Warwick University Satellite Team:
Laying the Foundations for CubeSat Capabilities
What is a CubeSat?
A CubeSat is a standard 10x10x10cm satellite, that is designed to provide
low cost space access for small scale payloads.
Long Term Aims
• Design and manufacture a space-worthy CubeSat
• Launch the CubeSat into low earth orbit
• Pursue links with industry
Objectives (2012/2013)
• Design and manufacture a fully functioning prototype CubeSat
• Send a prototype CubeSat into the stratosphere using a weather balloon
• Gain real-time temperature/pressure readings during the CubeSat’s
journey
• Obtain aerial photos from the CubeSat flight
The communications system for the prototype CubeSat will use an
external antenna to transmit the real-time data and images. This system
will enable the use of readily available communications components
that are easily compatible with the control system and allow a variety
of base stations to be used. Due to budget constraints the selected
communications system for the prototype will not be space-worthy;
this will need to be addressed in the future.
Processing unit
The CubeSat is controlled by an internally
mounted Arduino Leonardo, chosen for
the wide variety of input options and
supported protocols. Rapid programming
of the system is also possible thanks to the
large variety of libraries available for the
Arduino platform.
Power System
The electrical power system will mainly comprise of:
• Solar cells: Main power supply during flight, consisting of 6
photovoltaic cells distributed over 3 of the launch module sides.
• Battery: Lithium-ion batteries are preferred to other potential battery
technologies because of their high energy densities, allowing for
reduced weight/increased power.
• Voltage regulators: Maximum Power Point Tracking ensuring the
solar array outputs the maximum power at all times
The host board that the Arduino is mounted
on contains the internal sensors, and
headers for external sensors, cameras and
transceiver. For redundancy, there are two
host boards in the satellite, however only one
will be connected to the communications
system for complexity reasons.
Balloon launch
Project Management
This year’s launch will be used to test the prototype CubeSat’s power and
communication systems. A weather balloon will lift the CubeSat to a height
of 30km, after which a parachute deploy, slowing the CubeSat’s descent. A
GPS system with LEDs and sound transducers will aid the recovery process.
Simulations show that the balloon will rise at a speed of around 8m/s, while
traveling roughly 50km laterally, over a total of 1.5 hours; however the flight
is heavily weather dependent.
Week
Chassis
The CubeSat’s chassis is constructed from 6
milled aluminium panels secured with 8 fixings.
It has been designed with the goal of:
• Weight minimisation and maximisation of
interior volume.
• Simplicity of assembly
• Easy access to the satellite’s electronics and
payload
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Project Definition and Mission Statement
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Balloon Launch Mission Definition
Sponsorship Negotiation
Solar Cell
Battery
Processor Card
Chassis
Simulation
Design Phase
Mechanical Design
Payload
Thermal Housing
Design
Build
JPEG Camera
Chassis
Finite Element Analysis
With the parachute fully deployed, the maximum expected
impact velocity is around 7m/s. Based on this, finite element
drop test simulations have been carried out to ensure the body
can withstand impact velocities of up to 15m/s, giving a factor
of safety of 2. Initial tests showed excessive (greater than yield)
stress in panel corners and diagonal struts. The panel pattern
will be redesigned with larger radius corners to reduce stress
concentrations and with thicker diagonal members.
Insulation
The prototype CubeSat will use a passive thermal control system
consisting of a polystyrene insulation shell. This will ensure the
components remain at an operable temperature. Multilayer
insulation was considered ideal but eliminated for cost reasons.
Silica gel will be used to reduce moisture within the CubeSat.
Test
Build
Build
Descent and Recovery System
Design
Build
Design Freeze & Review
Electronic Power System
Design
Insulation
Mechanical Design
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Electrical Design
The CubeSat’s payload will
include:
• Internal and external
temperature sensors
• Two pressure sensors
• Two camera modules
• Custom payload
provided by Roke Manor
Research Ltd
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Build
PCB
Build and Test
Design
Payload
Specification
Comms System
BALLOON LAUNCH DATE
Project Overview
Electronics Design
Communications System
Build
Design Freeze & Review
Assembly and Launch Preparation
Preparation of Technical Report and
Budget
A budget spreadsheet containing
incoming (sponsorship in cash,
store credits, and funds carried
over from previous year) and
outgoing (administrative and
production costs) cash flows is in
place. Additionally any hardware,
software or training acquired from
the sponsors is included in order
to measure the total value of the
project.
Kindly supported by:
Edward Bilson
Manufacturing
Jinesh Patel
Thermodynamics
Elliott Baxter
Chassis Design
Nicole Blake
Landing System
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Ville Konsala
Recovery System
Jonathan Moss
Communications
Kristin Vollen
Power Supply
Rich Young
Control System