Objectives Overview Objective: Create an Earth field unit to test electrochemical sensors Deliverables: –Field-ready unit –Test data verifying requirements –Operational manual for use –Document proposing design solutions to make the instrument more Mars-ready Mars-applicable solutions do NOT have to be implemented on field unit

Requirements Overview Changes to PDD requirements: –Requirement 4.24 removed: MiDAs must no longer provide its own power –Will still be able to accept power from various sources –Power supply options will be included in design document Project Focus Change: –Complete autonomy no longer crucial component Increased reliance on experimenter to open valves and deliver inoculation sample Change at request of customer – tradeoff of autonomy versus reliability in field instrument Autonomy deemed out of the scope of this project Autonomy options will be included in design document –Autonomous data collection and storage, heating, cooling, and mixing still part of design

System Architecture

Chambers Reaction Chambers Reagent Water Chamber Autoclave Chambers and Cap

Subsystem Breakdown Chassis Environmental Chamber Pump and Mount

Electrical Block Diagram

Experiment Timeline minDescriptionMeasurementTestyes/noControlheatcool t = 0begin autoclave cycle again Is t = 317?yes off increment time, move to next step no continue autoclave cycle t = 318begin autoclave cycle again Is t = 635?yes off increment time, move to next step no continue autoclave cycle t = 636begin autoclave cycle again Is t = 953?yes off increment time, move to next step no continue autoclave cycle t = 954Autoclaving completevisualAre heater and cooler off?yesopen auto clave ejection valve and water valve perform next test noStop, check for failure stop Heater is off Cooler is off Are valves open?yespump 25mL water through autoclave increment time, move to next step begin soil transportation noStop, check for failure stop t = 955finish soil transportation temperatureIs pump done?yesclose valves, begin taking measurements, zero electrochemical sensors perform next test initialize sensorspressure no increment time, repeat inoculateElectro-chemicalIs data being recorded/electro-chemical zeroed? yesinoculate increment time, move to next step noStop, check for failure stop t = 956begin mixingtemperatureIs test chamber inoculated?yesturn on mixers perform next test temperature controlpressure nostop, check experiment for failure stop Electro-chemicalIs temperature <= 6°C?yes onoffperform next test no off perform next test Is temperature >=35°C?yes offonincrement time, repeat until t = no off increment time, repeat until t = 21116

Thermal Analysis

Mass Analysis Peristaltic Pump & Motor = 106g Shared Environment = 646g Reaction Chambers =173g Water Chamber = 132g Autoclaves = 263g Insulation = 20.5g Chassis = kg Sensors = 10.0g Valves = 454g Total = 2.95Kg

Power Summary

Autoclave Power Summary