Attitude Control of Vehicle Ikar at Orbiting and Placement of Globalstar Satellites
- Paper number
IAC-05-C1.3.01
- Author
Prof. Gennady Anshakov, State Research and Production Space-Rocket Center “TsSKB-Progress”, Russia
- Coauthor
Prof. Vladimir Matrosov, Russia
- Coauthor
Dr. Yevgeny Somov, Russia
- Year
2005
- Abstract
The well-known Russian {{it Soyuz}} launch vehicle (LV) is one of the world's most reliable and frequently used at orbiting spacecraft (SC) for Earth observation, weather and scientific missions, as well as for manned flights. For {{it Globalstar}} satellites launches, an upper stage in the form of vehicle {{it Ikar}} was added to the LV {{it Soyuz}} along with dispenser system. Built by the {{it TsSKB-Progress}}, the vehicle {{it Ikar}} have a mass of 820 kg and is located under the {{it Soyuz}}'s payload fairing. The {{it Aerospatiale}} (France) produced dispenser allows {{it Soyuz}} simultaneously to carry out four low-earth-orbit (LEO) {{it Globalstar}} satellites. 24 {{it Globalstar}} satellites, manufactured by the {{it Space Systems/Loral}} (USA), were launched aboard the {{it Soyuz/Ikar}} space vehicle in 1999 from the {{it Baikonur}} cosmodrome at 6 missions. During each mission at 3.5 hours after launch, next four {{it Globalstar}} SC were released at an orbit altitude of 920 km. Others 24 {{it Globalstar}} satellites were successfully orbited also in 1999 by the {{it Boeing}} LV {{it Delta II}}. This paper briefly presents the principle events, modes and regimes of the {{it Ikar}} attitude control, methods and software for design and flight support of the vehicle {{it Ikar}} motion control system (MCS) at the orbital placement of the {{it Globalstar}} satellites. The MCS consists of the following onboard units: {{it Sensors}} -- the Infra-Red Earth Sensor, the Altitude Earth Sensor and the Rate Gyro Sensor Block; {{it Actuators}} -- the correcting-braking reaction engine (CRE) with 2-DOF gimbaled chamber and a thrust of 2943~kN, two gear drivers with digital or width-pulse control on each axis of the CRE 2-DOF gimbal, 2 complete sets on 8 reaction engines with a thrust of 5.5~N and complete of 8 reaction engines with a thrust of 10.4~N; {{it Onboard computer}} for digital processing measurements and forming control, the MCS diagnostics and reconfiguration during the {{it Ikar}} mission. Original methods and own computer technologies were successfully applied for design, simulation and testing all the {{it Ikar}} MCS modes and regimes, taking into account all possible faults and the MCS reconfigurations. The {{it Ikar}} {{it nonlinear}} attitude dynamics in the {{it Initial Regime}} (damping, the Earth acquisition, radial and plane tracing, the attitude stabilization modes), the {{it Acceleration Regime}}, a two-stage {{it Separation Regime}} and also in the {{it Braking Regime}} were investigated in detail. Obtained design and space flight results for all 6 {{it Ikar}} missions, are presented.- Abstract document