Critical Design Review

1. Critical Design Review West Point-Beemer’s SLI Vehicle and Payload Experiment Criteria

2. Mission Statement • Experimental Test of Boyle’s Law with a 1 mile high power rocket launch • Requirements: • Launch vehicle to an altitude of one mile • Collect useful scientific data • Successfully recover rocket • Accomplish all other goals of the NASA SLI program • Mission Success Criteria • Launch vehicle to an altitude of one mile • Collect useful scientific data • Successfully recover rocket • Accomplish all other goals of the NASA SLI program

3. Design at System Level • Design Review at a system level • A. Updated Drawings and Specifications of systems • I. Recovery • Recovers rocket safely in compliance with NFPA 1127. See recovery subsection • II. Payload • Accomplishes scientific goal of flight, details in payload section • IIV. Electronics • Perfectflite MAWD Drogue charge at apogee, main charge at 500’ • Ozark Aerospace ARTS 2.0 Drogue 1 second after apogee, main charge at 450’ • BeeLine GPS in booster section • Standard BeeLine for backup in the payload section • Data Recorder • Remote Launcher IV. Stability/Booster Three ¼” Plywood fins built into an interlocking structure that makes up the whole booster. Enclosed in a tube that is removable. V. Ignition Remote launch system. 9.07 x 10 ^ -9 percent chance of being inadvertently activated by another user of the same type of system. Operates on 433.92Mhz

4. Pictures: Electronics, Remote Launch System

5. Testing • 3.7:1 Scale Test Flight, 12-17-06, success by all measures.

6. Testing • Fins Structure (Actual will only have 3 fins)

7. Testing • Electronics bay model

8. Preliminary Motor Selection • Animal Motor Works K975. Extremely unlikely that a smaller motor will be selected, 75mm and L motors cannot be used for various reasons

9. Demonstration of vehicle meeting all system level functional requirements • Current analysis and tests that have been performed on the booster, electronics and recovery sections show that all systems function as intended and as required to achieve mission success.

10. Relation of approach to workmanship and mission success • Care to ensure mission success will be in mind at all times during construction, testing, prepping and flying. Sloppy jobs and rushed work will not be accepted and will be redone until it is acceptable to achieve mission success.

11. Additional testing to be performed • Ejection charge and parachute deployment tests • Confirmation of the inability of the radio controlled ignition unit’s capability of being inadvertently actuated • Ground tests of all electronics before flight • Possibility of functional tests on motor igniters (tube representing motor core and nozzle with pressure and temperature sensors) • CP/CG relationship confirmation with fully loaded rocket • Fox Hunt with trackers • Simulate to the best of our ability the flight loads on the nose, body and fins that the vehicle will see in flight (apply estimated forces to proper areas) • Full scale flight test with all systems operational

12. Status and plans of remaining manufacturing • Complete final booster unit and electronics bay. • Paint rocket • Install all electronics and science

13. Integrity of design • A. Fin shape and style for mission • 1/4” plywood fins of similar size have flown to the speeds and experienced the loads that will be placed on our fins during flight. No concerns are foreseen • B. Proper use of structural elements • The been reviewed by engineers and the feedback provided was that 1/8” plywood could be used for everything but the fins themselves. Due to material availability, 1/4” plywood will be used throughout and will be sufficient for the flight.

14. Integrity Of DesignContinued C. Proper assembly procedures, attachment and alignment, solid connection points, proper load paths. • The precision fit interlocking structure used throughout most of the vehicle automatically align when assembled. TiteBond II, a type of alphaic resin, will be used for all wood to wood and wood to cardboard connections. These are the only type of glue connections in the rocket, and the use of wood glue on precision fit parts is nearly foolproof. The loads from the motor thrust will be distributed from the thrust ring on the motor, to the aft ring in the fin unit, to the body tube and truss structure, to the upper body tube and electronics bay, through the body tube to the nose. D. Motor mounting and retention • An internal masking tape ring will be used to retain the motor. The motor has no way to move within the rocket unless the fins, body tube and lower centering rings all fail, which is highly unlikely. E. Status of verification • The Perfectflite MAWD will be used to verify the altitude. It will be operational for flight as it is essential to vehicle operation.

