Our engineers who worked in Indian Space Research Organization were part of the development team that developed, maintained and operated the remote data acquisition and control system as part of the vehicle checkout system for the organization.

Business Situation

Testing and qualification of onboard subsystem in a launch vehicle is a colossal task. Handling of launch operations including automatic sequences during countdown is extremely complex and mission-critical. Any space research organization will require an automated checkout system that will qualify the onboard system before the launch, prepare the launch vehicle for the launch and issue the final ignition command after a countdown.

Solution

Our engineers who worked in Indian Space Research Organization were part of the development team that developed, maintained and operated the remote data acquisition and control system as part of the vehicle checkout system for the organization. This is a remote system that acts as an interface between the satellite launch vehicle and Launch Operations Control Center (LOCC) located 6 kilometers away. The system is located near the launch vehicle in an environment-shielded terminal room.

This remote system, being the front end interface to the launcher and launch vehicle systems, plays a critical role in the automated countdown sequence. It acquires and monitors onboard and ground parameters continuously till end of the countdown (T-Zero). The system analyzes the acquired data, on-the-fly, from redundant sources in system under test. On confirming an anomaly, it is capable of holding the countdown and executing the required recovery (roll-back) sequences automatically. The unit also provides for selectively over riding the surveillance parameters by authorized supervisory users.

Key Features

The system carries out the following responsibilities.

• Acquire analog and digital data from the Launch Vehicle periodically. There are various measurements including:
  • Pressure sensor outputs
  • Status of onboard valves and relays
  • Battery voltage levels
• Communicate the acquired data to LOCC
• Receive commands from LOCC
• Execute the received commands. There are various commands including:
  • Commands to operate valves in all stages of the launch vehicle
  • Commands to turn the external power supplies onboard systems on/off
  • Commands to turn internal batteries on/off
• Execute special health check algorithms on the vehicle parameters during Automated Launch Operations. Hold the countdown on an event of detecting any abnormality.

Hardware

• Scalable Instrumentation system using VXI bus as the platform
• Data acquisition system using multi-channel VXI DAQ modules
• Command interface using VXI relay devices
• GPIB based power supply interfaces
• High speed, dual channel serial communication link with Launch Operations Control Center

Software

• Windows NT based system with RTx
• Developed in Visual C++ /MFC
• Configuration data stored in MS Access database
• Interfaced with LabWindows to use LabWindows display controls
• Object Oriented Design using UML/Rational Rose

Benefits

• Unmanned, remote operations ensuring personnel safety.
• Automatic detection of anomalies and hold of countdown.
• Acquisition of complete data from onboard subsystems.