Nessie Neutrally-Buoyant Elevated System for Satellite Imaging and Evaluation

NESSIE NEUTRALLY-BUOYANT ELEVATED SYSTEM FOR SATELLITE IMAGING AND EVALUATION

1 Project Overview

Space Situational Awareness (SSA) • Determine the orbital characteristics of objects in space

Currently there are only two methods Radar • Expensive Telescopes • Cheaper, but can be blocked by cloud cover

Both are fully booked and can't collect enough data

Over 130,000,000 estimated objects in orbit

2 Introduction Solution Critical Project Elements Risk Analysis Schedule Our Mission:

MANTA NESSIE • Full-Scale SSA UAV • Proof of concept vehicle • Operates at 18000ft • Operates at 400ft AGL • Fully realized optical Scale • Payload bay capability 1 : 2.5 payload • Mass 1 lb • Mass 15 lbs • Contained in 4.9” cube • Contained in 12” cube • Requires 5.6 W of Power • Requires 132 W of Power • Provide path to flight at full-scale

3 Introduction Solution Critical Project Elements Risk Analysis Schedule Stay on a 65,600 ft to 164,000 ft distance from takeoff spot Legend: 10 arcseconds object  Requirements centroid identification 5. Point optical Dimness ≥ 13  accuracy, 3 sigma precision system, capture Operations flow apparent magnitude image, measure time and position 4. Pointing and stabilization check, 6. Store image autonomous flight and data

7. Start autonomous Loop descent to Ground Station when battery is low.

Constantly downlink 3. Manual ascent position and status above clouds, uplink data to ground station 8. Manual landing, Max 18,000 altitude ft from ground station uplink from ground station

1. System 2. Unload/ Assembly/ Prep. Ground Station End of mission 14 transportation hours after first ascent

Land 300 ft (100 yards) from takeoff spot Stay within 400 ft of takeoff spot Legend:

4. Systems check, 5. Continuously Collect  Requirements Manual flight acceleration data from  Operations flow onboard IMUs

Provide power and data connectivity to payload 6. Start manual descent to Ground Station when battery is low.

Downlink position 7. Manual landing, and status data to uplink from ground ground station station 3. Manual ascent, uplink from ground station Max 400 altitude ft

End of mission when 1. System battery reaches ~20% transportation 2. Unload/ Assembly/ Prep. Ground Station

5 Land 300 ft (100 yards) from takeoff spot Design Solution: NESSIE Torus Shaped Airship

● Torus Shaped Envelope: allows for optical observations vertically ○ Overall Diameter 19.90 ft ○ Inner hole diameter 10.10 ft ○ Has “hard points” for attachment ● Rigid frame: holds all components to the balloon ● Gondola: centrally located and holds payload and propulsion and electronics ● Tail: Provides static stability and control authority

7 Introduction Solution Critical Project Elements Risk Analysis Schedule Design Solution: NESSIE Torus Shaped Airship

8 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Gondola

Specifications

● Constructed Carbon fiber sheets ● Gondola holds all critical components ○ Flight Controller: Pixhawk 4 mini ○ Battery: 5200 mAh LiPo 4S ○ Propellers: 15.5”x 5.3 carbon fiber ○ Payload cube: 4.87” cube, 1lb ● Extra space for all wiring and additional items

9 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Gondola

Payload Specifications Battery ● Constructed Carbon fiber sheets ● Gondola holds all critical components ○ Flight Controller: Pixhawk 4 mini ○ Battery: 5200 mAh LiPo 4S ○ Propellers: 15.5”x 5.3” carbon fiber Flight ○ Payload cube: 4.87” cube, 1lb Controller ● Extra space for all wiring and additional items Propellers Brushless Motors

10 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Propulsion Specifications:

● Weight of motors and propellers = .902 lbs

● Propeller diameter = 15.5'' ● Max thrust: 14.81 N ● Maximum power in = 730 W ● Actuator on propulsion axle ● Separate electronic speed controller for each motor

11 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Balloon Specifications:

● Material: PVC 0.18 mm ● Weight = 44.03 lbs ● Volume = 888.60 ft3 ● R = 7.50 ft ● r = 2.45 ft ● Net lift = 10 lbs

12 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Balloon Specifications:

● Material: PVC 0.18 mm ● Weight = 44.03 lbs ● Volume = 888.60 ft3 ● R = 7.50 ft ● r = 2.45 ft ● Net lift = 10 lbs

13 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams

Specifications:

● Material = Carbon Fiber ● Thickness = 0.03” ● Outer diameter= 1.935” ● Weight of each arm = 0.83 lbs ● Weight of tail boom = 1.47 lbs

14 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams

Specifications:

● Material = Carbon Fiber ● Thickness = 0.03” ● Outer diameter= 1.935” ● Weight of each arm = 0.83 lbs ● Weight of tail boom = 1.47 lbs

15 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Structural Beams

10.87 ft Specifications:

● Material = Carbon Fiber

7.5 ft ● Thickness = 0.03” ● Outer diameter= 1.935”

● Weight of each arm = 0.83 lbs

● Weight of tail boom = 1.47 lb 7.5 ft

16 Introduction Solution Critical Project Elements Risk Analysis Schedule Hardware: Tail Specifications:

● Material = foam and epoxy composite

● Width of foam = .59''

