Prime Minister Narendra Modi addresses during the News9 Global Summit, in New Delhi, Monday, Feb. 26, 2024.
| Photo Credit: PTI

Prime Minister Narendra Modi on Thursday (January 16, 2025) congratulated scientists and engineers at ISRO on the successful docking of two satellites in space.

“Congratulations to our scientists at @isro and the entire space fraternity for the successful demonstration of space docking of satellites. It is a significant stepping stone for India’s ambitious space missions in the years to come,” Mr. Modi said in a post on X.

Space agency Indian Space Research Organisation (ISRO) successfully performed the docking of satellites as part of the Space Docking Experiment (SpaDeX), a crucial step towards several future missions, including setting up of the Bharatiya Antariksh Station.

The two satellites SDX01 (Chaser) and SDX02 (Target) which were launched by the PSLV C60 on December 30, 2024, successfully docked as the space agency officials from the Mission Operations Complex (MOX) at ISRO Telemetry, Tracking, and Command Network (ISTRAC) oversaw the complex docking procedure.

According to ISRO, the SpaDeX mission is a cost-effective technology demonstrator mission for the demonstration of in-space docking using two small spacecraft that was launched by PSLV.

In space, docking technology is essential when multiple rocket launches are required to achieve common mission objectives.

(with inputs from PTI)

New Delhi:

Indian Space Research Organisation, the Indian space agency, succeeded in docking or mating two Indian satellites in space Thursday morning. This is part of the Space Docking Experiment or SpaDeX. This was the fourth attempt when Indian scientists finally hit Bullseye.

At about 10 am ISRO announced Docking Success. “Spacecraft docking successfully completed! A historic moment. Let’s walk through the SpaDeX docking process: Manoeuvre from 15m to 3m hold point completed. Docking initiated with precision, leading to successful spacecraft capture. Retraction completed smoothly, followed by rigidisation for stability. Docking successfully completed. India became the 4th country to achieve successful Space Docking. Congratulations to the entire team! Congratulations to India!”

SpaDeX Docking Update:

Docking Success

Spacecraft docking successfully completed! A historic moment.

Let’s walk through the SpaDeX docking process:

Manoeuvre from 15m to 3m hold point completed. Docking initiated with precision, leading to successful spacecraft capture.…

— ISRO (@isro) January 16, 2025

Docking is a very complex process and ISRO attempted it cautiously doing several trials over a fortnight.

India used the indigenously developed Bhartiya Docking System to achieve this feat just before docking the satellites moved closer to each other at a speed of 10 millimeters per second.

ISRO succeeds in docking two Indian satellites in space orbiting at 475 kilometers above Earth. India becomes the fourth country after Russia, USA and China to have successfully learnt to dock. India launched the SpaDeX mission on December 30, 2024 using the PSLV rocket. Docking is an enabling technology for future missions like Chandrayaan-4 and Bhartiya Antariksha station.

On January 12, 2025, when the last attempt was made, the satellites were moved back and forth to achieve what ISRO had described as an “exciting handshake” of the two satellites in space.

Then two Indian satellites came as close as three metres in a trial attempt for space docking and are now moving back, the Indian space agency said this morning.

“A trial attempt to reach up to 15 m and further to 3 m is done. Moving back space crafts to a safe distance. The docking process will be done after analysing data further,” the Indian Space Research Organisation (ISRO) said in its last update of January 12, on the Space Docking Experiment (SpaDeX) mission.

Docking is a very complex process with the satellites being moved back and forth to achieve what ISRO has described as an “exciting handshake” of the two satellites in space.

The SpaDeX mission was launched on December 30 with the satellites, SDX01 (Chaser) and SDX02 (Target), being lifted off onboard a PSLV C60 rocket and placed into a 475-kilometre circular orbit.

Prime Minister Narendra Modi took to social media X (formerly Twitter) and congraulated scientists at ISRO and the entire space fraternity for the successful demonstration of space docking of satellites. “It is a significant stepping stone for India’s ambitious space missions in the years to come,” he said.

Congratulations to our scientists at @isro and the entire space fraternity for the successful demonstration of space docking of satellites. It is a significant stepping stone for India’s ambitious space missions in the years to come.

— Narendra Modi (@narendramodi) January 16, 2025

PSLV C60 rocket was launched on December 30, 2024, carrying two small satellites, SDX01 (Chaser) and SDX02 (Target). Photo: www.isro.gov.in

The docking of the two Space Docking Experiment (SpaDeX) satellites scheduled for January 7 has been postponed to January 9.

