ISRO is set to take a significant leap in space technology with the launch of its Space Docking Experiment (SpaDeX), scheduled for today at 9:58 PM from the Satish Dhawan Space Centre (SDSC) in Sriharikota, Andhra Pradesh, aboard the Polar Satellite Launch Vehicle (PSLV-C60). This mission will place India among a select group of nations with space docking capabilities.
What is SpaDeX?
The SpaDeX mission will deploy two small satellites, SDX01 (Chaser) and SDX02 (Target), into a low-Earth orbit at an altitude of 470 km. The main objective is to test and demonstrate the technology for rendezvous, docking, and undocking of spacecraft. This mission is particularly challenging due to the small size and mass of the satellites, requiring precise manoeuvres.
SpaDeX also acts as a stepping stone for autonomous docking systems, crucial for future lunar missions like Chandrayaan-4. By mastering these technologies, India aims to join the elite group of nations—including the US, Russia, and China—that have space docking expertise.
How Does Docking Work in Space?
Docking involves the precise alignment and physical connection of two spacecraft in orbit. For SpaDeX, the two satellites will initially be 20 km apart, gradually reducing the distance to just 3 meters over 24 hours before docking.
The satellites are equipped with a Differential GNSS-based Satellite Positioning System (SPS) to ensure accurate positioning. A novel RODP processor within the SPS calculates relative positions and velocities using carrier phase measurements from GNSS satellites. Data exchange between the two spacecraft is facilitated through VHF/UHF transceivers.
The Road to Launch
Developed by ISRO’s UR Rao Satellite Centre (URSC) with contributions from various ISRO centers, the SpaDeX satellites underwent full integration and testing in Bangalore before final preparations at the launch site. The mission’s orbital phase will be managed by ISTRAC, with support from ground stations.
For those eager to watch the launch, ISRO will stream it live on YouTube starting at 9:30 PM IST. SpaDeX represents a major milestone in ISRO’s journey, highlighting India’s advancing capabilities in space technology and exploration.
