scholarly journals High performance chirped microwave generator for space applications

Author(s):  
Giuseppe Brunetti ◽  
Giovanna Marocco ◽  
Mario N. Armenise ◽  
Caterina Ciminelli
Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1665 ◽  
Author(s):  
Ali Reza Zanjanijam ◽  
Ian Major ◽  
John G. Lyons ◽  
Ugo Lafont ◽  
Declan M. Devine

Poly (ether ether ketone) (PEEK) is a high-performance engineering thermoplastic polymer with potential for use in a variety of metal replacement applications due to its high strength to weight ratio. This combination of properties makes it an ideal material for use in the production of bespoke replacement parts for out-of-earth manufacturing purposes, in particular on the International Space Station (ISS). Additive manufacturing (AM) may be employed for the production of these parts, as it has enabled new fabrication pathways for articles with complex design considerations. However, AM of PEEK via fused filament fabrication (FFF) encounters significant challenges, mostly stemming from the semi crystalline nature of PEEK and its associated high melting temperature. This makes PEEK highly susceptible to changes in processing conditions which leads to a large reported variation in the literature on the final performance of PEEK. This has limited the adaption of FFF printing of PEEK in space applications where quality assurance and reproducibility are paramount. In recent years, several research studies have examined the effect of printing parameters on the performance of the 3D-printed PEEK parts. The aim of the current review is to provide comprehensive information in relation to the process-structure-property relationships in FFF 3D-printing of PEEK to provide a clear baseline to the research community and assesses its potential for space applications, including out-of-earth manufacturing.


1993 ◽  
Vol 11 (2) ◽  
pp. 137-146 ◽  
Author(s):  
J.W. Connell ◽  
J.G. Smith ◽  
P.M. Hergenrother

As part of a NASA program on high performance polymers for space applications, polymers containing silicon and phosphorus were prepared, characterized and exposed to an oxygen plasma under vacuum. Thin films of polyimides containing pendent siloxane groups, thermosetting resins contain ing silicon and poly(arylene ether)s containing phenylphosphine oxide were ex posed to a radio frequency generated oxygen plasma to assess their stability. The weight loss of the films was monitored as a function of exposure time and compared with that of Ultem® and Kapton® polyimide films of the same thick ness exposed under identical conditions. All of the experimental materials ex hibited better weight retention than either of the commercial polyimides. The thermosetting resins containing silicon and poly(arylene ether)s containing phosphine oxide exhibited only minor weight loss (0-5%) compared to that ex hibited by Ultem® (75-100%) and Kapton® (35-82%). Organic polymers con taining silicon are known to form silicates and silicon dioxide when exposed to atomic oxygen providing an in situ protective coating. Likewise, polymers con taining phosphorus have been shown to form an inorganic phosphate surface layer which subsequently provides protection from further oxidation. The same inherent characteristics that provide the polymers with atomic oxygen resis tance (i.e., high oxidation state or inorganic oxide formation) may also impart fire resistance. Materials containing phosphorus are known to exhibit good flame resistance. The chemistry, properties, limiting oxygen index and oxygen plasma resistance of these materials will be discussed.


2009 ◽  
Vol 29 (3) ◽  
pp. 259-267 ◽  
Author(s):  
S. Bhowmik ◽  
R. Benedictus ◽  
J.A. Poulis ◽  
H.W. Bonin ◽  
V.T. Bui

Author(s):  
F.A Cordisco ◽  
F. Antico ◽  
F. Dri ◽  
M. Knoblauch ◽  
M.D. Actis ◽  
...  

2002 ◽  
Author(s):  
Mariolino De Cecco ◽  
Stefano Debei ◽  
Gian P. Guizzo ◽  
Marco Pertile ◽  
Mirco Zaccariotto ◽  
...  

Author(s):  
C. Menon ◽  
J. F. V. Vincent ◽  
N. Lan ◽  
L. Bilhaut ◽  
A. Ellery ◽  
...  

In a domain such as space technology, where robustness, mass, volume and power efficiency are key, biological organisms may provide inspiration for new systems with high performance. By using micro-technology processes, designers of space systems may take advantage of the millions of years over which miniaturised mechanisms in plants and animals have been optimised for survival. Space exploration often requires systems equipped with drills, and miniaturised drillers could enable a number of new space operations. Two natural digging systems have been studied as potential miniature space digging systems; the ovipositors of the female locust and of sirex noctilio, a species of woodwasp. Being insectoid systems, the mechanics of their design work on an inherently small scale, though they are also thought to be scalable. Results of preliminary studies, performed during collaboration between the Advanced Concepts Team of ESA, the University of Bath, the University of Surrey, D’appolonia and EADS-Astrium, are presented and discussed. Engineering solutions are proposed and analysed to assess the potential of new bio-inspired miniaturised digging systems for space applications.


2001 ◽  
Author(s):  
Olivier Saint-Pe ◽  
Michel Tulet ◽  
Robert Davancens ◽  
Franck Larnaudie ◽  
Bruno Vignon ◽  
...  

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