SOURCE ; NEW18
Last Updated:December 25, 2024, 00:07 IST
The spacecraft has been designed and built by ISRO’s UR Rao Satellite Centre in Bengaluru. The centre’s director M Sankaran spoke exclusively with CNN-News18, explaining the significance of the experiment
A successful SpaDeX demonstration will not just show the world that India has mastered the art of space docking but will also play a big role in ISRO’s future ambitious missions. Image/News18
The Indian Space Research Organisation is ending 2024 on a high with the launch of the SpaDeX Mission scheduled for December 30 at 9.58 pm from Sriharikota. It is a mission for the demonstration of in-space docking using two small spacecraft launched by PSLV. This technology is essential for India’s space ambitions, such as the lunar sample return mission, building and operating Bharatiya Antariksh Station (BAS), and a crewed mission to the moon.
The spacecraft has been designed and built by ISRO’s UR Rao Satellite Centre in Bengaluru. The centre’s director M Sankaran spoke exclusively with CNN-News18, explaining the significance of the experiment.
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With SpaDeX, India is marching towards becoming the fourth country in the world to have space docking technology. “Docking basically is making two independent objects come together and join together and behave as if they are a single object. It is important for crewed missions to the moon or other planets; it’s not possible to achieve without docking technology. Even the Saturn 5 mission, which had a capacity of 150 tonnes, couldn’t do it without docking. For India, it is even more important because we don’t want to spend like Saturn 5 which was developed with the sole purpose of going to the moon and coming back. What is the use of that vehicle after that mission? That vehicle was retired after the Apollo flights. We are not going to spend money on a very high-capacity rocket just for one or two missions. We will not have any use of that rocket for anything else,” explained Sankaran.
ISRO’s launch vehicle has half or 1/3rd the capacity of Saturn. But by having this docking capability, ISRO plans to achieve what Saturn 5 or Starship plans to do, while using a smaller launch vehicle. Launch vehicles take up a big part of the budget in any space mission.
How will space docking take place?
Two spacecraft, named Chaser and Target, will be released in the same orbit but with some distance between them. Then ISRO will attempt to dock and undock these spacecraft.
“We will allow two satellites in the same orbit to get an inter-satellite distance of 10-20 km. Then we will give relative velocity to one satellite so that both are at the same velocity and maintain the same distance between them and go like a pair together. By increasing the relative velocity, we can increase or decrease the distance respectively. In the next set of manoeuvres we will progressively reduce the distance between them. From 20 km, we will bring the distance to 10 metres and 5 metres and allow it to dock. The whole activity will happen in 10-15 days from the time of the launch,” said M Sankaran.
Importance of SpaDeX
A successful SpaDeX demonstration will not just show the world that India has mastered the art of space docking but will also play a big role in ISRO’s future ambitious missions. This mission will be a forerunner for autonomous docking needed for future lunar missions like Chandrayaan 4 without the support of GNSS from Earth. “Chandrayaan 4 has been designed in such a way that docking is an essential technology available for that. Sapdex will feed into the actual realisation of Chandrayaan 4. This demonstration will give us confidence. Docking for Chandrayaan-4 will happen in a different kind of orbit. We have developed a number of sensors, algorithms, and software that will be validated during SpaDeX and they will be updated for the requirements of Chandrayaan 4,” explained Sankaran.
India’s ambitious goal of building a space station will also be dependent on ISRO demonstrating the docking technology. “For Bharatiya Antariksh Station, different modules need to be launched independently, and they have to be docked together to become a large space station. Whether it’s the crew going to the space station or sending supplies, all of them need a craft that can dock. It is an essential requirement for all this. It’s a mission enabler for many of these future missions,” Sankaran said.
Economical but challenges galore
ISRO is known for its economical missions and for not undertaking unnecessary trial missions. The same holds true for mastering docking technology. The Indian space agency has spent around 125 crore to build the two spacecraft and related instruments and is likely to spend another 250 crore on the launch vehicle.
However, the challenge for the satellite team was building small spacecraft and managing the smaller inertia. “The biggest challenge was to do it at a small scale, both in terms of money and physical shape. We cannot spend Rs 1,000-2,000 crore. We spent Rs 125 crore on this mission, plus the launch vehicle cost. The challenge of docking using a very small spacecraft is that the inertia of the spacecraft is very small. Even a small disturbance will make the satellite move away. Low mass and low inertia mean a small force can disturb it. It’s a 200 kg satellite. If we do this successfully, it’s a cakewalk to dock with heavier craft like for BAS,” said the director.
And once again, he said, ISRO is all set to make India proud and grab the attention of the whole world. “The success of Chandrayaan 3 has made people turn back and look at ISRO and India with renewed interest. The ability of India and Indians will be once more demonstrated to the whole world,” said a confident Sankaran.
