1. RockSat-C 2012 PDR Minnesota Sound Wreckers Preliminary Design Review University of Minnesota Alexander Richman Jacob Schultz Justine Topel Will Thorson 10/26/11 1

2. RockSat-C 2012 PDR Mission Overview Justine Topel 2

3. RockSat-C 2012 PDR Mission Overview Our mission is to design a system that actively removes noise in a test chamber during a rocket launch We require at least some reduction in intensity of noise in the test chamber compared to the control chamber as well as the safe operation of the entire payload. 3

4. RockSat-C 2012 PDR Mission Overview cont. We expect to show that this technique is a viable solution to noise sensitive testing onboard rockets. This would benefit any sound sensitive experiment onboard a rocket including any testing in which live subjects are used and it is desired to lower their stress levels. 4

5. RockSat-C 2012 PDR Theory and Concepts The theory of active noise cancellation is that when one sound wave meets another wave which is an inverse of itself the two waves cancel out and overall noise is reduced While no research has been done onboard rockets to our knowledge, active noise cancellation has successfully been used in many other aplications. 5

6. RockSat-C 2012 PDR Concept of Operations Data collection will begin upon the signal line going hot. We expect to see limited noise reduction during initial burns and maximum reduction after the completion of both burns and through reentry. 6

7. RockSat-C 2012 PDR Example ConOps t ≈ 15 min Splash Down -All systems on -Data collection running t = 0 min Apogee t ≈ 2.8 min Altitude: ≈115 km End of Orion Burn t ≈ 0.6 min Altitude: 52 km Altitude t ≈ 5.5 min Chute Deploys

8. RockSat-C 2012 PDR Expected Results 8 We expect to be successful in reducing the overall power of the wavelength spectra between about 50 Hz and 20kHz This means a reduction in amplitude at most of the frequencies within this range. –We are planning to use a middle range speaker, and thus will maybe see more response from 1kHz to 10kHz

9. RockSat-C 2012 PDR System Overview Alex Richman 9

10. RockSat-C 2012 PDR Subsystem Design – Physical Model 10 Power Supply Data Logger ANC System

11. RockSat-C 2012 PDR Design in Canister 11

12. RockSat-C 2012 PDR Critical Interfaces 12 At the PDR level you should at minimum identify these interfaces Interface NameBrief DescriptionPotential Solution ANC/STR The electrical power system and boards will need to mount to the canister plate to fix them rigidly to the launch vehicle. The connection should be sufficient to survive 50Gs in the thrust axis and 10 Gs in the lateral axes. We will screw the power supply and electronics for the ANC system directly into the Makrolon plate. DL/STR The data logger will need to mount to the canister plate rigidly. The connection should be sufficient to survive 50Gs in the thrust axis and 10 Gs in the lateral axes. In the same fashion as the ANC system the data logger will mount directly to the plate. CHM/STR The chambers must affix rigidly to the mid plate so that they survive 50Gs in the thrust axis and 10 Gs in the lateral axis. The base of the chambers will be welded to the mid plate ensuring a strong rigid connection. SPK/CHM The speakers must be placed inside the chambers so that they stay affixed and do not move in flight. Possible solutions include making a bracket that attaches to the base of the cylinder or some other kind of mount. MIC/CHM The microphones must attach to the top of the chamber so that they do not move during flight. A mount could be quickly designed to attach the microphones to the top of the chamber.

13. RockSat-C 2012 PDR System Level Block Diagram 13 DSP System speaker microphone Data Logger microphone Power Supply Wallops activation signal

14. RockSat-C 2012 PDR Requirement Verification 14 Requirement Verification Method Description The ANC system should cancel noise in a cylindrical chamber TestMock up chamber with a speaker and microphone will be made and tested for noise reduction. The power supply should have enough power to drive the speaker AnalysisThe speaker’s power requirements will be researched and the amount of power we can supply will be calculated. All components must fit within the canisterInspectionVisual inspection of the SolidWorks drawing will fulfill this requirement

15. RockSat-C 2012 PDR RockSat-C 2012 User’s Guide Compliance 15 Our estimated structure weight including canisters is 9.4 lbs. which is under the maximum weight we expected. Our predicted CG is.05 in above the geometric center. This does not account for the electrical components.

