The Indian Space Research Organization (ISRO) said on Sunday that the two small satellites launched earlier in the day are "no longer usable."

Developed by school students, the Earth Observation Satellite (EOS-02) and the AzadiSAT (Independence Satellite) were put into orbit. However, the "orbit achieved was less than expected."

"All the stages performed normal. Both the satellites were injected. But the orbit achieved was less than expected, which makes it unstable," the ISRO said. 

The AzadiSAT is a CubeSat, a square-shaped miniature satellite about the size of a Rubik's cube, was developed by 750 female students to mark the 75th anniversary of India's independence on August 15, according to media reports.

"AzadiSAT is an 8U CubeSat weighing around 8 kilograms. It carried 75 different payloads, each weighing around 50 grams and conducting femto-experiments. Girl students from rural regions across the country were provided guidance to build these payloads," the ISRO said in a statement.

"The Small Satellite Launch Vehicle (SSLV-D1) placed the satellites into 356 km x 76 km elliptical orbit instead of 356 km circular orbit. Satellites are no longer usable," the ISRO tweeted.

"Failure of a logic to identify a sensor failure and go for a salvage action caused the deviation," the ISRO said.

The body said a committee would analyze the situation and make a recommendation, which it will implement in developing the SLV-D2.  

"The maiden flight of the Small Satellite Launch Vehicle (SSLV) has been completed, and it performed all stages as expected. We know in the terminal phase of the satellite there has been data loss and so they are waiting for the status of satellite and vehicle performances," said ISRO Chairman S. Somanath. 

(With input from Xinhua)