Critical Design Review ….. Royal Ordnance,Summerfield 17 th February 2001

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

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

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

7. Open Rocketry Association Slide 7/14 Avionics • 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. Open Rocketry Association Slide 8/14 Recovery • Two parachutes, nosecone & side ejection • Primary apogee sensing trigger • Separate recovery circuit • Pyro release mechanism • Split nosecone • Backup timer

9. Open Rocketry Association Slide 9/14 Software / I.T. • 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. Open Rocketry Association Original payload selection Slide 10/14 Payload (1) • Suite of low mass, low power instruments • Possible multiplexing for more sensors

11. Open Rocketry Association Slide 11/14 Payload (2) • 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. Open Rocketry Association Slide 12/14 Payload (3) • 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. Open Rocketry Association Slide 13/14 Payload (4) • 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!