I. A. Galustov

Information about the orbital motion of spacecraft is available via Internet where one can find the two- line elements of the primary orbit. If we know the primary orbit, the coordinates of the launch site and the time we can restore the launch profile: we can evaluate the launch azimuth and the characteristic velocity required for the transition to the primary orbit. The work is presenting the procedure for evaluation of these parameters. With available data on the primary orbit we can evaluate the longitude of the ascending node for the time of the first crossing of the equator plane. Using the estimates of the ascending node, the time of the launch and the coordinates of the launch site we can evaluate the azimuth and the inclination of the launch. If the inclination of the launch orbit differs from the inclination of the primary deployment orbit then we have the case of launch with change of the inclination. The other parameters of the launch orbit and the characteristic velocity can be evaluated by solving Lambert problem for determination of orbital parameters using two positions and two reference times. The position for the left end should be above the launch site. The time corresponding to the left end belongs to the interval, which is located to the right from the time of the launch. Then we perform the search on possible positions and the times at the left end. The parameters of the launch orbit are selected to satisfy the conditions for the minimum altitude of the launch orbit and minimum module of characteristic velocity. The paper presents the analysis for the launches from Canaveral.