“The SpaDeX Docking scheduled on 7th is now postponed to 9th. The docking process requires further validation through ground simulations based on an abort scenario identified today. Stay tuned for updates,” the ISRO said in a post on Monday (January 6, 2025).

The ISRO was scheduled to carry out the docking experiment of the two small satellites, SDX01 (Chaser) and SDX02 (Target) in the early morning of January 7.

Following the launch of the PSLV C60 rocket carrying two small satellites, SDX01 (Chaser) and SDX02 (Target) on December 30, 2024, ISRO Chairman S. Somanth had announced that the docking process could happen in another week. “The nominal time will be approximately January 7,” Mr. Somanth said.

The postponement of the docking experiment by two days is not a cause of concern if the experiment is executed within the window that lasts till January 10.

After the satellite launch, U.R. Rao Satellite Centre Director M. Sanakaran said the docking is expected between January 7 and 10.

With the SpaDeX mission, the ISRO aims to exhibit technologies needed for spacecraft rendezvous, docking, and undocking using two small satellites which have been mastered by only an elite group of spacefaring nations.

The demonstration of this technology is essential for futuristic missions such as sending an Indian astronaut on the Moon, sample return from the Moon, the building and operation of the Indian Space Station.

New Delhi:

ISRO ended 2024 on a high with the successful launch of its 99th mission – the Polar Satellite Launch Vehicle or PSLV-C60 – which has two significant experimental missions – SpaDex and POEM-4. Even as these experiments continue into the new year, the Indian space agency looks to ride the high wave and has made a big announcement.

Indian space agency chairman S Somanath declared that 2025’s first mission will be ISRO’s landmark 100th mission. It will be in January, he confirmed, but did not reveal the date it is being planned.

He however mentioned that the 100th mission will on-board the Geosynchronous Satellite Launch Vehicle or GSLV Mk-II rocket. The mission will be to add to the Indian satellite navigation system being set up and expanded over time by ISRO. The mission will be titled the GSLV-F15/NVS-02 Mission. The payload will be the IRNSS-1K satellite, part of India’s navigation satellite constellation.

NVS or Navigation Satellite is part of the Navigation with Indian Constellation or NavIC – India’s version of a Global Navigation Satellite Systems or GNSS – similar to the Global Positioning System or GPS often used worldwide.

ALSO READ: ISRO’s SpaDeX Mission A First Step For India To Set Up Its Own Space Station

THE GSLV-F15/NVS-02 MISSION AND ITS OBJECTIVES

GSLV-F15 will be the 17th flight of India’s Geosynchronous Satellite Launch Vehicle or GSLV. It will also be the 8th operational flight of the GSLV (11th overall flight) with India’s indigenous Cryogenic stage.

The key objectives of the mission under the NavIC system will be to aid:

• Precision military activity
• Strategic applications
• Terrestrial, aerial, and maritime navigation
• Precision agriculture
• Geodetic surveying
• Emergency services
• Fleet management
• Location-based services in mobile devices
• Orbit determination for satellites
• Marine fisheries
• Timing services for financial institutions, power grids, and other government agencies
• Internet-of-Things (IoT) based applications

ALL ABOUT THE NVS-02 / IRNSS-1K SATELLITE

NVS-02, as the name suggests, will be the second in the series of 2nd-generation navigation satellites and the ninth satellite in the Navigation with Indian Constellation (NavIC). Just like its predecessor – NVS-01 – the NVS-02 will most likely have two kinds of payloads – navigation payload and ranging payload.

Image Credit: ISRO

The navigational payload is what transmits signals to users on Earth. It does so using three bands in the spectrum – L1, L5, and S band. Since time is relative, and many factors affect it, to have the precise time, an atomic clock is on-board this payload. It is usually a Rubidium atomic clock. A rubidium atomic clock measures the length of one second by counting the oscillations of rubidium-87 atoms. These clocks are so powerful that they have an accuracy of about three parts in 10 quadrillion, which means they can keep time within one second over 100 million years.

The ranging payload consists of a transponder. This helps the navigation satellite transmit time-stamped navigation signals to the receivers at the ground station. This information is then processed at the end-user stage to derive their exact position, speed, and time. This helps in providing seamless and non-stop service irrespective of weather conditions on Earth.

The 2nd-generation satellites in NavIC have a much more robust encryption system to keep all communications completely secure.