15. Safety And Failure Analysis

16. Recovery Subsystem • Kevin Rich, a licensed parachute rigger for man-rated parachutes will be assisting us with the recovery of the vehicle. With a final vehicle weight of about 21 pounds ready to fly, a parachute that can handle that weight and still recover at a safe rate of under 20 feet per second will be required. • Due to their extreme reliability and durability, a Rocketman R14-C, which can handle rockets from 20-35 pounds*, has been chosen. A Rocketman R3-C will be used as a drogue at apogee and the main R14 will deploy at 500’ AGL. The MAWD and ARTS will fire independent ejection charges housed in PVC caps to separate the body sections and allow the parachutes to come out. Calculations and tests will be done to determine the mass of the 4fg black powder required to reliably deploy the parachutes. • *www.the-rocketman.com

17. Recovery SubsystemContinued • The R3 will be attached to approximately 30 feet of 9/16” tubular nylon climbing webbing which will be attached to an eye-bolt in the top of the motor and a eye-bolt on the bottom of the electronics bay. A water knot with no quick links will be used for attachment. The main parachute will be attached in a similar manner using 20’ of 9/16” webbing attached to the eye-bolt on the top of the electronics bay. No quick links will be used in any part of the system as they only add more failure points and more things to forget. • The R14 will be packed in a custom made deployment bag that the team will work on with Kevin Rich. A small pilot parachute is likely to be used to pull the bag out of the tube and deploy the parachute. At this time, it is currently unknown whether or not the bag, pilot and nose will recover attached to the top of the canopy or separately.

18. Mission Performance Predictions • Criteria: Propel the vehicle to 1 mile (5280 feet) in a strait, stable flight that does not put forces on the vehicle that the vehicle cannot handle and successfully recover the vehicle within the field’s perimeter without violating the FAA waiver.

19. Flight Profile Simulations • Maximum altitude: 5760 Ft.-K975 in no wind • Maximum altitude: 5710 Ft.-K975 in 10 mph wind • Maximum altitude: 5598 Ft.-K975 in 20 mph wind

20. Validity of Simulations • The simulations show that ample extra altitude will be achieved unless the vehicle is more than 3 pounds overweight. Test flights with the actual vehicle will be used to tune the altitude and make sure that the Huntsville flight will achieve nearly exactly 1 mile • A static margin of 1.67, with the CG at about 57” and the CP at about 66”, is sufficient for stable flight

21. Stability

22. Payload Integration • A. Integration plan • The electronics/payload bay is specifically designed for easy integration of the payload and deployment electronics. The data collection device will be simply bolted to one of the 3 trusses that span the length of the payload bay. The 9v battery that it will run on will also be mounted with zip-ties to a truss. The data collection tubes will slide in precision cut holes in the two rings inside the bulkhead. To slide them in, one of the bulkheads on either end of the electronics bay will be removed by removing the eye-bolt on that end. This will expose the holes that the tubes slide into. They will then be slid in, secured with rings of masking tape to prevent them from sliding and the bulkhead and the eye-bolt will be replaced. • B. Interface • The final outside diameter of the data collection tubes has not been finally determined at this point; however it is known that it will be below 1.5”. 4 1.5” holes will easily fit in the electronics bay as shown in the picture earlier. The diameter of the holes in the final bay will be determined by using a caliper to measure the O.D. of the data collection tubes and put that value in AutoCAD so that the parts can be cut out accurately with the water cutting machine.

23. Payload IntegrationContinued • C .Compatibility • The separate parts will be separated by 1/4” trusses and should not pose any problems to each other. The ARTS will have aluminum foil to protect it from RF interference from the Beeline Tracker. Experience has shown that in close proximity they will interfere with each other and cause the ARTS to operate improperly. Other incompatibility issues are not expected due to previous experience • D. Integration • No simpler way of integrating the payload has yet been found. If any method is found that makes it easier to integrate the payload, consideration of a design change may be made, however, at this point, that is unlikely.

