Space Research Journal1819-3382xxxx-xxxxAcademic Journals Inc.10.3923/srj.2014.1.13SamwelS. W.1201471The presence of Atomic Oxygen (AO) in the Low Earth Orbit (LEO) environment
is considered one of the main reasons for the degradation of the surfaces exposed
to the Space Environment A spacecrafts orbital velocity of 7.8 km sec-1
may expose a spacecraft to a stream of AO at energy of approximately 5 eV. At
this energy, atomic oxygen initiates a number of chemical and physical reactions
with the materials. The degree of surface degradation is directly proportional
to AO fluence which, in turn, varies with several factors, such as: Spacecraft
altitude, orientation, orbital inclination, mission duration and solar activity
variation. The present paper concerns study the variation of the atomic oxygen
erosion with the previous mentioned factors. In addition a comparative study
of the atomic oxygen erosion effect of different spacecraft materials which
are widely used for space application is performed. The atomic oxygen interaction
model (ATOMOX) has been employed to evaluate the atomic oxygen flux, fluence
and material erosion, based on reference atmosphere and wind models. The computation
of neutral atmosphere composition is achieved using the standard NRLMSISE-00
model. Values of erosion yields have been established based on flight data.
The results obtained represent that the exposed materials onboard spacecraft
experience the most intense degradation at low earth orbit with lower altitudes
and inclination, for surfaces in the ram direction, for prolonged exposure and
at high solar activity. Also, it is found that according to the material sample
understudy, Teflon shows the higher resistivity for AO erosion, for polymers;
while it is Tungsten, in case of metals.]]>Allbrooks, M. and D. Atkinson,19921992Avcu, S. and B. Celik,20032003pp: 589594Banks, B.A., S.K. Miller and K.K. de Groh,20042004Banks, B.A., J.A. Backus, M.V. Manno, D.L. Waters, K.C. Cameron and K.K. de Groh,20092009Banks, B.A. and S.K. Rutledge,19881988Dooling, D. and M.M. Finckenor,19991999Duo, S.W., M.M. Song, T.Z. Liu and M.S. Li,20122 coatings prepared by sol-gel process protecting silver from atomic oxygen erosion.]]>121-12630443047Han, J.H. and C.G. Kim,200672218226Hasting, D. and H. Garrett,1996Hedin, A.E.,19919611591172Kiefer, R.L. and R.A. Orwoll,19871987Yokota, K., N. Ohmae and M. Tagawa,20062006pp: 141-152pp: 141-152Morrison, W. D., R.C. Tennyson, J.B. French and T. Braithwaite,19881988pp: 89109Picone, J.M., A.E. Hedin, D.P. Drob and A.C. Aikin,20022002Reddy, M.R.,199530281307Rohr, T. and M. van Eesbeek,20052005pp: 13Samwel, S.W. and A.A. Hady,20092009Shuvalov, V.A., G.S. Kochubei, A.I. Priimak, N.I. Pismennyi and N.A. Tokmak,200745294304Duo, S.W., M.M. Song, Y. Luo, T.Z. Liu and W.M. Gao,2011177686689White, C.B., G.T. Roberts and A.R. Chambers,2005512061213Zhang, L., C.W. Yan, Q. Qu, G. Sun, J.Y. Tong and C.N. Cao,200212869873