As in the case of US’ GPS, India’s NavIC also has dual use – civilian and military. NavIC was earlier named IRNSS or Indian Regional Navigation Satellite System, which had a much more limited coverage area.

Currently there are four global navigation systems – GPS from USA, GLONASS from Russia, Galileo from European Union, and BeiDou from China. India’s NavIC and Japan’s QZSS are still only regional, but may be global in the future.

The last GSLV mission was the GSLV-F14/INSAT-3DS Mission, which was launched on February 17, 2024. It placed the INSAT-3DS satellite payload into a GTO or Geosynchronous Transfer Orbit. The last GSLV mission used for NavIC was in May 2023, when ISRO launched NVS-02’s predecessor NVS-01. The mission was titled GSLV-F12/NVS-01 Mission.
 

New Delhi:

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 achieving that feat as ISRO’s last mission of 2024 – named SpaDeX – lift-off from Andhra Pradesh’s Sriharikota at 2200 hrs (10 pm) IST.

SpaDex is short for Space Docking Experiment. This involves an experimental docking, subsequent interlocking and pressure checks, and undocking of two satellites. The mission is important for ISRO’s future moon missions, including Chandrayaan 4. It is also particularly important for India’s plan to set up its own space station.

In October this year, the government had announced that India will have its own Space Station called the Bharatiya Antriksh Station by 2035.

ISRO’s PSLV-C60 carrying SpaDeX and its payloads, lifts off from the first launch pad at Satish Dhawan Space Centre, in Sriharikota

So far, there are two other space stations – the International Space Station, built by the United States (NASA) and Russia (Roscosmos). The US side of the ISS is built by NASA and European Space Agency or ESA. The second space station is being built by China, and is called the Tiangong Space Station. India aims to set up the third.

Every time astronauts or cosmonauts are sent to space, especially the International Space Station, the shuttle or capsule they travel in needs to perform a docking manoeuvre. Only after the docking procedure is complete, and the two objects are securely interlocked, can the astronauts get into the pressurised cabin of the space station.

ISRO’S DOCKING EXPERIMENT EXPLAINED WITH THE HELP OF ‘INTERSTELLAR’

Docking in space is one of the most difficult and complicated procedures – the slightest of errors can lead to a 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 has 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 lift-off at 2200 hrs (10 pm) IST on December 30 from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.

ISRO’s launch was onboard the workhorse PSLV-C60 rocket, which put the two spacecraft in low-Earth orbit, roughly 475 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 will first carry out several other experiments under the POEM-4 mission – a parallel mission to SpaDex (explained below).

The scientists sitting at ISRO’s mission control in Bengaluru are expected to initiate the intricate and precise docking and undocking manoeuvre in the later half of the first week of January. If successful, India will create history by becoming only the fourth nation in the world to possess such technological ability.

According to ISRO, the main objectives of the SpaDeX mission 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.

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

HOW THE INTERNATIONAL SPACE STATION WAS BUILT

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:

ISRO’S POEM-4 MISSION – AND 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 are part of the 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.
 

New Delhi:

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 achieving that feat as ISRO’s last mission of 2024 – named SpaDeX – lift-off from Andhra Pradesh’s Sriharikota at 2200 hrs (10 pm) IST.

SpaDex is short for Space Docking Experiment. This involves an experimental docking, subsequent interlocking and pressure checks, and undocking of two satellites. The mission is important for ISRO’s future moon missions, including Chandrayaan 4. It is also particularly important for India’s plan to set up its own space station.

In October this year, the government had announced that India will have its own Space Station called the Bharatiya Antriksh Station by 2035.

ISRO’s PSLV-C60 carrying SpaDeX and its payloads, lifts off from the first launch pad at Satish Dhawan Space Centre, in Sriharikota

So far, there are two other space stations – the International Space Station, built by the United States (NASA) and Russia (Roscosmos). The US side of the ISS is built by NASA and European Space Agency or ESA. The second space station is being built by China, and is called the Tiangong Space Station. India aims to set up the third.

Every time astronauts or cosmonauts are sent to space, especially the International Space Station, the shuttle or capsule they travel in needs to perform a docking manoeuvre. Only after the docking procedure is complete, and the two objects are securely interlocked, can the astronauts get into the pressurised cabin of the space station.

ISRO’S DOCKING EXPERIMENT EXPLAINED WITH THE HELP OF ‘INTERSTELLAR’

Docking in space is one of the most difficult and complicated procedures – the slightest of errors can lead to a 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 has 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 lift-off at 2200 hrs (10 pm) IST on December 30 from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.