24. Launch Concerns and Operation ProceduresVehicle Prep • Unpack shipping containers and verify packed contents are present. • Inspect all parts for damage. If damage is found, fix it if possible. • Assemble motor according to manufacture’s instructions. • Assemble electronics and payload bay • Set up lower electronics bay • Prep and install motor • Pack Recovery System • Slide lower tube onto booster section and secure with screws. • Slide upper tube onto coupler section of booster and secure with shear pins. • Install rail buttons • Give rocket final visual inspection and resolve any problems that may exist. • Verify from the Range Safety officer that the field conditions still meet acceptable launch criteria.

25. Launch Concerns and Operation ProceduresLaunching • Set up launch pad and launch controller. • Clear dry grass or other materials within the radius required by NFPA 1127. • Confirm that electronics (except tracking devices and the data recorder) are turned off. • Bring rocket out to the launch pad. • Load rocket on launch rail. • Power-up electronics • Confirm continuity on all 4 altimeter output channels and all 4 recording input channels. Also confirm tracking signals from both trackers. • Verify launch angle will place recovered rocket within the launch field. Adjust angle if needed. • Confirm all near-pad video recording devices are ready for flight • Power up remote launching device and confirm continuity from launch control. • Clear all non-essential personnel from the safety radius around the launch pad. • Install igniter into motor. Confirm igniter is all the way to the top of the motor to insure proper motor ignition. • Confirm continuity on all channels and trackers one final time. • Retreat to launch control area. • Alert everybody of the impending launch and make sure proper safety radius around the vehicle is clear. • Check continuity. Turn of continuity checker after check is done. • Arm launcher. • Count down from 5. • Launch vehicle.

26. Launch Concerns and Operation ProceduresPost Flight-Operations • Track rocket using primary GPS tracker and find rocket location. If GPS tracker is not sending a correct signal, use the backup tracker. • Go to location of vehicle • Approach vehicle perpendicular to center tubing section • Disarm all electronics. (Tracking and data recording electronics can be left on.) • Carefully confirm that all ejection charges have fired. (Use a mirror on a stick with a flashlight to look into tubes. Do not put face or other body parts over ends of tubes prior to confirmation). • If charges have all fired, disconnect recovery system. Transport the rocket back to the launch area. • Remove and clean motor case when it has cooled down. • Unscrew and remove airframe tubes from electronics bay. • Download flight and experiment data to laptop computer. • Turn off GPS and backup trackers and any other electronics that have not yet been turned off. • Remove any other non-shippable rocket components. • Pack rocket back in shipping container for trip home.

27. Safety And Environment • Andrew is our safety officer. He has experience in risk mitigation in complex, high risk high power rocket construction and flight. All participants will be required to show the necessary knowledge of our safety plan.

28. Failure Modes

29. Prevention of Inadvertent Activation of Remote Control Devices • Devices will utilize shunts and switches that break the circuit to prevent current flowing to igniters when device isn’t armed. • Devices will not be able to be actuated unless a unique 60ms code is received. • 9 x 10 ^-9 % chance of inadvertent activation by a non involved part

30. Personal Hazards

31. Personal HazardsContinued • Always wear safety glasses when dealing with rocket parts containing small hardware or pyrotechnic charges. • Never look down a tube with live pyrotechnic charges in it. • Always point rocket and pyrotechnic charges away from body and other people. • Avoid carrying devices that have live electrical contacts (radios, cell phones, etc.) while prepping live pyrotechnic charges. • Never arm electronics when rocket isn’t on pad unless the area has been cleared and everyone knows that pyrotechnic continuity checks are being done. • Always follow the NAR/TRA safety codes. • Always follow all applicable local, state and national laws and regulations. • Only the Level 2 certified mentor may handle the motor (CPSC regulations). • Do not allow smoking or open flames within 25 feet of the motor or pyrotechnics. • Avoid horseplay and idle conversation, focus on properly completing the task at hand. • Make sure the checklist is followed and all steps are completed properly in a though, workmanlike manner to assure mission success. • Since the motor for the flight utilizes snap rings to retain the ends of the motor, care must be taken when installing and removing snap rings. Snap rings can be sent flying at high speeds in unpredictable directions even if reasonable care is being taken, thus, all personnel within 25 feet of a snap ring installation or removal procedure will be required to wear safety glasses or move out of the area and keep eyes turned away from motor.

