India is close to taking another giant step in space technology with Indian Space Research Organisation’s SpaDeX mission, launching soon with PSLV-C60, to demonstrate in-space docking using two small spacecraft. This technology is key to future lunar missions, building Bharatiya Antariksh Station (BAS), and more.
With this mission India aims to join the elite club of nations with space docking capabilities.
On Saturday, the launch vehicle has been integrated and moved to the First Launch Pad at the Satish Dhawan Space Centre, SHAR, in Sriharikota for further integration of satellites and launch preparations, ISRO said in a social media post.
ISRO is yet to announce the launch date.
In-space docking, technology is essential when multiple rocket launches are required to achieve common mission objectives. Through this mission, India is marching towards becoming the fourth country in the world to have space docking technology.
The primary objective of the SpaDeX mission is to develop and demonstrate the technology needed for rendezvous, docking, and undocking of two small spacecraft (SDX01, which is the Chaser, and SDX02, the Target, nominally) in a low-Earth circular orbit.
Secondary objectives include demonstration of the transfer of electric power between the docked spacecraft, which is essential for future applications such as in-space robotics; composite spacecraft control and payload operations after undocking, said ISRO.
Mission Concept
The SpaDeX mission consists of two small spacecraft (about 220 kg each) to be launched by PSLV-C60, independently and simultaneously, into a 470 km circular orbit at 55 degree inclination, with a local time cycle of about 66 days.
The demonstrated precision of the PSLV vehicle will be utilised to give a small relative velocity between the Target and Chaser spacecraft at the time of separation from the launch vehicle. This incremental velocity will allow the Target spacecraft to build a 10-20 km inter-satellite separation with the Chaser within a day. At this point, the relative velocity between the Target will be compensated using the propulsion system of the Target spacecraft.
At the end of this drift arrest maneuver, the Target and Chaser will be in the same orbit with identical velocity but separated by about 20 km, known as Far Rendezvous.
After successful docking and rigidisation, 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, ISRO said.
New Technologies
The indigenous technologies developed for enabling this docking mission included docking mechanism; a suite of four rendezvous and docking sensors and power transfer technology, ISRO said.
The SpaDeX spacecraft were designed and realised by the UR Rao Satellite Centre with the support of other ISRO centres. . The full integration and testing of the satellite were carried out at Ananth Technologies, Bengaluru.
