SpaDeX first of many as ISRO prepares for Chandrayaan-4 Premium

ISRO conducts space docking experiments for Chandrayaan-4 mission, crucial for lunar soil sample return and future space missions.

There will be a series of space docking experiments before the Indian Space Research Organisation embarks on its Chandrayaan-4 mission to bring soil samples from the moon to the earth, ISRO has said.

On December 30, 2024, the C60 mission of the Polar Satellite Launch Vehicle (PSLV) placed two satellites, each weighing 220 kg, in orbit. They will rendezvous and dock with each other as part of ISRO’s first Space Docking Experiment (SpaDeX).

ISRO Chairman S. Somanath said “the nominal time” for the docking “will be approximately January 7.”  He added, “The two SpaDeX satellites have moved one behind the other, so over a period of time, they will pick up further distance. The distance will increase by 20 km over the next few days and then the rendezvous and docking process will start.”

For Chandrayaan-4, ISRO will launch the mission’s modules in two Launch Vehicle Mark-3 (LVM-3) rockets. At various points during the mission, the modules will undergo a series of docking and undocking manoeuvres before finally transporting a canister of lunar soil safely back to the earth.

Mr. Somanath had said on December 31, “2025 will be an exciting year as ISRO will launch four GSLV rockets, three PSLV launches as well as an SSLV launch.” (GSLV is short for Geosynchronous Satellite Launch Vehicle and SSLV for Small Satellite Launch Vehicle).

Docking is a crucial technology for India to master for Chandrayaan-4 as well as its forthcoming orbital Bharatiya Antariksh Station (BAS), expected to be ready by 2035, and for its goal to send an Indian astronaut to the moon.

Chandrayaan-4 study director P. Veeramuthuvel said, “Docking is important for all future missions of ISRO because you cannot launch everything in one go. So you need docking of modules in space. … There will be five modules in BAS, all of which require docking. This technology is crucial for bringing back the lunar soil samples and for India’s constant presence in space.”