● Width of epoxy = 0.01 mm

● Control Surface area = 298.7 in²

● Fixed angle of attack = 5˚

● Lift at 10 mph wind = 2.69 lbf

● Weight = 1.58 lbs

● Inverted vertical tail for less flow distortion from the envelope

17 Introduction Solution Critical Project Elements Risk Analysis Schedule Electronic Components

Tattu Li-Ion Flight Controller: Meishuo solenoid Battery PixHawk 4 Mini

Arduino Nano 33 Radio: HobbyKing BLE Sense PixHawk Radio Kit Servo Introduction Solution Critical Project Elements Risk Analysis Schedule 18 General Electronics FBD Legend Motor Shaft 5V Power IMU Battery IMU Power GPS Servo MavLink Data Sensor I2C Elevator Servo Controls Servo Receiver Release 14.8V Power Processor Pixhawk 4 Mini Valve

Telemetry ESC 1 Motor 1 MavLink UART

Ground ESC 2 Motor 2 5V BEC PDB Station LEDs Battery

19 Introduction Solution Critical Project Elements Risk Analysis Schedule Critical Project Elements

20 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gas Envelope Why is this a Critical Project Element? ● NESSIE is a mission driven lighter-than-air airship. In order to meet these requirements, a balloon must be built and interfaced with a gondola.

Relevant Requirements ● FR1: System shall support a scaled optical payload. ○ DR1.2: System shall dedicate1 lb to the payload. ○ DR1.5: Payload bay shall provide at least 100° Field of View (FOV). ● FR 2: System Shall operate at 400ft AGL. ○ DR 2.3: System shall be less than 55 lbs. ● FR 3: System shall station keep in altitude and position. ○ DR 3.1: Shall provide sufficient lifting force.

21 Introduction Solution Critical Project Elements Risk Analysis Schedule Balloon Specification Equations

1) Airship mass = mass of ( + + ) displaced air = 2π 𝑚𝑚𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 𝑚𝑚𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒+ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑚𝑚𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 2 2 𝑎𝑎𝑎𝑎𝑎𝑎 𝑟𝑟 𝑅𝑅 2) Geometric relationship 𝜌𝜌 sin + + between Radii based on = 2 FOV and optics location 𝐹𝐹𝐹𝐹𝐹𝐹90 + 𝑟𝑟 ∗ tan 2𝑟𝑟 𝑑𝑑 𝑅𝑅 𝐹𝐹𝐹𝐹𝐹𝐹 3) Mass of envelope and = 4 π + 2 π helium based on densities 2 2 2 𝑚𝑚𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒+ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝜌𝜌𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑟𝑟𝑟𝑟𝑟𝑟 𝜌𝜌ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 𝑟𝑟 𝑅𝑅 Design Material DR3.1 Unknowns  Choices Properties

22 CPE Gas Envelope Evidence Toroidal Balloon Cross-section DR1.2 

DR1.5 ft 

DR2.3 

44.08 + 9 + 1 = 54.08 lbs

23 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gas Envelope Requirements Met Requirement How Met Met

DR1.2 System shall dedicate 1 lb to the Balloon allows for 1 lb Payload payload.  DR1.5 Payload space shall provide a housing Balloon allows for 110° FOV location where an optical system would  have a field of view(FOV) over 100 degrees. DR2.3 System shall comply with FAA hobbyist Balloon, gondola, and Payload regulations. (55 lb max takeoff weight) are 54lb  DR3.1 The system shall provide sufficient net Balloon will be neutrally buoyant lifting force to attain desired altitudes. at 400 ft AGL at Boulder with  full load

24 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Why is this a Critical Project Element? ● NESSIE is a mission driven lighter-than-air airship. In order to meet these requirements, a gondola must be built to carry electrical components and interfaced with the balloon.

Relevant Requirements ● FR1: System shall support a scaled optical payload. ○ DR1.2: System shall dedicate 1 lb to the payload. ○ DR1.4: System shall provide a 4.87”x 4.87”x 4.87” payload bay. ○ DR1.5: Payload bay will provide at least 100° Field of View (FOV).

25 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Propulsion axle: ● Maximum normal stress of 62.5 MPa  ● Yield strength of carbon fiber is ~ 120 MPaFR1 DR2.2  ● Simplified beam analysis confirmed results

26 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Balloon arms: ● Maximum normal stress of 96.35 MPa FR1  ● Maximum tensile yield strength of carbon fiber is ~ 120 MPa. DR2.2 ● Simplified beam analysis confirmed results.

27 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Gondola Structure Requirements Met Requirement How Met Met

DR1.2 System shall dedicate 1 lb to the Gondola can support a 1 lb payload. payload 

DR1.4 System shall dedicate a 4.87"x4.87"x4.87" A 4.87"x4.87" square is available volume to the payload. within the gondola  DR1.5 Payload space shall provide a The payload bay is located at the housing location where an optical center of the gondola and allows  system would have a field of view(FOV) for a 110° FOV over 100 degrees.

28 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Communications Why is this a Critical Project Element? ● NESSIE is controlled manually by a handheld transmitter. A reliable communication link between the ground station and the aircraft will need to be maintained at all times to provide command and control.

Relevant Requirements ● DR3.3: The aircraft shall be controllable by manual RC controller. ● FR4: System shall transmit status and location data to the ground station and also receive control instructions from the ground station. ○ DR4.1: The system shall maintain a positive link margin (>0 dB). ○ DR4.2: The ground station shall have the ability to transmit to the aircraft. ○ DR4.3: The aircraft shall have the ability to transmit to the ground station.

