The Indian Space Research Organisation successfully launched PSLV-C53 which placed three Singapore satellites in orbits. The fourth stage of the rocket then turned into an orbital platform for scientific experiments as it began to circle the earth.
At 6.02pm, PSLV, in its 55th mission and 15th mission using PSLV-Core Alone variant, lifted off from the second launch pad at Satish Dhawan Space Centre in Sriharikota. Around 18 minutes after the lift-off, the rocket injected three Singapore satellites into their respective orbits.
Isro chairman S Somanath said, “PSLV-C53 has placed the satellites in precise orbits. I thank NSIL for yet another mission. Many more missions are on the way for our customers all over the globe. ”
The satellites include DSEO, a 365kg electro-optic, multi spectral payload that will provide full colour images for land classification and serve humanitarian assistance and disaster relief needs. The second satellite is 155kg NueSAR, Singapore’s first small commercial satellite carrying a SAR payload and can provide images in day and night and under all weather conditions. The third satellite is 2.8kg Scoob-1, the first in the student satellite series (S3-I), a hands-on student training programme from the Satellite Research Centre at Singapore’s NTU School of Electrical and Electronic Engineering.
After the satellites were injected, the PS4 or the fourth stage of PSLV turned into an orbital platform — PSLV Orbital Experimental Module — to perform in-orbit scientific experiments. It is for the first time that the PS4 stage is orbiting the earth as a stabilised platform.
POEM is carrying six payloads, including those from two Indian space start-ups — Digantara and Dhruva Space — enabled through INSPACe and NSIL.
The Isro chairman said, “After the primary mission, the PSLV fourth stage is going to write some poems in orbit. The POEM is going to be functional after this, taking over the control of the primary mission computer to another computer. The fourth stage will be powered, generating power on board and will be stabilised with altitude control. It will host some experiments by some of the young startups enabled by INSPACe. ”
Somanath said normally the fourth stage ends up as debris. But, Isro has introduced solar panels, computers, a control system to fire its thrusters and sensors to look at the stars and find its own position, and receive commands. He said the fourth stage can be used like this when the load is light like on the PSLV-C53.
“On missions with higher payloads, such as an upcoming launch with a 1.5 tonne satellite, there will be too little propulsion left to operate the POEM,” he added. This is the second time the fourth stage is used. It was reignited on an earlier mission.
Mission director S R Biju said PSLV was in a different configuration this time. “It is the Core Alone version. We are coming back with this variant after a pretty long time. We had to introduce some changes to improve the production of PSLV, so that we can meet the growing demand of customers, which we have implemented and it has yielded results. ”
Biju said, “It is continuing its mission. We will take over PSLV, give some energy to PS4 and try to do some very cost effective experiments which can satisfy the growing demand of startups, our student community and our scientific community. Left to itself, it would have taken its own course, tumbled, wobbled or it would have somersaulted.
He added: “But given some more energy, probably we will be able to continue the active PS-4 for some more time, so that the platform is available. You keep some scientific payloads there so that it can serve a secondary purpose also. ” He said, “The idea for this mission was conceptualised in a record three months. It is effectively two missions rolled into one. Huge effort has gone into this from all centres of Isro. ”
It is Isro’s second mission this year. It was the second dedicated commercial mission of NewSpace India Limited.