Browsing by Author "Serfontein, Zaria"

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    Application of nanosatellites for lunar missions
    (IEEE, 2021-06-07) Bellome, Andrea; Nakhaee-Zadeh, Aydin; Zaragoza Prous, Guillermo; Leng, Louis; Coyle, Matthew; D'Souza, Sharon; Mummigatti, Suchetan; Serfontein, Zaria
    Two major themes for the space sector in recent years have been the resurgence of missions to the Moon, facilitating the expansion of human presence into the Solar System, and the rapid growth in CubeSat launches. Lunar missions will play an important role in sustainable space exploration, as discussed in the Global Exploration Roadmap. The Roadmap outlines the next steps for the current and next generation of explorers and reaffirms the interest of 14 space agencies to return to the Moon. Over the past decade, a more daring approach to space innovation and the proliferation of low-cost small satellites have invited commercialization and, subsequently, have accelerated the development of miniaturized technologies and substantially reduced the costs associated with CubeSats. In this context, CubeSats are increasingly being considered as platforms for pioneering missions beyond low-Earth orbit. This paper describes a 3U nanosatellite mission to the Moon, designed as part of the UKSEDS Satellite Design Competition, capable of capturing and analysing details of the lunar environment. To achieve the primary mission objectives, a camera and an infrared spectrometer have been included to relay information about historic lunar landmarks to Earth. The design was developed to be integrated with Open Cosmos' OpenKit and reviewed by experts in the field from SSPI. The paper includes a detailed assessment of the current state of miniaturized instruments and the quality of scientific return which can be achieved by a lunar CubeSat mission. This concludes in an overall feasibility study of lunar CubeSats, a discussion of the current limitations and challenges associated with CubeSat technologies and a framework for future missions.
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    Drag augmentation systems for space debris mitigation
    (Elsevier, 2021-06-01) Serfontein, Zaria; Kingston, Jennifer; Hobbs, Stephen; Holbrough, Ian E.; Beck, James C.
    Space debris is a critical threat to future and on-going missions. The commercialisation of the space sector has led to a rapid growth in the number of small satellites in recent years, which are adding to the already high number of objects currently in low-Earth orbit (LEO). Low-cost small satellites operators are under increasing pressure to comply with debris mitigation guidelines as part of the application process for a launch licence. Drag augmentation systems are a potential low-cost and low-impact solution for small satellites. By increasing the effective area of a satellite, and therefore its drag, these sails reduce the de-orbit period of a satellite, subsequently reducing the probability of significant collisions and supporting the sustainable use of space. Cranfield University are developing a family of drag augmentation systems (DAS) to assist in the long-term conservation of the space environment. The DAS are lightweight, cost-effective, reliable sails deployed at end of mission. Currently three of the drag sails designed, manufactured, and tested at Cranfield University are in orbit and two of the devices have successfully deployed their sails. This paper will discuss these sails and will highlight results from recent studies; examining the scalability of the system, the vehicle dynamics after sail deployment, the medium-term impact of the sail on the host satellite's ability to continue operations, and the long-term effect of the sail on the demisability of the satellite. The DAS technology has a strong enabling potential for future space activities, allowing satellites to operate responsibly and sustainably.
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    Drag augmentation systems for space debris mitigation
    (International Astronautical Federation, 2020-10) Serfontein, Zaria; Kingston, Jennifer; Hobbs, Stephen; Holbrough, Ian E.; Beck, James C.
    Space debris is recognised as a critical threat for the space industry. The proliferation of small satellites has invited commercialisation and subsequently, the growing number of satellites are adding to the already high number of objects currently in low-Earth orbit (LEO). Low-cost small satellites are under increasing pressure to meet debris mitigation guidelines and failure to comply could result in a launch licence being denied. Drag augmentation systems increase the drag area of a spacecraft, minimising the de-orbit period and thus reducing the probability of significant collisions and supporting the sustainable use of space. In response to the growing number of small satellites (10-500 kg) unable to de-orbit from low-Earth orbit within 25 years, Cranfield University has developed a family of drag augmentation systems (DAS). The DAS are lightweight, cost-effective sails deployed at end of mission and are reliable solutions for deorbiting small satellites, assisting in the conservation of the space environment. Three drag sails designed, manufactured and tested at Cranfield University are currently in orbit, with two sails already successfully deployed. This paper details the sails and will discuss findings from recent studies; examining the system’s scalability, the post-deployment vehicle dynamics, the medium-term impact of the sail on the satellite’s ability to conduct science and the long-term effect of the sail on the satellite’s re-entry and demise. The DAS technology have a strong enabling potential for future space activities, allowing satellites to operate responsibly and sustainably.
