Rocket Based Deployable Data Network
University of New Hampshire Rocket Cats
Collin Huston, Brian Gray, Joe Paulo, Shane Hedlund,
Sheldon McKinley, Fred Meissner, Cameron Borgal
2012-2013 Flight Readiness Review
Submission Deadline: March 18, 2013
Overview
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Objective
Launch Vehicle Design and Dimensions
Key Design Features
Motor Selection
Mass Statement and Mass Margin
Stability Margin
Recovery Systems
Kinetic Energy
Predicted Drift
Test Plans and Procedures
Full-scale Flight Test
Recovery Testing
Summary of Requirements Verification
Payload Design
Key Design of the Payload
Payload Integration
Interfaces
Summary of Requirements Verification
Objective
• The UNH Rocket Cats aim to create a Rocket
Based Deployable Data Network (RBDDN). The
objective is to design a low cost data network
that can be deployed rapidly over a large area
utilizing rockets.
Launch Vehicle Dimensions
Vehicle Dimensions
• 75.2” in length
• 4” Outer Diameter
• 10” Span Diameter
Key Design Features
• 2+1 event recovery system to allow safe
vehicle recovery with separate payload
ejection
• Piston based ejection system for the main
parachute
• Removable aluminum bulkheads to allow for
full tube access
• Fiberglass and Kevlar reinforced blue tube
Motor Selection
• Cesaroni Technology Inc. K740-CS Reloadable Motor
• Total Length: 15.9 in (4 grain)
• Diameter: 54 mm
• Launch Mass: 51.8 oz.
• Total Impulse: 1855 Ns
• Average Thrust:747 N
• Maximum Thrust: 869 N
• Burn Time: 2.48 seconds
• Thrust to weight ratio: 9:1
• Exit Rail Velocity : 45.17 ft/s
Mass Statement
Component:
Mass:
Notes:
Motor Casing
12.15
Weighed with retention ring
Fin Can
52.75
Includes retention ring
Secondary Payload
20.3
With electronics and threaded rod
Removable Bulkhead
6.6
With eyebolt
Drogue
5.5
With Harness and Nomex
Avionics Bay Tube
4.3
With epoxied t-nuts
Avionics
16.1
With avionics, batteries, nuts, threaded rod
Drogue Bulkhead
4.85
Main Bulkhead
5.35
Piston
6.5
Main Harness
5.85
Parachute Bay
10.95
Main Parachute
10.7
With Quicklink
Main Payload
29.2
With electronics and threaded rod
Payload Recovery
14.4
With battery and fixing bolt
Nosecone
15.25
Empty
Payload Parachute
4.25
With Nomex, Harness and Quicklink
Motor (J740)
51.84
Mass (loaded)
Ballast
19.2
Added to removable bulkhead
Total
296.04
With Nomex blanked
Stability Margin
• Static Stability Margin
– 1.81 calibers
• Center of Pressure
– 53.5” from the nose tip
• Center of Gravity
– 46.3” from the nose tip
Recovery Systems (Parachute Selection)
Section
Parachute
Choice
Area
[𝒇𝒕𝟐 ]
Drogue
Public Missile
Works PAR-30
4.91
Payload
Public Missile
Works PAR-24
Main
Sky Angle 44
𝑪𝒅
𝒇𝒕
Velocity [ 𝒔 ]
Kinetic
Energy
[ft*lbf]
.75
54.80
600.34
3.14
.8
35.64
65.5
21.1
1.87
14.2
29.7
Recovery Systems (Altimeter Selection)
Altimeter
Selection
Primary
Deployment
Altitude
Secondary
Deployment Altitude
Primary
PICO-AA2
Apogee
700’
Backup
ADEPT DDC22
Apogee
700’
Payload
PICO-AA1
Apogee+50s
None
(700’ from vehicle)
Kinetic Energy
• KE =
1
𝑚𝑣 2
2
• The kinetic energy values shown are
calculated from the chosen parachutes for the
rocket
Section
Parachute
Choice
Velocity (ft/s)
Kinetic Energy
(ft*lbf)
Drogue
Public Missile
Works PAR-30
54.8
600.34
Payload
Public Missile
Works PAR-24
35.64
65.5
Main
Sky Angle 44
14.2
29.7
Predicted Drift
Vehicle
Wind Speed [mph]
Estimated Drift [ft]
0
8
5
440
10
850
15
1300
20
1800
Deployed Payload
Wind Speed [mph]
Estimated Drift [ft]
0
8
5
440
10
1041
15
1862
20
2483
Vehicle Testing and Procedures
Function
Testing Procedure
Charge Testing
The recovery systems were ground tested
by prepping the rocket and ejecting the
parachutes and primary payload.
Fin Testing
Fin flutter was tested theoretically with fin
flutter velocity theory and then compared
to physical testing in a wind tunnel.
Parachute Testing
Parachute testing was conducted by
dropping the primary payload and vehicle
off of a tall structure with the parachutes
open to study the velocity at impact.
Altimeter testing
Altimeter testing was conducted within a
pressured chamber and also by creating
an impulse on the accelerometer.
Tests of the Staged Recovery System
• Deployed the main and drogue parachutes.
• Deployed the nose cone.
• Successfully tested the main parachutes ejection charge potential of deploying
the nose cone in the event of a nose cone deployment failure
Ejection charge testing set up.
Successful deployment of main
parachute and nose cone by main
parachute charge.
Full-scale Flight Test #1
• Successful exit from rails
• Successful main payload deployment
• Issues with vehicle recovery systems caused total parachute failure or
“lawn dart”
• Failure causes determined and improved through post flight
inspection
Full-scale Flight Test #2
• Mission success for all vehicle requirements
• Payload flown with mass simulators
• Drift well controlled in high winds
Summary of Requirements Verification
(Vehicle)
• Cesaroni K740:
– Apogee of 5,282 feet (AGL)
• Altimeters:
– PICO-AA2 (primary), ADEPT DDC22 (primary backup), and PICOAA1(nose cone)
• Vehicle velocity:
– 0.58 Mach
• Recoverable & Reusable:
– Non-degradable and reusable materials were used.
• Independent Sections:
– 3 sections, nose cone, booster section, and parachute bay.
• Prepared for flight within 2 hours:
– Full scale test launch took 1 hour and 36 minutes to fully prepare.
Summary of Requirements Verification
(Continued)
• Remain in launch ready state for 1 hour:
– Estimates suggest 8 hours of functionality before any functionality is
lost.
• Rail size:
– The rocket is functional with a 10 10 rail size.
• 12 volt direct current firing system:
– Succesfully launched full scale with a 12 volt current firing system.
• No external circuitry
– There is no external circuitry.
• Commercially available motor:
– Cessaroni K740
• Total impulse less than 5,120 Ns:
– 1855 Ns
Summary of Requirements Verification
(Continued)
• Ballast:
– The ballast is less than 10% of the unballasted vehicle mass.
• Successful full scale launch:
– Successful launch was completed on March 17, 2013
Payload Design Overview
• Primary payload
– Deployed payload in nose cone
– Atmospheric and GPS sensor
data
– Transmit and store sensor data
• Secondary payload
– GPS sensor data
– Act as node in network,
transmit,
and receive relevant data
Primary payload exploded diagram
Primary payload in nose cone
Payload Sled Design
• Fiberglass trays with
aluminum threaded rods
and Delrin® blocks
• Machined aluminum rear
bulkhead and fiberglass
front bulkhead
• Primary sled dimensions:
11.5” x 3.75”
• Secondary sled
dimensions: 7” x 3.9”
Primary Payload Components
• Arduino Nano
– Barometer: BMP085
– Humidity and Temperature: SHT15, Cantherm
MF51-E thermistor
– Ambient Light: PDV-P9200
– Ultraviolet: PC10-2-TO5
• Raspberry Pi
• GlobalSat BU-353 GPS
• Xbee 900 Pro
Secondary Payload Components
• Raspberry Pi
• GlobalSat BU-353 GPS
• Xbee 900 Pro
Secondary payload model render
Payload Testing and Procedures
Function
Testing Procedure
Battery Life testing
Allow the system for extended lengths of
time under battery power.
Xbee range testing
Ground station yagi antenna and smaller
payload antennas are coupled to the Xbee
transmitters and tested for transmission
distance.
Software testing
Packets of data are sent between the
payloads and ground station to verify
transmission integrity and packet handing.
Sensor testing and calibration
Atmospheric sensors tested on the
prototype circuit board for continuity and
are calibrated against known conditions
for accuracy.
Strength Testing/Integrity
Drop testing and launches to verify system
hardware integrity.
Payload Integration
• Sled containing primary payload is secured in
nosecone using external bolts
• Sled containing secondary payload is secured in
rocket body using the same method.
Interfaces
• Primary payload connects to recovery system
via direct wired connection
• Communication to ground station and
deployed nodes via Xbee 900mHz connection
• Avionics are isolated in separate bay
• Testing for effects of EMI performed
• 1” Launch rails
Conclusion
The team has built and tested a rocket for competition in
the NASA-USLI. We are excited to travel to Huntsville and
show off our hard work.
Questions?