Ensuring the proper end-of-life dismantling of spacecraft/ Satellites using CuAlNi memory alloys
Creators: name:  F. FOUCHE 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: SYSTEM INTEGRATION
SPACE

description: Abstract Ensuring the proper end-of-life dismantling of spacecraft/ Satellites using CuAlNi memory alloys: Florian Fouche (1) (1) Nimesis Technology, 4, Rue des Artisans - 57245 Mecleuves - France, Tel : +33 3 87 74 26 87, Email : f.fouche@nimesis.com Abstract: According to the American association: Union of Concerned Scientists (UCS), 2,666 active satellites dedicated to earth observation were circling around our planet in March 2020. Among the active satellites listed by the UCS, the operational lifespan varies from 1 to 20 years. The time until atmospheric re-entry depends on the altitude of the spacecraft and can vary from 6 months (low orbit) to several thousands of years (geostationary satellites). The rise of debris formation in orbit is increasingly jeopardising the sustainable operation of spacecrafts and asks for policy measures to ensure spacecraft demise after their end of life. A satellite that is insufficiently disintegrated after atmospheric re-entry can cause impact damage and casualties on Earth. With the number of re-entries increasing in the years to come, it is crucial to ensure effective dismantling of spacecrafts. Actual technologies use the programmed explosion of pyrotechnic charges, which exhibit sensitivity to chemical changes. Or employ technologies based on the use of low melting point alloys, these last are sensitive to creep and fail at functioning at high temperature. These systems are not reliable after a long period in space. For that reason and based on our companys expertise in shape memory alloys, we are developing a cost-efficient strategy of uncontrolled re-entry, that disintegrate the spacecraft into sufficiently small fragments to minimise the impact damage on ground or possibly ensure complete disintegration. This idea is possible using CuAlNi memory alloys, that have already been selected for aerospace applications and offer possibilities at transformation points up to 250C. These last are designed to sustain 30 years on orbit, and upon thermal initiation during re-entry, triggering the fragmentation of spacecrafts. We are working to implement a passive system that will be activated just as the temperature rises. So that the system will only be activated due to an atmospheric re-entry. The strategy is to be executed at the end of the satellites life and, depending on the speed and angle of re-entry, the temperature of the satellite will be set according to the altitude, so that the activation can be adjusted to match this last. Its function will be to separate the structural elements. Ensuring the fact that our products, SMA actuators, can provide their function beyond 30 years, and their performance can be predicted is the aim of our development. Clearly, possible degradation mechanisms in orbit must be understood including the development of fundamental performance models. The final objectives can be summarized into removing the technological barrier for sustaining up to 30 years more in orbit, in order to offer an efficient design for demise solutions on one hand, and a strong range of products for satellite dismantling on the other. References: [1] I. Perez-Landazabal, V. Recarte, V. Sanchez-Alarcos, M.L. No, J. San Juan: Study of the stability and decomposition process of the phase in CuAlNi shape memory alloys; Materials Science and Engineering A 438440 (2006) 734737. [2] J. Van Humbeeck, M. Chandrasekaran, The Influence of Post QuenchAgeing in the Beta- phase on the Transformation Characteristics and the Physical and Mechanical Properties of Martensite in a Cu-Al-Ni Shape Memory Alloy; ISIJ International, Vol. 29 (1989), No. 5, pp. 388~394