NASA SL Flight Readiness Review

Transcription

1 NASA SL Flight Readiness Review University of Alabama in Huntsville 1

2 LAUNCH VEHICLE 2

3 Vehicle Overview Vehicle Dimensions Diameter: 6 fairing/4 aft Length: 106 inches Wet Mass: 41.1 lbs. Center of Pressure: Center of Gravity: Payload Deployable Rover Autonomous Retractable solar panels L12 x H3 x W4 Weight: 7 lbs. 3

4 Vehicle CONOPS 4

5 Forward Overview Consists of: Nose cone Fairing Transition Forward coupler Purposes: House and protect rover and deployment piston Transition between main body tube and fairing 5

6 Nose Cone 3D printed 6 in. tall elliptical shape 2 in. shoulder Houses solenoid for retention Aluminum bulkhead for flush contact with rover 6

7 Solenoid Three solenoids with ½ in. aluminum rods Will reliably retain the rover during flight Retract upon receiving signal after landing Makes nose cone ejection easier 7

8 Solenoid Arduino Nano with XBee 5V supply Spring assisted release of 8 oz. load Solenoids pull with oz. 8

9 Fairing Houses rover and piston G12 fiberglass in. long 6.17 in. outer diameter 6.0 in. inner diameter Secured to transition with ¼-20 bolts Secured to nose cone with solenoid pins 9

10 Piston 6 in. tall coupler section 0.25 in. thick aluminum bulkhead Used to push rover out of the fairing 10

11 Transition 3D printed forward and aft pieces with sparse in-fill for weight reduction 0.25 in. thick aluminum insert Threaded inserts with ¼-20 bolts hold pieces together 11

12 Coupler 9 in. long Sits within aft transition piece Secured by threaded rod in tension between bulkhead and transition insert U-bolt attached to aft bulkhead for main parachute 12

13 CENTRAL SUBSYSTEM 13

14 Central Subsystem Overview Central Subsystem responsibilities: Primary coupler between airframes Flight Avionics Ejection System Tracking and Ground Station Recovery System USLI PDR 14

15 Coupler Altimeter calculates altitude Charges deploy recovery system Carbon fiber protects avionics from RF interference Aluminum bulkheads serve as protection from ejection charges Redundant charges/circuits 15

16 Coupler Change: Switches rotated 270deg Interfaces with forward and aft sections via removable rivets and shear pins, respectively Interfaces with recovery system via U-bolts 16

17 AFT SUBSYSTEM 17

18 Aft Overview Components Lower Recovery Bulkhead Fin Can Assembly Fins (x4) Rail Buttons/Standoffs Thrust plate Motor case retention 18

19 Aft Body Tube 42 in. section of G-12 Fiberglass tube Cut to length with wet saw Fin slots cut using wooden jig guided router Fin Can retention holes drilled using 3-D printed template 19

20 Aft Recovery Bulkhead 6061T-6 Aluminum Machined in-house using CNC Pocketed to reduce weight U-Bolt for lower recovery Secured to Aft Airframe using four 4-40 bolts Dimension 3.9 in. dia. 20

21 Fins Trapezoidal Fin set (x4) G-10 Fiberglass Wet sawed in house Change since CDR L1420 Flight: 3.5 in. height L1520 Flight 3.25 in. height 21

22 3-D printed in-house ABS plastic Attached to aft using 24x 4-40 bolts 4 bolts holding each each fin in place Dimensions 9.75 in. length, 3.9 in. outer dia., 2.9 in. inner dia. Fin Can 22

23 Fin Can Change Press fits in the bottom did not stay in plastic 6 motor retention/thrust plate holes 4 holes now 4-40 through holes, secured with nuts 2 remaining holes tapped for larger screws 23

24 Thrust Ring 6061T-6 Aluminum Machined in-house Take motor thrust load Not transferred to ABS plastic Dimensions in. outer dia. 3.9 in. inner lip dia in. lip 24

25 Motor Retention Ring 3-D printed from ABS plastic in-house Held to fin can using two 6-32 screws Retains motor into Aft body tube Dimensions in. outer dia in. dia. Inner lip 0.25 in. lip 25

26 Rail Buttons Large Airfoiled 1515 Rail Buttons Commercially Available Attached to Aft Airframe 3-D printed Standoffs Accommodate for reduced aft airframe (4 in. dia.) 26

27 RECOVERY SYSTEM 27

28 Recovery System Drogue Parachute Deployment: Deployment at apogee Fruity Chute CFC-18 (Cd = 1.5) Shock Cords: ½ in. Kevlar (50 ft.) Connected between aft bulkhead in lower airframe and avionics bay housing. Descent speed under drogue: ft./s Main Parachute Deployment: Deployment at 600 ft. above ground level Fruity Chute 96 Iris Ultra (Cd = 2.2) Shock Cords: ½ inch Kevlar(50 ft.) Connected between fairing bulkhead and avionics bay housing. Descent speed under main: ft./s USLI PDR 28

