ISRO's SPADEX Mission Accomplishes Second Docking Of Satellites In Space With Full Autonomy

Hyderabad: The Indian Space Research Organisation (ISRO) has successfully demonstrated the second docking of the SPADEX satellites, SDX 01 and SDX 02, on April 20, 2025, at 8:20 PM. The mission also exercised and accomplished power transfer from SDX 02 to SDX 01 and vice versa on April 21, 2025.

This time, the docking was completed with full autonomy from an inter-satellite distance of 15m till docking. Notably, in the first docking attempt, an additional hold point was manually exercised at an inter-satellite distance of 3m.

"The demonstration of the fully autonomous second docking along with power transfer marks the completion of an important milestone in the SPADEX mission," ISRO said in a press release.

The second docking experiment involved operating a heater element in one of the satellites through power from the other satellite. The duration of power transfer was approximately 4 minutes, and the performance of the satellites was within expectations, ISRO added.

Before the docking experiment, ISRO conducted extensive ground simulations and on-orbit trials, integrating insights from the first docking and undocking experiments. The space agency says that these preparations greatly enhanced its confidence in the success of the second docking demonstration.

Docked images from SDX 01 and SDX 02 (Image Credits: ISRO)

Celebrating the success of the second docking of SPADEX satellites, Jitendra Singh, Minister of Science and Technology, stated that further experiments are planned in the next two weeks.

To recall, the SPADEX mission was launched aboard ISRO's PSLV-C60 launch vehicle on December 30, 2024. Thereafter, the satellites were successfully docked for the first time on January 16, 2025, followed by a successful undocking on March 13, 2025. The successful SPADEX mission placed India among the elite group of nations capable of performing space docking, a technology crucial for building larger structures in space like the planned Bharatiya Antariksh Station and enabling tasks like refuelling, maintaining satellites, and much more.

Also read: How ISRO's SPADEX Mission Sets Stage For Bharatiya Space Station, Chandrayaan-4