Mont Alto Projectile Project (M.A.P.P.) Critical Design Review

1. Mont Alto Projectile Project (M.A.P.P.)Critical Design Review Penn State Mont Alto 12/17/08

2. Team Members Kylie Flickinger – Mechanical Engineering Adam Kuhlman – Data Acquisition William K. McDannell Jr. – Software Chris Small – Strain Gauge Board Robert Stottlemyer – Team Leader Tim Svirbly – Test Equipment Development

3. Abstract The purpose of this experiment is to investigate the mechanical stresses in an elastic structure during the flight of a sounding rocket. The structure proposed consists of a circular plate, the deck plate, which is supported by four longerons, which connect in turn to circular plates at either end of the longerons simulating a payload section of previous sounding rocket flights. A dummy mass is attached to the center of the deck plate. During the flight, dynamic loads in the axial and lateral directions will cause the deck plate to deflect. The resulting deformation will be measured at selected points using strain gauges connected to electronic boards to obtain time-varying voltage signals which in turn will be digitized and stored for later analysis. The obtained data will be compared to theoretical predictions. Careful pre-flight calibration of the entire data stream will be conducted.

4. Mechanical Subsystems • Bottom Plate • Deck Plate • Top Plate • Longerons • Test Weight • Trays for Boards • Braces • Electrical Subsystems • G-Switch + Latched Relay • Battery and Regulation • Strain Gauge Boards • Strain Gauges • Controller + A/D conversion • Data Storage Subsystem Requirements

5. Schematic/Drawings/Analysis See next slides

6. Brace A

7. Brace B

8. Brace C

9. Bottom Disk

10. Deck plate

11. Top disk

12. Longeron

13. Tray A

14. Housing , Battery + G-switch

15. Test weight

16. Assembly Mont Alto

17. Block Diagrams Honeywell Aichi BU Magnetometers PSU MA Strain Gauges Strain Gauge Controller A/D Data Card Power G-switch Launch safing Controller A/D Data Card Power G-switch Launch safing

18. Strain Gauge Circuit

19. Strain Gauge (Up Close)

20. Strain Gauges • After testing in SolidWorks, we determined that the deck plate would not deform enough for the strain boards that we built for the USERS program to amplify the signal enough to get meaningful data using metal strain gauges. After research, we decided to use semi-conductor strain gauges, which have a gauge factor of ~60 times that of a metal foil strain gauge. We will implement them in a configuration that would both double signal output and reduce concerns about temperature sensitivity. Using this configuration should allow us to use our boards from the USERS program with only minor changes.

21. G-Switch + Latched Relay

22. Controller + Memory • Memory Needs : 12 Analog Signal Streams each digitized at ~250 samples/second to be sampled for 750 seconds at 2 bytes per sample = 4.5 Megabytes • Data stored on a SD card inserted into Miniboard (45mm x 55 mm) - www.futurlec.com/mini_sc.shtml standard SD or SPI communication. 3 Volt power • Microcontroller Board – www.microchip.com/wwwproducts/devices.aspx?ddocname=en024691 Model : PIC24HJ256GP206 , 18 channels 12 bit A/D conversion at up to 500 ksps, 2-UART,2-SPI, 2-12C digital communication, 3 to 3.6 Volt power with on-chip 2.5 Volt power regulator, size 1.0”x2.2” . Programming language C

23. Special Requirements Shift in center of mass along length axis on rocket

24. Commands and Sensors • Always On – Triggered by the G-Switch • Turned off by microcontroller before splash down • 12 Analog Signal Streams each digitized at ~250 samples/second to be sampled for 750 seconds at 2 bytes per sample = 4.5 Megabytes • Data stored on a SD card Miniboard (45mm x 55 mm) - www.futurlec.com/mini_sc.shtml • Microcontroller Board (protopic 28) – 1.0” x 2.2” – www.microchip.com/wwwproducts/devices.aspx?ddocname=en024691 Model : PIC24HJ256GP206 , 18 channels A/D conversion, on-chip 2.5 Volt power regulator • Strain Gauge: Vishay or Semiconductor (to be decided) • Data Acquisition Controlled by Microcontroller initiated by power on