29 Recovery System Tests Full Scale Charge Testing Full Scale Flights 29

30 Kinetic Energy Required that each individual section will have a maximum kinetic energy of 75 ft-lbf Terminal velocity under drogue: ft./s Terminal velocity under main: ft./s Upon landing the vehicle will be broken into three major components tethered together Vehicle Section Mass (lbm.) KE (ft-lbf) Fairing Coupler Aft

31 Drift Analysis CRW Drift Model Assumes: Apogee is directly above the launch rail The parachute does not open immediately The drift distance stops once a component lands Horizontal acceleration is solely based on relative velocity Drogue parachute is negligible once the main is fully deployed Universit y of Alabama in Huntsvill e USLI PDR V relative Wind Speed (mph) 0 mph 5 mph 10 mph 15 mph 20 mph RASaero Drift Distance (ft.) CRW Model Drift Distance (ft.) UAH SLI PDR 31

32 Drift Analysis Cont. CRW Monte Carlo Analysis Varies coefficient of drag and apogee Cases run at constant 0, 5, 10, 15, and 20 mph winds Largest Drift at ~685 ft. Largest Drift at ~2738 ft. 32

33 Ground station Ground station written in MATLAB Receives GPS sentences Writes raw data and parsed data to separate files Sends signal to rocket to deploy payload The rover will transmit all saved sensor data to the ground station Ground station will save rover data for post processing 33

34 GPS Tracking System CRW uses a circuit for tracking and payload deployment consists of an Xbee Pro S3B RF module, a Teensy MCU, and an Adafruit MTK339 GPS Chip Xbee transmits GPS coordinates to a receiver connected to the ground station laptop. Structure Integration 3D printed mount to secure tracker and its essentials within the transition section of the rocket. Three axis security and battery retention to ensure components are kept in tact 34

35 Deployment Electronics Payload Deployment Electronics Schematic Arduino-like MCU Xbee Pro S3B RF Module Adafruit GPS Module Hot Wire 35

36 Deployment Electronics Operated remotely from ground station Teensy MCU receives signal to power hot wire Hot wire cuts fishing line holding piston spike in place Releases spike and punctures CO2 cartridge to deploy rover 36

37 Avionics Recovery Avionics Subsystem 2 PerfectFlite StratoLoggerCF altimeters; each with a 9V battery and SPDT momentary activation switch 4 Safe Touch terminals, E-matches, and black powder charges Full redundancy in avionics and ignition 37

38 Avionics Normally Closed SPDT Pull Pin Microswitch Prevents detonation during assembly Helps preserve battery life Primary Drogue charge fired at apogee Secondary fired one second after Primary Main fired at 600 ft. Secondary fired at 550 ft. Primary charges are roughly 3.0g for main and 2.25g for drogue Secondary charges are 0.5 g larger than primary 38

39 SIMULATIONS 39

40 Motor Change Coefficient of Drag poorly translated from subscale to full scale Full-scale Test Flight 1 6,893 ft. Resulting apogee broke 5600 ft. waiver Motor changed to Aerotech L1520T 40

41 Motor Description Aerotech L1520T-PS Burn Time: 2.4s Max Thrust: lbf Average Thrust: lbf 41

42 Wet Mass 41.1 lbs. Dry Mass 32.6 lbs. Mass Budget Component Name Weight (lb.) [All weights include hardware] Fairing Section Nose Cone 2 Nose Cone Electronics 1 Fairing Body Tube 3.21 Rover 7 Inner Transition 1 Piston Bulkhead CO2 System Transition Bulkhead 1.34 Piston Transition Tracker Forward Coupler 0.59 Forward Coupler Bulkhead Forward Airframe Forward Body Tube Main Parachute 1.6 Shock Cord Av Bay Assembly 3.02 Aft Airframe Aft Body Tube 2.42 Fins (x4) Drogue Parachute Shock Cord Aft Bulkhead Fin Can Motor Retention Ring/Thrust Plate Motor Case Total 31.1 Ballast 1.5 Ballasted Total

43 Flight Prediction Motor Burnout 2.6 sec. Apogee sec. Main Deployment 59.7 sec. Recovery 121 sec. 43

44 Flight Prediction (Wind) OpenRocket Simulation (wind) 44

45 Flight Prediction (Wind) RASaero Simulation (wind) 45

46 Stability Margin Burnout 3.2 cal. Rail Exit

47 Monte Carlo Simulation 1-D method of analysis Cd = 0.34 Varied conditions Cd ± 5 Vehicle mass ± 2.5 Prop. mass ± 5 Case mass ± 2.5 Measure Value (ft.) Mean Median Std. Dev Max Altitude Min. Altitude

