Orbital Calculations With The Telescope. The Astrod 1 Refers To The Amount Of Research

As a first step of ASTROD (Astrodynamical Space Test of Relativity using Optical Devices), ASTROD I is to have one spacecraft launched to a solar orbit to range optically with ground station to test the experimental project for ASTROD and to meet important scientific goals. These scientific goals include an improvement in measuring solar-system parameters, a better precision of spacetime, and a slightly better for detecting gravitational waves.Considerded Newtonian Law, Sun, 8 large planets, Pluto, Moon ,3 asteroids(Ceres, Pallas, Vesta), and post-Newtonian effect, a Planet ephemeris and the spacecraft's orbit in 2015 are researched. Because a laser beam is transmitted to the spacecraft which will be near the other side of the sun and the laser takes about several hundres seconds to fly from a ground station to the S/C, the Telescope Pointing Ahead is considered. This paper presents the way of estimate the orbit precision if fills the mission, the relation between the Telescope Pointing Ahead and the position of the earth and the spacecraft, and the mission time and the telescope pointing ahead are fixed. Another, the spacecraft and the earth station are introduced in this paper.