The Indian Space Research Organisation (ISRO) will be launching its 100th satellite on January 12 (Friday).

The 31 satellites with a combined weight of 1,323 kg have been integrated with the PSLV-C40 for deploying them in the earth's lower orbit after lift off.

The launch vehicle is carrying 31 satellites: 28 from six other countries and three from India, including the country's 100th. This was one of the keenly followed missions in the aftermath of an expected failure suffered in August a year ago.

The 28 global customer satellites are being launched as part of the commercial arrangements between ISRO and Antrix Corporation Ltd., a company under Department of Space. The last launch of IRNSS-1H - India's first privately built satellite - on August 31 past year had failed because of a freak accident.

ISRO is helping not just India but several other countries in putting communication, navigation and other satellites into orbit. PSLV-C40 was launched from the First Launch Pad (FLP) of Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, Andhra Pradesh.

"The microsatellite will be India's 100th satellite in space", ISRO Satellite Centre Director M. Annadurai had told IANS on Tuesday.

He said the previous launch faced a heat shield problem and an ISRO committee has addressed it and taken steps to ensure the vehicle was "robust". "This is a technology demonstrator and the forerunner for future satellites of this series", the ISRO said. This mission had lasted two hours and 15 minutes, ISRO scientists said.

359 km polar SSO after bringing down the orbital height by reigniting the fourth stage of PSLV twice. ISRO had successfully launched Cartosat-2 Series satellite on June 22, 2016.

It will mark the PSLV's return-to-flight after a four-month grounding in the wake of a failure in August.