HELSINKI — India completed the docking of two spacecraft in orbit, marking a crucial step forward for the country’s robotic lunar and human spaceflight plans.
The Space Docking Experiment (SpaDeX) launched on a PSLV rocket from Satish Dhawan Space Centre in Sriharikota Dec. 30. The two, 220-kilogram SpaDeX spacecraft, SDX01, the chaser spacecraft, and SDX02, the target, were sent into orbit around 475 kilometers above the Earth.
The pair were originally planned to dock around Jan. 7, but unexpected drift in the position of the satellites led to delays. After concerns the docking attempt would need to be delayed until March, ISRO completed the docking late Jan. 15 Eastern.
“Maneuver from 15m to 3m hold point completed. Docking initiated with precision, leading to successful spacecraft capture,” ISRO stated via the X.com social media platform.
It makes India just the fourth country, after the United States, Soviet Union/Russia and China, to complete a docking of two spacecraft in orbit.
Indian Prime Minister Narendra Modi, who was at the ISRO office in Bangalore for the docking attempt, posted his congratulations on X.
“Congratulations to our scientists at ISRO and the entire space fraternity for the successful demonstration of space docking of satellites. It is a significant stepping stone for India’s ambitious space missions in the years to come,” Modi’s post read.
Dr. V. Narayanan, who assumed charge of ISRO Jan. 13, taking over from outgoing chairman S. Somanath, congratulated the agency team following the successful docking.
The SpaDeX mission is part of India’s efforts to become the fourth country to develop independent human spaceflight capabilities with its Gaganyaan program, with a first crewed flight currently planned for 2026. Uncrewed test flights are scheduled for 2025. The country plans to establish the Bharatiya Antariksha Station in orbit by 2035 and a crewed lunar landing by 2040.
The docking technology will also be needed for India’s Chandrayaan-4 lunar south pole sampling mission, expected to launch around 2027 or 2028. Docking will be required to get samples collected from the surface from an ascent vehicle and into a service module capable of returning to Earth.
The SpaDeX mission includes an indigenous, low-impact docking system with an approach velocity of about 10 millimeters per second, as well as a Laser Range Finder (LRF), Corner Cube Retro Reflectors, and other advanced sensors to facilitate precise docking maneuvers. A GNSS-based Relative Orbit Determination and Propagation (RODP) processor will be used for accurate relative positioning.
SpaDeX Docking Update:
SpaDeX satellites holding position at 15m, capturing stunning photos and videos of each other! 🛰️🛰️
#SPADEX #ISRO pic.twitter.com/RICiEVP6qB
— ISRO (@isro) January 12, 2025
Next launch activities, new launch pad
India is targeting a record year for launches, with 10 orbital missions planned, including private company Skyroot Aerospace planning its first Vikram-1 rocket launch. India’s next launch appears set to be a GSLV launch of the NVS-02 navigation satellite from Sriharikota. That launch is expected no earlier than Jan. 26.
The India cabinet Jan. 16 approved a Third Launch Pad (TLP) at Satish Dhawan Space Centre at Sriharikota to support next generation launch vehicles and enhance the country’s launch capacity. India plans to develop a reusable Next Generation Launch Vehicle (NGLV).
