Balloon Enhancement ProjectPresented by the Balloon Boys:

MIDN 1/C TeepenMIDN 1/C Sellers

MIDN 1/C Santucci MIDN 1/C Lewkowicz

Advisors: Jin Kang, CDR Bob Bruninga, CDR Jeff King

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Balloon Enhancement ProjectThe mission of the Balloon Enhancement Project is to enhance the process of

small satellite research and development to allow for greater precision and

ease of testing. The Balloon Enhancement Project employs automation and

integrated user control to ensure mission success.

Mission elements:

- The Balloon Filling System

- Payload Container

- BEPSAT-1U

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The Balloon Filling System

Mission ObjectivesThe objective of The Balloon Filling System is to autonomously fill a weather

balloon in a timely manner that meets the user’s desired specifications.

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Requirement StatusThe balloon shall be able to be autonomously filled within 10% of target lift using only user inputs

Tank sensors shall be able to make measurements key parameters

Tank shall stop filling once desired key parameters are reached within 10% of target lift

Balloon interface shall be able to provide secure link to other interfaces while filling

Balloon interface shall have the ability to dock and undock with the other interfaces via user without damaging balloon

Balloon interface shall provide an airtight seal

User interface shall be able to receive user input to control tank output

User interface shall be able to convert user input to desired gas quantity delivered to balloon

User interface shall autonomously shut down in event of mission parameter failure

User interface shall be able to receive user input to instantaneously cease filling

User interface shall display measurements of key parameters during filling process

The system shall be able to run on internal power

System shall take no longer than 30 minutes to fill

System shall weigh less than 22.7 kg

The system shall be usable by one person

System shall not exceed a volume of a 45 cm cube

The system shall be mobile 7

The Balloon Filling System

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Concept of Operations

Prior to launch

1) Charge battery and

laptop

2) Check weather

conditions

3) ensure program is

downloaded on laptop

Setup

1) Place box on flat surface

2) Attach laptop to Arduino and regulator to helium tank

3) Setting regulator pressure to 50 psi

4) Attach balloon to filler using the hose clamp

5) Turn on The Box

Operation

1) Load program on computer

2) Enter the payload mass,outside temperature and pressure, and desired altitude

3) Monitor until system indicates the balloon is full

4) Remove balloon

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The Balloon Filling System

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Main Systems- Battery: Provides power to the mass flow controller due to its higher power draw

- Mass: Provides a positive reading on the scales, where the balloon lift is then measured by difference

- Arduino: Processes the inputs from the user’s computer and measurements from the box and halts

flow when parameters are met

- Solenoid Valve: Controls the flow of helium into balloon based on commands from the Arduino

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Components and SpecificationsOverall Specifications: - Designed for a 1200g balloon

- Capable of filling balloon within 10% of desired altitude- Rated for temperatures between 5-50 °C

Battery: Lead Acid Battery, 12V 5.0 Ah

Processor: Arduino Uno

Scale: Pressure Sensitive Resistor, Rated between 0.3-10kg

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Hose Clamp Scale Solenoid Valve

Mechanical Systems and Design Features

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Materials and Mass

Total Mass = 13.98 kg = 30.82 lbf

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Electrical/Power SystemsPower (W)

0.6

0.2

0.1

Scale ArduinoProcessor

Solenoid Valve

Powered by user’s computer

Powered by batteryItem Maximum

Power

Scale 0.1 W

Processor 0.2 W

Solenoid Valve 0.6 W

Total 0.9 W

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Command and Data HandlingFill Criteria:

- Measured scale lift compared to desired

lift within +/- 10 %

- Scale readings within parameters of +/-

grams filled

- Compare mass flow meter to actual scale

lift within +/- 10 %

- After all criteria are met, flow into

balloon will be halted

- Real time outputs will be displayed

BFS Graphical User Interface

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Logic Diagram

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Alternate Designs

● Previous designs for the payload container included

a machined carbon fiber box, that had rounded

corners to prevent puncturing the balloon. Unused

due to cost inefficiency and shape complexity.

