In a sign that its SpaDex experiment involving space docking is experiencing technical issues, the Indian Space Research Organisation (Isro) has delayed an undocking manoeuvre that was scheduled soon after the successful docking on January 16.
Space docking refers to the joining of two fast-moving satellites in space.
On January 29, Isro chairman V Narayanan indicated that the space agency is still conducting a review of the undocking process and that the move could take a while. He was speaking after the launch of the NVS-02 satellite by the GSLV-F15 rocket.
Isro sources have indicated that “there are some issues with the docking experiments” and that the “undocking has not been possible yet”.
Isro had on January 16 announced the successful docking in space of two satellites it had launched on December 30 which were moving at a speed of over 28,000 kmph. The SpaDex experiment made India the fourth country in the world — after the US, Russia and China — to successfully demonstrate the capability of docking spacecraft.
“SpaDeX Docking Update: Post docking, control of two satellites as a single object is successful. Undocking and power transfer checks to follow in coming days,” ISRO had reported on its official social media handle on January 16.
Ahead of the mission’s launch, the agency had said, “After successful docking and rigidization, electrical power transfer between the two satellites will be demonstrated before undocking and separation of the two satellites to start the operation of their respective payloads for the expected mission life of up to two years.”
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On February 2, Switzerland-based s2a systems which develops and operates “systems for Space Situational Awareness” posted images on social media indicating that the SpaDex satellites are still in a docking position.
“SpaDeX A & B during today’s pass over South America, 2025-02-02, 01:19:06 UTC,” s2a systems reported on social media with visuals of the docked SpaDex satellites in space.
Replying to a query on SpaDex on January 29, Narayanan said in Sriharikota that they have to think of the money involved in such projects and utilise it to the maximum. “Now we are in the process of reviewing when to do the undocking, the power connections and when to totally separate them again and dock again. All these processes are going on. We do not want to undock and leave it,” the Isro chairman said.
“We have loaded five kg of propellant on both the satellites. The propellant is needed for docking and undocking exercises. Currently we have 60 to 70 per cent of the propellant (as of January 29) remaining in the spacecraft. There are going to be a lot of experiments in the docking, undocking, power connection exercises and it is not a one time exercise,” he said.
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“Both the satellites are currently moving as one entity and we want to study if things are going correctly and whether they can be controlled together. After complete review and freezing of the experiments that we have planned we may discuss after a month or two,” he added.
Isro sources said the agency has “not been able to undock” the satellites yet.
Space docking is considered essential technology for India’s future space ambitions such as bringing back a sample from the Moon, the plan to build its own space station, the Bharatiya Antariksh Station (BAS), and a possible human landing on the Moon.