‘Another milestone’: ISRO creates history with successful SpaDex mission, India joins elite space club

The Indian Space Research Organisation (ISRO) announced the successful launch of its historic Space Docking Experiment (SpaDeX) mission from Sriharikota. 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 Space Docking Experiment is a pivotal mission for India, aimed at demonstrating orbital docking technology, which is essential for future human spaceflights and satellite servicing missions.   

The launch, originally scheduled for 9:58 pm on December 30, was pushed back to 10:00 pm. The space agency did not immediately provide a reason for the change. 

SpaDeX mission is a cost-effective technology demonstrator mission for the demonstration of in-space docking using two small spacecraft launched by PSLV.  

This technology is essential for India’s space ambitions such as Indian on Moon, sample return from the Moon, the building and operation of Bharatiya Antariksh Station (BAS), etc. In-space docking technology is essential when multiple rocket launches are required to achieve common mission objectives. Through this mission, India is marching towards becoming the fourth country in the world to have space docking technology. 

The SpaDeX mission involves two satellites, SDX01 (the Chaser) and SDX02 (the Target), designed to dock in low Earth orbit. This technological feat is crucial for India’s future endeavors, including lunar expeditions and the development of a national space station. ISRO has confirmed that the PSLV-C60 is ready, with the launch vehicle integrated and moved to the First Launch Pad for final checks. 

The mission begins with the separation of the Target satellite 15 minutes post-launch, followed shortly by the Chaser. Using precise incremental velocity adjustments, the Target spacecraft will drift 10-20 km apart from the Chaser, setting the stage for a series of calculated maneuvers. These include progressive reductions in inter-satellite distance, ultimately leading to docking — a milestone expected to occur in early January 2025. 

The process is expected to take place about 10-14 days after the scheduled lift-off. 

Adding to the mission’s complexity, the PSLV-C60 will also carry 24 payloads as part of the PS4-Orbital Experiment Module (POEM-4). These payloads reflect ISRO’s push to integrate cutting-edge research into operational missions, underscoring India’s rapid progress in space exploration. 

The docking technology would also be utilised when multiple rocket launches are planned to achieve common mission objectives. This would be ISRO’s last mission in 2024.