● Previous designs for the filling system involved using

a mass flow controller to measure the exact amount

of gas entering the balloon. Unused due to high cost

of mass flow controller, nearing ~$1600.

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System Tests

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Results● Error in BFS code caused the filling to stop prematurely

● Successive runs of the BFS code allowed for manual filling

● Backup measurement using precalculated water jug worked very well

○ Possible future system design

● Mechanical systems worked as expected

● Balloon reached between 99,000-105,000 ft

○ Target altitude was 104,000 ft

○ Time between GPS telemetry packets did not allow for resolving official altitude

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The Payload Container

Mission ObjectivesThe mission of the payload container is to carry the payload(s) and provide power and comms for the

duration of the flight.

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Requirement Status

The payload shall be operational for mission duration

The power system shall be able to operate within a range of temperatures between 0 to 50 deg C

The payload shall be powered for the duration of flightThe payload power system shall be two fault tolerantThe payload shall be able to determine its height above ground within 25 ftThe payload shall emit noise when the user is within 15.24 m from the payload

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Payload Container Design

● The payload container was constructed using low density styrofoam.

● Epoxy sealant was used to secure the walls of the payload container.

● Paracord transversed the sides of the container.

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Mass Budget

Item Description Quantity Weight

(g)Total Weight

(g)Structure

Styrofoam Cooler, paracord, parachute, carabiners, fishing line, and radar 1 547 547Box Lid 1 29 29Tape 1 20 20

Electrical SystemsUC Santa Barbara Payload 1 460 460BEPSAT 1 272 272Total 1328

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Thermal Design

● The system is designed to be operated with a minimum external temperature of -60 °F due to low

temperatures in the upper atmosphere.

● In order to protect electronic components in the system, chemical warmers in addition to thermally

insulated material will be used to allow the internal operating temperature to remain between 0 and

120 °F.

● The expected average temperature at 100,000 ft is -50 °F

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Communications● Uses communication board from BEPSAT

● Antenna hangs out bottom of container

● Sends telemetry data and payload data

● SPOT system used as telemetry backup

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SPOT

● SPOT Tracker - Service that provides Satellite GPS

● Does not provide tracking at 60,000+ ft

● Longitude and Longitude relayed every 15 minutes

● Used to determined location once landed as APRS

would not get signal

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Alternate Designs● Box with thicker walls was produced but deemed too heavy

● Original design used an off the shelf styrofoam ice chest, but logistical issues prevented us from

obtaining the chest

● In attempt to prevent parachute line tangling, we considered adding a ring around the lines. However,

the ring added too much weight, so the team went with light plastic tubing to prevent tangling when

tumbling

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System Tests● Styrofoam was tested in a vacuum chamber to see how it would react to the high altitude

environment

● Full system test performed during launch of weather balloon

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Results

● The container performed its main mission of carrying the payload throughout its

flight

● Failure of the BEPSAT-1U prevented it from providing power and comms

● Successfully broadcasted GPS location data

● The container broke on landing and is only good for one use

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BEPSAT-1U

Mission Objectives

The mission of the BEPSAT is to provide GPS location data and telemetry data to the user, to enable payload

tracking capabilities. The BEPSAT is also capable of handling up to six 5V digital outputs, to enable future

missions to power other payloads for multisystem testing on balloon launches.

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Requirement Status

The payload shall be powered for the duration of flight

The payload power system shall be two fault tolerant

The payload shall be able to recognize a private abort signal

The payload shall be able to determine its height above ground within 25 ft

The payload shall update its altitude at least every 5 s

The platform shall be able to receive signals from the user

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BEPSAT● The BEPSAT used in the payload container is

designed to transmit APRS location data, telemetry,

and as well power additional payloads to be tested.

● The BEPSAT is exactly the same as the PSAT-1U

used by the Astro department, with the exception

that it does not contain its own payload, Attitude

and Dynamics Control System (ADCS), or satellite

body.

