Thursday, 16 September 2021

CPUT launches third satellite mission

INNOVATION: MDASat-1a, MDASat-1b and MDASat-1c in the CPUT cleanroom after integration was completed. INNOVATION: MDASat-1a, MDASat-1b and MDASat-1c in the CPUT cleanroom after integration was completed.

CPUT will launch the first South African constellation of three satellites for Maritime Domain Awareness (MDA) this summer.

The mission, named MDASat-1 will be CPUT’s third satellite mission, following on ZACube-1’s (TshepisoSat) and ZACube-2’s successful development, launch and operation.  The head of the Africa Space Innovation Centre, as well as the local node of F’SATI, Prof Robert van Zyl says the MDASat-1 will use Automatic Identification System (AIS) data to monitor ship movements within South Africa’s Exclusive Economic Zone (EEZ). AIS is a radio system used for the tracking of maritime traffic, primarily for collision avoidance. The location messages received by the satellites from ships in the ocean beneath is downloaded daily from the satellite when it passes over the ground station at CPUT.

Recently, the three flight models (FMs) of the MDASat-1 constellation reached the flight acceptance review (FAR) milestone. “The primary objective of the FAR is to confirm that the verification processes used during this mission demonstrated that the satellites are free of workmanship errors and are subsequently ready for operational use in space,” Van Zyl remarks. The FAR was attended by various stakeholders in the local space industry.

To achieve this milestone, the MDASat-1 constellation had to go through various assembly, integration, and testing phases. Firstly, the satellites had to be assembled in CPUT’s cleanroom facility by the mission engineers. A cleanroom is a room that has a controlled level of pollutants, such as dust and it is used to integrate the satellite’s sensitive subsystems.

After all the satellite subsystems were integrated, functional tests were performed to verify that the satellites are working as designed.  “The satellites also went through an environmental testing campaign to prove to the launch providers that the satellites will survive the mechanical shocks during the launch campaign,” Van Zyl continues.

“For example, the MDASat-1 constellation underwent mechanical vibration testing to demonstrate that the satellites can withstand the vibration environment encountered during launch.”

Thermal cycling of the MDASat-1 constellation was performed in the thermal chamber at CPUT. Thermal cycling tests are performed to verify that the satellites can operate within its designed temperature range.

Furthermore, Van Zyl states that the MDASat-1 constellation underwent a bakeout test. “The purpose of bakeout is to reduce to an acceptable level the outgassing rates of flight equipment associated with instrumentation that is sensitive to molecular contamination and the verification that this level has been achieved.”

With the conclusion of the flight acceptance review, the satellites are now ready for launch. In addition, CPUT recognises the continued financial support from the Department of Science and Innovation, which recently visited the institution, and its agencies, the South African National Space Agency, the Technology Innovation Agency and the National Research Foundation for contributing to the locally produced state-of-the-art satellite missions.

Written by Des