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Questions & Answers that were not answered during the October 13 webcast!

From our archives:
We would like to know if it would be possible to use plastic or aluminum in construction on Mars? We have discussed what we could use to store our food and water, and want to recycle everything we can. We know that aluminum shouldn't rust, and we thought that if we filled cans with dirt, they could be used in constructing homes or buildings, and the dirt would add to the insulating factor. Then we thought plastic might be a good way to store water, and possibly could be used in construction also......but it might biodegrade in the Martian elements. We are trying to be wise in the way we use our resources. Thank you for your help.

ANSWER from Andrew Petro on March 10, 2000:
You have some good ideas. Aluminum is used for many things in space and it should be OK on Mars. The idea of filling used containers with dirt is really good. I don't know a lot about all the different kinds of plastics but you are right to be concerned. There may be some kinds of plastics that would have a problem on Mars but there may be other types that are OK. We may need to learn a little more about the conditions on Mars in order to be sure.

From A.T.P. group, working on a habitat we could live in on Mars. We were trying to figure out what material to build a dome with when we came across a problem: What would insulate our dome more efficiently, plastic or glass?

Answer from Bill Clancey: I'm not an expert on materials, but I think one would need to consider not just the insulation value, but also
1) the radiation (is a glass dome safe on Mars?) and
2) the effect of the cold & UV (would plastic become too brittle?).

There are several projects to build habitats that are documented on the web. Most impressively, see:
The gallery (  provides a good index, with ideas about other kinds of materials that could be made on Mars.

Many science fiction stories and this Homestead project examine the possibility of living in caves or underground. Students should consider why that's a good option, too.

From Katie: Can we use battery powered objects on Mars?

Answer from Jennifer Heldmann: Yes, batteries work on Mars. In fact, the Mars rovers Spirit and Opportunity that are roving on Mars right now use rechargable batteries (in addition to their solar panels).

From Erin: Can we use radios on Mars? Can disposable cameras work on Mars?

Answer from Jennifer Heldmann: Radios should work on Mars. Since Mars is so remote we likely won't have a lot of interference with others using the same radio frequency. 
Disposable cameras (if designed correctly) could also work on Mars. What would you need for a disposable camera? Would you bring a darkroom with you to develop the film? What other options might make things simpler? How about digital cameras? 

From Sarah: Have the Martian ice cpas been explored?

Answer from Jennifer Heldmann: We have explored the Martian ice caps from orbit but we have never landed there! Not yet, anyway. However, the next mission NASA is planning to send is called Phoenix and it will land at a high latitude with the goal of scooping of some of the ice that we think is on Mars! Phoenix will land in the "Martian Arctic".
You can search for more information about Phoenix online. Here are two websites to start with:

From J. Ditze: Is the snow going to melt on Mars?

Answer from Jennifer Heldmann: This is a great question and is precisely what we hope to learn through our work at Lassen! We don't know if the snow will melt on Mars. That is why we are collecting data at Lassen to use in our computer models to simulate how snow behaves. Then once we verify that these models are correct and that they work on Earth, we can use them for Mars to see if the snow will melt or not.

From Z. Richards: What materials shield humans from radiation?

Answer from Jennifer Heldmann: There are many materials that shield humans from radiation. Water can shield us from radiation. Martian regolith may also be able to shield us from radiation so perhaps we should pile a lot of Mars dirt on top of our habitat. On Earth we have the Earth's magnetic field which helps deflect much of the harmful radiation that comes from space so that it doesn't reach us here on the surface. But what about Mars? Mars doesn't have such a strong magnetic field, so what does that mean for the amount of radiation that would reach the planet's surface?


The following are questions from Chaise:
1. Could we colonize on Mars' moons?

Answer from Jennifer Heldmann: That is a good question. Some people have thought about going to the moons of Mars before going to Mars itself. Going to the one (or both) of the Moons would introduce many new engineering challenges. For example, Phobos and Diemos are small, so what does that mean for the gravity on the surface of these Moons? Is it more or less than on the surface of Mars? Could we land there? Try to find some images of the Moons -- what does the surface look like?   

2. If we lived near the volcanoes, would we might be able to colonize around them?

Answer from Jennifer Heldmann: This is an important consideration for landing site selection. Volcanoes might be useful to humans because if there is a higher amount of heat in the subsurface then maybe water could be liquid underground instead of being frozen permafrost which is common on Mars. We would also want to look at the topography and make sure we could land there -- for example, the landing site can't be too steep. We would also want to understand any volcanic system that we are near so that there isn't an eruption too close to us! 

