In News:

The Indian Space Research Organisation (ISRO) is set to launch its Space Docking Experiment (SpaDeX) mission, a key milestone in India’s space capabilities. The mission will deploy two 220-kg satellites, SDX01 (Chaser) and SDX02 (Target), into a 740 km orbit using the PSLV-C60 rocket. SpaDeX aims to demonstrate the technology for satellite docking, a critical component for future space missions such as lunar exploration and the development of India's own space station, Bharatiya Antariksh Station (BAS).

Key Objectives of SpaDeX Mission:

• Primary Objective: To demonstrate the rendezvous, docking, and undocking of two small spacecraft (SDX01 and SDX02) autonomously.
• Secondary Objectives: Include testing electric power transfer between the docked spacecraft, composite spacecraft control, and post-docking payload operations.

The mission will see the two spacecraft gradually approach each other, performing a series of maneuvers, starting at a 20 km distance and closing to millimeter-scale distances before docking. Once docked, they will execute secondary tasks, such as scientific payload operations, using advanced technologies including high-resolution cameras, multi-spectral payloads, and radiation monitors.

Technological Innovations:

• Docking Mechanism: An indigenous, motor-driven, low-impact, androgynous docking system with capture, extension/retraction, and rigidization mechanisms. Both spacecraft are equipped with identical docking systems to simplify operations.
• Advanced Sensors: The spacecraft will use a Laser Range Finder (LRF), Proximity & Docking Sensors (PDS), and Rendezvous Sensors for precise distance measurement and to guide the docking process.
• Inter-Satellite Communication: The spacecraft will employ autonomous inter-satellite links (ISL) for real-time communication and data sharing.
• RODP Processor: This system, based on GNSS, ensures accurate position and velocity determination for the spacecraft during the docking procedure.

Significance of the SpaDeX Mission:

• Technological Milestone: SpaDeX positions India as the fourth country, after the US, Russia, and China, to develop space docking technology.
• Space Exploration: The successful demonstration will facilitate future space exploration, including Chandrayaan-4 and interplanetary missions.
• Modular Space Infrastructure: Space docking is essential for building multi-modular space stations, which allows the construction of large structures in space and enhances flexibility for future missions.
• Satellite Servicing: Docking enables satellite servicing, including repairs, refueling, and upgrades, which increases the operational lifespan of satellites.

SpaDeX Mission for India’s Space Station:

The SpaDeX mission is a crucial step towards India’s plans for the Bharatiya Antariksh Station (BAS). This will be India’s first modular space station, designed to conduct advanced scientific research, including in life sciences and medicine. BAS is expected to begin operations by 2035, and the development of docking technology is pivotal for its assembly and operation.

Mission Launch Details:

The PSLV-C60 rocket is set to launch the SpaDeX mission from Sriharikota. The mission is a demonstration of India's growing space capabilities and its indigenous technologies, including the Bharatiya Docking System (BDS).

Challenges and Technological Requirements:

The docking process requires extremely precise maneuvering, as the two spacecraft will be traveling at speeds of 28,800 km/h and must reduce their relative velocity to just 0.036 km/h before docking. This level of precision is crucial for future missions involving spacecraft servicing, crew transfers, and the construction of space infrastructure like BAS.

In addition to the docking demonstration, SpaDeX will carry 24 academic and startup payloads aboard the PSLV’s fourth stage, POEM (PSLV Orbital Experimental Module-4), offering a valuable platform for microgravity research.

Future Prospects:

The success of SpaDeX will pave the way for more complex missions, such as India’s lunar and Mars exploration programs, the development of the Bharatiya Antariksh Station, and international collaborations in satellite servicing and space infrastructure.