● The Balloon Boys lead the front in working with CDR

Bruninga to develop the latest design of PSAT-1U’s

for future groups to be able to imitate and mass

produce for satellite launch availability

Entire BEPSAT system

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Power Budget

● The PSAT-1U is powered by NiCd batteries due to high reliability and low cost

● The entire system runs at 5.6 W-h, since it operates at 4V at 1400mA-h

● Each battery runs at 1.2-1.4V, and the board consists of three cells of two batteries in parallel

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APRS Communications

● The PSAT is designed to communicate on the 144.390 frequency

● The PSAT transmits APRS data every minute on the minute, and transmits telemetry every two

minutes

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SATT4 Battery-Comms Interface● The battery board powers the communication

board, as well as other payloads. In order to

accomplish this it needs to output 5V

● In order to obtain the 5V necessary from the 4V

outputted from the battery board, the Pololu 5V

Boost Step Up Inverter is used to correct this.

● Several pins had to be identified for the main

connections, namely the S0-S1 jumper and S4-S5

switch. Along with this, pins for the different digital

outputs were also identified

Comms board with interface pins in yellow boxes

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Block Diagram of SATT4 to Battery Board connectionsPololu 5V Boost Step Up Inverter

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Results● Prior to launch, a subsystem consisting of 2 Lithium Ion batteries was developed to be a

supplementary lifetime booster for the BEPSAT

● Upon use, the BEPSAT began wildly transmitting and washing out the 144.390 wavelength, as well as

other frequencies. Prior to the live testing, the PSAT had been successfully testing in its fully

assembled position.

● After being reset from this, the BEPSAT was no longer capable of transmitting to APRS

● The cause of this could have either been the transmitter being blown out by the additional power, or

the additional RF interference caused destructive interference and killed the communications board

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Conclusion

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Balloon Launch

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Program BudgetItem Quantity Total Cost

Balloon Filling System

High Pressure Tubing 9 ft $12.60

Solenoid Valve 1 $88.40

Arduino Processor 1 $25.00

Scales 3 $18.00

20 lb Mass 1 $115.00

Battery 1 $18.00

Casing 1 $50.00

Miscellaneous Variable $31.00

Total $358.00

Payload Container

Styrofoam Container 1 $15

Nylon Parachute 1 $16

Weather Balloon 1 $90

Fishing Line and Paracord 60 ft $4.15

Miscellaneous Var $3.85

Total $129.00

BEPSAT-1U

PSAT-1U Satellite 1 $3000

Program Total Budget $348744

Mission SafetyMajor Risks

1. Electric shock to hardware and or

students

2. High gas pressures

3. Snow/ Rain

4. Circuit failure

5. Payload landing in inaccessible area

Likelihood

Severity45

Mission StatusMilestone/Date 24AUG18 31AUG18 07SEP18 29OCT18 20NOV18 28NOV18 25JAN19 15FEB19 12APR19

Project Initiation Complete

Proposal Review Complete

Requirements Review Complete

Preliminary Design Review Complete

Critical Design Review Complete

Manufacturing Readiness Complete

Testing Readiness Complete

Flight Readiness Complete

Launch Complete46

Project Critiques● Lack of system testing led to multiple failures during launch

○ Backup systems proved useful and effective

● The PSAT should not have last minute adaptations that are untested

● Have more realistic budget constraints

● Have better idea of what PSAT was being used for and start planning and work earlier

● Purchase styrofoam cooler instead of manufacturing one

● The project put too much focus on paperwork over actual engineering and production

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Future Work● Balloon Filling System

○ Make system fully independent - add user controls on system

○ Add capability to autonomously launch balloon

● Payload Container

○ Add commanded system to terminate flight

○ Add parachute deployment system to prevent potential tangling during descent

○ Include more features to allow the system to be found easier upon landing

● BEPSAT-1U

○ Utilize the six 5V digital outputs to turn on/off additional payloads

○ Integrate component to terminate flight, possibly with one of the digital outputs

○ Develop additional battery life pack that works with the current system

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The Team

Michael SellersChief EngineerEmail: m195826@usna.edu

Jacob TeepenTeam LeadEmail: m196342@usna.edu

Michael SantucciAssistant EngineerEmail: m195682@usna.edu

David LewkowiczAssistant EngineerEmail: m193780@usna.edu

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Questions?