MDASat- a nanosatellite constellation to improve the South African Maritime domain awareness capability

摘要

MDASat is a series of planned nanosatellite constellation that will provide maritime domain awareness services to primarily to South Africa and the African continent. The missions are being developed by the Cape Peninsula University of Technology (CPUT) in collaboration with members of the South African space industry. The programme is funded by the South African government's Department of Science and Innovation in support of Operation Phakisa, an initiative with the goal of unlocking the economic potential of South Africa's maritime domain, which, by estimation, could contribute up to ZAR177 billion to the GDP and 1 million jobs by 2033. The ZACube series of satellites is being developed within the nanosatellite programme at CPUT, which has produced two satellites to date: ZACube-1, also known as TshepisoSat, launched on 21 November 2013, and ZACube-2, launched on 27 December 2018. These satellites are used as technology demonstrators that feed technology into the MDASat programme. The MDASat constellation will support the Automatic Identification System (AIS), a terrestrial radio system used for collision avoidance among ocean vessels, as well as the VHF Data Exchange System (VDES), which is being designed as an extension to AIS, greatly expanding its capabilities, adding additional services and including support for satellite links. AIS was designed to use terrestrial coastal AIS stations to communicate with ships and its coverage is typically limited to several tens of nautical miles from the coast. The use of an AIS receiver on a satellite can potentially provide global AIS coverage, removing the aforementioned terrestrial coverage limitation. ZACube-2, developed as a precursor satellite for the MDASat mission, is a three-unit CubeSat that carries an advanced software defined radio (SDR) payload that implements an AIS receiver. The SDR payload is reconfigurable in-flight in anticipation of the implementation of the full VDES standard, as well as other communica