3. If we colonized on Mars, how would we get food (i.e. meat)?

Answer from Jennifer Heldmann: This is a good question for mission designers. Of course it is very expensive and very time-consuming to ship all our food from Earth, isn't it? If we want to stay on Mars and colonize the planet then we might want to be self-sufficient and grow our own food, just like we do on Earth. What would you need to do this? Can you imagine greenhouses on Mars where we could grow crops? How would we accommodate livestock so we could have things like meat?

The following are questions from Garrett:
1. How would we transport material from Earth to Mars?

Answer from Jennifer Heldmann: We have to use rockets to launch material off of the Earth and then put it in a cruise trajectory to Mars. Once we get to Mars then the spacecraft has to enter the martian atmosphere. Since the spacecraft is traveling so fast it gets very hot due to the friction with the atmospheric molecules (even though there is very little atmosphere on Mars!). Then we have to decide what is the best way to land on the surface of Mars? We can use retro-rockets to slow the spacecraft down for a nice landing. The MER rovers used big airbags that allowed the spacecraft to land and bounce around on Mars but allow the rovers to survive. In your design you should figure out a way to avoid a crash landing on Mars!

2. How would we design suits to withstand the heat that is on Mars?

Answer from Jennifer Heldmann: Designing suits is a tough job. Not only do you have to shield the astronaut from the harmful martian environment (low pressure, low temperature) but you also have to try to keep the astronaut comfortable in the suit (when you are outside working hard do you ever get really hot and start to sweat?). Plus the astronaut has to be able to do his/her job while wearing the suit - things like collecting samples, deploying field equipment, maybe driving a Mars rover? We can test these suits here on Earth before sending them to Mars, both outside with people doing field work and also in special chambers that can replicate the low pressure and/or low temperature environment of Mars. What sorts of things might you test?

3. How could we build a habitat that could withstand extreme heat and pressure?

Answer from Jennifer Heldmann: Building a habitat is also a tough job. Engineers have to design a habitat that will survive the extreme conditions on Mars, including low temperature, low pressure, and other things such as gusts of wind, possible dust storms, etc. Engineers can mathematically model how a material and/or design might respond to such conditions. We also need to understand what the people living in the Habitat will need on Mars. Will they need a laboratory for scientific research? Will they need a machine shop to build equipment? How about a kitchen for their food? Do they need bedrooms? There is a lot to consider when designing a Habitat. A good place to start is to think of all the conditions that the Habitat must survive (temperature, pressure, etc) and also the needs of the users (the astronauts).

4. Could we melt the ice caps to get fresh water? Would we have to sanitize it first?

Answer from Jennifer Heldmann: We know that the polar caps contain water ice so yes, in theory we could melt the ice caps and get water. However, we do not know if the ice is pure or if it contains anything else within it so we would want to test the water first and make sure it is ok. That would tell us if we need to sanitize it.

5. How could Mars have dried out, if it is farther than we are from the sun? The Earth has a stronger atmosphere than Mars.

Answer from Jennifer Heldmann: One of the biggest questions planetary scientists are trying to answer is where did all the water go that used to be on Mars! Some is probably underground as frozen ice. Some is frozen in the polar caps. Some may be deeper underground, perhaps as liquid in the form of groundwater. A very small amount of water vapor is in the atmosphere. There may have been more there in the past.
However, because the atmosphere of Mars is so much less dense than the atmosphere of Earth and because Mars is so much colder, liquid water is not stable on the surface of Mars. It will boil and freeze very fast, all at the same time. So today we can't have open oceans of water on Mars like we do on Earth.

6. How could we design a barrier for incoming asteroids?

Answer from Jennifer Heldmann: That is a good question that we haven't even solved for Earth yet! There have been thoughts of trying to nudge the asteroid into a different orbit - how might you do that? 

From Mary Betke's 8th grade:
Habitat/Living Group (1st/7th period)

Is it true that astronauts recycle urine for extra water?

Answer from Jennifer Heldmann: Researchers are working on this technology. We don't have full recycling yet -- Here are a few links:

Have the astronauts on the space station experimented with growing food there?

Answer from Jennifer Heldmann: Yes, there have been several experiments on both the space shuttle and space station for growing plants in the microgravity environment. Here are some links:

Do you think it is possible to grow food on Mars?

Answer from Jennifer Heldmann: Hopefully we will be able to grow food on Mars! We have been experimenting with plant growth on the shuttle and space station. Also, here at NASA Ames we have conducted experiments to grow plants in simulated martian soil. So far we are optimistic that we will eventually be able to grow plants on Mars.

Are there any analogs for growing food on Mars?

Answer from Jennifer Heldmann: In the Canadian Arctic and the Mars analog site located on Devon Island there is a Mars analog greenhouse. Here is a link for more information.
There are also webcams here so you can follow the progress of the plants!

Do you have to be secured down when you sleep in space?

