Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
19 November 2024 | Story Pat Lamusse | Photo Supplied
Space and satellites 2024
During the visit to the Naval Hill Planetarium, were from the left, Dr Mart-Mari Duvenhage and Prof Matie Hoffman from the UFS Department of Physics, Consul General Stephanie Bunce and Vanessa Toscano from the US Consulate, and Dinah Mangope from the Department of Physics.

A delegation from the United States (US) Consulate General in Johannesburg, including Consul General Stephanie Bunce and Public Affairs Officer, Vanessa Toscano, visited the Bloemfontein Campus of the University of the Free State (UFS). Consul General Bunce met with the acting Vice-Chancellor and Principal of the UFS, Prof Anthea Rhoda, and the Dean of the Faculty of Natural and Agricultural Sciences, Prof Paul Oberholster. The US delegation also visited the Naval Hill Planetarium.

The UFS recently received a grant from the US Embassy to fund a project to promote science education by highlighting the role of satellites in our lives. Colleagues from the Department of Physics had the opportunity to demonstrate first-hand how the planetarium technology will be used to implement the project, which poses the question – what if something happens in space that interferes with the thousands of satellites we use for communication, weather prediction, navigation, banking … surveillance?

Thanks to this grant, the UFS will explore these questions and contribute to space situational awareness (SSA) and space domain awareness (SDA). SSA involves knowledge about the orbits of spacecraft and space debris. SDA refers to the knowledge and understanding of all activities occurring within the space domain.

There are currently at least 10 000 active satellites in Earth orbit, most of which are in low Earth orbit (LEO). However, in addition to satellites, there are well over 45 000 objects larger than 10 cm in orbit, including more than 35 000 pieces of space debris, such as dead satellites, rocket bodies, and pieces from breakups and collisions. Since 1991, there have been at least six unintentional collisions between active satellites and space debris.

Space turned out to be not as big as once thought, especially not in low Earth orbit (LEO – altitude less than 2 000 km). To make things worse, there are plans to launch up to 100 000 new satellites into LEO over the next decade.

Prof Matie Hoffman from the UFS Department of Physics notes, “We live in an era when the space economy is growing fast and the number of objects in Earth orbit, including satellites and space debris, is increasing rapidly. This poses risks to operational satellites. Recent publicity around Elon Musk’s Starlink satellites has generated additional interest around this topic. It is important to raise awareness of the challenges, which will allow scientists to mitigate them.”

The project will involve expertise in optical satellite observations from the University of Michigan through Prof Patrick Seitzer, international patron of the Friends of Boyden Observatory, and the American Museum of Natural History (AMNH). The grant will fund planetarium upgrades that will enable education on space and satellites, as well as optical satellite observations from Boyden Observatory. Beneficiaries will include learners, higher education institutions (both locally and in the US), and the public. South African project partners will be the South African National Space Agency (SANSA), the Future African Space Explorers’ STEM Academy (FASESA), and satellite-related companies in South Africa.

The Boyden Observatory is ideally situated to provide valuable optical satellite observations in an area of the sky that is not accessible from existing satellite observing facilities, especially for objects in LEO. In fact, the first observation of space debris in geosynchronous orbit was from Boyden Observatory in 1967.

The project will be rolled out from the end of 2024, harnessing facilities at both Boyden Observatory and the Naval Hill Planetarium.

News Archive

Water erosion research help determine future of dams
2017-03-07

Description: Dr Jay le Roux Tags: Dr Jay le Roux

Dr Jay le Roux, one of 31 new NRF-rated
researchers at the University of the Free State,
aims for a higher rating from the NRF.
Photo: Rulanzen Martin

“This rating will motivate me to do more research, to improve outcomes, and to aim for a higher C-rating.” This was the response of Dr Jay le Roux, who was recently graded as an Y2-rated researcher by the National Research Foundation (NRF).

Dr Le Roux, senior lecturer in the Department of Geography at the University of the Free State (UFS), is one of 31 new NRF-rated researchers at the UFS. “This grading will make it possible to focus on more specific research during field research and to come in contact with other experts. Researchers are graded on their potential or contribution in their respective fields,” he said.

Research assess different techniques
His research on water erosion risk in South Africa (SA) is a methodological framework with three hierarchal levels presented. It was done in collaboration with the University of Pretoria (UP), Water Research Commission, Department of Agriculture, Forestry and Fisheries, and recently Rhodes University and the Department of Environmental Affairs. Dr Le Roux was registered for 5 years at UP, while working full-time for the Agricultural Research Council – Institute for Soil, Climate and Water (ARC-ISCW).

Water erosion risk assessment in South Africa: towards a methodological framework
, illustrates the most feasible erosion assessment techniques and input datasets that can be used to map water erosion features in SA. It also emphasises the simplicity required for application at a regional scale, with proper incorporation of the most important erosion-causal factors.

The main feature that distinguishes this approach from previous studies is the fact that this study interprets erosion features as individual sediment sources. Modelling the sediment yield contribution from gully erosion (also known as dongas) with emphasis on connectivity and sediment transport, can be considered as an important step towards the assessment of sediment produce at regional scale. 
 
Dams a pivotal element in river networks

Soil is an important, but limited natural resource in SA. Soil erosion not only involves loss of fertile topsoil and reduction of soil productivity, but is also coupled with serious off-site impacts related to increased mobilisation of sediment and delivery to rivers.

The siltation of dams is a big problem in SA, especially dams that are located in eroded catchment areas. Dr Le Roux recently developed a model to assess sediment yield contribution from gully erosion at a large catchment scale. “The Mzimvubu River Catchment is the only large river network in SA on record without a dam.” The flow and sediment yield in the catchment made it possible to estimate dam life expectancies on between 43 and 55 years for future dams in the area.
 
Future model to assess soil erosion
“I plan to finalise a soil erosion model that will determine the sediment yield of gully erosion on a bigger scale.” It will be useful to determine the lifespan of dams where gully erosion is a big problem. Two of his PhD students are currently working on project proposals to assess soil erosion with the help of remote sensing techniques.

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept