The Indian Space Research Organizaon (ISRO) has achieved its groundbreaking feat of successfully docking the twin satellites. Spadex mission was launched on 30th December 2024 which was the last of ISRO in the bygone year. The historic moment comes days after the launch of the mission. Notably, India is the fourth country to achieve this milestone joining the elite club of countries USA, Russia and China. But what is the Space-Docking technology, what is the big deal about it and why the world is all up for it? The answers to these questions are answered in the details below:

What is Space docking technology?

Space docking is a complex process of joining two separate aircrafts in the space, a rendezvous. The docking is a success when the spacecrafts find one another and the two of them have to be in the same orbit, that’s when the Chaser starts to approach the Target. It is followed by berthing, which is a mating operation in which the passive module or vehicle is placed in the mating interface of another space vehicle by using a robotic arm. Space docking was first developed by USA for its Project Gemini in 1966 which was successful in the third attempt.

ISRO's historic achievement

The Spadex mission (Space docking experiment) had two small aircrafts that weighed about 220kg each. The twin satellites were launched independently and at the same time by PSLV- C60 into a 470 km circular orbit inclined at 55 degrees. The Chaser SDX01 and the Target SDX02 were travelling in the space at a decidedly chosen speed. At the time of separation, the velocity was shifted in order to allow the spacecrafts to build a distance of 10-20 km between them. By the end on 16th January, distance between the Target and Chaser was managed to be at a distance of 15m, which was maneuvered closer until they were 3m apart. The connectors were locked together. After screwing it properly, forming an airtight passage for safely transferring material or crew, finally completing the space docking. Earlier, the docking was scheduled on 7th January 2025, which was delayed for 2 days. Finally, on Sunday the scientists could maneuver the spacecrafts closer. As per ISRO, there were indigenous technologies developed for the mission, like the docking mechanism, power transfer technology, inter-satellite communication link among others.

The big deal about space docking

Docking plays a pivotal role when it comes to space technology. That is the reason why the world is running behind it. The purpose behind is:

As per ISRO, the primary objective of Space docking is to develop and demonstrate the technology required for rendezvous, docking and undocking of spacecrafts in the low Earth orbit. It helps in:

The servicing and refueling of satellites which extends their operational lives, further helping with reduced costs and sustainability;

The technology is important for the crew transfer in spacecrafts and connectivity with the space stations. It ensures safety and effeciency in the missions involving manpower;

The interplanetary missions far beyond the Earth’s orbit require the technology for long duration missions;

Missions that involve multiuple spacecrafts to function together essentially require the docking technology. This includes assembling space stations and satellites in the space;

A test of the autonomous docking capabilities will improve the flexibility in operations to manage multiple spacecrafts in orbit. Electrical power transfer between docked spacecrafts is necessary for future robotic operations;

Payload operations carried on to demonstrate the functionality of experiments. The robotic arm designed for space applications is a part of it;

The countries are also trying to rush after it so that they can become the part of the rich elite group of countries that has only USA, Russia, China and now India. This will be a significant achievement for the countries to stand among the handful in the global space arena.

India’s comparison with the world

India’s space missions are known for being the most cost-effective, costing even less than the Hollywood sci-fi movies. As an example, India’s last before the Spadex which was the Chandrayaan 3 cost the country $75 million. Comparing to this, NASA’s Maven Mars orbiter cost $582 million. The Spadex was also carried on a tight budget only. Moreover, it is the fourth country to achieve a successful landing on the lunar surface. Again, it is the fourth country to dock the satellites into space. It is not that India is one among the superpowers of the space. But as it is going ahead in the space race, the country can surely be called as the rising space power. Further with advancing technologies, working out on international collaboraons with other nations, and developing a diversified launch platform, India can potentially be among the top elites in the outer space.

Upcoming missions of ISRO

ISRO has many upcoming missions in the pipeline starting from the year 2025 and the following years after. Some of these are:

Gaganyaan 1: The expected launch of the mission is February 2025, which is the basis for Indian Human Spaceflight Programme. NISAR in Q1 2025, followed by Gaganyaan 2 and Gaganyaan 3 in Q1 2025 and Q3 2025 respectively. The Chandrayaan 4 is a planned lunar sample-return mission of ISRO. But it will undergo in 2027-28. The other notable mission is the construction of the Bhartiya Antariksh space station which is planned between 2028-2035.

With this, we can call it for a proud moment for ISRO and India. Achieving this signicant milestone has marked ISRO in history. When USA and Russia are investing billions in their space missions, the delight for us is achieving the feat in such a cost-effective manner. Many more achievements shall come further; India is currently on Cloud 9 after reaching the space!