ISRO set to launch crucial SpaDeX mission today

ISRO's Space Docking Experiment onboard a PSLV rocket later on Monday has been rescheduled by two mins, the space agency said.

A key milestone in India's space programme, the mission will lift off at 10 pm on Monday instead of the originally planned 9.58 pm, ISRO said. However, there was no immediate information on the reason behind the rescheduling.

"Launch Day is here. Tonight at precisely 10 pm, PSLV-C60 with SpaDeX and innovative payloads are set for liftoff," ISRO said in an update on Monday.

"Space Docking Experiment is a pioneering mission to establish India's capability in orbital docking, a key technology for future human spaceflight and satellite servicing missions," the space agency added.

The 25 hour countdown which commenced on Sunday night at 9 pm was proceeding, an ISRO official said.

A cost-effective technology demonstrator mission for in-space docking, it would make India join an elite list featuring China, Russia and the US.

The mission will be launched from the first launch pad at this spaceport here and would carry SpaDeX with two spacecraft as the primary payloads along with 24 secondary payloads.

The in-space docking technology would be essential for taking up India's ambitions in space including sending humans to the Moon, bringing samples from there, and also building and operating the country's own space station- Bharatiya Antariksh Station.

The docking technology would also be utilised when multiple rocket launches are planned to achieve common mission objectives.

ISRO said the two spacecraft in the PSLV rocket-- Spacecraft A (SDX01) and Spacecraft B (SDX02) would be placed in an orbit that would keep them 5 km apart from each other. Later, scientists at ISRO headquarters would try to bring them closer up to 3 metres which would subsequently lead them for merging together at an altitude of about 470km above Earth.

The process is expected to take place about 10-14 days after the scheduled lift-off on Monday, ISRO officials said.

In the SpaDeX mission, Spacecraft A carries a High Resolution Camera, while Spacecraft B has Miniature Multispectral Payload and a Radiation Monitor Payload. These payloads would provide high resolution images, natural resource monitoring, vegetation studies among others.

Apart from this significant mission, scientists would also conduct the PSLV Orbital Experimental Module-4 (POEM-4) in which 24 payloads--14 from ISRO and 10 from industry and academia, would be placed in the desired orbits one after the other over a 90 minute period after the lift-off.

The life of the payloads in the fourth stage would be about three to four months. The vehicle for the PSLV-C60 mission used here would be the 18th Core-Alone variant.

This would be ISRO's last mission in 2024 and the PSLV-C60 is the first vehicle to be integrated up to the fourth stage at the PSLV Integration Facility that has been established in Sriharikota.