ISRO Report on SSLV Mission Failure

February 2, 2023

In August 2022, the Indian Space Research Organization launched the Small Satellite Launch Vehicle (SSLV). It carried two satellites and both satellites were rendered unusable. The mission was declared a failure. ISRO recently released a report detailing the reasons for the failure of the mission. ISRO investigation concluded that vibration disturbances were the major reason for the mission failure.

What happened?

The SSLV-D1 was programmed to place the satellite in a 356 km orbit. Instead, it placed the satellite in a 76-km orbit. This happened because of sensor failure.
The wrong orbital placing happened because of a shortfall in velocity.
During the second stage of separation, vibrational disturbances occurred. These vibrations caused the Inertial Navigation System to malfunction and net result the sensors became faulty.

Background

The SSLV is a three-stage launch vehicle. On the other hand, PSLV is a four-stage launch vehicle. Also, SSLV had a new inertia navigation system that ISRO was using for the first time. It used enough gyros (6) to monitor the rotation rates. All sic gyros experienced measurement saturation during the flight.

About SSLV

SSLV was designed for smaller satellites. These launch vehicles were designed to carry 500 kg of payload. The main objective was to reduce the burden of PSLV.