Page 16 - EngineerIT July 2022

AMATEUR RADIO

AMSAT SA makes great

progress on AfriCUBE

MSAT SA, a volunteer group of radio amateurs, engineers and technicians
embarked several years ago on a CubeSat satellite project. From the outset it
Awas decided to build a satellite from scratch, to design and construct all the
various components and not to buy a complete kit and put it together like a monkey
puzzle. There were two reasons for this, the obvious main one being a lack of funding
but the most important one is to give people the opportunity to share and develop
skills. In a project like this, people come and go, making the management of a project
more challenging but in that process, more people share and develop their own skills
and make an overall contribution.
The first space frame was developed and built by radio amateur Deon Coetzee
ZS1DE in his garage in Cape Town. He mentored a student from Stellenbosch University,
Francois Oberholzer, who took Deon’s design and developed a modular space frame
as part of his engineering degree project. Many radio amateurs and engineers have send them to admin@amsatsa.org.za
contributed to the project by designing and building prototypes of power supplies, by 15 August for evaluation. Documents
control circuits and transponders. Each one has contributed and often introduced new should be in MS word format.
ideas which have never been considered or tested before. This all led to the position Funding remains a big issue, even if
AMSAT SA is in at this time, ready to build an engineering model and ultimately the final most of the parts are home-constructed.
satellite to be launched. The current design includes a digital transponder which has Companies and individual are invited to
opened up new operating modes from the earlier FM design. become sponsors. Various options are
After several recent design reviews, modifications have been made to the structural available. n
design of the space frame, to facilitate the deployment of additional solar panels and
antennas for the uplink (435 MHz band)) and downlink (145 MHz band). For more details visit
Bearing in mind that a single unit CubeSat measures only 10x10x10cm and has www.amsatsa.org.za or email
a weight restriction limit of 1.2 kilograms, building in four fold-out solar panels to admin@amsatsa.org.za and support
supplement the available power produced by the static panels is a complicated task. informal technology development in
The original designs were produced by Frik Wolff, ZS6FZ but due to pressure of South Africa.
work and being out of town for long stretches, Anton Janovsky took over this function
while continuing to work on the software required to control the satellite. He recruited
a student from the University of Johannesburg as an intern to work on the mechanical
part of the CubeSat. Jacques Burger is studying industrial design and has made a
remarkable contribution to the technical aspects of releasing the antennas and the
fold-out solar panels after launch. The team recently also addressed the complication of
various switching required to power on the satellite after launch and the release of the
antennas and panels.
The reworked design of the placing of the various sub-boards has made more space
available for the inclusion of a camera and several science projects.

Learner and student science projects
It was always AMSAT SA’s intention to invite learners and students to submit ideas and
designs for science projects, but it was hesitant to make that call. With more space
on one of the printed circuit boards and the marginally greater power available from
the fold-out solar panels, AMSAT SA is now calling for school and university science
project ideas and designs. Obviously, the projects must be small in size and operate
on little power but modern, powerful devices are able to produce some interesting
science experiments. The onboard telemetry system will be used to send the science
experiment’s output to the ground in a format that will allow for easy interpretation of
the experiment’s output. Jacques Burger UJ student working on the
Learners and students are invited to submit ideas in as much detail as possible and AfriCube space frame design

EngineerIT | July 2022 | 14