What is SpaDeX mission?
The SpaDeX Mission is a space docking experiment mission of India’s space agency, Indian Space Organization (ISRO). Which was launched from Shree Harikota on 30 December 2024 through a PSLV-C60 rocket into low earth orbit (approximately 470 km above the Earth’s surface), through which two spacecraft, SDX01 (chaser) and SDX02 (target), were sent, and a successful docking experiment was carried out between the chaser and target spacecraft on 16 January 2025 (i.e., both spacecraft were successfully joined with each other). With this, India became the fourth country to be successful in a space docking experiment; before this, only America, Russia, and China had achieved success in space docking. India’s This is the second consecutive historic success in space. Before this, in the year 2023, ISRO had achieved historic success in the Chandrayaan-3 mission, through which the Vikram lander was successfully landed on the south pole of the moon.
How was the docking experiment conducted between chaser and target?
First, the chaser and the target were placed in low Earth orbit (LEO) at a distance of about 20 km from each other, then the chaser was moved towards the target, first 5 km, then 1.5 km, then in increments of 500 m, 225 m, 15 m, and 3 m, it was brought closer to the target, and then the docking experiment was conducted. This experiment was not easy. First, this experiment was to be conducted on 7 January, but it was postponed due to technical problems. The next date was 9 January, but it was again postponed due to some technical problems in docking. After this, the next date was 12 January, when both the spacecraft were brought close to 3 m, and then they were carefully taken away from each other. Then came that exciting day of January 16 when the docking experiment was successfully conducted. With this, India became the fourth country to achieve success in space docking.
Mission Objective
The primary objective of the Spadex mission was to deploy two spacecraft (chaser and target) into the lower orbit of the Earth and conduct a docking experiment between the both spacecraft.
secondary objective:
- Demonstration of the transfer of electric power between the docked spacecraft, which is essential for future applications such as in-space robotics,
- Demonstrate the potential for extending the life of the target spacecraft
- Composite spacecraft control and Payload operations after undocking
Spadex’s spacecraft Chaser and Target
Both spacecraft, SDX-01, which is the chaser, and SDX-02, which is the target, weigh around 200 kilograms each. Both spacecraft carry a differential Global Navigation Satellite Systems GNSS-based satellite positioning system (SPS), like all ISRO satellites in low Earth orbit, which provides a PNT (Position, Navigation, and Timing) solution for the satellites. In SpaDeX, a novel RODP processor is included in the SPS receiver, which allows accurate determination of the relative position and velocity of the chaser and the target. By subtracting the carrier phase measurements from the same GNSS satellites in both Chaser and Target SPS receivers, highly accurate relative states of the two satellites are determined. These spacecrafts are androgynous in nature, i.e. either of the spacecraft can act as chaser (active spacecraft) during docking. They are equipped with solar panels, lithium-ion batteries, and a robust power management system. The Attitude and Orbit Control System (AOCS) includes sensors such as star sensors, sun sensors, magnetometers, and actuators like reaction wheels, magnetic torquers, and thrusters.
- A High-Resolution Camera (HRC) with a 4.5 m IGFOV and a swath of 9.2 x 9.2 km (snapshot mode) and 9.2 x 4.6 km (video mode) from a 450 km altitude is mounted in SDX01.
- A Miniature Multi-Spectral Payload (MMX) is mounted in SDX02. This has four VNIR bands (B1/B2/B3/B4) at 450 nm to 860 nm and a 25 m IGFOV with a swath of 100 km from a 450 km altitude. The imaging is useful for natural resource monitoring and vegetation studies.
The spacecraft are also carrying scientific instruments which will then be deployed. Over the next two years, they will measure radiation in space and monitor natural resources on Earth
What does the success of the SpaDeX mission mean?
Now with the success of the SpaDeX mission, India will be able to launch its fourth lunar mission, Chandrayaan-4, which is a mission to bring samples from the moon.
India will now be able to build its own space station in space, for which many modules from earth will be taken into space and joined together, for this the space docking system will be very useful.
SpaDeX will also be very helpful in India’s Gaganyaan mission, in which an Indian astronaut will be sent to space.
The docking system will also be very useful in India’s mission to send astronauts to the moon in 2040.
Some important facts about SpaDex Mission
- The mission was launched by PSLV-C60 on 30 December 2024 from the Satish Dhawan Space Center in Sriharikota.
- Under the mission, two spacecraft SDX01 or Chaser and SDX02 or Target were launched, each weighing approximately 220 kg. The docking experiment was successfully conducted on 16 January 2025.
- Both spacecraft were launched into low Earth orbit, approximately 470 km above the Earth’s surface, and deployed at a distance of about 20 km from each other.
- After separation, the payloads on both spacecraft will remain operational for two years.
- Docking experiment was successfully conducted on 16 January 2025.
Conclusion
The success of Spadex is a historic moment for India, this success shows how fast India is moving forward in the field of space, this is a stepping stone for India, ISRO has given an opportunity to India to be proud, Every Indian is proud of ISRO.
