ISRO is preparing to launch its “Space Docking Experiment” (SpaDeX) mission on Monday at 9:58 pm from the Satish Dhawan Space Centre (SDSC) SHAR in Sriharikota. The PSLV-C60 rocket will carry the mission into space.
Objective of SpaDeX Mission
The main goal of SpaDeX is to test and develop the technology required for the rendezvous, docking, and undocking of two small spacecraft, SDX01 (Chaser) and SDX02 (Target), in low-Earth orbit. ISRO highlighted that docking small spacecraft demands greater precision than docking larger ones. This mission will pave the way for future autonomous docking technologies needed for lunar missions like Chandrayaan-4, which will not rely on Earth’s GNSS support.
Advanced Technology for Precise Positioning
Both SpaDeX spacecraft are equipped with a differential GNSS-based Satellite Positioning System (SPS) for Position, Navigation, and Timing (PNT) solutions. A new RODP processor in the SPS receiver allows the accurate measurement of relative position and velocity between the Chaser and Target spacecraft. By comparing carrier phase measurements from the same GNSS satellites, ISRO can precisely track the relative states of the two satellites. The VHF/UHF transceivers in each spacecraft enable the transfer of GNSS satellite measurements between the spacecraft.
Collaboration and Testing Process
The UR Rao Satellite Centre (URSC) led the design and development of the SpaDeX spacecraft, with contributions from several other ISRO centers, including VSSC, LPSC, SAC, IISU, and LEOS. After completing all tests and clearances, the spacecraft were integrated at M/s Ananth Technologies in Bangalore, under URSC’s supervision. The spacecraft are now at SDSC for final preparations ahead of the launch. ISTRAC will manage the spacecraft in orbit, with support from ISRO’s ground stations and external partners
