Diplomatic concerns, faster launch: Why Isro needs a new spaceport

Prime Minister Narendra Modi on Wednesday laid the foundation stone to develop the second spaceport for India in Tamil Nadu’s Kulasekarapattinam.Â

The new proposed spaceport is over 700 kilometres away from the Indian Space Research Organisation’s (Isro) Sriharikota launch facility and is being developed to launch smaller satellites to Low Earth Orbit (LEO).Â

But why did we need a new spaceport? Before we look into it, let’s look at Isro’s current launch facility.Â

PSLV

LAUNCHING FROM SRIHARIKOTA

Since its establishment in the late 1970s, the Satish Dhawan Space Centre (SDSC) in Sriharikota has been pivotal in executing numerous launches, making it a cornerstone for India’s space missions.

Sriharikota’s location on India’s East Coast is not just a matter of geographical convenience but a strategic choice that significantly enhances the efficiency of rocket launches.Â

Its proximity to the equator is particularly advantageous. The Earth’s rotation from west to east is fastest at the equator, providing rockets launched from this location with an additional push.Â

This natural boost, courtesy of the Earth’s rotational velocity, allows for a reduction in the fuel required for the rocket to achieve orbit. Consequently, this increases the capacity for payloads, making launches more efficient and cost-effective.

Flight profile of GSLV launching from Sriharikota. (Photo: Isro)

This feature makes Sriharikota particularly well-suited for missions targeting equatorial orbits, which are orbits aligned with the Earth’s equator. Such orbits are commonly used for communication and weather satellites, as they provide optimal coverage of the Earth’s surface.

Sriharikota’s proximity to the sea is another advantageous factor. Launching rockets over water minimises risks to populated areas in the event of malfunctions or accidents. In the event of a mishap during launch or ascent, rockets and their debris fall harmlessly into the ocean, reducing the likelihood of damage to property or harm to people on the ground.Â

Also, this helps in discarding the spent initial stages of the launch vehicles safely away from populated areas.

WHY ISRO NEEDS A NEW SPACEPORT 

As India expands its space endeavours, additional launch infrastructure becomes apparent. This is even more relevant, particularly for accommodating smaller rockets with smaller payloads (a few hundred kgs) and missions requiring polar orbits.

While Sriharikota excels at launching heavier rockets, it presents challenges for launch vehicles, such as the Polar Satellite Launch Vehicle (PSLV) and the newly inducted  Small Satellite Launch Vehicle (SSLV) designed to deploy 500 kg satellites.Â

Also, when launching rockets into polar orbits from Sriharikota, the trajectories necessitate flying over Sri Lanka, posing safety concerns.Â

The direction in which a spacecraft is launched, called the azimuth, is essential for determining its orbit. (Photo: Isro)

To address these issues, rockets execute fuel-intensive manoeuvres to diminish payload capacity for smaller rockets like SSLV. This technique, known as “dog-legging,” involves altering the rocket’s trajectory mid-flight to avoid geopolitical obstacles.

Additionally, the direction in which a spacecraft is launched, called the azimuth, is essential for determining its orbit. For example, GSLV launches at an azimuth between 104 degrees and 107 degrees, allowing it to follow a path over the Bay of Bengal.Â

On the other hand, PSLV launches at an azimuth of 140 degrees or more for polar satellites, requiring a slight change in direction to avoid flying over Sri Lanka.

PSLV

With Kulasekarapattinam as India’s second spaceport, these challenges are set to be addressed. The strategic selection of this location leverages the rotational direction of Earth, facilitating more fuel-efficient launches.Â

Additionally, its coastal positioning minimises the risk of launch vehicle debris impacting inhabited areas, thus enhancing safety protocols.

This development is not merely an expansion of India’s capacity for space launches but also a pivotal move towards capturing a larger share of the global spacecraft launch market.Â

(This is an authored article by Manish Purohit. Manish is a solar energy and spacecraft solar panel expert with extensive experience in managing critical space missions, including Chandrayaan-2 and Mangalyaan)