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    Effects of long-term exposure to the low-earth orbit environment on drag augmentation systems
    (IAF, 2020-10-14) Serfontein, Zaria; Kingston, Jennifer; Hobbs, Stephen; Holbrough, Ian E.; Beck, James C.; Impey, Susan A.; Aria, Adrianus Indrat
    Spacecraft in low-Earth orbit are exposed to environmental threats which can lead to material degradation and component failures. The presence of atomic oxygen and collisions from orbital debris have detrimental effects on the structures, thus affecting their performance. Cranfield University has developed a family of drag augmentation systems (DAS), for end-of-life de-orbit of satellites, addressing the space debris challenge and ensuring that satellites operate responsibly and sustainably. Deorbit devices are stowed on-orbit for the duration of the mission lifetime and, once deployed, the devices must withstand this harsh low-Earth environment until re-entry; a process which can take several years. The DAS’ deployable aluminised Kapton sails are particularly susceptible to undercutting by atomic oxygen. In preparation for commercialising the DAS, Cranfield University and Belstead Research Ltd. have submitted several joint proposals to better understand the degradation process of the drag sail materials and to qualify the materials for the specific application of drag sails in low Earth Orbit (LEO). This paper will outline the proposals and the expected benefits from the projects. Additionally, collisions with debris could accelerate the degradation of the system and generate additional debris. This paper will discuss a future ESABASE2 risk assessment study, aiming to quantifying the probability of collisions between the deployed drag sail and orbital debris. The atmospheric models required to simulate the aforementioned risks are complex and often fail to accurately predict performance or degradation observed in the space environment. A previous UKSA Pathfinder project highlighted this issue when different atmospheric models with varying levels of solar activity yielded drastically different re-entry times. Since Cranfield University has two deployed drag sails in orbit, previous de-orbit analysis performed using STELA and DRAMA will be updated and the simulations will be compared to actual data. This paper will conclude in a summation of the different on-going research projects at Cranfield University related to commercialising the DAS family. This research will benefit the wider space community by expanding the understanding of the effects of long-term exposure on certain materials, as well as improving the validity of future low Earth atmospheric models.
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    ItemOpen Access
    Effects of long-term exposure to the low-earth orbit environment on drag augmentation systems
    (Elsevier, 2021-06-10) Serfontein, Zaria; Kingston, Jennifer; Hobbs, Stephen; Impey, Susan A.; Aria, Adrianus Indrat; Holbrough, Ian E.; Beck, James C.
    Spacecraft in low-Earth orbit are exposed to environmental threats which can lead to material degradation and component failures. The presence of atomic oxygen and collisions from orbital debris have detrimental effects on the structures, thus affecting their performance. Cranfield University has developed a family of drag augmentation systems (DAS), for end-of-life de-orbit of satellites, addressing the space debris challenge and ensuring that satellites operate responsibly and sustainably. De-orbit devices are stowed on-orbit for the duration of the mission lifetime and, once deployed, the devices must withstand the harsh low Earth environment until re-entry; a process which can take several years. The DAS’ deployable aluminised Kapton sails are particularly susceptible to undercutting by atomic oxygen. In preparation for commercialising the DAS, Cranfield University are investigating the degradation process of the drag sail materials, with the end goal of qualifying the materials for the specific application of drag sails in low Earth orbit (LEO). This paper will outline the proposed research and the expected benefits from the projects. This paper will conclude in a summation of the different on-going research projects at Cranfield University related to commercialising the DAS family. This research will benefit the wider space community by expanding the understanding of the effects of long-term exposure on certain materials, as well as improving the validity of future low Earth atmospheric models.