scholarly journals Nonlinear analysis of thermal behavior for a small satellite in Low Earth Orbit using many-node model

2017 ◽  
Vol 20 (K2) ◽  
pp. 66-76
Author(s):  
Chung Ngoc Pham ◽  
Anh Dong Nguyen ◽  
Hieu Nhu Nguyen
Keyword(s):  
Temperature Limit ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Solar Irradiation ◽  
Solar Array ◽  
Earth Orbit ◽  
Small Satellite ◽  
Simulation Purpose ◽  
Allowable Temperature ◽  
Cover Plates

In this paper, nonlinear thermal responses of a small satellite in Low Earth Orbit (LEO) are analyzed using many-node model. The main elements of primary structure of the satellite include six rectangular cover plates and a solar array linking with satellite's body. These elements can be modeled as different lumped thermal nodes. We use an eight-node model for estimating temperatures at nodal elements i.e. six nodes for cover plates, and two nodes for front and rear surfaces of the solar array. The nodes absorb three major heat energy sources from the space environment consisting of solar irradiation, Earth’s albedo and infrared radiation. The established system of thermal balance equations for nodes is nonlinear and is solved by a numerical algorithm. For simulation purpose, it is assumed that the satellite always remains Earth-pointing attitude during motion. Temperature evolutions of nodes in time are explored in details. The obtained results show that the predictive temperature values of nodes are within the allowable temperature limit range of the satellite.

scholarly journals The Effect of Low Earth Orbit Atomic Oxygen Exposure on Phenylphosphine Oxide-Containing Polymers

2000 ◽  
Vol 12 (1) ◽  
pp. 43-52 ◽  
Author(s):  
John W Connell
Keyword(s):  
Thin Film ◽  
Atomic Oxygen ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Earth Orbit ◽  
Cooperative Effort ◽  
Flight Experiment ◽  
Oxygen Exposure ◽  
Atomic Oxygen Exposure ◽  
Phenylphosphine Oxide

Thin films of phenylphosphine oxide-containing polymers were exposed to low Earth orbit aboard a space shuttle flight (STS-85) as part of flight experiment designated Evaluation of Space Environment and Effects on Materials (ESEM). This flight experiment was a cooperative effort between the NASA Langley Research Center (LaRC) and the National Space Development Agency of Japan (NASDA). The thin-film samples described herein were part of an atomic oxygen exposure (AOE) experiment and were exposed to primarily atomic oxygen (∼1×1019 atoms cm−2). The thin-film samples consisted of three phosphine oxide-containing polymers (arylene ether, benzimidazole and imide). Based on post-flight analyses using atomic force microscopy, x-ray photo-electron spectroscopy and weight loss data, it was found that the exposure of these materials to atomic oxygen (AO) produces a phosphorus oxide layer on the surface of the samples. Earlier work has shown that this layer provides a barrier towards further attack by AO. Consequently, these materials do not exhibit linear erosion rates which is in contrast with most organic polymers. Qualitatively, the results obtained from these analyses compare favourably with those obtained from samples exposed to AO and/or an oxygen plasma in ground-based exposure experiments. The results of the low Earth orbit AO exposure on these materials will be compared with those of ground-based exposure to AO.

scholarly journals The affect of the space environment on the survival ofHalorubrum chaoviatorandSynechococcus(Nägeli): data from the Space Experiment OSMO on EXPOSE-R

2014 ◽  
Vol 14 (1) ◽  
pp. 123-128 ◽  
Author(s):  
R. L. Mancinelli
Keyword(s):  
Survival Rate ◽  
Uv Radiation ◽  
Molecular Probes ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Dust Particles ◽  
Most Probable Number ◽  
Earth Orbit ◽  
Probable Number ◽  
Space Vacuum

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.

Development of 400 V Solar Array Technology for Low Earth Orbit Plasma Environment

2006 ◽  
Vol 34 (5) ◽  
pp. 1986-1996 ◽  
Author(s):  
S. Hosoda ◽  
T. Okumura ◽  
J.-H. Kim ◽  
K. Toyoda ◽  
M. Cho
Keyword(s):  
Low Earth Orbit ◽  
Solar Array ◽  
Earth Orbit ◽  
Plasma Environment ◽  
Array Technology

scholarly journals In Situ Measurement of Carbon Fibre/Polyether Ether Ketone Thermal Expansion in Low Earth Orbit

Aerospace ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 35 ◽  
Author(s):  
Farhan Abdullah ◽  
Kei-ichi Okuyama ◽  
Isai Fajardo ◽  
Naoya Urakami
Keyword(s):  
Thermal Expansion ◽  
Carbon Fibre ◽  
Material Science ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Small Satellite ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
Orbit Data

The low Earth orbit (LEO) environment exposes spacecraft to factors that can degrade the dimensional stability of the structure. Carbon Fibre/Polyether Ether Ketone (CF/PEEK) can limit such degradations. However, there are limited in-orbit data on the performance of CF/PEEK. Usage of small satellite as material science research platform can address such limitations. This paper discusses the design of a material science experiment termed material mission (MM) onboard Ten-Koh satellite, which allows in situ measurements of coefficient of thermal expansion (CTE) for CF/PEEK samples in LEO. Results from ground tests before launch demonstrated the feasibility of the MM design. Analysis of in-orbit data indicated that the CTE values exhibit a non-linear temperature dependence, and there was no shift in CTE values after four months. The acquired in-orbit data was consistent with previous ground tests and in-orbit data. The MM experiment provides data to verify the ground test of CF/PEEK performance in LEO. MM also proved the potential of small satellite as a platform for conducting meaningful material science experiments.

Verification of solar array design for low earth orbit spacecraft under worst case scenario

2018 ◽  
Author(s):  
Ahmed Mokhtar Mohamed ◽  
Fawzy ElTohamy H. Amer ◽  
R. M. Mostafa ◽  
Walid A. Wahballah
Keyword(s):  
Low Earth Orbit ◽  
Solar Array ◽  
Earth Orbit ◽  
Case Scenario ◽  
Worst Case ◽  
Array Design ◽  
Worst Case Scenario

Internal Charge Estimates for Satellites in Low Earth Orbit and Space Environment Attribution

2017 ◽  
Vol 45 (8) ◽  
pp. 1985-1997 ◽  
Author(s):  
Robert J. Redmon ◽  
Juan V. Rodriguez ◽  
Carl Gliniak ◽  
William F. Denig
Keyword(s):  
Low Earth Orbit ◽  
Space Environment ◽  
Earth Orbit ◽  
Internal Charge

Surface molecular degradation of 3D glass polymer composite under low earth orbit simulated space environment

2010 ◽  
Vol 95 (6) ◽  
pp. 987-996 ◽  
Author(s):  
Firas Awaja ◽  
Jin Bum Moon ◽  
Shengnan Zhang ◽  
Michael Gilbert ◽  
Chun Gon Kim ◽  
...  
Keyword(s):  
Polymer Composite ◽  
Low Earth Orbit ◽  
Space Environment ◽  
Earth Orbit

Highly durable hydrophobicity in simulated space environment

RSC Advances ◽  
2014 ◽  
Vol 4 (54) ◽  
pp. 28780-28785 ◽  
Author(s):  
Ruisheng Guo ◽  
Haiyuan Hu ◽  
Zhilu Liu ◽  
Xiaolong Wang ◽  
Feng Zhou
Keyword(s):  
Low Earth Orbit ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Space Environment ◽  
Earth Orbit

Perfluoropolyether-infused porous anodic alumina maintains superhydrophobicity durably under simulated space irradiations at low earth orbit (LEO).

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