ISRO gears up for SpaDEX launch: All you need to know

The Indian Space Research Organisation (ISRO) is on the cusp of a significant achievement with its SpaDeX mission, scheduled for launch on Monday, December 30. The mission’s objective is to accomplish a notable space docking feat, a challenge that has only been conquered by the US, Russia, and China to date. The Space Docking Experiment (SpaDeX) mission will ascend aboard the PSLV-C60 rocket at exactly 10:00:15 PM from Sriharikota.

The SpaDeX mission is an initiative to establish India’s proficiency in orbital docking, a crucial technology for future human spaceflight and satellite servicing missions. The PSLV will launch two small spacecraft — SDX01, the Chaser, and SDX02, the Target — each weighing approximately 220 kg. These satellites will unite or connect for docking in a low-Earth circular orbit.

The indigenous technology employed for this mission has been christened the ‘Bharatiya Docking System’. It encompasses a docking mechanism, a suite of four rendezvous and docking sensors, power transfer technology, indigenous novel autonomous rendezvous and docking strategy, and an inter-satellite communication link (ISL) for autonomous communication between spacecraft, integrated with inbuilt intelligence to comprehend the states of the other spacecraft, among others.

Mastering the space docking technology may not only catapult India into the elite club of spacefaring nations. It is also pivotal for India’s forthcoming space missions including the Moon mission, establishing the Indian space station, and lunar missions like Chandrayaan-4 without the support of GNSS from Earth.

According to ISRO, it will also demonstrate “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”.

The ISRO mission is a critical stride towards achieving several future objectives — retrieving a lunar sample, setting up a space station, and sending a human to the Moon. The International Space Station (ISS) for instance, comprises various modules that were launched separately and then assembled in space. The ISS is maintained operational as modules carrying astronauts and supplies from Earth periodically dock with it; these modules also bring the older crew on the station back to Earth.

The SDX01 satellite is equipped with a High Resolution Camera (HRC), while SDX02 carries two payloads: a Miniature Multispectral (MMX) payload and a Radiation Monitor (RadMon).

The fourth stage of the launch vehicle will carry several innovative experiments, including a biological experiment for the very first time. The fourth stage of the launch vehicle will be utilized as POEM — or PS4 Orbital Experiment Module — to demonstrate 24 technologies, including 10 technologies from start-ups and educational institutions.

For the first time, an ISRO mission will carry a biological experiment. The CROPS (Compact Research Module for Orbital Plant Studies) experiment will observe the germination of seed and sustenance of a plant up to a two-leaf stage. Other experiments include a Debris capture Robotic Arm that will use a visual feed and object motion prediction to capture debris, and another moveable robotic arm that may be used in servicing satellites in space in the future.

Composite spacecraft control, including remotely controlling it both in space and from mission control, is another key mission.NASA’s space shuttle was used by the United States to construct the US side of the International Space Station. Russia too used their own space shuttle to build the Russian side of the International Space Station. While NASA had a series of space shuttles, starting with Columbia and evolving into Challenger, Discovery, Atlantis, and Endeavour, Russian space agency Roscosmos named their space shuttle Buran.

“The launch vehicle has been integrated and now moved to the First Launch Pad, for further integration of satellites and launch preparations,” ISRO said in a post on X.