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A review of the design of KS-NSB-1 mission, including the main payload, continuous wave beacon, software engineering, camera package, airframe, and ground tracking software.
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KS-NSB-1 Critical Design Review KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Presentation Overview S. Rawashdeh J. Bratcher J. Smathers S. Rawashdeh T. Clements J. Delgado T. Clements S. Rawashdeh J. Bratcher • Introduction and Environment • Main Payload • Continuous Wave Beacon • Software Engineering • Camera Package • Airframe • Ground Tracking Software • Mass and Power Budgets • Remaining Schedule
Intro and Environment Samir Rawashdeh KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Mission Goals • Learn to build, launch and track balloons. • Test technologies for future missions. • Training the KySat08 team on relevant technologies and design processes. 10 July, 2008
Expected Environment • 100,000 feet (~30 km) • -40 Degrees Celsius • Near Vacuum • Spin • Landing Impact
System Overview • APRS Tracking • Sensor Pack • Digital Cameras • CW Beacon • ... “should” add a picture of the package here 10 July, 2008
HMR3300 Magnetic Compass Measuring Magnetic Flux Density Range ± 2 Gauss Resolution 0.1 milli-Gauss ( Magnetic field at Equator =~ 0.3 Gauss )
MPX4250 Pressure Sensor Temperature Compensated Over –40° to +125°C Pressure Range: 20 to 250 kPa Sensitivity: 20 mV/kPa (1 Atmosphere = ~100 kPa)
LM335 Temperature Sensor Temperature Min -40 deg C Temperature Max 100 deg C Sensitivity: 10 mV/Deg K
Main Payload Jason Bratcher KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Continuous Wave Beacon Jason Smathers KS-NSB-1 CDR Lexington, KY 10 July 2008 http://www.kysat.com
CW Beacon • Transmits call sign, pressure data, and temperature in Morse code. • Uses off the shelf beacon keying circuit combined with a cricketsat transmitter. • Serves as a redundant system 10 July, 2008
CW Beacon Transmission Call Sign Bln Bk 000 000 000 000 K....15 seconds of unmodulated carrier
Beacon Keyer • Pre-programmed • PIC 505 Micro controller • 4 ADC inputs 0-5V • Pressure Sensor • MPX4250AP • Output .5V-1.8V • Lowest Pressure 20 kPa • Temperature Sensor • 10 mV/K 10 July, 2008
Cricketsat Transmitter • 433 MHz UHF • 10 mW Output • Modified for use with tape measure dipoles • Expected slant range 102 miles
Ground Station Tracking • Kenwood THD7A radio and hand held Yagi. • Laptop running Cwget and Sony Soundforge. • Considering Spectran spectral analysis software.
Conclusion Powered by two 9V batteries in parallel. Testing still needs to be done along with ground station equipment to verify that the system works. Audio software needs more testing.
Software Engineering Samir Rawashdeh KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Flight Software Overview • TI-MSP430 16-bit microcontroller • CrossWorks IDE, C Language • Pumpkin Development Kit • KySat and SpaceExpress code base 10 July, 2008
FS Development • Based on Space Express • Update hardware drivers from KySat • Import File System • Interface Magnetometer • Record data and write on SD Card 10 July, 2008
Log File • T:00001107 (11.07 seconds) • C1:00002951 (CPU Temperature) • C2:00001431 (External Temperature) • P:00002783 (Pressure Sensor) • M:-850,403,-1222 (X,Y,Z Magnetic Field Intensity in 0.1 milli-gauss) 10 July, 2008
Post Recovery Data Processing • MATLAB Script to parse and process log file and produce plots, at recovery site. 10 July, 2008
Camera Package Twyman Clements KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Canon A570 IS Specs • Can take photos at multiple resolutions: • 3072 x 2304 (7.1MP) • 1600 x 1200 • Price: ~$174 • Has documented flight heritage with CHDK firmware add-on.
Calculations for 3072 x 2304 • Photo size: ~3MB • 2000MB (SD card) / 3MB = 667 photos • 4 hours (est. flight time) = 240 min • 240 min / 667 photos = 1 photo / 22 s
Calculations for 1600 x 1200 • Photo size: ~.32MB • 2000MB / .32MB = 6250 photos • 4 hours = 240 min • 240 min / 6250 photos = 1 photo / 2.3 s
Conclusion • 2 cameras • One mounted on +Z (to Earth) • One mounted on –X (to horizon) • CHDK script settings • Reset. • Set aperture to wide angle. • Set camera focus to manual:infinity.
Conclusion (cont.) • Set JPEG compression to superfine. • Turn off display to save battery life. • Set camera to take a photo every 30 s. • Retain default maximum resolution (3072 x 2304, 7.1MP)
Freeze Test Specs • On Thursday July 3rd we conducted a freeze test on both Canon cameras to be used during the NSB flight. • Test Temp = -30 C° • Test Duration = 130 minutes
Freeze Test Conclusions I • Both cameras worked as expected. • Took a picture approximately every 30 seconds. • The small deviations in timing were due to the cooling of the oscillator. • The timing error should not be a major concern.
Freeze Test Conclusions II • Experienced some fog issues at the end of the test. • This was due to opening the refrigerator door and allowing moisture to enter. • Raises a good questions about coating the lenses in an anti-fog solution to prevent any freezing on the lenses.
Test pictures • Normal picture • Checking up • Fog Pictures
Airframe Jessamyn Delgado KS-NSB-1 CDR Lexington, KY 10 July 2008 http://www.kysat.com
Airframe Materials • Polystyrene Shell • Provides thermal resistance from outer surface, structural rigidity, and shock resistance. • Foam rubber landing bag • To protect our expensive instrumentation from impact from below. • Outer abrasion jacket • Rip-stop Nylon cover keeps circuits dry and provides a means for attaching link lines.
Construction New drawings of airframe are unavailable. Please refer to the actual airframe at the front of the room.
Optional Stabilization Disk • Low Priority Stabilization Disk • Circular stabilization disk • Untested • Needs to be built • According to current data, may not be necessary, so is listed as low priority.
Final Tasks • Testing • Freeze Test on Hot Glue • Shock testing on stitching • Run through of launch site checklist • (Optional) Testing on Stabilization Disk • Integration • Install components on slide out board • Install batteries and run lines • Mount Antennas • Install mechanism for side camera attachment.
Ground Tracking and Logistics Twyman Clements KS-NSB-1 CDR Morehead, KY 10 July 2008 http://www.kysat.com
Hardware and Tracking • Three tracking devices: • Bill Brown’s GPS • Radio Beacon • GPS system attached to main circuit board • Tracking Configuration: • Launch Site Team • Chase Car Team 1 • Chase Car Team 2