Autumn 2012
project, as it opens up many possibilities for
payloads and development.
Warwick University Satellite
Project: Autumn 2012
Newsletter
History
With previous work on the European Student
Moon Orbiter (ESMO) project having been
completed and the project drawn to a close by
the European Space Agency (ESA), the
direction of satellite team activities at
Warwick have changed as of the 2012/2013
academic year. Previous work focused on
development of the electrical power system
for the larger ESMO craft. This year a new
project has begun to develop the capabilities
and knowledge from the ESMO projects,
named Warwick University Satellite (WUSAT).
WUSAT
Primarily, efforts focussed on cultivating
contacts in the UK satellite industry and
establishing the project aims.
It was suggested that launching a ‘CubeSat’
would be suitable long-term aim for the
A CubeSat is a nanosatellite, typically a cube
10cm wide, with a mass of up to 1.33kg. They
were developed in 1999 by both California
Polytechnic State University and Stanford
University for use in space exploration and
science by academics worldwide.
Many
CubeSats are sent up on the same rocket,
reducing costs for each project.
With the project’s purpose decided, the main
aims for this year’s team is to establish the
technical specification and to design, build and
send a prototype up into the Earth’s
Stratosphere using a weather balloon.
Longer term aims are still to be decided, and
are open to guidance from our generous
sponsors.
Progress
Research has been conducted for the balloon
launch next spring and, amongst revealing
legal and functional requirements, has found
that the prototype is likely to reach a height of
30km or more. Recovery is major
consideration as balloons can easily travel
250km from the launch point, which could
mean landing in the North Sea. Another issue
is atmospheric conditions at this altitude, in
particular the temperature dropping as low as
-60°C. This presents a number of different
challenges compared to operating in space,
but should produce useful information for
future project teams.
Electronics
The electronic team has mainly been working
on the control, power and communications
systems so far. We have chosen the Arduino
platform for rapid development. Two Arduino
boards will be used for redundancy and
because of size constraints that the larger
boards cannot meet. Data from sensors
included on separate PCBs will be captured on
SD cards inside that we hope to recover.
The power budget is an on-going concern, and
once the system level design has been agreed
this can be completed. As this is still on-going,
research efforts have been focused on general
technologies that might be of consideration
when determining the choice of battery,
power
system
implementation
and
conditioning, and solar cells. In general terms
it was found that lithium-ion batteries might
Autumn 2012
be suitable due to their typically more
efficient performance.
Preliminary research into power system
architecture indicated that a Maximum Power
Point Tracking (MPPT) approach might be
better suited for low earth orbit (LEO)
missions. This is similar to the ESMO EPS
research undertaken by Warwick allowing us
to potentially reuse some of the design work.
Typical figures for other CubeSats indicate the
potential for using two photovoltaic cells per
CubeSat side, thus totalling to about 10-12
cells depending on whether 5 or 6 sides are to
be used. The number (and quality) of solar
panels used will strongly depend on budget
constraints
and
potential
sponsoring
opportunities.
machined from solid or rapid prototyped). A
detailed prototype frame design is still under
development, but initial iterations have been
modelled and FEA drop-tested within
SolidWorks, one of the project's sponsors.
Fit Chassis
volume maximisation and the facilitation of
easy assembly and disassembly so that access
to the internal components is relatively
straight forward. To facilitate this, the chassis
will be constructed from assembled
Aluminium components (as opposed to
Mechanical
On the mechanical side, the team has
focussed their efforts towards chassis
development. A fit chassis, for identifying how
the PCBs and other components fit into the
chassis, is currently in the process of being
manufactured by Warwick Engineering. The
mechanical specification for the prototype
chassis has also been defined, with key
requirements being mass reduction, internal
Prototype chassis undergoing drop tests in
SolidWorks
A website has been set up for the new project
(www.warwick.ac.uk/cubesat)
and
is
continually updated with the latest news and
sponsors for the project. It will be maintained
with photos of the team, and news and
information pages, among others.
The Team
This year’s team is formed of 8 students, with
responsibilities split between Mechanical &
Manufacturing, Electronics & Systems and
Project Management. The team also consists
of three PhD researchers with previous ESMO
experience and the project director, Dr Bill
Crofts.