32. Environmental Concerns • All waste materials will be disposed of using proper trash receptacles, biodegradable and flame resistant recovery wadding will be used. Practice launches will only occur with local fire department permission if dry grass conditions exist. Bureau of Land Management regulations will be followed when doing test launches on BLM land. Solid rocket motor manufacture’s instructions will be followed when disposing of any rocket motor parts. Consideration of environmental ramifications will be made regarding applicable activities.

33. Payload Criteria • We have determined after continued testing that a syringe will not provide a sufficient force to push a liner potentiometer. That moves us to our third measuring design. We will use a strain gauge on a flexible diaphragm at the end of our gas sample tubes. This device will have to be calibrated for pressure to resistance ratios, and we will be testing the ideal gas law (PV=nRt) with changing pressure as our variable instead of changing volume. Strain gauges are on order and should be delivered next week. Until then we are testing with a disassembled digital scale. We are very interested in seeing the effects of the launch on the flexible diaphragm end and gauge. We will use 12” X 1” pvc tubes as our sample chambers and rubber sheeting as the diaphragm

34. The custom data recorder!

35. Specs on recorder • Sample rate: 20Hz • Channels: 6 analog • Memory: 262144bits, 32768bytes, 16384samples • Sample size: 12bit • Recording time: 136.5 seconds • Size: 1x2in • Power requirement: 5.5V-12V(9V nominal) • Processor: Microchip PIC16F88 (see www.microchip.com) • Oscillator speed: 8MHz • Download connection: RS232 serial at 9600baud • Recording start trigger: Break wire, start on open

36. Payload Concept Features and Definition • Proposed science payload will test different gasses to confirm that they behave according to Boyle’s Law. By testing various gasses in the range of pressures and temperatures found in a rocket flight to 1 mile, we hope to accomplish this. • We haven’t seen any other teams attempt a science experiment like this. We feel that because of that, it is unique and that it will provide a suitable challenge to us for this project. • The problems that we have encountered with measuring the changes in the gases has shown us that there is considerable challenge in this project

37. Science Value • Comparison of theoretical calculations of gas behavior to results of launch test will confirm success of the experiment. Variables such as barometric pressure and temperature on launch day will need to be recorded and factored into the projected results of the experiment. Projected results will be calculated using proven behaviors of the various gasses used in the experiment. Matching results between the collected data and calculated projection will determine success of the flight. The variables would be the temperature and pressure of the gas and the original amount of gas on ground level will be the control. Our predicted data will be graphed against our actual results after the flight using a spreadsheet program.

38. Safety and Environment • Andrew is our safety officer. Andrew has more experience with rockets than anyone else on the team. • Our current main concern is in the attachment of the strain gauges to the diaphragm. We will have to calibrate each tube individually to maintain accuracy. We will mount our tubes with the strain gauges facing to the top of the rocket so inertia does not rip them off during launch.

39. Outreach • We have had our Rocket display at the local library for the month of December. • We are teaching rocketry to the 4-H club in Beemer on January 27th. • We will be discussing our rocketry and our project with the West Point Optimists club on February 14th • We are sharing some resources with the Benson SLI team

40. Activity Plan • Budget ~ $2,750. We hope to get a local grant to cover the extra expenses or raise the money elsewhere. • Timeline • First test flight preliminarily planned for Feb. 24 • Continuing to order parts and do construction as things are finalized • Flight Readiness Review Full timeline in CDR Document

41. Summary • In summary we feel that we are still on track both budget and time wise for successful completion of this project.