1. Smart Water Rocket System Group 6
Connor Phillips (EE)
Kyle Moran (CE)
Gabriel Fernandez (EE)

2. Sponsor

3. Space Trek's Water rocket program
Space Trek is a summer camp at Kennedy Space Center for middle school, high school, and college students
One of their many science experiments is a water rocket capable of launching up to 100 feet in the air
Prior to launch there is a pre-flight analysis simulation that lets students adjust and test different flight parameters (water volume, air pressure, launch angle)

4. Water rocket contd.
Once the camp attendees have their flight specifications, they move outside to a field to launch the water rockets
The rocket is filled and then pressurized using a bike pump, mounted on the Launchpad, and then fired by pressing a red button
When the rocket reaches the peak of its trajectory, a gyroscope activates a mechanical system to release the parachute
After retrieving the rocket measurements are recorded from the on-board altimeter

5. Water Rocket Launch

6. Goals and objectives
Automate the rocket launches to create a better experience for both students and staff
Replace on-board altimeter with custom altimeter with wireless data transmission capabilities
Allow students to use a mobile application to review the data from their launches and easily compare between groups

7. specifications
Altimeter must be less than 10 grams and fit into the rocket without changing its center of mass
Launch pad angle plate must be motorized for more precise angles
Data must be transmitted wirelessly without the need to take the altimeter out of the rocket
Altimeter must be water resistant in case of leakage

8. Block diagram

9. MCU
Arduino Uno
TI MSP430

10. Altimeter Pressure GPS Radar Pros: Pros: Pros: Cons: Cons: Cons:
Cheap
Low voltage
Cons:
Slightly inaccurate
Pros:
Accurate
Cons:
Expensive
High power consumption
Pros:
Direct altitude measurement
Cons:
Antenna requirements

11. BMP-180 I2C Low Power Breakout board easily available Inexpensive
Small
Good Resolution

12. Accelerometer Triple-Axis
Used to obtain velocity in a 3 dimensional space
More than required

13. ADXL345
I2C
Low Power
Small
Very Common

15. Communications Bluetooth
Pros – straight forward implementation, handles data well when paired
Cons – bad range, might not show data in real time, can lose data when unpaired
Wi-Fi
Pros – works at greater ranges than Bluetooth and won't lose data
Cons – Wi-Fi connection in the launch zone isn't strong

16. Programming microcontroller
Collect data from sensors – velocity, height and distance
Sensors include a pressure sensor and accelerometer
Transmit Data wirelessly to ground
Ensure consistent and reliable data for comparison
Essentially designing an altimeter with wireless transmissions

17. Mobile Application Tablet Located at launch station
Accepts data from custom altimeter in rocket
Organizes data by groups and inserts into database
Uploads data to simple web server for later comparison
Will have the option to view most recent launches for quick review

18. Sequence Diagram
Shows flow from altimeter receiving data to transmitting back to the ground
Takes into account failed packets and bad connections
Will store data onboard temporarily until a good connection has been made
Students will be locked from launching rocket until instructor has given permission

20. Class Diagram
Shows relationship between different modules of the rocket and how it connects to the tablet on the launch pad
Altimeter in rocket will gather data from onboard sensors and transmit wirelessly to the tablet
Tablet will interpret data and fill out a database for each group and transmit that data to a remote server for later viewing from the classroom

22. LaunchPad Tablet
Using an Android Tablet for lower cost and easy replacement
More familiarity designing in Android
Will be programming application in Android Studio
Stretch goals include adding a lock feature to prevent launches until authorized (key switch and 4-pin code)
Must be able to interact with microcontroller in the rocket

23. Launchpad automation
The current water rocket platform involves an angle plate that is adjusted by manually loosening and tightening a knob to set a desired launch angle
A stepper motor will be connected to a microcontroller and operated using an LCD with +/- to adjust the angle
To power the automation a large capacity battery will be used

25. Automation design
Space Trek has a 3D-printer on site which can be used for parts to modify current launch pad
Angle plate modified to adjust angle with stepper motor
System will be attached underneath each launch pad
Protecting from some of the water thrust but ultimately the motors and MCU will have to be housed in a water resistant container

26. Stepper motor selection
Stepper motors will be used to automate the launchpad because DC are generally for high rpm and servo motors are high rpm and accurate, but generally more expensive than stepper motors
Servo motors require a feedback mechanism and support circuitry to drive positioning
Stepper motors are low cost, slow rotating, easy to set up and control (a stepper motor is built for position control)

27. Selecting a Battery Stepper motors require continuous power by design
Large capacity to endure all of the launches during experimentation
Durable because it will be used outdoors
Chose lead-acid because they are relatively cheap so that they can be replaced
High capacity, reliable and long lasting

28. Projected Costs Component Cost Lead-Acid Battery $18
Stepper Motor (x4)
$20
Arduino Uno (x2)
n/a
ATMega328p (x2) $8
BMP180 $4
ADXL345 $7
Bluetooth Module (x2)
Li-Po Battery
Misc. Mechanical Parts
$30
Misc. Electronics
$50
Breakout Boards
$16
PCB
$200
TOTAL
$381

30. Work Distribution Launchpad Altimeter Software Connor Phillips X
Gabriel Fernandez
Kyle Moran

31. Questions?