Chandrayaan-3 mission: How Sriharikota became Isro’s ideal launchpad

Subject: Geography

Section: Places in news

Context:

India’s third lunar mission and second attempt to soft-land on the Moon, the Chandrayaan-3, took off on Friday at 2:35 pm from the Satish Dhawan Space Center (SDSC) in Sriharikota.

There are three major rocket launch sites in India:

Satish Dhawan Space Centre (SDSC), Sriharikota:

Sriharikota is a spindle-shaped island on the east coast of Andhra Pradesh.
The SDSC is the country’s only spaceport from where spacecraft and satellites are launched.
It became operational on October 9, 1971, with the flight of ‘Rohini-125’, a small-sounding rocket, and was initially known as SHAR (Sriharikota Range).
But in September 2002, the space centre was renamed Satish Dhawan Space Centre SHAR to honour mathematician and former ISRO’s Chairman Satish Dhawan.

How was Sriharikota selected as the launch site?

The search for a launch site began in 1960s when Vikram Sarabhai and EV Chitnis started looking for a launch site on the east coast of the country.
In March 1968, Chitnis contacted then Director of Industry of Andhra Pradesh, Abid Hussain, who helped him acquire information and prepare maps for potential sites, including Sriharikota.

Why was Sriharikota chosen?

There were two primary reasons for selecting Sriharikota as the launch site.
- One, it is on the east coast which facilitates the launching of the rockets in an easterly direction.
- Two, its proximity to the equator.
By launching a rocket eastwards, one can take advantage of Earth’s rotation.
For a launch site close to the equator the magnitude of the velocity imparted due to Earth’s rotation is about 450 m/s, which can lead to a substantial increase in the payload for a given launch vehicle.
Geostationary satellites must necessarily be in the equatorial plane.
So, for such satellites, the closer the launch site is to the equator the better it is.
There were other considerations also, such as it was a largely uninhabited area and closer to the sea.
This helped ensure that the flight path of launch vehicles or rockets is entirely over the sea, so that impact of separated rocket hardware can take place on the high seas without any constraints.

Vikram Sarabhai Space Centre or Thumba:

Thumba Equatorial Rocket Launching Station (TERLS) is an Indian spaceport established on 21 November 1963.
Operated by the Indian Space Research Organisation (ISRO), it is located in Thumba, Thiruvananthapuram, Kerala, which is near the southern tip of mainland India, very close to Earth’s magnetic equator.
It is currently used by ISRO for launching sounding rockets.

Abdul Kalam Island:

Formerly known as Wheeler Island, Dr Abdul Kalam Island is an island located in the coastal outskirts of Odisha, India, which hosts the Integrated Test Range missile testing facility.
It is operated by the Defence Research and Development Organization (DRDO) and is host to most of the military missile testing in India.
Its main purpose is to make an advancement in the development of launch vehicle technology in India.

Search for a new launchpad:

ISRO is considering a second launchpad in Kulasekarapattinam, a town in the Thoothukudi (Tuticorin) district of Tamil Nadu
Why?
- Proximity to the seashore makes Thoothukudi ideal for “straight southward” launches. From Sriharikota, such southward-bound launches are not possible as the rockets have to fly around Sri Lanka.
- Nearness to the equator: Like the Sriharikota spaceport in the Satish Dhawan Space Centre, Thoothukudi was selected as a spaceport due to its nearness to the equator. A rocket launch site should be on the east coast and near the equator.
- Logistical ease: ISRO has its Liquid Propulsion Systems Centre (LPSC) at Mahendragiri in Tirunelveli district, where it assembles the second and fourth-stage engines for the PSLV. Instead of transporting the second and fourth stages to Sriharikota from Mahendragiri, it would be easier to shift them to the launch pad if it is built in Kulasekarapattinam, which is around 100 km away.

Who was Satish Dhawan?

Born in Srinagar, Dhawan was an Indian rocket scientist, known as the ‘Father of Experimental Fluid Dynamics research’ in India.
He is also one of the foremost researchers in the field of turbulence and boundary layers.
In 1972, Dhawan succeeded Vikram Sarabhai as the Chairman of ISRO.
In the decade following his appointment, he directed the Indian space programme through a period of extraordinary growth and spectacular achievement.
His efforts led to operational systems like INSAT- a telecommunications satellite, IRS – the Indian Remote Sensing satellite and the Polar Satellite Launch Vehicle (PSLV) that placed India in the league of space-faring nations.
It was after his death in 2002 that the space centre in Sriharikota was renamed the Satish Dhawan Space Center to honour his legacy.