Annotation: For monitoring rocket flight and determining accuracy of spacecraft injection into the planned orbit, it is necessary to ensure the reception of telemetry data from the launch vehicle. Telemetry data receiving stations may be located either on land or on shipboard. When the antenna system of such station is placed on shipboard, ship roll and ship drift have the most considerable impact on the antenna guidance accuracy. To ensure the guidance accuracy of the telemetry receiving antenna set, placed on shipboard, the control algorithm was designed. It was offered to use triaxial rotary support with axis of reflector inclination angle to meet the requirements specified. In the article, the connection between kinematic parameters of the antenna rotary support drives and parameters of the space launch vehicle motion were identified, rotation angles of the antenna drives along the three axes were determined, and the law of angular velocity variation along the azimuthal axis, including the maximum feasible angular velocity provided by the azimuthal axis drive, was chosen. Numerical simulation of antenna guidance algorithms that provide stable signal receiving under conditions of ship roll was carried out in the visual development environment of Embarcadero RAD Studio XE6. Several variants for operation of the rotary support drives of the antenna set were chosen for mathematical simulation; disturbing conditions of ship roll and ship drift were analyzed and chosen for ships with small displacement. The simulation validated the designed antenna control algorithm and showed that the requirements for the cinematic parameters of the antenna drives were reduced under conditions of ship roll when the axis of reflector inclination angle was introduced; and accelerometer unit or GPS receiver installed in the antenna structure additionally increased the accuracy of target designation of the antenna and improved its guidance accuracy

Annotation: Under the Sea Launch program when developer of the Zenit-3SL ILV control system issued the permission to launch in the conditions of drift from the design launch point of the Odyssey launch platform, the problem of drift parameters monitoring at the Sea Launch Commander ACS appeared. To ensure the payload orbiting accuracy the following maximum permissible values of platform drift parametres were determined: • maximum velocity of platform drift – no more than 0,32 m/s; • maximum acceleration of platform drift – no more than ±0,05 m/s2; • maximum distance of platform drift from design launch point – no more than 1950 m. The article includes the computation algorithm of the platform drift parametres to calculate velocity and acceleration of the drift, as well as distance from the design launch point to the actual point of the platform location. Geographical coordinates – latitude and longitude of the platform according to the GPS sensor, installed on the platform are used for calculations. These values during prelaunch processing of the ILV are transmitted to the assembly and command ship’s workstation for calculation of loads in the ILV root section at the rate of once in a second. During one of the Sea Launch missions, C++ program was developed and installed on the loads calculation workstation, realizing the computation algorithm offered by the authors of this article. This program displayed in real time the monitored parametres of the platform drift, and monitored the tolerable limits. During the same mission, the correctness of the developed algorithm and program were confirmed during the special experiment on the launch platform drift in the launch point. In future, they were used during the subsequent missions of the Sea Launch program.