SPADEX Mission of ISRO: Docking Time | UPSC

On December 30, 2024, the Indian Space Research Organisation (ISRO) successfully launched the PSLV-C60 rocket carrying the Space Docking Experiment (SPADEX Mission) payload from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh. With this historic mission, India has become the fourth country in the world after the United States, Russia, and China to attempt a complex spacecraft docking maneuver in orbit.

What is the SPADEX Mission?

SPADEX, or Space Docking Experiment, is a mission designed to develop and demonstrate technology for spacecraft docking and undocking using the Bharatiya Docking System. This mission will show India’s ability to dock two satellites in space, a complex task achieved by only a few nations. Completing SPADEX will help prepare for future missions like Chandrayaan, Gaganyaan, and the Bharatiya Antriksh Station.

Mission Objectives

The primary objectives of SPADEX include:

• Demonstrate Rendezvous and Docking: Develop and showcase technology for spacecraft docking in orbit.
• Controllability in Docked Condition: Prove that the docked spacecraft can be controlled effectively.
• Test Power Transfer: Experiment with transferring power between the docked satellites.
• Independent Payload Operations: Conduct independent operations with the spacecraft after docking.

What is Space Docking?

Space docking is the process of connecting two spacecraft while they are in orbit. It involves bringing two objects in space, often with extremely high velocities, into proximity so they can physically link together and form a single unit. This technology is vital for space activities, including satellite servicing, space station operations, and deep space missions.

Docking is a complex procedure that requires precise navigation, control, and communication between the spacecraft. It is carried out in two stages: rendezvous and docking.

1. In the rendezvous phase, two spacecraft approach each other from different orbits or altitudes.
2. During the docking phase, one spacecraft (the “chaser”) physically attaches to another (the “target”), often using docking mechanisms that lock them together.

Docking Process for SPADEX

In the SPADEX mission, two small and identical satellites, SDX01 (the “Chaser”) and SDX02 (the “Target”), will be launched into low Earth orbit about 470 kilometers above our planet. Each satellite weighs around 220 kilograms and travels at an impressive speed of 28,800 km/h. To successfully dock in space, they will need to slow down their relative speed to just 0.036 km/h.

ISRO engineers will use advanced onboard systems to carefully guide the satellites into position for docking. The process will rely on the Bharatiya Docking System, which is specially designed to securely connect the two satellites, even in the challenging environment of space.

Future Mission Benefits from SPADEX

• The technology will aid interplanetary missions for refueling and crew exchanges.
• SPADEX will enable future missions that require docking technologies.
• ISRO can extend satellite lifespans through servicing missions.
• It will support the operation of space stations like the Bharatiya Antriksh Station.

Conclusion

The SPADEX mission is a major achievement for India in space docking technology. With an investment of 320-330 crores, it places India among the top spacefaring nations and opens the door for future space exploration. As ISRO plans for the future, SPADEX will be important for new missions and working with other countries in space. By mastering docking technology, India is preparing to lead in the next phase of space exploration.