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: Imagine doing that work in a Fullairplanes, Pressure ATVs, Suit rovers 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 Quantum theory of light 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 Experiment Reflectance Transmission Absorption Mirror* Aluminum 77% 88% 2% 1% 21% 11% *Readings for both 'clear' and 'tint' settings were the same within measurable error 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!