1. Critical Design Review ….. Royal Ordnance,Summerfield 17 th February 2001 National Rocketry Competition 2001 Open Rocketry Association Slide 1/14

2. Open Rocketry Association Slide 2/14 Road map 1. Introduction 2. Aerodynamics 3. Structure 4. Avionics 5. Recovery 6. Software / I.T. 7. Payload 8. Onward and upward!

3. Open Rocketry Association Slide 3/14 Introduction Team of postgraduates and employees of OU On campus in Milton Keynes Backed by Science Faculty About 6 active members

4. Open Rocketry Association Slide 4/14 Aerodynamics Utilised RockSim v5.0 Analysis for Aerotech J700 motor Length = 200cm, diameter = 11cm Predicted mass = 5.5kg CG = 99.484cm, CP = 126.595cm Ogive nose cone Estimated peak altitude ~ 1.2km

5. Structure (1) Open Rocketry Association Slide 5/14 External resin-coated cardboard shell Internal (load-bearing) wooden structure Rail guided removable assembly Detachable motor mounting Structure allows easy housing of sensors

6. Structure (2) Open Rocketry Association Slide 6/14

7. Avionics Open Rocketry Association Slide 7/14 On-board data storage desired Commercial unit for speed / simplicity R-DAS chosen Accelerometer -50..+50 g, 0.1 g res P sensor 20..105 kPa, 0.09 kPa res 6 analogue user input channels, 10 bit Max sampling rate = 200 samples/s 4 user available digital input channels 32 Kbytes RAM memory RS232 link for data retrieval

8. Recovery Open Rocketry Association Slide 8/14 Two parachutes, nosecone & side ejection Primary apogee sensing trigger Separate recovery circuit Pyro release mechanism Split nosecone Backup timer

9. Software / I.T. Open Rocketry Association Slide 9/14 No need for OBSW if using R-DAS May need s/w to interpret data Intranet used for internal data etc. Setting up external web site (commercial ISP) Offer of space on Final Frontier web site

10. Payload (1) Open Rocketry Association Slide 10/14 Suite of low mass, low power instruments Possible multiplexing for more sensors Original payload selection

11. Payload (2) Open Rocketry Association Slide 11/14 Accelerometer 1 ± 50g unit (R-DAS) for z-axis 2 ± 2g units for x/y acceleration Analog Devices accelerometers Different sampling rates to record different phenomena Snatch loads Mechanical method of measuring loads on parachute deployment. Simple Hook’s Law deformation of various materials.

12. Payload (3) Open Rocketry Association Slide 12/14 Pressure transducers - Gives airspeed (for a nose mounted Pitot tube) - Gives angle of attack (P diff across body) - Gives altitude (using internal sensor as a barometer) - Gives a general indication of flow-field over the body - R-DAS contains Motorola MPXS4100 - 20 to 105 KiloPascals at 0.09 KiloPascals resolution Temperature - Simple thermocouple sensor and amplification to measure temperature at various points of the rocket body.

13. Payload (4) Open Rocketry Association Slide 13/14 Camera - 24 images at 640x480 pixels - On-board data storage (!) - COTS product - <100g without casing - 10 second image refresh time - Views through port in outer skin - Possibility of including filters for certain wavelengths - Requires external (electronic) timing and triggering mechanism High altitude atmospheric sampler - Retrieval of a sample of gas from near apogee

14. Open Rocketry Association Slide 14/14 Onward and upward! Currently acquiring components Construct flight model structure Finalise and breadboard payload concepts Calculate final mass budget => parachute size Test recovery system (e.g. frangible bolts, deployment) Perform structural load tests Integration of all components Safety review & Milestone 2 LAUNCH!