack of air long before they starved.
Having said all that, perhaps it could be used, in some limited form, to shave off a few extra pounds for a Mars mission? heh heh - Edible spacecraft!
Let us cut the Gordian Knot by simply admitting reality: why bother going to Mars in the first place?
Answer: Because otherwise NASA has no particular point, use or value.
Response: Disband NASA. Deorbit ISS. Promote local commercial space travel. Going to Mars will take care of itself when someone actually has a viable reason to go there.
1) "Anyone got a grasp on how to calculate the shipping costs for tons of goods to Mars orbit?"
A: Ask UPS or FedEx. DO NOT ask USPS or NASA.
2) "...going to Mars will get steadily easier in the 21st century."
A. That's assuming the d*ckwads in charge of the US right now don't destroy the country first.
I am thinking you should send robots that can be controlled, multiple 3D printers, 3D Printer raw materials. This can be used to build alot of stuff at the site and unexpected stuff. What would it take to turn martian dirt and materials into inputs for 3D printers? I realize not everything could be done this way but I have to this the amount is non-trivial.
The carbon is most likely from exhaled CO2 and the big advantage of growing food is not only less food but also less oxygen to ship. There is also the added bonus of eating fresh food instead of some hydrated junk
"Why not send fat astronauts?"
Their health insurance premiums would be too high.
you wouldn't stock a Mars mission at CostCo just before launch.
I believe the ultimate goal should be to make that very thing not only possible but routine.
Send somebody who eats shit. I suggest Keith Olbermann.
"Why not send fat astronauts?"
Hey, I resemble that remark. I ain't going nowhere without 4 star hotels, good food, and plentiful adult beverages.
Mars will not be a tourist destination in my lifetime. If you want to go there, on anything other than an exploratory basis, you will need to build nuclear (preferably fusion) powered ships. I am guessing no earlier than the 23rd Century.
Ok Wilson, you made me laugh! Bravo!!
Mars will likely be a one-way trip for any astronauts landing on the planet surface. If they stay in orbit, they probably won't need 5 years to complete their mission since advanced rockets might get us to Mars in several weeks or a few months. So, astronauts on the surface will most definitely need their own means to supply food and water. These facilities are likely best constructed here on Earth first as modules and then taken up into orbit (hopefully via space elevator), where they can then be launched in unmanned ships to land on the Martian surface in preparation for colonizers.
xxx said: plus, i would think on mars you could extract oxygen from the co2 in the atmosphere, so all you would need is some relatively light hydrogen to combine with the extracted oxygen to form water
that should make up for any losses from trying to reclaim water from waste
The Martian atmosphere is not very dense (less than 1% of that of the Earth).
And of course there's the slight problem of the energy required to turn CO2 into O2 + C, without already having plants there to do it for you using sunlight (which is itself problematic, a bit, since the solar flux is considerably lesser... 44% of Earth's, on average).
That's a non-starter.
"Growing food" is what you do when you're thinking of a colony. A research base? It's almost never going to be cost-effective.
(Indeed, their concern here is for provision on the flight to and from Mars as much as while they're there - and growing food shipboard is even less plausible than doing it on Mars; it's never* going to be cost-effective for such a short duration.)
(* Assuming non-pseudo-magical technological advancement or radically different valuations.)
We need a system of propulsion where a Mars trip takes weeks, not years.
We are probably a 100 years from being able to sustain a Mars mission, and that's if we get cracking on solving the problems.
It's not feasible to take everything you might need with you. So anything that can be utilized from the martian environment, should be. However, we don't even know what there is to utilize or where to find it. Figuring that out requires scores hundreds of real prospecting missions by landers more in the weight class of a Bobcat rather than what we've been sending on the rover missions. We have to do some mining in preparation for a martian economy of sorts because its simply unfeasible for the colony to depend entirely on resupply from earth.
Anything that can be done by a machine should be. That means leveraging remote automation heavily. Any human exploreres need to arrive on Mars and find most everything waiting on them. It can't be like going to the moon. They'll be years of launching things to Mars and preplacing them prior to sending any humans.
While briefcase fission power plants will be the backbone of the early energy economy, its essential that we find a way to provide power to the settlement in the long term. That means finding the martial equivalent of oil, whatever that turns out to be, that allows for a degree of self-sufficiency.
I personally think the first mission is going to have to have 5 years of food with them. That's because you can't ask people to depend on untested farming practices on a whole other planet. It's great if you can get farming up and running on Mars, but that's more important for the second round of explorers or colonists than the first round. The first time, you have to bring everything you need to go and come back even if everything goes wrong.
What all this adds up to is that we have to get the cost of getting out of Earth's gravity well down by a couple orders of magnitude because it means lifting hundreds of tons of equipment up into orbit and sending it to mars. It's not a trivial task, nor does it involve a trivial amount of social and political will. Given that the first world nations are finding it hard to induce their citizens to have the will to have children, I just don't see the current me centric culture as being one that supports exploration of outer space in any form.
Biosphere 2, anyone?
Wish I could dig up the old Steve Benson cartoon on that debacle. I still remember the caption: "Snow Job and the several dwarfs." Back when Benson was still funny.
"I ain't going nowhere without 4 star hotels, good food, and plentiful adult beverages."