29 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Communications Most Relevant Factors from Link Budget

Paramter Value USB mini Tx power [dBm] 20 Mission PixHawk Space Loss (447ft) [dB] -74.4 DR3.3  Planner Rx/Tx Kit DR4.2  Rx power received [dBm] -99.7 ● ArduPilot Mission Planner allows external RC controller to be used for control Rx Sensitivity[dBm] -117

Resulting SNR 9.16 ● PixHawk has I2C connection to interface with IMU DR4.3  ● PixHawk supports MavLink, so data will be DR4.1  transmitted

30 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Communications Requirements Met

Requirement How Met Met

DR3.3 The aircraft shall be controllable by manual RC A handheld controller is controller. used  DR4.1 The system shall maintain a link margin of 0 dB or Positive link margin greater throughout the duration of its flight.  DR4.2 The ground station shall have the ability to transmit Controller connected via to the aircraft. USB to Mission Planner  DR4.2 The aircraft shall have the ability to transmit to the I2C connection allows ground station. transmission 

31 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Control Authority Why is this a Critical Project Element? ● NESSIE must be controllable in order to execute its mission. Control allows it to fly up to a commanded altitude and position, collect data, and then return, all while enduring wind gusts and other perturbations.

Relevant Requirements ● DR2.2: System shall be capable of surviving gusts up to 5 mph. ● DR3.2: System shall maintain target altitude within 50ft. ● DR3.4: The system shall be capable of maintaining its horizontal position within 50 ft.

32 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Control Authority-Evidence

● Drag force was predicted based on Flight Expected Drag Margin empirical models and CFD Condition Force 10 mph 13.5 lbf 1.3 lbf ● Each propeller provides 7.2 lbf of thrust relative wind placed 12.9'' from CG. 3.2 ft/s 9.0 lbf 5.8 lbf descent ○ Tilt rotor allows for multiple directions of thrust

DR2.2 ○ Maximum yaw moment provided by  propellers is 15.48 lbf ft ● Manually controlled DR3.4  ● Naturally points into the wind due to weathervane stability

33 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Control Authority-Evidence

Testing effect of 25 ft perturbation in altitude Assuming V and g are constant and W = = ( ) 𝐹𝐹𝑏𝑏 𝜌𝜌𝑎𝑎𝑎𝑎𝑎𝑎𝑉𝑉𝑔𝑔0 ●Δ𝐹𝐹𝑛𝑛𝑛𝑛At𝑛𝑛 Boulder𝑉𝑉𝑔𝑔0 𝜌𝜌𝑎𝑎𝑎𝑎 400ft𝑎𝑎 @400𝑓𝑓 AGL,𝑓𝑓−𝜌𝜌𝑎𝑎𝑎𝑎 results𝑎𝑎 @425𝑓𝑓 𝑓𝑓in 0.04 lbf opposite to perturbation. This will always be true ● Small, but constant, and therefore allows a vertical station keeping

DR3.2 

34 Introduction Solution Critical Project Elements Risk Analysis Schedule CPE Control Authority Requirements Met

Requirement How Met Met

DR2.2 System shall be capable of surviving gusts up to Designed to counter 5 5 mph. mph constant wind  DR3.2 System shall maintain target altitude within Neutrally buoyant system 50ft.  DR3.4 The system shall be capable of maintaining its Positive link budget horizontal position within 50ft 

35 Introduction Solution Critical Project Elements Risk Analysis Schedule Risk Assessment: Initial Logistical Risks

Top Project Risks 1 2 3 4 5 Insignificant Negligible Moderate Extreme Significant LR1 Craft is destroyed Almost E Certain LR2 Insufficient storage space D Likely LR2 LR3 No data is collected C Possible LR4 Physical injury to personnel or bystander B Unlikely

A Rare LR1, LR3, LR4

36 Introduction Solution Critical Project Elements Risk Analysis Schedule Risk Assessment: Mitigated Logistical Risks

Top Project Risks 1 2 3 4 5 Insignificant Negligible Moderate Extreme Significant PR1LR1 CraftCraft isis destroyeddestroyed Almost E Certain PR2 CreateInsufficientCreate SOP’s,SOP’s, testingtestingstorage checklist,checklist, space incrementincrementincrement testtesttest magnitudemagnitudemagnitude D Likely LR2 PR2PR3LR2 Insufficient/inadequateInsufficientNo data is collectedstorage space storage space C Possible PR3PR4 WorkNoPhysicalContact data with facilities injuryfacilitiesis collected management to management personnel to identify quality storage space PR3 Noor bystander data is collected PR4LR3 NoPhysical data injuryis collected to personnel B Unlikely or bystander PR4 PhysicalCreate testing injury checklist to personnel Create testing checklist, monitor data LR1 LR3 or bystander A Rare PR4 acquisitionPhysical duringinjury flight to personnel LR4 LR4 Physicalor bystander injury to personnel or bystander

Create safety checklist, test zone, spot checks and safety equipment

37 Introduction Solution Critical Project Elements Risk Analysis Schedule Risk Assessment: Initial Component Risks

Top Project Risks 1 2 3 4 5 Insignificant Negligible Moderate Extreme Significant CR1 Battery overheats/ Almost E CR1 explodes Certain CR2 Propellers break during operation D Likely CR3 Balloon envelope ruptures C Possible CR4 Tail & boom break during landing B Unlikely CR4

A Rare CR3 CR2

38 Introduction Solution Critical Project Elements Risk Analysis Schedule Risk Assessment: Mitigated Component Risks

Top Project Risks 1 2 3 4 5 Insignificant Negligible Moderate Extreme Significant CR1 Battery overheats/ Almost E CR1 explodes Certain CR2 FollowPropellers SOP’s frombreak manufacturer during operation D Likely CR2 Propellers break during CR3 operationBalloon envelope ruptures C Possible CR3 VisuallyBalloon inspect envelope connections ruptures and wear CR4 ofTail component & boom break during landing CR3CR4 BalloonTail & boom envelope break ruptures during B Unlikely CR4 landing CR4 AcquireFollowTail & handling handlingboom instructions breakinstructions during from from A Rare CR3 CR2 vendorlanding CR4 Tail & boom break during landing

