India’s latest rocket flies but payloads don't prosper

Satellites end up in 'unusable' orbit

India's small satellite launch vehicle (SSLV) made a spectacular debut launch on Sunday, but the mission fell short of overall success when two satellites were inserted into the incorrect orbit, rendering them space junk.

The SSLV was developed to carry payloads of up to 500kg to low Earth orbits on an "on-demand basis". India hopes the craft will let its space agency target commercial launches.

Although it is capable of achieving 500km orbits, SSLV's Sunday payload was a 135kg Earth observation satellite called EOS-2 and student-designed 8kg 8U cubesat AzaadiSAT. Both were intended for a 356km orbit at an inclination of about 37 degrees.

The rocket missed that target.

Indian Space Research Organisation (ISRO) identified the root cause of the failure Sunday night: a failure of logic to identify a sensor failure during the rocket stage.

(1/2) SSLV-D1/EOS-02 Mission update: SSLV-D1 placed the satellites into 356 km x 76 km elliptical orbit instead of 356 km circular orbit. Satellites are no longer usable. Issue is reasonably identified. Failure of a logic to identify a sensor failure and go for a salvage action

— ISRO (@isro) August 7, 2022

ISRO further tweeted a committee would analyse the situation and provide recommendations as the org prepared for SSLV-D2.

ISRO chairman S Somanath further explained the scenario in a video statement, before vowing to become completely successful in the second development flight of SSLV. "The vehicle took off majestically" said Somanath, who categorized the three rocket stages and launch as a success.

"However, we subsequently noticed an anomaly in the placement of the satellites in the orbit. The satellites were placed in an elliptical orbit in place of a circular orbit," caveated the chairman.

Somanath said the satellites could not withstand the atmospheric drag in the elliptical orbit and had already fallen and become "no longer usable". The sensor isolation principle is to be corrected before SSLV's second launch to occur "very soon".

Although ISRO has put on a brave face, it's hard to imagine the emotions of the school children who designed AzaadiSAT. According to the space org, the satellite was built by female students in rural regions across the country, with guidance from the team of of student space-enthusiast org Space Kidz India.

EOS-2 was designed by ISRO and was slated to offer advanced optical remote sensing in the infrared band with high spatial resolution. ®