How ISRO's Last Mission Of 2024 Would Put India In Elite Global Space Club

Only three countries in the world - United States, Russia, and China - have the ability to carry out docking of two spacecraft or satellites in outer space. India is now on the cusp of joining that elite global space club with the last mission of 2024 named SpaDeX scheduled for lift-off on December 30.

SpaDex is short for Space Docking Experiment.

Every time astronauts or cosmonauts are sent to space, especially the space station, the space shuttle they travel in needs to dock with a spacecraft or space station. Only after docking is complete and secured can the astronauts get into the pressurised space station.

Docking in space is one of the most difficult and complicated procedures - the slightest of errors can lead to a massive catastrophe - an example of which was shown in the epic sci-fi movie Interstellar - where Cooper and the crew had to navigate a near-impossible and heart-pounding docking scenario after a minuscule error by Dr Mann sends the Endurance space station into an uncontrolled spin due to a catastrophic decompression. The scene highlights a complex docking manoeuvre.

Just like in the movie, where there was a Lander spacecraft and a Courier spacecraft, ISRO's mission on December 30 will also have two spaceships - the Chaser (SDX01) and the Target (SDX02), each weighing 220 kilograms. As the names suggest, the aim of the mission will be for the chaser to chase the target while both are orbiting Earth at a high speed and dock with it expeditiously.

ALL ABOUT ISRO'S SPADEX MISSION

The SpaDex mission is scheduled for lift-off at 2158 hrs (9:58 pm) IST on December 30 from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.

ISRO's launch will be onboard the workhorse PSLV-C60 rocket, which will put the two spacecraft in low-Earth orbit, roughly 470 km above the Earth's surface. The inclination of the two spacecraft will be at 55 degrees facing the Earth. After being deployed in a circular orbit, the two spacecraft will grow apart by around 20 kilometers over 24 hours. The scientists sitting at ISRO's mission control in Bengaluru will then initiate the intricate and precise docking and undocking manoeuvre.

According to ISRO, the main objectives of the mission will include:

• To develop and demonstrate the technology needed for rendezvous, docking, and undocking of two small spacecraft.
• The 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, including remotely controlling it both in space and from mission control.
• Payload operations after undocking.

A successful docking and undocking would catapult India in the league of a select few in space technology.

This mission is crucial for India's ability to set up its own Space Station. It will also give India's RLV or Reusable Launch Vehicle - India's variant of NASA's iconic space shuttle - docking capability in future.

India's Reusable Launch Vehicle or RLV

Among other key missions, 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.

NASA's Space Shuttle (L) and Russia's Space Shuttle (R)

Here is a insightful video of how the International Space Station - the largest man-made space object - was built by the US and Russian space shuttles using the docking mechanism and robotic arms in addition to astronauts and cosmonauts:

EXPERIMENT WITH MICROGRAVITY

Besides the space docking manoeuvre, there is another key mission objective. ISRO plans to experiment with microgravity during the PSLV rocket's fourth-stage. ISRO aims to use the spent fourth stage, which it has termed POEM-4 or PSLV Orbital Experimental Module 4, as a platform for carrying our experiments with microgravity.

According to the space agency, it provides an opportunity for the scientific community to carry out certain in-orbit microgravity experiments for an extended duration of up to three months using the POEM platform, which otherwise would end up as space debris immediately after the mission objective of injecting the primary payloads of the mission.

A total of 24 payloads will be flown in this POEM-4 mission, of which 14 payloads are from ISRO/DOS centres and 10 payloads are from various Non-Government Entities (NGEs) comprising Academia and Start-ups that have been received through IN-SPACe.

One of the fourteen payloads by ISRO is of a robotic arm - again a crucial element to constructing India's own space station in future. For now the experiment will involve a robotic arm to demonstrate the capturing of tethered debris.

As India and the rest of the world prepare to 'have a blast' on New Years' Eve, Scientists at ISRO are readying themselves for the blast-off (lift-off) which will help India enter a new era in space technology.