Utilize capture straps on balloon envelope before craft lands on ground

39 Introduction Solution Critical Project Elements Risk Analysis Schedule Testing and Verification

Fall FOV Test  Wind Speed Test  Semester

Manual Avionics Power Envelope January Controller Test Test Test Test

March Gondola Shaker Table Test Gondola Control Surface Test

Complete System Test: April Airworthiness Outdoor Flight Indoor Flight Test Test Test

40 Introduction Solution Critical Project Elements Risk Analysis Schedule Initial System Tests

Avionics Test

- Ensure all avionics are electrically connected - Ensure all avionics – servos are physically connected - Verify all surfaces are working properly with ground-control readout

Power Test

- Determine the amount of power the system will consume – run all avionics on full power and measure the current draw with ammeter - Quantify the amount of power needed for the final field test - Compare these values to the predicted model

41 Introduction Solution Critical Project Elements Risk Analysis Schedule Initial System Tests

Manual Controller Test

- Establish the connection between the avionics and the manual controller - Perform full surface check with inputs from the controller – verify that commands are received Envelope Test

- Perform fill test with air for the envelope and measure leakage over time with a pressure transducer recording the data in LabVIEW – ensure the envelope still has positive pressure (is not deflated) - Quantify leakage that would occur for the final field test - Compare values to the predicted model

42 Introduction Solution Critical Project Elements Risk Analysis Schedule Gondola Shaker Table Test

DR 1.1: System shall minimize vibration frequencies greater than 6.7Hz for the payload.

Testing: Gondola system will be subjected to shaker Shaker table table test to determine vibration frequencies of the 5 mph wind. For this test, frequencies of 30Hz, 60Hz, If the vibration frequencies recorded are 90Hz, and 120Hz will be used, as 120Hz is the less than 6.7Hz then DR 1.1 will be frequency of the motors (7200 rpm). An satisfied. If this is not met immediately, accelerometer attached to the gondola and payload test will be modified for an in- bay will send data to the DAQ saving files in flight accelerometer test with mitigation LabVIEW for later analysis. from envelope.

43 Introduction Solution Critical Project Elements Risk Analysis Schedule Gondola Pre-Flight Check

FR 3: System shall be capable of attaining a specific altitude and station keeping at that altitude.

Testing: A full surface pre-flight check of the gondola system shall be performed to determine the abilities of each lifting surface for station keeping purposes. This is normal for other FAA RC aircraft.

If the angle of attack of the elevator can extend fully in both directions and the full thrust test causes the gondola to lift, FR 3 will be satisfied. Elevator test

Full thrust test 44 Introduction Solution Critical Project Elements Risk Analysis Schedule Indoor Flight Test

DR 3.3.1: The aircraft shall take-off safely DR 3.3.2: The aircraft will land without harming any parts of the system

Testing: System will have a fully integrated indoor test to 10 ft determine its ability to take-off and land safely. Loose safety lines will be attached in the case of motor failure to ensure no loss of the torus.

If the system is able to receive a command to fly up and down without crashing or flying away, DR 3.3.1 and 3.3.2 will be satisfied.

45 Outdoor Flight Test: FR 2: System shall be capable of operating at 400ft AGL DR 2.1: System shall maintain the necessary thermal environment of no lower than 32 °F FR 3: System shall be capable of attaining a specified altitude and station keeping at that altitude Testing: System will perform a final outdoor flight test to determine operating conditions at 400 ft altitude. The IMU/GPS will record all atmospheric values.

If the system can maintain a temperature of no lower than 32 degrees, survive 5 mph wind gusts, and ascend to 400ft AGL without becoming unstable, FR 2, DR 2.1, and FR 3 will be satisfied. Example Outdoor Test Flight Setup

● Location: ○ Boulder Colorado – Boulder Model Airport ● Objectives: ○ Explore torus controllability and handling capabilities ○ Record atmospheric data for system characteristic analysis post-flight ● Used to test requirements: ○ DR 1.1 - Vibration ○ FR 3 - Station keeping ○ FR 4 - Telemetry ○ FR 2 – Altitude

47 Introduction Solution Critical Project Elements Risk Analysis Schedule Project planning-Org Chart

48 Introduction Solution Critical Project Elements Risk Analysis Schedule Project planning

Legend Work Breakdown Structure CompletedTBD ScheduledTBD

Course Management Electrical Software Structural Deliverables Testing

Critical Design Define testing Schedule Wiring Schematics Software FBD CAD Design Review methods

Hardware Structural Fall Final Report Risk Assessment Firmware analysis Write SOP’s verification Simulation Analysis

Manufacturing Work Breakdown Hardware Firmware Component stress Create safety plan Status Report Schedule calibration update/editing test

Test Readiness Hardware Simulated Mission Conduct subsystem Budget Shaker test Review integration Planner flight test tests

Materials/Parts Integrated system Integrated system Integrated system Electrical AIAA Paper Ordering test test test Structural Verify project Spring Final Report Post-test analysis Post-test analysis Post-test analysis requirements met Conduct full system tests Project Final Report 49 Introduction Solution Critical Project Elements Risk Analysis Schedule Project planning

MSR

TRR

50 Introduction Solution Critical Project Elements Risk Analysis Schedule Cost planning: Totals Component Cost Estimated Cost + Shipping Budget Margin Shipping Gas Envelope $1375 $250 $1625 $1804 ~10%

