Where No One Has Gone Before…

1. Where No One Has Gone Before… E80: The Next Generation Section 1, Team 1 Student 1, Student 2, Student 3, and Student 4 May 5, 2008

2. Introduction Overall Objectives Overall Strategy Develop a method for reading and interpreting data retrieved Determine the physical properties of the rocket used Test and verify the sensors that would be used to obtain the desired data • Use various data to piece together an accurate picture of rocket flight • Model rocket flight and compare predicted values to collected data from actual rocket flight

3. Background: The Rockets • Three rocket designs • Large, medium, and small • RockSim • Simulates the launches to give predictions

4. Background: The Sensors • R-DAS • 5 V range • Onboard storage and telemetry • Sensors • IMU • Temperature and Pressure • Modal vibrations

5. Launch Procedure • Launch site: Lucerne Valley Dry Lake • 3000 ft. elevation • Telemetry and rocket prep stations • Timed deployment of parachute as backup • Extensive safety precautions • Range safety officers • Extreme care handling motors and other explosives • All spectators alert during launch • Immediate recovery and data access

6. Rocket 1: Large IMU • Launched on April 19th with a G339N motor • Notable windspeed during launch (15-25 mph) • Objective: Use data from accelerometers and gyroscopes to model the rocket's flight • Did not have all calibration equations

7. Rocket 1: Large IMU • Z accelerometer data, integrated twice, yields an informative plot • RockSim predicts apogee at about 180 m. • Small error in calibration propagates significantly

8. Rocket 1: Large IMU

9. Rocket 2: Large Vibration • Launched on April 26th with a G339N motor • Equipped with 16 piezoelectric strain gauges: 6 selected along the rocket body • Objective is to collect data on modal vibrations experienced by the rocket during flight

10. Rocket 2: Large Vibration • All sensors read two large spikes • Spike at ignition • Spike at parachute deployment • Spikes tend to be larger on sensors nearer the nose

11. Rocket 2: Large Vibration • Fourier transform does not reveal any resonant peaks • Results consistent across all sensors

12. Rocket 3: MediumTemperature and Pressure • Launched on April 26th with a G61W motor • Sensors on board • 4 Thermistors • 2 Pressure Transducers • 2 Accelerometers • Flight Objective • Observe temperature fluctuations during flight • Determine flight profile from pressure and acceleration readings

13. Spike in fin thermistor reading at landing Rocket 3: MediumTemperature and Pressure • Internal avionics are protected • Temperature offset between different makes of thermistors

14. IMU noise can be neglected Data does not compare well with RockSim predictions Bad accelerometer data and calibrations Rocket 3: Medium Temperature and Pressure • Converted pressure readings from both IMU and RDAS show an identical flight profile

15. Rocket 4: Small IMU • Launched on April 19th with a G149 motor • Parachute fails to deploy • Fatal flat spin; rocket destroyed • Objectives • Cope with poor data • Consider data immediately prior to rocket destruction

16. Rocket 4: Small IMU • Spikes caused by significant changes to forces acting on the rocket • Substantial oscillation upon downward flight

17. Rocket 4: Small IMU • Strange shape of height trajectory caused by a lack of gravitational force on the R-DAS accelerometer • Reaches apogee at time and altitude consistent with RockSim prediction

18. Recommendations • Some calibrations curves were inaccurate or missing • 200 Hz sampling rate of R-DAS limits accuracy of vibration and acceleration analysis • Limited sensor sensitivity • Pressure changes measured in discrete steps • No measured vibration for most of the flight

19. Conclusions • Despite limitations, enough data and tools were provided to establish a coherent picture of each flight • Learning to cope with deficient tools and bad data is worthwhile • Valuable field experience

20. Acknowledgements • E80 Faculty: Professors Spujt, Cardenas, Miraghaie • E80 Proctors • Mudd Amateur Rocket Club (MARC)

21. References Spjut, Erik and Cardenas, Mary (2008). E80 The Next Generation Spring 2008. Retrieved 25 Apr. 2008 from http://www.eng.hmc.edu/NewE80/.