As The Twilight Of 2024 Begins, India Plans To Shine In The Sky

Just a day remains for the sun to go down the horizon for the year 2024 and India plans to shine in the sky in an unprecedented way by launching its latest space exploration mission. Today (30th December) the Indian Space Research Organization (ISRO) will launch its ambitious SpaDeX mission with the help of PSLV (Polar Satellite Launch Vehicle) C60. The launching event is scheduled to be around 10 PM.

The SpaDeX mission is unprecedented and its success will elevate India’s position in space exploration to be the fourth country in the world to have accomplished it. SpaDeX is the short form of ‘Space Docking Experiment’ and it is a predecessor of ISRO’s attempt to build India’s space station named ‘Bharatiya Antariksh Station’ (BAS) as well as for the Chandrayaan-4 mission. 

Why SpaDeX is Ambitious?

Perhaps it is not so difficult for us to imagine, at least in 2024, how spacecraft carry satellites to orbit or how astronauts go to space. But it remains still little difficult to think of joining instruments or satellites or spacecraft together in space or replacing them with new ones. This is in simpler words docking and undocking in the space and it is essential if we think about India setting up a space station—a long-lasting station in the space where people go and carry out research. It is like a laboratory in the space.  India aims exactly this—to have its space station in the form of BAS by 2035. Moreover, Chandrayaan-4 will require two separate launches and dockings in space.

The SpaDeX mission will have PSLV C60 rockets that will carry two satellites, namely SDX01 and SDX02 dubbed as the ‘Chaser’ and the ‘Target’ respectively. Each of them weighs 220 kilograms. After the launch from Sriharikota spaceport in Andhra Pradesh, the satellites will voyage in the low earth orbit, dock and then undock. In summary, the two satellites will be docked and undocked in space. Remember, the low earth orbit spans an orbital range closest to Earth with an altitude of nearly 2000 kilometres or less. 

Both the satellites will be launched in a 470-km circular orbit. Once they are in the intended orbit, the launch vehicle will provide a small relative velocity between them. This will allow the satellites to drift away from each other.

After a distance of 10-20 km is achieved between the satellites within a day, the propulsion system on the “Target” satellite (SDX02) will be fired in order to counter the relative velocity. This will result in stopping the satellites from drifting further. at this stage, both the satellites will move with the same velocity and in the same orbit. But the distance of 20 km between them will still be maintained.

“Chaser” satellite which is the SDX01 will then begin to gradually reduce the distance between them and finally join with the Target satellite. This is the stage when the two satellites are docked. The docking will be video-graphed with a camera tilt mechanism. Once the docking is complete, the satellites will transfer electrical power between themselves. The challenge in the process is the small size of these satellites which will require greater precision. In the case of a space station or the lunar mission, bigger satellites will be docked together.

Hereafter, the satellites will undock and move into separate orbits to carry out experiments for the next two years. A high-resolution camera has been installed in the Chaser (SDX01). The Target satellite (SDX02) will have a multispectral payload (Instrument) aimed at monitoring natural resources and vegetation. In addition, it will contain a radiation monitor to study space radiation and create a database. In the fourth stage, the launch vehicle will carry out several innovative experiments, including a biological experiment for the very first time.

All eyes are now on the launch of the satellites with PSLV C60. A success today will pave the path for tomorrow to have a space station of our own like the ISS (International Space Station) of NASA (National Aeronautics and Space Administration) with collaboration with space agencies from other countries or the Tiangong Space Station of China and the Salyut 1, the first one launched by Soviet Russia in 1971. 
Hope India will shine brighter in space in the new year.