Helium (1882 cuft) $1215 $0 $1215 $1500 ~20%

Carbon Fiber $424 $200 $624 $650 ~4.5%

Batteries/Charger $362.64 $20 $382.64 $400 ~4%

Propulsion $341.8 $0 $341.8 $421 ~15%

Flight Controller $210 $0 $210 $210 0%

Tail and Pins $110.97 $0 $110.97 $120 ~9%

MISC. $325.99 $395 ~17%

Totals $4835.24 $5500 ~12%

51 Introduction Solution Critical Project Elements Risk Analysis Schedule Cost Breakdown

Allocated Section Funds

Balloon $ 1625

Helium $ 1215

Structure $ 907.33

Electronics $ 1087.91

Margin $ 664.76

Total $ 5500

52 Introduction Solution Critical Project Elements Risk Analysis Schedule Cost planning: Funding

Funding Source Program Funds Notes

AES Class Funds $5000

CU Innovation & Entrepreneurship Seed Funding Grant $500 Potentially can be tapped for $500 each month if Initiative physical product progress can be demonstrated

Engineering Excellence Fund EEF Grant $3000* Pending

Total $5500 *EEF Not Acquired yet, need CDR up-to-Date budget ($8500*)

53 Introduction Solution Critical Project Elements Risk Analysis Schedule Path Forward Exceptions Timeline • Special Authority for Certain Unmanned Aircraft • Must allow at least 120 days for review of Section Systems (Section 44807) 44807 petition • Exception to fly an unmanned aircraft that weighs 55 lbs • Expected response to COA application within 60 days or more of application submission • Separate “full” COA to fly above 400 ft • At least 180 days of wait time • COA application must have exemption and registration numbers

Funding Regulations • MANTA team will be responsible for securing their • Potential to lobby the FAA for updated/new own funding regulations regarding drone airships • Work with Dr. German to determine: • Most effective way to lobby the FAA • How long it would take for changes to go into effect • MANTA will be subjected to FAA and CU regulations if team is affiliated with the university

54 Introduction Solution Critical Project Elements Risk Analysis Schedule Summary

● Presented NESSIE’s full design ● Verified Functionality and meets requirements ● Laid down test schedule ● Planned the remaining time and money in project

55 Questions?

56 Slide Manager

1. Project Overview 6. Risk Assessment

2. Project Mission 7. Testing

3. Hardware Solution 8. Project Planning

4. Electrical Solution 9. Finance

5. CPE's

57 Back-up Slide Manager

1. Structural Analysis 6. Electronics

2. Control/Stability 7. Risk

3. Optical System 8. Testing

4. Balloon Equations 9. Cost

5. Field of View 10. Thermal

58 Structural Analysis – Propulsion Axel

● Worst case of loading is at max thrust:

Using a simple beam model, the maximum normal stress in the propulsion axel was calculated to be 43.30 MPa and the maximum shear stress to be 1.6 MPa.

59 Structural Analysis – Balloon Arm

● Worst case of loading is at max thrust where we have the largest drag:

Using the same approach as the propulsion axel, the maximum normal stress in the balloon arm was calculated to be 10.52 MPa and the maximum shear stress to be 0.2227 MPa.

60 Structural Analysis – Tail Boom

FEM analysis outputted a maximum stress of 10.26 MPa. The yield stress of ABS is ~ 30 MPa, resulting in an FOS of 2.9.

61 Structural Analysis – Motor support

FEM analysis outputted a maximum stress of 62.1 MPa. The yield stress of carbon fiber is, resulting in an FOS of 2.9.

The FEM results were checked with a simple beam model that provided a maximum normal stress of 13 MPa and a maximum shear stress of 0.23 MPa

62 Structural Analysis – Tail Structure

FEM analysis outputted a maximum stress of 0.594 MPa.

63 Aircraft Stability - Roll

COM – Center of mass COV – Center of volume Fb – Buoyabt force gamma – Angle between the horizon and airship omega – Angular velocity

64 Aircraft Stability - Roll

Assuming: Small angle theory, rigid body rotating about COM.

Modeling as a one DOF, two cylinders having buoyant force and drag force as damping, the dynamic model is derived.

65 Aircraft Stability - Pitch

Linearized dynamics response of STATIC pitch disturbance, using small disturbance theory.

66 Optical System Mount Minimum Pointing Angle

Assumptions: • Ideal telescope transmittance 0.81 • Diameter based on typical lenses for space photography ≅ • Atmospheric properties are constant at each angle

Angles below 30° make reaching limiting magnitude more difficult

67 Optical System Mount FOV

Assumptions: • Time and date were carefully selected to ensure a fly-by • Orbit used one-body model • P erfectly conical F OV

FOV needs to be greater than 94°; this FOV gives an opportunity window of 24 seconds

68 S ystem Transmittance through Atmosphere

= −𝑙𝑙𝑙𝑙 𝜏𝜏 𝑒𝑒 𝑎𝑎 𝑙𝑙 𝑅𝑅 ϴ ( + ) cos( ) 𝜙𝜙 𝜙𝜙= sin −1 𝑒𝑒 ϴ+90 −𝑅𝑅 ℎ ∗ 𝜃𝜃 ℎ 𝑎𝑎 = 180 𝑅𝑅( + 90)

𝜔𝜔 −sin𝜙𝜙 − 𝜃𝜃 : angle from horizontal to target object = c: atmospheric constants Assumptions: cos( )𝑎𝑎 𝑅𝑅𝑒𝑒 θ 𝜔𝜔 𝑅𝑅 l: distance through atmosphere ● Atmospheric𝑙𝑙 constants scale linearly. h: altitude of aircraft − θ 𝜔𝜔 R : ra dius of E a rth ● Aircra ft is clos e to ea rth (not in orbit) R :dis ta nce from E a rth’s center to edge of● Earth’s radius is constant e 69 atmosphere a Apparent Magnitude Equation From Astronomical Optics

