Mars Airship by jwhart1

Last crawled date: 3 years ago

This submittal is for a mobile rigid airship Mars base. For the 2014 NASA Mars base challenge.
It is assumed that a manned mars mission would run 5-10 years, and that the range of any rovers, etc in a stationary base would be limited to a few hundred kilometers. With a mobile base, any site on Mars can be studied.
The base survivability will be improved by being nomadic, whenever a surface exploration is not underway the base can be in motion to keep up with the sunlight or avoid inclement weather (using some orbital weather satellites).
The top of the airship will have greenhouses and solar arrays (my model shows two greenhouses and three solar arrays. And the lower portion will be the living quarters, laboratory, and engines.
It is assumed that the mobile base will act primarily as a robot control center and repair facility. Most of the scientific/exploratory missions will still be handled by robtots, but the robots will be controlled, deployed/retrieved, and maintained by the crew of the mobile base. This will allow ongoing long term scientific/exploratory missions while the base stays in motion.
The dirigible gas can be hydrogen, left over or reclaimed from propulsion fuel tanks. The martian atmoshpere is mostly low pressure CO2 so there will be little risk of fire.
And if the crew, a few years into the mission, decides to paint a giant skull and crossbones on the side of the base, and start saying "Yar" or "Ya har" a lot, we can all consider that to be awesome.
Update June 10, 2014
-Added more verticle beams, because the loading of the horizontal beams (in my imagination) resulted in too much deflection due to the weight of the greenhouses.
-Changed the engines from propeller looking devices to a more printer friendly turbine-like design. Didn't mention it before, but these ought to be electric powered given the need for a renewable power source (because re-supplying from earth is prohibitively expensive).
-Added some tubes for personnel, power, and gas exchange between the lower quarters and the greenhouses.
A challenge question that may arise is, given the very low atmospheric pressure on Mars, is feasible to float anything on it? Technically, the answer is yes. If you throw a less dense gas than CO2, say hydrogen into a balloon on Mars, the balloon will expand until pressures are approximately equal, and the balloon will have some small lifting force on it. Just like a helium balloon in the earth's primarily nitrogen atmosphere. Still there are limitations in the amount of lift that can be generated due to the low pressure, but some of this will be countered by the lower gravity (Revision, no it will not, the lower gravity is nothing but a problem in this bouyancy situation, see below). In the end, it'll amount to figuring out how much mass can be lifted per cubic liter of balloon, and from there figuring out how big a balloon is needed.
Final Update
-Design has been modified to improve printability, while complementing the more important design aspects. Printability has been improved from "needs an SLS machine" to "hey, I bet I could make that work with a few settings adjustments."
Final Science Update
Some Lift Chicken Scratches:
Martian atmospheric pressure at top of Olympus Mons = 0.03kPa
Average Martian atmospheric pressure = 0.6kPa
Minimum Martian Temperature = 130 kelvin
Maximum Martian Temperature = 308 kelvin
From the ideal Gas Law:
Density(kg/m^3) = P(Pa)/[R(kgK)T(K)]
R_CO2 = 189
R_H2 = 4157
Lifting Gas Volume from the model
(assuming 1 mm = 1 meter) is equal to 195000 m^3
Pressure(Pa)
Temperature(K)
Volume(m^3)
Max ship Load (kg)
30
130
195000
227.3
30
308
195000
95.9
600
130
195000
4550
600
308
195000
1920
Based on those calculations, the ship will have to be extremely light
with a load less than 1 ton. Obviously the ship doesn't appear to be operable at altitudes comparable to the top of Olympus Mons, but there may be happy middle ground.