Select people not prone to alcoholism and adult beverages will lubricate human relations rather than disrupt them.
Testing for genetic traits better be well advanced before the crew is selected.
Ok, this might be kind of stupid, since I'm not a scientist. But if there is oxygen, carbon, and hydrogen on mars, can't nanotechnology (potentially, I don't mean currently) make carbohydrates?
Are you familiar with the "Mars Direct" plan? Its a very popular proposal put forward by a pair of NASA engineers, back in 1990. The whole idea is a "live off the land" approach, including making rocket fuel with Martian materials (using a hundred year old technolgoy). First, one sends the supplies and a return vehicle to Mars, and have it begin processing fuel when it arrives. Since nothing's alive on this mission, it can take a slower, less-direct path. Then, when the return vehicle's fueled, you send the astronauts - for them, its a 6 month trip, followed by a 12 month stay on Mars, then a 6 month trip back to Earth. So its a total of two years for the astronauts, using old technology, for a (comparitively) cheap price - and the last I heard, this is the approach NASA wanted to use.
I'm not sure where the "5 year" trip estimate (quoted by the NASA food expert) is coming from - it seems to be a throwback to the old "Battlestar Galactica" approach. Use a huge ship, crammed full of cutting edge technologies, and carrying everything the astronauts might possibly need. That was the old Werner Von Braun approach - the only catch is it would be fiendishly expensive and (potentially) take decades to develop. The Mars Direct approach, conversely could be done now*, with current tech
*because of the orbital paths, you can only send a Mars Direct-style mission on certain years
I was impressed by Elon Musk's comments on going to Mars.
The most important thing is to not let the government run the project.
I remember reading a Sci-Fi novel years ago where the concept was something like, sending robots to develop planets for human habitation. When the conditions were ready for humans the robots thawed human embryos and raised them to adulthoodhood. The humans then went on to colonize the planet for later human visitors.
This may still be the most viable plan for developing space colonies, leave out the frozen embryos for the Mars trip though..
Anybody thought about crop failure?
Like they're not eating "shitburgers" already? Maybe at a couple of removes, but still. Perhaps they need to recruit some astronauts who grew up on farms, and are aware of such realities.
Yes, nobody is currently planning a mission to Mars that lasts long enough that dehydrated food wouldn't be the weight saving option. Even the most intensive hydroponics is fairly heavy compared to it's output of food. You'd need a mission length in decades for it to make sense.
What *might* make sense would be to grow locally some herbs, salad greens. Not for their nutritional value, but just for the variety.
Why is there always such an obsession w Mars? So far away. Who is gonna want to b gone for eleven yrs, at least?
We barely know the moon, and it is so much closer and easier to supply/aid/rescue, if need b.
Ralph-- or, is it, Raif-- Kramden had it right: to the moon, baby, to the moon!
Humans aren't going to Mars. Not now. Not ever. Deal with it.
I see no need to go to Mars, but if we were to go a multi-year trip is idiotic.
When Mars is near opposition, a trip to Mars can be made in about 22 days, using a constant 0.1 g acceleration to the half-way point then a 0.1 g deceleration to Mars. Robotic refueling ships can be placed as needed along the path. Less on-board fuel is needed; less food for the trip; less concern about equipment failures; and the 0.1 g provides 'gravity' so there is less worry about loss of muscle and bone mass. The ship can be smaller and easier/cheaper to build and launch.
Humans will have to terraform and then inhabit Mars.
It's too risky to keep all human eggs in one basket, so to speak.
Could be binary humans, though.
We are probably a 100 years from being able to sustain a Mars mission
Wrong. Your only off by 90 to 95 years.
3.8 pounds of food per day
I've been using 8kg per day for unrecycled life support. Oxygen(0.9kg) hydrated food(2.6kg or 5.7 lbs.) and water for my calculations.
In about three years give or take, a Dragon lander will be able to put more than 10 mT safely and accurately on mars for about $100m to $200m.
Which would allow unrecycled full life support for five years for a dozen ISRU researchers for something like... $2.25b but wait, there's less...
Given power (say a 40kw suitcase nuke (google it) and solar panels they can produce there own oxygen, water and methane fuel. So they only need food.
Dehydrated food supplies only require 0.7kg per day, cutting your support cost to less than a tenth...
Meaning annual support to keep a dozen researchers on mars could be as little as $50m per year. We have to wait about three yrs for the equipment,
but it's 90% developed already. The researcher are going to be learning to farm so they will supplement the already full life support with
regular home grown food. The only thing holding us back is guts.
Do we have any?
By the way... it pays for itself several times over. Once banks start financing the trip, everyone that wants to can go... not just the rich.
memomachine's comment is spot on. Mars is a bridge too far. First we need an effective Earth-orbit payload delivery system, like the electro-magnectic track launcher so well described in Analog over 20 years ago. Then a functional and multi-tasking geosynchronal space station (or three) with self-energy production ability. That will provide a platform from which we can establish a lunar base of at least "The Moon is a Harsh Mistress" quality. Once we have regular Earth-orbit and space station lunar traffic, we can begin to exploit the asteroids for materials and energy to build space factories to outfit further exploratory efforts.
Mars is just not on the list until then.