Indian small satellite launcher premiere (SSLV) failed to reach orbit on August 6 when the rocket’s launch stage malfunctioned.
The three-stage vehicle, capable of placing a payload of up to 500 kilograms into a 500-kilometer low-Earth orbit, took off at 23:48 east of the Satish Dhawan Space Center n1 launch pad, carrying a 135-kilogram Earth observation. satellite EOS-02 built by the Indian space agency ISRO and the eight kilogram cube for AzaadiSATmade by Indian students.
Live footage showed a 34-meter rocket, emblazoned with India’s national flag, hovering in the air. The bottom three stages of the rocket run on a solid fuel, polybutadiene ending in hydroxyl, while the final stage, called Speed Trimming Module (VTM), uses hydrazine-fueled propellants and mixed nitrogen oxides for their precise charge dispersion.
The flight events visible on the live stream screen indicate that the rocket’s flight started smoothly. The first leg separated about two minutes after takeoff as scheduled, and the second leg did so 3.5 minutes later. The separation of the third stage took place 10.7 minutes after takeoff. The last data available on the screen was that the injection module ignition started 10.8 minutes after takeoff but was cut off after only a tenth of a second. At one point, the image shows the EOS-02 satellite deployment of the module.
S. Somanath, President of ISRO, said shortly after that the first three stages had gone according to plan, but a some data loss occurred in the final phase of flight. He did not release additional details on the matter, but said more details would be announced later. ISRO then ended the launch webcast.
Hours later, ISRO announced that the VTM was not working, placing the satellite in an elliptical orbit of 76 by 356 kilometers instead of the planned circular orbit of 356 kilometers. Satellite is no longer usable ISRO said, and possible re-entry via the Pacific Ocean.
ISRO says that logic failure to identify sensor failure and taking corrective action resulted in the satellite being placed in the wrong orbit. ISRO did not specify whether this was related to the VTM propulsion engine shutting down after a tenth of a second.
This SSLV issue has been reasonably identified, but we’ll dig deeper. Somanath said in a video posted on the ISRO website. This system has drawbacks that we need to look at very carefully.
He pointed out that the first three steps all worked as expected. The overall performance of the vehicle is very good during the mission , he stated. In addition to VTM damage, we found no other anomalies. All the other new stuff that was put into this rocket worked really well.
He is optimistic that the problem will be resolved soon. We hope that with minor fixes and further re-validation of these fixes through a sufficient amount of testing, we’ll be back soon for the launch of the next SSLV development flight, SSLV-D2.
ISRO developed the SSLV with the aim of providing cheaper and more flexible access to outer space, compared to its two operational vehicles, the Polar Satellite Launch Vehicle (PSLV) and the Geosynchronous Satellite Launch Vehicle (GSLV). For this, SSLV has been designed to be configured with a simple modular interface, and vehicle assembly can be carried out both horizontally and vertically.
Development of the SSLV began in 2017 with the initial goal of a first launch in early 2019. Its development has been delayed by both technical issues, including a first-stage engine failure during static fire tests in 2021, as well as an overall pandemic-related slowdown in India’s space activities.
