Development of Control and Guidance System for SLV-3, India's First Satellite Launch Vehicle - Some Reflections
- Paper number
IAC-07-E4.3.03
- Author
Dr. Sudhakara Rao, Narvik University College, India
- Year
2007
- Abstract
SLV-3, India’s first satellite launch vehicle developed in the 70’s and launched successfully in 1980, had four solid stages. The first three stages were 3-axis stabilized and the fourth stage was spin stabilized.
SLV-3 used an open loop guidance system with a vehicle attitude programmer (VAP) providing preprogrammed pitch attitude commands from lift-off to third stage separation. A platform based inertial measurement unit (IMU) was used for attitude reference. An analog autopilot was used for processing the attitude data and rate gyro outputs. The IMU, VAP, rate gyro package, autopilot electronics and other instrumentation and R.F systems were housed in the equipment bay in the third stage. In the first three stages, control power plants were used for generating the control force in each axis to correct the attitude errors. Development of such a control and guidance system was challenging especially when there was no previous experience or any foreign know how in this area. This paper describes personal reflections of the author who was closely associated with the development of many of these critical subsystems at Vikram Sarabhai Space Centre, Trivandrum #, about the technology challenges during development and testing of such systems.
The development strategy was to test many of the developmental models in sounding rocket flights to gain confidence on the design. Successes of these flights led directly to development of control and guidance system for SLV-3. To achieve high reliability, quality control norms were generated as there were none existing in VSSC at that time and implemented for printed circuit boards (PCB). Procurement of MIL grade electronic components, their screening were addressed well in advance for their availability for card fabrication.
Wiring of PCBs was done in a clean laminar flow tables with trained technicians using recommended tools. Similar standards were also generated for mechanical systems.
The paper presents details about the design reviews and rigorous testing done to enhance the reliability. Details about control systems design and analysis of the autopilot, 6-D simulations, real time simulations using the hybrid computer and finally the hardware-in-loop simulation for end –to- end checks of the control and guidance system are also given in the paper. A few details about the management of the project and the development tasks are also described. These include matrix management approach for project management, constant schedule review and follow-up, rigorous review of design, failure and nonconformance review. The paper concludes with the acknowledgement to many individuals who were associated with the development.
*Dy. Director(Retd), VSSC, Trivandrum, presently Visiting Professor, Narvik University College, Narvik, Norway. E-mail: drksrao2000@yahoo.co.in #The author was in charge of Control and Guidance Division, Avionics Group
- Abstract document
- Manuscript document
IAC-07-E4.3.03.pdf (🔒 authorized access only).
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