= 2.5 log[ ] 0.7 2 Eq 17.3.5 𝑆𝑆𝑆𝑆𝑅𝑅 𝑚𝑚 − 2 𝑁𝑁0𝜿𝜿𝜿𝜿Δ𝛌𝛌𝐷𝐷 𝑄𝑄𝑄𝑄 = 0.5 2.5 log[ ] 0.7 2 2 Eq 17.3.6 ● SNR (Signal-to-Noise ratio) =𝑆𝑆𝑆𝑆 20 𝑅𝑅 ɸ 𝑚𝑚 𝑚𝑚푚 − 2 ● D (lens diameter) = 8.5 [cm]𝑁𝑁0𝜿𝜿𝜿𝜿Δ𝛌𝛌𝐷𝐷 𝑄𝑄𝑄𝑄 ● t (capture time) = 1 [s] ● N (photons/(s cm^2 nm) = 10e4 ● (transmittance modifier) = 0.8 0 ● (bandpass of sensor) = 350 [nm] ● Qκ (quantum efficiency) = 0.6 ● m’(skyΔλ apparent magnitude) = 21 ● (sensor angular size) = 5 pi/180 ● (system transmittance through atmosphere) = ? ɸ 70 𝜏𝜏 Opportunity Window S imulation

o Using the TLE for the ISS on March 2nd 2019, a camera simulation is done based on FOV.

Assumptions: • Camera is 18000 ft above sea level • Camera always has line-of-sight • Orbital perturbations ignored • Perfectly conical FOV

71 Electronics Schematic

72 Frequency f0 MHz 915 Speed of Light c m/s 299792458 Wavelength λ m λ = c/f 0.327642031 Link Budget 0 Block Variable Units Equation Value

PA Power PPA dBm 20 TX Match Loss LMatchT dB TX source PTX dBm 20 TX connector loss LConT1 dB (from Connector Loss sheet) -0.57 TX cable loss LCabT dB (from Cable Loss sheet) -0.374015748 TX connector loss (remote antenna) LConT2 dB (from Connector Loss sheet) 0 TX power PT dBm PT = PTX(C&C Loss) 19.05598425 TX antenna gain GT dBi -15 Effective (Isotropic) Radiated Power EIRP dBm EIRP = PT GT 4.055984252 Distance d m 136.3

Channel Medium Loss Factor L0 dB (from Medium Loss sheet) 0 2 Free Space Loss LFS dB LFS = (λ/4πd) -74.36612222 Power at RX Antenna, Free Space Path PChanFS dB PChanFS = LFSL0 EIRP -70.31013797

Flat Earth Loss (Includes Ground Bounce) LFE dB (from Ground Multipath sheet) -88.41927462 Multipath Loss LMP dB Obstruction Loss LObs-Total dB 0

Power at RX Antenna, Flat Earth Path PChanFE dB PChanFE = LFEL0LMPLObs EIRP -84.36329036 RX antenna gain GR dBi -15 RX connector loss LConR1 dB -0.57 RX cable loss LCabR dB 0.280511811 RX connector loss (remote antenna) LConR2 dB 0

RX power, Free Space Path PRFS dBm PRFS = PChanFS GR(C&C Loss) -85.59962616

RX power, Flat Earth Path PRFE dBm PRFE = PChanFE GR(C&C Loss) -99.65277855

Receiver Sensitivity Calculations Variable Units Equation Value RX Noise Figure NF dB 7

Operating Temperature T0 K 290 Effective Noise Temperature Te K Te = T0(NF - 1) 1163.442978 Boltzmann's constant k J/K 1.38E-23

Receive Bandwidth BWRX MHz 0.012 Antenna Temperature TAnt K 300 Noise Power (at RX) Pn dBm Pn = k(TAnt + Te)BWRX -126.1556386 Signal to Noise Ratio SNR dB SNR = P /P 9.155638626 RX RX RX n 73 S ensors S pecifications

74 Controls S pecifications

What kind of control device will be used?

-Control s urfa ce /prope lle r?

75 P rocessor S pecifications

76 CPE Electrical Design Why is this a Critical Project Element? ● The aircraft and each subsystem requires power to function.

Relevant Requirements ● DR1.3: System shall provide 5.57 W to the payload. ● DR3.5: System shall maintain aircraft power through a mission window of up to 8.9 hours. ○ DR3.5.1: The power for the aircraft and all its components will last 40 minutes or more under constant use. ○ DR3.5.2: The power supply for the aircraft will be easily removable, replaceable, and rechargable.

77 Battery Tattu 5200mAh 14.8V Lipo Battery Pack DR3.5.2 

Expected battery voltage discharge curve

Specifications:

● Voltage = 14.8 V (4S) ● Height = 1.32"

For 1 Lipo pack (3.7 V) ● Capacity = 5200 mAh ● Width = 1.77" Source: genstattu.com ● Weight = 0.962 lbs ● Length = 5.24" 78 Power budget DR1.3 

Component Max Power Req Uncertainty Margin (20%) Battery Value Characteristic Optical Payload 5.57 W 0 W 1.114 W Voltage 14.8V (4S)

ESC -> Motor 29-730 W 2.9-73 W 5.8-146 W Capacity 5200 mAh

Servo 2.5 W 1.5 W 0.5 W Sustained 35 C Discharge Rate Solenoid 0.6 W 0.15 W 0.12 W Sustained Power 2693.6 W Capability GPS module 90 mW 1 mW 18 mW Total Energy 76.96 Wh Comms 0.5 W 0.1 W 0.1 W Available

Stationkeeping Total: 69.16 W 8.901 W 7.532 W Key assumptions used in generating the power budget table: (x2 motor, x2 servo) -Motors will average 25% throttle during station-keeping (29 W) Descent Total: 1465.59 W 149.101 W 146.618 W -Motors will utilize 100% throttle during descent (730 W) (x2 motor, x2 servo) -Servos will be actuated for 10% of the total mission uptime 79 Flight/Mission Time

For the system to maintain aircraft power through an 8.9-hour window, it is most efficient to recharge drained batteries during subsequent flights. Using a 40 W charger would require 7 batteries total.

