Reconnaissance on Mars Creation of a Mars Hangar S. Andrew Ning, Krystle Farnsworth, Robert Lawton, Brian Riddle, David Allred
Mars Exploration • Assemble and repair machinery: airplanes, ATVs, rovers • Imagine doing that work in a Full Pressure Suit
Creation of an Intermediate Environment • Allows design of a suit with greater mobility, dexterity, and visibility Mars Homestead Project @ M.I.T.
95% CO2, 2.7% N2, 1.8% Ar, .13% O2, .07% CO Surface pressure is approximate 6-7 millibars Average Temperature = -55°C 78% N2, 21%O2, .9% Ar, .03% CO2 Surface pressure is about 1.01 bar Average Surface Temperature = 15°C
Biological Concerns • Mars has insufficient oxygen (Gas Composition) • Mars has insufficient vapor pressure (Pressure Regulation) • Mars is too cold (Temperature Regulation)
Solution: Space Suits • Full Pressure Suits (FPS) used in past NASA explorations protect against thin atmospheres, low pressures and cold temperatures • Downside: The large pressure differential created makes movement awkward and large helmets limit visibility
Ideal Pressure • Lower pressure differential decreases fatigue and increases productivity. Especially gloved hand fatigue. • Too low of pressure presents risk of hypoxia. Need to maintain sufficient partial pressure of oxygen in lung alveoli. • Too high of pressure presents risk of oxygen toxicity.
Mixed Gas Composition One approach to avoid oxygen toxicity and flammability hazards is to use a mixed gas suit Drawbacks: • More expensive to continually monitor both oxygen and nitrogen partial pressure • Adds weight and volume • Increases risk for decompression sickness
Other Problems • How do we do heavy duty work? These Full Pressure Suits (FPS) lack dexterity, mobility, visibility, and are high in energy cost. • Longevity. FPS take a long time to take on and off. Also need to consider repeated decompression.
Our Solution: Build a “Mars Hangar” • An intermediate environment can be used to provide external pressure- Compress existing Mars air to >0.5 Bar Sprung Instant Structures
Intermediate Environment Suit • Used as a supplemental suit • Not gas-tight suit (thin like a flight suit) • Oxygen Face Mask • Microwave absorbent material
Benefits of a “Mars Hangar” • We can increase the pressure while using a thinner suit, so motion is much less restricted • With a higher pressure we can use mixed gases • Can decrease or eliminate decompression time • Taking suit on and off is much more time efficient • Allow us to use local resources to supply and exhaust air – saves on costs • Increased mobility makes it much easier to assemble and repair airplanes, ATVs and rovers
Decompress in “Mars Hangar” • Pre-breathe 100% Oxygen • Inert Environment • Can still do productive work
Temperature Regulation • Long range heating by directed microwaves – minimize bulkiness of suit • Deliver the heat energy directly rather than heating empty space, a plus for energy poor environments like Mars • Can be more efficiently reflected than infrared • Easier to produce and direct than infrared
Electrochromic Materials • Transport hydrogen ions from a storage area through a conducting layer into electrochromic material • By applying a voltage we can reversibly change the window from a clear state to a darkened state NREL of the DOE
Why didn’t the microwaves switch? • We used an electrochromic mirror that uses two electrically conductive transparent coatings • The microwaves didn’t even reach the electrochromic material
Where do we go from here? • Needs a smaller plasma frequency than conventional materials (lower conductivity) • Make our own electrochromic material using Tungsten-Bronze, Ruthenium-Oxide, or Vanadium-Oxide • Use a microwave mirror with co-planar switchable links • Use of materials that rotate polarization (we can use polarized microwaves to switch from absorbing to reflecting)
Summary • Building and operating machinery will be essential in Martian exploration. • Intermediate environments will be very useful and can be developed by: • Building a Mars air pressurized hangar • Developing a thin, flexible, low weight, intermediate environment suit • Using directed heating by microwaves • Thus, we can provide sufficient pressure, oxygen and temperature while dramatically decreasing the bulkiness of the space suit. This will increase mobility, dexterity and visibility. • Things will get done!