16. RockSat-C 2012 PDR Subsystem Design Active Noise Cancellation Subsystem Alex Richman and Will Thorson 16

17. RockSat-C 2012 PDR ANC: Block Diagram 17 Experimental Chamber Dummy Chamber Control Systems Power Supply Mic Preamps Power amplifier Mic Speaker Data Logger DSP In Out

18. RockSat-C 2012 PDR ANC: Trade Studies 18 The following trade study shows the differences between the Pyle Pro PMHMS20 Omni-Directional Microphone and the Dayton Audio EMM-6 Electret Measurement Microphone. As of now, we will go with the EMM- 6, subject to further testing. Microphone EMM-6PMHMS20 Cost 89 Availability 10 Frequency Response 109 Size 79 Sensitivity 107 Average: 98.8

19. RockSat-C 2012 PDR ANC: Trade Studies 19 The following trade study shows the differences between the Dayton ND90-8 3-1/2" Aluminum Cone Full-Range Driver 8 Ohm and the Tang Band W3-881SJ 3" Cast Frame Neodymium Driver. Currently, the W3- 881SJ looks to be a better choice, but we are interested in the aluminum cone of the ND90-8. Speaker ND90-8W3-881SJ Cost 109 Availability 10 Frequency Response 810 Diameter 99 Depth 710 Average: 8.89.6

20. RockSat-C 2012 PDR ANC: Trade Studies 20 This trade study shows the overview of DSP versus a prebuilt IC designed to cancel noise. As we are in the preliminary stages of the ANC design, we are not sure which solution will be more robust at the time being. We hope to discover quickly when prototyping gets underway. DSP vs ANC DSPANC IC Cost 10 Availability 10 Ease of Implementation 47 Risk of Complications 64 Customizability 96 Average: 7.87.4

21. RockSat-C 2012 PDR ANC: Risk Matrix 21 Consequence ANC.RSK.1 ANC.RSK.2 ANC.RSK.4 ANC.RSK.3 Possibility ANC.RSK.1: microphone fails in flight causing the amplifier to stop sending cancellation sound ANC.RSK.2: the speaker creates a positive feedback and breaks itself, causing a mission failure ANC.RSK.3: the launch is delayed and our data requires more memory than initially predicted, much more memory available ANC.RSK.4: The launch is delayed by an hour putting a strain on the power budget

22. RockSat-C 2012 PDR Prototyping Plan Will Thorson 22

23. RockSat-C 2012 PDR Prototyping Plan 23 Concern about the efficiency and ability to cancel noise in the chamber DSP Test our hypothesized noise cancellation in mock ups. Risk/ConcernAction What will you build/test between now and CDR to mitigate risk?

24. RockSat-C 2012 PDR Project Management Plan Jacob Schultz 24

25. RockSat-C 2012 PDR Organizational Chart Our sponsor is the Minnesota Space Grant Consortium 25 Project Manager Jacob Schultz System Engineer Will Thorson Faculty Advisor Ted Higman Sponsor MSGC Faculty Advisory William Garrard Safety Engineer Justine Topel Testing Lead Alexander Richman Structure Jacob Schultz Justine Topel ANC/ Electrical Will Thorson Alexander Richman

26. RockSat-C 2012 PDR Schedule 26

27. RockSat-C 2012 PDR Budget 27 ItemSupplierEstimated, Specific CostNumber RequiredTotal CostNotes MicrophoneParts Express$48.263$144.78Including one back up for testing. SpeakerParts Express$26.803$80.40Including one back up for testing. DSPTI$13.352$26.70 Not commited to a DSP solution or a noise cancelling IC solution as of yet. ANC ICAustria Micro Systems$3.802$7.60Including back up chip. Data LoggerDATAQ$5991$599.00May be able to use last years data logger. Misc. ElectronicsDigi-Key$100.00N/A$100.00Various Resistors, Inductors, Caps, etc. High Fidelity Audio AmplifiersDigi-Key$19.364$77.44Including back up chips in case of soldering failures. Mic PreampsDigi-Key$5.004$20.00Back up chips included. Testing Materials???????$200.001 Machine TimeUniversity of Minnesota$400.00N/A$400.00for chambers and structural materials Total (No Margin):$1,655.92 Total (Margin):$2,069.90

28. RockSat-C 2012 PDR WBS 28 StructureElectrical Obtain electronics dimensions from electrical team Perform test calculations on the structure design Make any alterations necessary to keep design safe Prototype and test ANC system Finalize list of required electronics Finalize Power supply system

29. RockSat-C 2012 PDR Before CDR we plan to –Prototype the ANC system –Finalized CAD drawings and build details –Contact machine shop about construction of parts –Perform calculations testing the structure under G loads. Conclusion 29