DR3.5  Expected Ascent Time: 365.4 sec DR3.5.1 Expected Descent Time: 41.4 sec 

Expected Observation Window: 41.46 min

80 Electrical Design Requirements Met Requirement How Met Met DR1.3 System shall provide 5.57 W to the payload. Power budget  DR3.5 System shall maintain aircraft power through a Power budget mission window of up to 8.9 hours.  DR3.5.1 The power for the aircraft and all its Power budget components will last 40 minutes or more  under constant use. DR3.5.2 The power supply for the aircraft will be easily Inherent in LiPo batteries removable, replaceable, and rechargeable. 

81 P roject Risk Phase Risk: Phase 1: Ordering/ Phase 2: Shipping/ Phase 3: Assembly/ Phase 4: Testing shipping of materials storage of materials Manufacturing Costs exceed budget Items misplaced Materials broken Craft undergoes rapid unscheduled disassembly Items are on backorder Items damaged during unpacking Parts not manufactured Physical injury to personnel or to spec bystander Shipping time too long Storage space insufficient Insufficient spare parts Pilot not available for testing

Materials broken during Physical injury to No data collected shipping personnel or bystander

Component Structure Electronics Risk: Propellers break during testing Envelope ruptures Battery overheats/ Motors seize/break explodes Linkages break Tail & boom break during Servos seize/break IMU breaks landing Lines to control surfaces break Pixhawk breaks during testing

82 P roject Risk: Risk Ma trix

Consequence Single minor Multiple minor Single moderate injury to Multiple severe Multiple severe injury to single injuries to a single person or multiple injuries to one injuries to People personnel single person minor injuries to multiple person multiple people personnel

Little data loss No data Data acquired NESSIE: Available facilities Limited facility space No available Facilities Risk Rating Matrix space available facilities space < $10 Loss $10 ~ $100 loss $100 ~ $500 loss $500 ~ $1000 Exceeds $1000 Cost loss loss

< 1-day delay 1-day ~ 1-week 1~2-week delay 2-week ~ 1- Exceeds 1- Time delay month delay month delay 1 2 3 4 5 Probability Frequency Insignificant Negligible Moderate Extreme Significant > 85% > 5 E Almost Certain 11 16 20 23 25

50% ~ 85% 4 ~ 5 D Likely 7 12 17 21 24 Likelihood 20% ~ 50% 3 ~ 4 C Possible 4 8 13 18 22

5% ~ 20% 2 ~ 3 B Unlikely 2 5 9 14 19

< 5% < 2 A Rare 1 3 6 10 15

83 P roject Risk: Risk Determination

 Calculation method:

max(Likelihood) x max(Consequence) (Value 1 ~ 25)

 Example:

Likelihood Consequence Value

Risk Probability Frequency People Data Facilities Cost Time Value

Propellers break 3 2 1 - - 5 4 15

Propellers break easy and there are 3-5 times opportunity for them to break. If they break during testing, personnel could be injured, and the balloon envelope is likely to be catastrophically damaged and will need to be replaced.

84 Outdoor Flight Test Animation

10 ft

Ground Station 85 Outdoor Flight Test Animation

400 ft

Ground Station 86 Test Card Example –Outdoor F lig ht Te s t

87 Cost planning: Vehicle Electronics Component Vendor Lead Cost Estimated Budgeted Margin Notes Time Shipping Battery Tattu + Gens Ace $362.64 $20 $400 ~4

Radio SparkFun 0 – 2 $45 0 $45 0 Includes two antennas and cabling. Weeks Transmitter and reciever already owned Pixhawk mini SparkFun 0 – 2 $210 0 210 0 Includes PX4M, PDB, GPS Module, weeks Mounting and cables 3x Servos Hobby King 1-2 $62.58 $5.89 90 23.92% Actuates control surfaces and tiltrotor weeks tilt 2x Brushless motors KDE Direct 1 week $185.90 $0* 186 0 *Free shipping over $149 KDE3510XF-715 4x 15.5” x 5.3 Propellors KDE Direct 1 week $155.90 $0* 235 ~34% *Free shipping over $149 (CW&CCW) KDE-CF155-DP IMU/PAYLOAD Sparkfun 0 – 2 weeks $40 0 80 80 50%

FLIGHT CONTROLLER: Teammate Flora 0 0 0 0 0 FREE *normally ~$90 Tactic Pure Reliable 2.4 TOTAL $1062.02 $25.89 1246 ~12 88 Cost planning: Vehicle Structure Component Vendor Lead Cost Estimated Budge Margin Notes Time Shipping t Gas Envelope Larger than Life 2-3 $1375 $250 $1804 ~10 Includes fill hose, patch kit, 100’ Inflatables weeks tether line, storage bag Helium (1882 cuft) CU Boulder 1 week $1215 $0 $1500 19% 2x fills (needs verification in writing) Carbon fiber tubes DragonPlate.com 1-2 $376 $200 $600 4% Used for structure of blimp 2x 8ft, 1.875” weeks Carbon fiber tube DragonPlate.com 1-2 $48 $0* $50 4% For Tiltrotor axle 1x 4ft, 0.625” weeks *Shipped with other Carbon Carbon Fiber Sheet DragonPlate.com 1-2 $153 $0* $160 4% Gondola Structure weeks *Shipped with other Carbon 2x 50ft 550 cord McGuckins 1 week $19.57 $0 $20 2% Rope for additional attachment Hardware Pins/Faseners/Screws Home Depot 1 week $20 $0 $20 0% General mounts and attachment points for structure Polystyrene Foam and Blick/Home depot 1-2 90.76 $6 $100 9% Tail adhesive weeks Total Structure $3297.33 $456 4254 12 $3713.33 estimated Total 89 Cost Thermal Requirements

