ISRO SpaDeX | Rendezvous in Space | Scale Model

The SpaDeX Mission was a technology demonstrator mission for in-space docking using two small spacecraft. This technology is essential for India's space ambitions for Indian on Moon, sample return from the Moon and the building and operation of Bharatiya Antariksh Station (BAS)

Objectives

The primary objective of the SpaDeX mission was to demonstrate the technology needed for Rendezvous, Docking, and Undocking of two small spacecraft SDX01, the Chaser and SDX02, the Target, in a low-Earth circular orbit.

The indigenous technologies developed for enabling this docking mission were:

•Docking mechanism
•A suite of four rendezvous and docking sensors
•Power transfer technology
•Indigenous novel autonomous rendezvous and docking strategy
•Inter-satellite communication link for autonomous communication between spacecraft
•GNSS-based Novel Relative Orbit Determination and Propagation processor to determine the relative position and velocity of the other spacecraft
•Simulation test beds for hardware and software design validation and testing

This mission will be a forerunner for autonomous docking needed for future lunar missions like Chandrayaan-4 without the support of GNSS from Earth.

Docking Mechanism

The docking mechanism was a low-impact docking system and is a peripheral docking system. The mechanism has one degree of freedom for extension and uses two motors. Multiple test beds tested the hardware and software simulation of the docking kinematics to verify and finalise the docking approach parameters.

The SpaDeX mission had its first successful docking of the two satellites on January 16, 2025. The undocking of these satellites was successfully completed on March 13, 2025. The SpaDeX mission was launched on December 30, 2024 by the PSLV-C60 rocket