Recent efforts toward the minimization of GTO objects and its practices in NASDA

Abstract For the safety of space activities, minimization of orbital life of the mission-terminated upper stages has been a matter of concern to NASDA. With the advent of the H-II launch vehicle, active measures to decrease orbital life by the low thrust firing of the second stage in a quasi-retrograde direction to lower the perigee height has become possible. In test flights Nos. 2 and 3 of the H-II which have been conducted in 1994 and 1995 for the geostationary mission, this reduced thrust firing of the second stage engine, called “idle mode burn” has been conducted. In test flight No. 2, more than 100 km perigee height reduction was obtained. As a result, orbital life was reduced to about 7 months. This paper outlines the concept of perigee height reduction together with some analytical results for the evaluation of Iuni-solar perturbation effects on the orbital life of objects on geostationary transfer orbit.