Requirement Description DR 2.1 System shall maintain the necessary thermal environment of no lower than 32 degrees F

90 Material Characteristics

Gondola: Aluminized Mylar Envelope: PVC infrared 0.58 thermal 0.92 𝞮𝞮infrared 0.58 𝞮𝞮thermal 0.45 𝞪𝞪thermal 0.044 𝞪𝞪 𝞮𝞮thermal 0.17

91 𝞪𝞪 The rma l - Assumptions

Assumptions for critical design level analysis:

● TLifting Gas = TAtmosphere ● Air acts as a calorically perfect gas ● Helium acts as a calorically perfect gas ● S un acts as a blackbody ( Sun= 1) ● Earth acts as a blackbody ( E a rth= 1) ● Envelope can be modeled𝞮𝞮 as a flat plate 𝞮𝞮

92 Test Environment

○ S tandard day conditions, standard atmosphere

o Flight ceiling of 5.728 kft above sea level

o 400 ft altitude from takeoff in Boulder (5.328 kft)

93 Test E nvironment Visualization

Blue represents heat tra ns fe r by convection Red represents heat tra ns fe r by radiation 94 Te s t E nvironme nt He a t B a la nce

Envelope:

Gondola:

95 Net Heat Transfer - E nvelope

96 Net Heat Transfer - Gondola

97 Convective Heat Transfer

98 Aircra ft The rma l R a dia tion The ory

•Both the envelope and the gondola will radiate thermal energy • Assuming the lifting gas temperature will be equal to the atmospheric te mpe ra ture • The battery being used will need to be kept at a minimum temperature of 32 oF • Heat will be generated by electronics in the gondola, so this will change the thermal radiation in the future

99 Thermal Radiation Out of E nvelope

100 Dire ct S ola r R a dia nce The ory

•Thermal radiation from the S un/Moon is a bs orbe d dire ctly by the a ircra ft • Radiation flux depends on angle between normal to the surface and the rays from the S un/Moon

•Multiply through by absorptivity and upper surface area to determine heat tra ns fe r

Note: this method a s s umes the a ircra ft is s ta tiona ry a nd o that the S un/Moon travels 180 ove r the a ircra ft 101 Direct Radiance - E nvelope

102 Direct Radiance - Gondola

103 Indire ct Irra dia nce /R a dia nce The ory

Hea t flux Hea t tra ns fer •Infrared energy emitted by the •Uses the infrared absorptivity of sun/moon is reflected off of the clouds aluminized mylar a nd s trikes the bottom of the a ircra ft •Multiply by the estimated area of the •clouds are at the same temperature lower half of the envelope/gondola as the atmosphere

•F c represents the percentage of cloud cove r, from 0-100% •Uses the infrared emissivity of aluminized mylar

104 Indirect Radiance - E nvelope

105 Indirect Radiance - Gondola

106 S te a dy-S tate S imulation: Conditions

● Heat transfer modes: ● S imulation conditions:

○ Radiation ○ T0 = 277.59 K

○ Convection ○ Tatm = 277.59 : 276.80 K

○ h = 0.4831 W/m2/K ● S olutions: ○ ϵ = 0.59 ○ Te mpe ra ture ○ 200 steps @ 1 second/step ○ Tota l He a t F lux ○ 3.19 MW/m3 of internal heat ○ Directional Heat F lux generation

○ The rma l E rror ■ Maximum continuous power from 107 E S Cs and motors S te a dy-S ta te S imula tion: Tota l He a t F lux

108 S te a dy-S ta te S imula tion: Dire ctiona l He a t F lux - Is ome tric ● F ig ure s from Ans ys he re

109 S te a dy-S ta te S imula tion: Dire ctiona l He a t F lux - F ront ● F ig ure s from Ans ys he re

110 S te a dy-S ta te S imula tion: Dire ctiona l He a t F lux - Rear ● F ig ure s from Ans ys he re

111 S te a dy-S ta te S imula tion: Te mpe ra ture

● F ig ure s from Ans ys he re

112 S te a dy-S tate S imulation: Thermal E rror

● F ig ure s from Ans ys he re

113 S te a dy-S tate S imulation: Conclusions

● At s tea dy-state conditions, i.e. hovering at maximum altitude, gondola internal temperature will not rise above allowed maximum operating temperature (85 oC = 358.15 K)

114 Transient S imulation: Initial Conditions

● Heat transfer modes: ● Initial conditions:

○ Radiation ○ T0 = 277.59 K

○ Convection ○ Tatm = 277.59 : 276.80 K

○ h = 0.4831 W/m2/K ● S olutions: ○ ϵ = 0.59 ○ Te mpe ra ture ○ 200 steps @ 1 second/step ○ Tota l He a t F lux

○ Directional Heat F lux

○ The rma l E rror 115 Transient Simulation: Total Heat Flux

116 Transient S imulation: Directional Heat Flux - Is ome tric ● F ig ure s from Ans ys he re

117 Transient S imulation: Directional Heat Flux - F ront

● F ig ure s from Ans ys he re

118 Transient S imulation: Directional Heat Flux - Rear

● F ig ure s from Ans ys he re

119 Transient S imulation: Temperature

● F ig ure s from Ans ys he re

120 Transient S imulation: Thermal E rror

● F ig ure s from Ans ys he re

121 Transient S imulation: Conclusion

● More heat build up at rear of the gondola due to less convection

○ Not large enough to pose a serious threat to electronics in the gondola ● Temperature of the gondola will remain within P ixhawk 4 Mini operating temperature range (223-358.15 K)

122