The in-space vacuum deposition of reflective mirror coatings (Conference Presentation)

Author(s):  
Alex Ignatiev ◽  
Ronald S. Polidan
Author(s):  
J. M. Corbett ◽  
J. Fairchild ◽  
F. W. Boswell

Fine-structure in spotty electron diffraction riiig patterns has previously been observed for specimens made up of MgO smoke particles of cubic morphology. This fine-structure was shown to arise from refraction effects in the small cubes (Sturkey & Frevel). We have recently observed a different type of fine structure in patterns from MgO films prepared by vacuum deposition (Fig. 1). This fine-structure consists of sets of regularly spaced fringes occurring at random orientations in the rings. The fringes may be seen in Fig. 2 which shows a segment of the (200) ring magnified 7x from the pattern in Fig. 1. It was considered possible that each set of fringes might arise from two superimposed diffraction’ spots from suitably situated crystallites in the specimen. Experiments have been conducted which clearly demonstrate that the fringes do in fact arise in this way.


2003 ◽  
Vol 8 (5-6) ◽  
pp. 30-32
Author(s):  
B.E. Paton ◽  
◽  
E.A. Asnis ◽  
S.P. Zabolotin ◽  
P.I. Baranskii ◽  
...  

Author(s):  
В. М. Жихарєв ◽  
В. Ю. Лоя ◽  
А. М. Соломон ◽  
Я. В. Грицище

2014 ◽  
Vol 14 (1) ◽  
pp. 123-128 ◽  
Author(s):  
R. L. Mancinelli

AbstractWe have shown using ESA's Biopan facility flown in Earth orbit that when exposed to the space environment for 2 weeks the survival rate ofSynechococcus(Nägeli), a halophilic cyanobacterium isolated from the evaporitic gypsum–halite crusts that form along the marine intertidal, andHalorubrum chaoviatora member of the Halobacteriaceae isolated from an evaporitic NaCl crystal obtained from a salt evaporation pond, were higher than all other test organisms exceptBacillusspores. These results led to the EXPOSE-R mission to extend and refine these experiments as part of the experimental package for the external platform space exposure facility on the ISS. The experiment was flown in February 2009 and the organisms were exposed to low-Earth orbit for nearly 2 years. Samples were either exposed to solar ultraviolet (UV)-radiation (λ > 110 nm or λ > 200 nm, cosmic radiation (dosage range 225–320 mGy), or kept in darkness shielded from solar UV-radiation. Half of each of the UV-radiation exposed samples and dark samples were exposed to space vacuum and half kept at 105pascals in argon. Duplicate samples were kept in the laboratory to serve as unexposed controls. Ground simulation control experiments were also performed. After retrieval, organism viability was tested using Molecular Probes Live–Dead Bac-Lite stain and by their reproduction capability. Samples kept in the dark, but exposed to space vacuum had a 90 ± 5% survival rate compared to the ground controls. Samples exposed to full UV-radiation for over a year were bleached and although results from Molecular Probes Live–Dead stain suggested ~10% survival, the data indicate that no survival was detected using cell growth and division using the most probable number method. Those samples exposed to attenuated UV-radiation exhibited limited survival. Results from of this study are relevant to understanding adaptation and evolution of life, the future of life beyond earth, the potential for interplanetary transfer of viable microbes via meteorites and dust particles as well as spacecraft, and the physiology of halophiles.


1971 ◽  
Vol 42 (6) ◽  
pp. 2487-2493 ◽  
Author(s):  
D. K. Hohnke ◽  
H. Holloway ◽  
E. M. Logothetis ◽  
R. C. Crawley
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document