ESA GNC Conference Papers Repository
Principals of Integrated INS/GLONASS+GPS GNC Systems for Space Launchers. Results of Realized Missions and Future Prospects
The paper describes the new concept of the development of inertial/satellite navigation systems for launch vehicles and upper stages. The analysis of the interval-inertial-relating approach to formation of redundancy of satellite measurements is presented as a basis for the new concept. By this approach the GLONASS+GPS data acquisition is realized not at a point of time (as in case of the time-point method used traditionally for dynamic objects) but at a certain time interval. This approach did not find application till recently neither in aircraft, nor especially in space rocketry with its high speeds. The reasons for it are delays in use of incoming satellite measurements and, therefore, the problems of recovery of quick-changing apparent movement parameters at the delay interval. The technique allowing to overcome these problems and to extend the above approach on real-time processing of trajectory measurements for guidance of dynamic objects is given. Also the method of inertial errors identification with the use of GLONASS+GPS measurements is developed in the context of the above approach. The achieved results laid the groundwork for the new version of the dynamic filtration method. It allowed to integrate inertial and satellite navigation for solution of problems of space launchers guidance with improved accuracy and became the base of the onboard software for space launchers inertial/satellite GNC systems. The results of the first successful applications of the inertial/GLONASS+GPS GNC system during Fregat upper stage missions (injection of Meteor-M satellite on 17 September 2009, six Globalstar satellites on 19 October 2010, Meridian-M satellite on 2 November 2010, etc.) are discussed. According to measurements of the ground tracking stations, attained accuracy of the main controlled orbit parameters, as compared with purely inertial navigation, was 5 7 times better for LEO, 3 10 times better for MEO, and 7 100 times better for GTO and GEO. These missions are the examples of the worlds first practical implementation of integrated inertial/satellite GNC systems on space launchers. In conclusion, the future prospects and potential benefits of application of integrated GNC systems, including opportunity of long missions like high-accuracy payload injection into GEO directly at the final orbit slot, are reported.