Answer from Jennifer Heldmann: Yes, you should be secured down when you sleep in space because otherwise you would float around! You don't want to get hurt by banging into a wall or some other object when you are asleep. Here is a link about sleeping in space:

We are unsure about the air pressure on Mars and how it might affect us. Can you tell us a little about that?

Answer from Jennifer Heldmann: The air pressure is VERY low on Mars - the density of the air is 100 less than on Earth. The pressure is so low that liquid water is not stable -- it is below what we call the "triple point" and so it will boil, even at the low temperatures on Mars. That means you can't just walk outside on Mars without a spacesuit because humans need the pressure to be higher to survive.

What kinds of plants do you think would be most likely to thrive on Mars?

Answer from Jennifer Heldmann: That is a good question. What plants would you suggest that we test? We have never grown plants on Mars so we don't know what will thrive. A variety of plants have been tested and seem to do ok.

Protection/Clothing (3rd period)

What new technologies are being tested for spacesuits? Are these being tested specifically for wearing on Mars?

Answer from Jennifer Heldmann: An interesting new spacesuit technology is the mechanical counterpressure suit (MCP). There is a project called MarsSkins that is looking at this new type of suit.

Is NASA considering wearing a spacesuit made from a different material than what was worn on the Moon?

Answer from Jennifer Heldmann: Yes, NASA is looking at alternatives to the suits worn on the Moon during Apollo. Those suits were very large and bulky which made it hard for the astronauts to work. They also had some problems with the lunar dust getting into some of the joints and seals on the suits. Mars has a lot of dust on the surface so this is something we need to look into.

Transportation (4th period)

Do you think it is possible to power a vehicle with the materials found on Mars?

Answer from Jennifer Heldmann: Hopefully we will be able to power the vehicles, habitats, etc. with materials found on Mars. One idea is to use the carbon dioxide in the atmosphere of Mars and process this into rocket fuel and liquid water. What else might we be able to use on Mars? Think about what we use on Earth -- would we have rocks on Mars? Can we mine the surface and subsurface of Mars? Can we drill for material?

How was the Moon buggy powered?

Answer from Jennifer Heldmann: The lunar rover was powered by batteries. Here is a website with much additional information on the moon buggy:

How are the two Mars rovers powered? We guess solar.

Answer from Jennifer Heldmann: Yes, Spirit and Opportunity (the two Mars rovers) are solar powered (they have solar panels) and they also have rechargable batteries.

Assistance (8th period) -- Hopefully Bill Clancy will be able to answer soon.

Would it be possible for an "assistant" to switch from voice command to keyboard?

Answer from Bill Clancey: Yes, this would be possible if you were inside the habitat, for example, or in a pressurized rover. When do you think a keyboard is more convenient than voice? Can you think of ways using voice command would be easier than using the keyboard?  Would it be possible to use the conventional keyboard when you are wearing a space suit?

Do you have any designs for assistance robots currently in the works?

Answer from Bill Clancey: Yes, we have developed and tested such systems for five years. See for example this link:
Or read the reports from Crew 38 at the Mars Desert Research Station --

How do you think a robot assistant should move around on Mars?

Answer from Bill Clancey: It depends where the people are going and how fast the people are moving. If the Mars crew is in a fast pressurized rover, they would probably like some robots to follow them, right? How fast can the MER rover move? Why is it so slow?

Geologists often work on the sides of hills or cliffs, and deep in ravines. Could a robot on wheels go where people climb? How could we move the robot assistant to where it needs to be?

Sometimes we will want robots to go where it is unsafe for people, or where we lack the necessary tools and equipment. For example, what is the highest mountain on Mars? Do you think people will go to the top first or robots?  Why?

What is the PSA (Personal Satellite Assistant) designed to do for an astronaut?

Answer from Bill Clancey: You can learn about the PSA at this link: or (Quest's educational site for PSA)

By the way, I found this by doing a Google search with the words "Personal Satellite Assistant" -- I look up things like this, even if I have some knowledge, just to read first-hand what the scientists and engineers have to say.

Science/Instrumentation (2nd period - these are the ones who watched the webcast live)

What tools do you think someone exploring Mars would need the most?

Answer from Jennifer Heldmann: The best way to figure this out is to do field work here on Earth that is similar to what we would do on Mars and then see what equipment we needed the most. From the webcast and from the images posted online, what tools did you see us using a lot?

What kind of navigating system would you need?

Answer from Jennifer Heldmann: Good question. On Earth when we do field work we rely on GPS for navigation. We also use things like topographic maps, aerial photos, etc. We don't want to get lost on Mars so good navigation capabilities are very important!

Is it possible to have a GPS like system on Mars?

Answer from Jennifer Heldmann: We could have GPS if we have a constellation of GPS satellites orbiting around Mars like we have orbiting around the Earth. Do you think this might happen someday?

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NASA Official: Mark León
Last Updated: May 2005
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