25. Test Plans • Mechanical Stress Distribution • SolidWorks • Thin Plate Theory • Static Force Rig (similar to the one we used for USERS) • G-Switch and Latched Relay • Spring loaded launch in a controlled setting • Ensure compliance with no-volts requirement when integrated with power supply • Strain Gauges • Temperature sensitivity • Circuitry and Signal Strength – simple beam test • Compare to metal foil strain gauges • Calibration • Data Acquisition/Storage • Store and retrieve data • All electronics: Burn in period

26. Timeline • By the end of fall semester (12/19/08) • Critical design review completed • Begin ordering parts • Wrap up design phase • Over Christmas Break (12/19/08 – 01/12/09) • Continue ordering parts • Begin planning build phase • Beginning of Spring Semester (01/12/09) • Meet to plan build phase • Take an inventory of parts • Between (01/12/09 – 03/15/09) • Build Phase • Manufacture circuit board for data collection • Alter strain gauge boards • Manufacture testing rigs—Static force rig like we used for USERS, Spring mechanism to test G-Switch • Manufacture G-switch • Manufacture plates, longerons, alter dummy weight from USERS, braces, and housing for battery and g-switch. • Between (3/15/09 – 4/25/09) • Testing Phase • Test performance of Semiconductor Strain Gauges—Compare to metal foil strain gauges. Also test temperature drift. • Static force rig similar to the one we used for testing for the USERS project • Test performance of G-Switch and power supply • see that it meets launch safing no volts requirements. • Use spring mechanism to test the performance of the “ball and tube” part of the G-Switch • Test performance of Data Acquisition unit • Burn in period for electronics • Preliminary Integration Phase (4/25/09 – 5/3/09) • Assemble structure • Attach strain gauges to test points in structure • Integrate electronic components—manufacture wire harnesses • Have structure ready to install in can • Finals week (5/4/09 – 5/8/09) • See you in June!

27. Parts List Mechanical parts # Item Status # Item Status 4 Brace A designed 1 Test Weight Completed 4 Brace B designed 4 Trays Completed 8 Brace C designed 1 Bottom Disk designed 1 Deck Plate designed 1 Top Disk designed 4 Longeron designed • Not at the nut and bolt level… just major hardware that will be purchased or built in house • Lead times (This can make or break a project) • Distributors • Manufacturers • Cost (Don’t forget to consider shipping and tax)

28. Parts list, cont. Electronic Parts : # Item Status 2 Strain gage board Modification needed 1 Power regulator board Modification needed 1 G-switch and associated electronics - needs more design work 1 data acquisition/storage + controller - needs more design work

29. RockSat Payload Canister User Guide Compliance • Mass, Volume • Estimates of mass include everything shown in slide 16 . Missing are the electronic boards ( 4 of 4”x4” ) for MA and electronic board and tray/box for BU m = 10.86 lbs (< 12.75, the heavy test mass can be reduced) Center of mass 0.35” off axis and 1.06” below geometric center. Because electronic boards and tray for the BU experiment have not been included, the center of mass will move slightly closer to the geometric center. Entire structure fits into a cylinder of 9” (<9.2) diameter and 9.275” (<9.4) height leaving 0.125” for washers. Connection with 5 bolts to top and bottom bulk head , respectively, is provided.

30. RockSat Compliance - continued • Payload Activation a battery , a G-switch, and shorting wires to Wallops shorting plug form a complete loop with electric current flowing only if both the G-switch and shorting plug are in closed position simultaneously. Once current is flowing a circuit consisting of a second battery (ies) and all electronic boards is activated using a solid-state latched relay and switch transistor. This second loop maintains itself even when the G-switch subsequently falls back into its open position (during ballistic flight phase). See slide 29

31. Shared Can Logistics Plan • Boston University (Mike Ruane) • Penn State Mont Alto (Zig Herzog) Sharing mechanical structure but independent power supply, controller, data acquisition, and data storage. Possibility of future sharing of these items is not excluded .

32. Management Dr. Siegfried Herzog Penn State University at Mont Alto Assistant Professor of Mechanical Engineering 1 Campus Drive Mont Alto, PA 17237 Tel (717)-749-6209    Fax (717)-749-6069 E-Mail: hgn@psu.edu Dr. Michael Ruane Professor, ECE Dept., Boston University 8 St. Mary's Street, Boston, MA 02215 Phone: 617-353-3256 617-353-6440 fax E-Mail: mfr@bu.edu

33. Conclusions • Lab space available • Students are nervous but excited • We have some previous experience with the USERS program and can re-use some parts • We aim to finish by the end of April (end of the spring semester) • Looking forward to beach time! 