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

Introduction Overall Objectives 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 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

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

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

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

Rocket 1: Large IMU Launched on April 19 th 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

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

Rocket 1: Large IMU Time (seconds after launch) Rotational Event 0.5Change from CCW to CW 5.5Parachute deploys 7.5Stop; continue CW 11Change from CW to CCW 18.5Change from CCW to CW 27Change from CW to CCW 31.17Impact

Rocket 2: Large Vibration Launched on April 26 th 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

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

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

Rocket 3: Medium Temperature and Pressure Launched on April 26 th 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

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

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

Rocket 4: Small IMU Launched on April 19 th 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

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

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

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

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

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

References Spjut, Erik and Cardenas, Mary (2008). E80 The Next Generation Spring Retrieved 25 Apr from