Successful docking of SpaDeX Satellites (for second time)

Context

ISRO successfully conducted the second docking experiment of the SPADEX mission, involving two satellites — SDX-01 and SDX-02. This time, the docking was performed fully autonomously from a distance of 15 metres. Following this, ISRO also demonstrated inter-satellite power transfer, marking a significant milestone in India's space technology capabilities.

What is ‘Docking’ in Space?

Docking refers to the process where two spacecraft physically connect with each other while in orbit.
It involves aligning and bringing together one spacecraft with another, typically to transfer crew, materials, or resources like power and fuel.
Docking is critical for:
- Space station operations
- Satellite servicing and refuelling
- Multi-spacecraft missions
- Human spaceflight support systems
It can be manual, semi-autonomous, or fully autonomous, depending on the mission design and technology.

Key-Details of the Second Docking Experiment

Autonomous Docking: The second docking was conducted without manual intervention, unlike the first attempt in 2023 where a manual hold was placed at 3 meters.
- This time, docking occurred completely autonomously from 15 metres to contact.
- Prior to this attempt, extensive ground simulations and in-orbit trials were conducted using insights from the first experiment.
Power Transfer Demonstration: Power was transferred from SDX-02 to SDX-01 and vice versa. The power supported the operation of a heater element in the receiving satellite.

Fact-Box (SPADEX Mission)

Launched in: 2024
SPADEX stands for Space Docking Experiment.
It is a "cost-effective technology demonstrator mission" for the demonstration of in-space docking using two small spacecraft launched by PSLV.
The mission aims to demonstrate technologies related to orbital rendezvous, docking, and proximity operations.
SpaDeX involves two small satellites, designed for in-orbit operations such as rendezvous, docking, and resource sharing:
- SDX01 (Chaser)
- SDX02 (Target)