48 Full-scale Flight Test 1 Launch Conditions for Flight 1 Date February 24 th, 2018 Location Wind Samson, AL ~6 mph Temperature 89 F Motor Launch Angle 2 Projected Altitude Actual Altitude Aerotech L1420R 5626 ft ft. Apogee at 23.5 seconds Resulted in Motor Change Not a qualifying fly Nose Cone detached during main parachute deployment 48

49 Full-scale Flight Test 1 Key Flight Components Wet Mass (lb) Stability Margin (cal.) T/W Cd

50 Full-scale Flight Test 2 Launch Conditions for Flight 2 Date March 3 rd, 2018 Location Wind Samson, AL ~6 mph Temperature 80 F Motor Launch Angle 0 Projected Altitude Actual Altitude Aerotech L1520T 5131 ft ft. Apogee at 19.3 seconds Slight weathercocking (~10 ) Qualifying flight Successful flight and recovery 50

51 Full-scale Flight Test 2 Key Flight Components Wet Mass (lb) Stability Margin (cal.) T/W Cd

52 LAUNCH PROCEDURES 52

53 Launch Day Procedures Overview Full scale launch procedures have been implemented and continuously improved Minimizes time assembling at field Allows team to have safety in terms of time Field operations are split between sub-teams to be done simultaneously Verification signatures required for each subteam s sections Step-by-step process that begins with packing and assembling the day before the launch 53

54 Launch Day Procedures Loading of energetics is reserved to the last minute before check out Ejection charges and motor installation will be performed by team mentor Safety monitor delegates tasks and oversees all assembly procedures 54

55 Pre Travel Pre-Launch Procedure At Field Assembly Overview Charge Installation Motor Installation Check Out and Launch Charge Preparation Forward Assembly Procedures Verify Final Configurations Rocket and Payload Assembly Rover Preparation Check out with RSO Pack Items for Travel Recovery Harness Preparations Launch Recovery Electronics Preparations 55

56 Safety Concerns Payload Risk of payload escaping fairing due to main parachute rapid deceleration. Risk of Deployment system unintentionally triggered Risk of Nose Cone retention system triggered unintentionally Vehicle Weather cocking (SM>2.0) 56

57 Payload Switched from shear pins to 0.5 in. aluminum pins powered by solenoids. Vehicle Mitigations for current concerns Ballasted to have lower stability margin closer to 2.4 New simulations show better altitude results 57

58 Completed Tests Fairing Drop Test Simulating a deceleration equal to or more than that of the parachute opening Results Test can produce forces that sheared nylon pins New retention method have been verified by the test before second flight. 58

59 Future Testing Vibration Tests are changed to Drop test Drop test of the Deployment system Drop test of the solenoid pin system Drop test of Rover Rover Operational test Software trials are currently underway Tests are done as new parts arrive 59

60 PAYLOAD 60

61 Mass Simulator Used for initial test flights Foam added to meet proper dimensions of rover Tethered to U-bolt in transition and Eyebolt on Simulator, covered by fairing 61

62 Chassis 5 Plates of Aluminum 6061-T6 Sidewalls 0.25 in. thick Base, front, and back plates in. thick When assembled, 12 x 4 x in. Assembled using 2-56 and 4-40 steel screws Construction delayed McMaster-Carr sent wrong size plates Machinist and Equipment availability limited 62

63 Wheel Assembly Spokes Aluminum 6061-T x 0.5 x in. Three 6 ft. long bars cut into in. to make 36 spokes Hinges Aluminum 6061-T x 0.25 x 0.75 in. Ordered longer bars and cut to 0.75 in. Spoke Feet 3D printed ABS Rectangular hole 0.25 x 0.5 in. Reprint needed because it did not properly fit due to shrinkage 63

64 Wheel Assembly Milled out of 0.25 in. thick Aluminum 6061-T6 Pocketed excess aluminum to save weight Machinist and equipment availability delayed construction until after FRR Extension springs connected to spoke and spring on opposite side using braided fishing line Diameter: Integrated 5.7 in., Deployed 16 in. 64

65 Stabilizing Arm and Hinge 3D printed ABS using Fortus in UAH machine shop 11 x 0.75 x 0.25 in. Torsion springs fit properly as shown by testing 65

66 Lid 3D printed using Fortus in UAH machine shop Fixed lid bolted to chassis and houses solar panels Sliding lid driven by motor with 3D printed gear Has been printed, but waiting on solvent bath 12 x 4 x 0.5 in. when assembly is closed 12 x 7.25 x 0.5 in. when assembly is open 66

67 Electronics Tray 3D printed ABS using Fortus in UAH machine shop 11.5 x 3.75 x 2 in., tight fit in chassis Some changes needed: One additional support Holes added for electronics and assembly 67

