DYNACUBE TO EXPLORE THE SOUTH ATLANTIC ANOMALY
After launch DynaCube, a one-unit CubeSat being constructed by
Interns at the Denel Dynamics Engineering Academy will be exploring
the South Atlantic Anomaly during orbits over the area.
South Atlantic Anomaly (SAA), off the coast of Brazil, is an area
where the Earth's inner Van Allen radiation belt comes closest to
the Earth's surface dipping down to an altitude of 200km This leads
to an increased flux of energetic particles in this region and
exposes orbiting satellites to higher than usual levels of
radiation. The effect is caused by the non-concentricity of the
Earth and its magnetic dipole. The South Atlantic Anomaly is of
great significance to satellites and other spacecraft that orbit the
Earth at several hundred kilometres altitude; these orbits take
satellites through the anomaly periodically, exposing them to
several minutes of strong radiation, caused by the trapped protons
in the inner Van Allen belt.
has reported that modern laptops have crashed when space shuttle
flights passed through the anomaly, and the SpaceX CRS-1 Dragon
spacecraft attached to the International Space Station during
October 2012 experienced a transient problem as it passed through.
It also here where SunSat, South Africa’s first satellite, stopped
operating when it onboard computer was damaged.
DynaCube includes sensors to measure radiation levels, magnetic
flux, structural temperature chances, the effect of radiation on
commercial off-the-shelve components (COTS) and the effectiveness of
the radiation shielding. “Unlike other cubesats, DynaCube has a
solid space frame to give more protection to radiation”, Rick Botha,
Project Manager of the payload said.
DynaCube Project Team leaders (L-R) Rick Botha,
Jean-Paul Appel, Esabe Brink, Yoshlyn Naidoo, Motheo Motlhabane,
all engineers who graduated from various universities in South
Africa, spent last year working on the project to gain practical
experience before they are assigned to various departments in the
company. The Interns were tasked with designing, manufacturing and
commissioning a 1 U Cube Satellite and its associated ground support
systems. Three teams were formed, with each team having specific
objectives. Team Ground Zero was responsible for the Ground Control
Station as well as communications equipment on-board the satellite.
Team Virtuoso was responsible for the On-board Computer (OBC), the
power system, the satellite structure and telemetry data. The main
tasks of Team Frodo were to specify the satellite payload, the
required sensors, the attitude control and the launch of the
was decided, in the early stages of the project, that a duplicate
satellite should be built which will remain on Earth to allow
software maintenance and troubleshooting on the ground before
uploading changes and updates to the satellite in orbit.
secondary payload is a camera capable of taking images and sending
them to the OBC for storage. It was decided that a VGA serial JPEG
camera would be used, as it would be able to take photographs fast
enough to prevent blurring, whilst also doing its own image
launch will most likely only happen close to the end of 2013 and
possibly only as late as the end of 2014. The funding of the launch,
which may be as high as R1 300 000, is a challenge that still needs
to be overcome.
systems have been tested and are now ready for integration. Although
the Interns have come to the end of their year and will start their
careers in various departments of Denel Dynamics, they are dedicated
to complete the project in their free time. Currently three of the
group have obtained their amateur radio license. DynaCube will
operate on Amateur Radio frequencies which were coordinated by the
IARU Satellite Advisory Panel. DynaCube will operate on a downlink
of 145,980 MHz,
an uplink on 435,050 MHz with a tracking beacon on 145,840 MHz.
inside the DynaCube Ground station
Listen to an
interview with members of the DynaCube Team