Control of a space vehicle descent in atmosphere

A problem of sliding descent of a space vehicle in atmosphere is considered on the basis of a platformless inertia! system. The algorithms of longitudinal and lateral distance control on final miss providing high control accuracy and possibility of lateral manoeuvring are presented. An estimation of navigation errors of the non-corrected platformless inertial system is carried out. It is stated that when using this system a discent accuracy can be 10-15 km. The method of such system aerodynamic correction on accelerometer measurements is worked out. The correction accuracy is investigated in dependence on the nominal motion parameters of descended apparatus, nominal descent trajectory is estimated and investigated. The nominal trajectory provides a high accuracy of aerodynamic correction of platformless inertial system, provides possibility of a wide lateral manoeuvring and a great reserve of longitudinal and lateral distances. An estimation of navigation errors of the corrected platformless inertial system is carried out. It is stated that an application of the elaborated method of such system aerodynamic correction permits to provide a descent accuracy of 2-3 km. A comparison of the considered system and the descent control system for "Soiuz-TM" space vehicle is carried out. It is shown that for the same instrument set and accuracy characteristics of measuring devices a descent accuracy is increased 10 times due to the proposed control algorithms.