spadex-mission-what-it-means-for-india

As 2024 draws to a close, the Indian Space Research Organisation (ISRO) is set to make history with the launch of its SpaDeX mission on Monday, December 30, 2024. 

Set to take place at 10 PM from Sriharikota, this landmark mission will demonstrate a technology that is crucial for India’s ambitious space goals—space docking. 

With two spacecraft weighing 200 kg each, the mission is a significant step forward, positioning India to join an exclusive club of spacefaring nations capable of conducting complex orbital operations. 

But the implications of the SpaDeX mission extend far beyond this demonstration, serving as a cornerstone for India’s future in space exploration.

The importance of space docking

Docking technology is fundamental to many advanced space operations. It involves bringing two independent spacecraft together in orbit, allowing them to join and behave as a single entity.

 

For India, mastering this process is a prerequisite for several high-profile missions, including crewed lunar expeditions, the Bharatiya Antariksha Station (BAS), and lunar sample return missions such as Chandrayaan-4.

M. Sankaran, Director of ISRO’s UR Rao Satellite Centre, explained that docking technology is essential for any crewed mission to the Moon or beyond.

Without it, sending humans and equipment to the Moon or other distant destinations would be impossible. SpaDeX is India’s attempt to master this technology, with the goal of becoming the fourth country in the world to achieve successful space docking after Russia, the United States, and China.

How the mission works

The SpaDeX mission will use two spacecraft—Chaser and Target—launched into the same orbit by the Polar Satellite Launch Vehicle (PSLV). Initially, the spacecraft will be positioned several kilometers apart.

 

Over the next 10-15 days, ISRO will use its precise technology to gradually reduce the distance between the two, eventually bringing them to within 5 metres of each other before docking.

According to Sankaran, the process will involve adjusting the relative velocity between the two spacecraft to keep them at the right distance. By controlling this velocity, the distance can be adjusted to bring the spacecraft closer, allowing them to dock successfully. 

This precision maneuvering in low-Earth orbit will demonstrate India’s capabilities in performing space docking, a feat that has previously been mastered by only three other nations.

🎉 Launch Day is Here! 🚀

Tonight at precisely 10:00:15 PM, PSLV-C60 with SpaDeX and innovative payloads are set for liftoff.

SpaDeX (Space Docking Experiment) is a pioneering mission to establish India's capability in orbital docking, a key technology for future human… pic.twitter.com/147ywcLP0f

— ISRO (@isro) December 30, 2024

 

A step for India’s space ambitions

Beyond the immediate goal of demonstrating docking, the SpaDeX mission is critical for India’s broader space agenda. As Dr S. Somanath, ISRO’s Chairman, noted, docking technology is integral to future missions like Chandrayaan-4, which will require autonomous docking capabilities for lunar exploration. 

SpaDeX will provide the confidence and data needed to refine this technology for use in more challenging missions, such as the Chandrayaan-4 mission, where docking will need to occur in elliptical orbits—far more complex than the circular orbits used in SpaDeX.

Further, India’s goal of building its own space station—the Bharatiya Antariksha Station (BAS)—depends on mastering docking technology.

 

The BAS will consist of multiple modules that need to be launched independently and docked together to form a cohesive station. Docking will also be critical for crew transportation to the station and for supplying the station with necessary resources.

Economic efficiency and innovation

One of the defining features of ISRO’s missions is their cost-efficiency, and SpaDeX is no exception. The total cost of the mission is Rs 125 crore for the development of the two spacecraft and related instruments, with an additional Rs 250 crore for the launch vehicle. 

Despite this relatively low cost, the SpaDeX mission has the potential to yield massive returns in terms of technological advancements and future mission capabilities.

The mission also showcases India’s commitment to developing Indigenous technologies. The spacecraft, docking mechanisms, and sensors involved in SpaDeX are all homegrown, with ISRO even patenting its unique docking system.

The technology developed through SpaDeX will not only benefit future missions but could also be leveraged in future collaborations with other spacefaring nations and industries.

A step towards global space leadership

The success of SpaDeX will position India as a major player in space exploration, not just as a satellite-launching powerhouse but as a nation capable of conducting complex space operations. 

Dr Somanath noted that this mission is more than just about docking; it will also demonstrate India’s ability to execute a variety of space tasks, such as satellite repair, refueling, and debris removal—all of which are vital for the future of space exploration.

India’s space community is gearing up for more advanced tests, with SpaDeX seen as a stepping stone to future lunar missions. 

Docking at the Moon will involve more challenging conditions, including elliptical orbits and the need for absolute precision in docking at high speeds. 

The data from SpaDeX will be used to refine the technology for such advanced missions, including Chandrayaan-4 and potential human missions to the Moon.

Challenges

Achieving precise docking in space is no easy feat. As Dr Somanath explained, the spacecraft involved in the docking process will be moving at speeds of 7,800 meters per second, and their relative velocity must be reduced to just centimetres per second to prevent collisions. 

In the vacuum of space, where there is no gravity to simulate the conditions of Earth, this required ISRO to develop highly innovative hardware and robotic test setups.

The challenges of space docking are compounded by the need to ensure the safety of the spacecraft during docking and undocking. 

The docking mechanism needs to capture and hold the spacecraft firmly while aligning them with extreme precision, ensuring no damage occurs during the process. 

This level of accuracy is vital for future missions, especially those involving human life or highly sensitive equipment.

While the SpaDeX mission will be a landmark achievement for India, it represents just one part of a larger space exploration vision.

As ISRO continues to push the boundaries of what is possible in space, SpaDeX is considered vital in providing the foundation for many future missions, including those involving human spaceflight and also the establishment of an Indian space station.