Chennai, Apr 21 (IANS): The countdown for the Saturday afternoon launch of India's Polar Satellite Launch Vehicle (PSLV) that would carry two Singaporean satellites has started and is progressing, a senior official of Indian Space Research Organisation (ISRO) said on Friday.

During the countdown, the rocket will be fuelled and the health of the rocket as well as that of the satellites will be monitored.

At 2.19 p.m. on April 22, 2023 the core alone variant of the PSLV rocket (code named PSLV-C55) will blast off from the Sriharikota rocket port carrying two Singaporean earth observation satellites - TeLEOS-2 weighing 741 kg, the 16 kg Lumilite-4.

These two apart, there will be seven non-separable experimental payloads which will be part of the rocket's final stage (PS4).

ISRO uses the final stage (PS4) of the PSLV rocket as an orbital platform for in-orbit experiments and has named it as PSLV Orbital Experimental Module (POEM).

Just over 19 minutes into its flight, the PSLV-C55 will orbit the TeLEOS-2 satellite and it will be followed by Lumilite-4 soon after.

With the launch of 36 OneWeb satellites in March this year, ISRO has launched 422 foreign satellites. The number is expected to go up on Saturday.