'Exciting handshake': Two satellites launched by ISRO for space docking close in to 3 metres in trial attempt

The Indian Space Research Organisation (ISRO) on Sunday said the two satellites launched for the space docking experiment came just three metres in a trial attempt for an "exciting handshake". The space docking mission, SpaDeX, will see the Chaser satellite approach and dock with a Target satellite while both fly about 70 kilometres above Earth.

The statement by ISRO said the two satellites are in good condition. "A trial attempt to reach up to 15 m and further to 3 m is done. Moving back spacecrafts to safe distance The docking process will be done after analysing data further," the latest update from the space agency said.

The trial began on Friday evening when the satellites were separated by 1.5 km and by Saturday morning, the distance was reduced to 500 m. By evening, the satellites were separated by a distance of 230 m and on Sunday morning, it came further close at 15 metres and then 3 metres.

The mission was launched on December 30 as the PSLV C60 rocket carrying the two 220-kilogramme satellites lifted off from the Satish Dhawan Space Centre in Sriharikota. Though the space docking was initially planned for January 6, it was postponed twice. Postponing the January 6 demo, the ISRO said the docking process requires further validation through ground simulations based on an abort scenario identified.

Also read: India becomes 4th nation to achieve space docking as ISRO spacecraft gets injected into right orbit

Though it attempted the docking again on January 7, during the bid to initiate the drift on Chaser to move towards Target from 500 m to 225 m, the ISRO said the drift was more than expected, post non-visibility period.

The Space Docking technology is essential for space programmes like India on the Moon, sample return from the Moon, the building and operation of Bharatiya Antariksh Station (BAS) etc. One of the key goals of the SpaDeX mission is to demonstrate the transfer of electric power between the docked satellites.

A successful demonstration of the SpaDeX will make India the fourth nation to master the complex technologies that are crucial for its future missions. NASA was the first to initiate the technology when its Gemini programme successfully docked the two spacecraft in orbit in the 1960s. This paved the way for future missions to the Moon, such as the Apollo programme. NASA continues to use docking technology today with the International Space Station (ISS), where spacecraft regularly dock to deliver astronauts and supplies.

Russia, through its space agency ROSCOSMOS, also managed to do the same. Its Soyuz spacecraft docked with an American Apollo spacecraft, showcasing advanced docking technology and international collaboration.

China too successfully demonstrated the technology through its Tiangong programme when its Shenzhou VIII spacecraft successfully docked with Tiangong-1 in 2011.