%0 Journal Article %T Eclipses intervals for satellites in elliptical orbit under effects of solar radiation pressure and earth’s oblatness %J Al-Azhar Bulletin of Science %I Al-Azhar University, Faculty of Science (Boys) %Z 1110-2535 %A M. N., Ismail %A A., Bakry %A H. H., Se lim %A M. H., Shehata %D 2015 %\ 06/01/2015 %V 26 %N Issue 1-B %P 17-22 %! Eclipses intervals for satellites in elliptical orbit under effects of solar radiation pressure and earth’s oblatness %K Perturbations Theory %K Circular orbital motion %K Earth’s gravity %K Radiation pressure effects %K Shadow function %R 10.21608/absb.2015.22633 %X The eclipse of a satellite in elliptical orbit is studied. The geocentric angle in the orbital plane between the perigee and conjunction point is determined. Eclipse times and duration of eclipse for elliptical orbits are obtained. The effects of the direct solar radiation pressure on the orbital elements are calculated taken into account the eclipses intervals. An application on the MOLNIYA 1-87 artificial satellite is done. %U https://absb.journals.ekb.eg/article_22633_75059c37f65006e2b5b55a02f6363bbf.pdf