1. Colorado Space Grant Consortium DemoSat-B Colorado State University Matthew Jui, Ian Patterson, Mark Spowart, Todd Wallis June 8 2011 Colorado Space Grant Consortium DemoSat-B Colorado State University Matthew Jui, Ian Patterson, Mark Spowart, Todd Wallis June 8 2011 Critical Design Review 1

2. 2 The payload for the CSU DemoSat-B 2011 project is a ‘CO 2 mapping with respect to altitude System’, C-MAS. This payload will measure concentrations of carbon dioxide in the atmosphere throughout its flight and then will be matched with corresponding altitudes upon recovery. Although weather balloons with similar measuring equipment are launched daily, what makes C-MAS unique is that the data that is taken is done so at a much higher altitude and at a lower cost, while still maintaining a high level of accuracy. Overview Objectives Payload will measure concentration of CO 2,RH, temperature and pressure at intermittent altitudes Payload will operate by itself for 200 minutes and take data for both ascent and descent Optional Objectives Payload will visually record weather conditions through an attached camera or video camera Topic Background Multiple organizations have conducted similar research but with different techniques. (sample from aircraft, and Space observation)

3. 3 CO 2 concentrations are cyclical but are increasing by about 2 ppm/yr. Current CO 2 concentration at sea level is 394.4ppm Although this is a relatively small overall concentration, it is an important component of the earth’s atmosphere because it emits and absorbs infrared radiation at wavelengths that play a significant role in the greenhouse gas effect A peak in annual concentration levels happens in Spring when plants are in full bloom In July we expect to see relatively constant concentrations throughout the atmosphere CO 2 concentrations in our atmosphere

4. 4 Schematic of major Internal Components

5. Pump provides volumetric sample air flow through system Heater brings sample air temp to w/ in sensor operating temp CO2 meter measures CO2 concentrations, RH, Temp – Data logger saves all data including external pressure sensor 5

6. Mission Requirements Matrix RequirementMethodStatus The payload must not exceed a weight of 1.5 kg.Design, Test The payload must operate on 9V or less.Design, Test The payload’s center of gravity (CG) shall be as close to the geometric central axis as possible. Design, Analysis The inlet air must be heated to approximately 0 C before interacting with the CO 2 sensor. Design, Analysis The payload will record CO 2, temp, RH, pressure values every 30 seconds for a minimum of 200 minutes. Design, Analysis The payload’s shell will protect the internal components against a load of 15 g’s. Design, Analysis The internal components will remain secured to the mounting plate when exposed to a load of 15 g’s. Design, Analysis Completed project must cost under $1000.Plan The spacecraft must be capable of meeting all mission objectives. Design, Test 6

7. 7 Electronics Schematics

8. 8 Flow Chart Block Diagram

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11. Subsystems Overview Power Subsystem Battery must stay between 32 and 140 F during all operation Voltage must be regulated from 7.4 to 5V depending on the circuit element Air Flow Subsystem Flow rate minimum of.3 liters per minute No detectable leaking may occur between inlet and exit Air must be maintained above 0 C Heating Subsystem Must maintain both air flow and power subsystem heat requirements Sensor Subsystem Must take accurate measurements of both CO2 concentration and internal pressure

12. Parts List

13. Test Plans TestStatusResultNotes dropcompletesuccess Stair pitchcompletesuccess whipcompletesuccess coolerpendingLiquid Nitrogen Vacuum chamber Scheduled for 7/1 Must be flight ready

14. 14 Bubble Test Used to measure volumetric flow rate

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