ISRO’s launch was onboard the workhorse PSLV-C60 rocket, which put the two spacecraft in low-Earth orbit, roughly 475 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 will first carry out several other experiments under the POEM-4 mission – a parallel mission to SpaDex (explained below).

The scientists sitting at ISRO’s mission control in Bengaluru are expected to initiate the intricate and precise docking and undocking manoeuvre in the later half of the first week of January. If successful, India will create history by becoming only the fourth nation in the world to possess such technological ability.

According to ISRO, the main objectives of the SpaDeX mission 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.

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

HOW THE INTERNATIONAL SPACE STATION WAS BUILT

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:

ISRO’S POEM-4 MISSION – AND 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 are part of the 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.
 

New Delhi:

There is a traffic jam in space! It has forced the Indian Space Research Organisation (ISRO) to postpone the launch of the Polar Satellite Launch Vehicle (PSLV) by two minutes. Earlier, the PSLV-C60 that would launch the SpaDeX mission or the Space Docking Experiment was to be launched at 9.58 pm, but now it has been pushed to 10 pm.

The launch has been postponed due to “conjunctions with other satellites in the same orbit”, Dr S Somanath, Chairman of ISRO, told NDTV.

This is not the first time ISRO has had to reschedule its launch due to congestion in the orbit and flight path of the rocket.

Experts at ISRO found that some satellites from the Starlink constellation were coming in the way. Today, there are about 7,000 Starlink satellites in the low Earth orbit. This is a constellation owned by American billionaire Elon Musk and his company SpaceX. Starlink provides satellite-based broadband internet connectivity across the world. Ultimately, the total number of Starlink satellites is expected to go up to about 12,000.

Also Read | ‘SpaDeX’ Mission: How ISRO Will Dock Two Satellites In Space

For long, scientists and engineers from many space agencies have been complaining that these massive constellations will cause traffic jams in space. On top of that, there is the presence of space debris in copious amounts that also poses a huge risk to satellites.

In 2023, India had to postpone the launch of its Chandrayaan-3 mission by a few minutes almost for the same reasons.

The SpaDeX Mission

The PSLV C-60 mission has innovation written all over it, with the rocket and the satellites integrated and tested for the very first time at a private entity, Ananth Technologies. At the Satish Dhawan Space Center, Sriharikota, the rocket was also assembled in a new facility. Further, the space docking experiment is a big bold innovative step that will pave the way for its use in futuristic missions like Chandrayaan-4 and the making of the Bhartiya Antariksha Station.

In addition, the fourth stage of the PSLV which usually turns into space debris has been converted into an active un-crewed space laboratory. The last stage of the rocket has been re-purposed to become an orbital laboratory and from robotic experiments to growing cowpea seeds to testing green rocket fuel all will be tested on the PS4-Orbital Experiment Module, designated as POEM. It is carrying 24 experiments in space including taking three live biology experiments for the very first time by India.

India’s space program is set to achieve another milestone with the Space Docking Experiment (SpaDeX) on its 62nd Polar Satellite Launch Vehicle (PSLV) mission. ISRO will attempt the docking and undocking of two satellites in orbit, a feat mastered only by Russia, the United States, and China.

This landmark mission, described as a “bold step” by ISRO Chairman Dr S Somanath, will use indigenous technology.

“When you have multiple objects in space that need to be brought together for a specific purpose, a mechanism called docking is required. Docking is the process by which two space objects come together and connect. This can be done using various approaches: soft mechanisms, hard mechanisms, or pressurized compartments for human transfer. For example, on the International Space Station, crew modules dock at the station, equalize pressure, and transfer people,” Dr Somanath told NDTV.

This capability is central to future ambitions, including India’s Bharatiya Antariksha Station (a proposed Indian space station), human spaceflight programs, and lunar sample return missions such as Chandrayaan-4.

During docking, there is a “target” object and a “chaser” object. The chaser follows the target, comes into proximity, and establishes a connection.

With the SpaDeX mission, India aims to join the exclusive club of nations capable of space docking.

“The success of this mission will position India as a major spacefaring nation, not just in launching satellites but in conducting complex space operations,” Dr Somanath said.

New Delhi:

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

US AND RUSSIA – RIVALS ON EARTH, UNITED IN SPACE

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:

ISRO’S 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.