68 Hardware in the Loop Test Model Used for initial testing of motors and other electronics Proved functionality of stabilizing arm Showed correlation between motors and accelerometer Electronics initially tested using breadboards 68

69 Updated Electronics Block Diagram Camera has own SD card, only powered by Arduino Solar Panel does not charge battery, but powers LED 69

70 Updated Power Budget Part Current (ma) Voltage (V) Adj. Current (ma) Duty Cycle (%) Time (hr) Capacity (mwh) Arduino Mega Camera GPS IMU Press/Temp Wheel Motors Lid Motor Radio Transmit Radio Idle DataLogger Power Required 8478 Li-Po Battery Safety Factor

71 Mass Budget Changes since CDR: Wheel Assembly decreased Stabilizing arm and lid assembly increased Component Mass (lbm.) Chassis 2.0 Wheel Assembly (2) 2.1 Lid Assembly 0.8 Stabilizing Arm Assembly 0.3 Electronics 1.3 Fasteners & Adhesives 0.5 Total

72 Software Flow 72

73 Software Flow Written in the Arduino IDE Developed in C++ Incorporates various Adafruit libraries for the chosen sensors Using SPI, I2C, and UART to communicate with various sensors 73

74 REQUIREMENTS VERIFICATION 74

75 Launch Vehicle Requirements Verification Met and documented all NASA Launch Vehicle Requirements Safety requirements require a signoff in the SOPs Derived Requirements: DV-001: Nose cone must remain attached throughout launch, demonstrated in fairing drop tests and flight test 2 DV-003: Safely transfer load path from 4 in. to 6 in. body tube, demonstrated from FEA on transition insert and flight tests All other requirements can be found in document 75

76 Payload Requirements Verification E-002 & E-003 For deployable rover, the rover shall deploy from the internal structure of the launch vehicle via trigger E-004 & E-005 For deployable rover, the rover shall autonomously move at least 5 ft from the launch vehicle and deploy the solar panels All requirements verified through demonstration Operational tests will be done on March 7 th and Deployment tests on March 11 th 76

77 Payload Requirements Verification DP Rover shall be able to take temperature, pressure measurements, as well as images Demonstration verified The successful operation of the sensors were demonstrated by the preliminary operational test. DP-009 Rover shall be able to retract the lid, covering the solar panels Will be verified through demonstration after obtaining lid The mechanism that opens the lid of the rover will be able to close the lid as well, as demonstrated by the initial operational testing March 9 th 77

78 Payload Requirements Verification DP-012 Rover shall successfully navigate the launch field despite weather or physical conditions of the field Will be verified through testing & demonstration Rover will have folding wheels that expand to three times the initial diameter. The wheels will be tested on a variety of surfaces and demonstrated in a full scale flight test on March 9 th. More verifications found in document 78

79 PROGRAM MANAGEMENT 79

80 Timeline 80

81 Timeline Upcoming Milestones FRR Presentation (15 March 2018) Launch in Childersburg (10 March 2018) Electronics Deployment Testing (7 and 8 March 2018) Full Rover Testing (5 to 9 March 2018) Launch Week (4 April 2018) Dynetics Tour (4 April 2018) Rocket Fair (6 April 2018) Competition Launch (7 April 2018) 81

82 Budget Total Full Scale Budget Total Cost Rover Electronics Rover Structure Motors Recovery Electronics Airframe $- $1, $2, $3, $4, $5, $6, Launch Vehicle On The Pad Budget Budget Summary Spent Budget Summary Budgeted Total Rover Motors Recovery Electronics Airframe $- $ $1, $1, $2, $2, Launch Vehicle Spent Launch Vehicle Budgeted 82

83 Outreach Individuals Type of Event Date Individuals Type of impacted or Event Date Engagement impacted or Engagement expected Girl s Science and September 23, expected Girl s Science and September 23, Direct Interaction 80 Engineering Day 2017 Direct Interaction 80 AIAA Engineering Holy Family Day 2017 AIAA School Holy Family November 10, 2017 Direct Interaction 64 Engineering School November 10, 2017 Direct Interaction 64 Engineering December 20-22, Cub Scout STEAM December , Cub Scout STEAM 2017 Direct Interaction 65 Camp December 27-29, Direct Interaction 65 Camp December , FIRST Lego 2017 League FIRST Alabama Lego January 20, 2018 Direct Interaction 62 State League Competition Alabama January 20, 2018 Direct Interaction 62 State Competition Science Olympiad March 3, 2018 Direct Interaction 34 Science Olympiad March 3, 2018 Direct Interaction 34 Total Number

84 Outreach FIRST Lego League Alabama State Championship Sensor Workshop Buzzer, flashing LEDs, Light Sensor, Rotary Angle Sensors Xbee Radios messaging Science Olympiad Battery Buggy and Mousetrap Vehicle Events Construction reviews, scoring event, discussion of vehicle runs 84

85 Questions? 85