“Expect Space Docking In Few Days, Satellites In Good Health”: ISRO Chief


New Delhi:

India’s first attempt to dock two live satellites in space has not been abandoned and the docking could actually take place in the next few days, ISRO Chairman Dr S Somanath has confirmed.

“Space crafts are at a distance of 1.5 km and on hold mode. Further drift to 500 m is planned to be achieved by tomorrow morning,” the Indian Space Research Organization or ISRO said in a statement.

The choreographed dance of satellites in space as part of India’s first Space Docking Experiment after initial hiccups is now progressing well and the ISRO is hopeful that the docking, or mating of the satellites, in space could happen soon enough.

India made two attempts for docking on January 7 and 9 but glitches in the process made scientists at the space agency abandon the attempts and many feared that India’s big experiment in the New Year, of mating two Indian space crafts in outer space flying at 470 kilometers above Earth, could well be abandoned. But now Dr Somanath has given confidence that things could well be back on track.

“The satellites are in very good health and safe and if all goes well docking will be attempted in the next few days,” Dr Somanath said  speaking to Akashvani News.

“The space docking experiment is our first attempt to try out the docking and every first attempt has its own challenges. We are learning our baby steps now, some of the attempts we did not materialize into final docking. But we have learnt all the lessons, did all the corrections and once again the satellites are coming closer. In the coming days we will decide to do the docking. We are finalizing some of the trimming maneuvers and programs that will help us to do the docking safely. We need to do many corrections and amends to do all of the planned things, also to make sure that nothing untoward happens,” Mr Somanath said, underscoring that “our satellites are in very good health and the docking will happen in a few days from now”.

On being asked if the SpaDeX mission has been a success so far, Dr Somanath added: “The success … the ultimate goal though is docking, but every step we learnt through this process is a journey and through that we learnt many things. Formation flying is another that we have, keeping them at a known distance and fly them is another critical knowledge we need since a combination of propulsion and sensors and up to this it has worked very-very well. Up to now, it is going very smoothly.”

The first attempt on January 7 was abandoned as an ‘abort scenario’ needed more simulation and then the docking scheduled for January 9 was called off as the satellites had drifted far apart’. Scientists at the ISRO are hopeful that the docking could well be attempted soon.

On December 30, ISRO’s workhorse, the Polar Satellite Launch Vehicle (PSLV), lifted off with twin 220-kg satellites for space and released in a 470-km circular orbit.

Docking is a complex maneuver perfected only by China, the US, and Russia.

ISRO’s SpaDeX mission involved two satellites separated by 20 km in a 470 km circular orbit. A chaser and target satellite move at a speed of 28,800 kmph, or 10 times the speed of a bullet, but they appear to be stationary due to zero relative velocity.

When the docking process begins, the satellites will be brought closer. The chaser will approach the target with progressively reduced inter-satellite distances of 5 km, 1.5 km, 500 m, 225 m, 15 m, and 3 m, ultimately leading to the precise docking of the two spacecraft.

When the docking happens, the chaser will move closer to the target at a speed of 10 mm per second and hold onto the target.

The system developed indigenously, is named Bhartiya Docking System. Incidentally, the ISRO has taken a patent for this technology. The mission’s success is crucial for completing future programmes such as Chandrayaan 4 and making the Bhartiya Antariksh Station and Gaganyaan.