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The Union Cabinet has approved the setting up of a third launchpad at the Satish Dhawan Space Center (SDSC) in Sriharikota, Andhra Pradesh.

About the Satish Dhawan Space Center (SDSC)

It is India’s only spaceport, where spacecraft and satellites are launched.

It became operational in October 1971, with the flight of ‘Rohini-125,’ a small-sounding rocket.

Initially called SHAR (Sriharikota Range), the space center was renamed in 2002 to honor Satish Dhawan, the former ISRO Chairman.

Third launchpad at SDSC in Sriharikota

The third launchpad will support ISRO’s future plans to use the Next Generation Launch Vehicle (NGLV), which is under development. This will help ISRO become more capable and ready for upcoming space missions.

Why was Sriharikota selected as the launch site?

• East Coast Location: The east coast allows rockets to be launched eastwards, taking advantage of Earth's rotation, which increases the velocity and payload capacity of rockets.
• Proximity to the Equator: Being close to the equator enhances the efficiency of rocket launches, especially for geostationary satellites, which need to be in the equatorial plane.

What other factors made Sriharikota an ideal location?

Apart from its location, Sriharikota was largely uninhabited and near the sea, which ensured that the flight path of rockets would be over the sea, minimizing risk. Any rocket hardware that separated during the launch could safely fall into the high seas.

Who was Satish Dhawan and why is the space center named after him? 

Satish Dhawan was a renowned Indian rocket scientist, often called the 'Father of Experimental Fluid Dynamics Research' in India.

He was appointed Chairman of ISRO in 1972, and he guided significant achievements in the Indian space program, including the development of the INSAT and IRS satellites.  

Following his death in 2002, the space centre was renamed in honour of his contributions to the country's space exploration.

What is a Satellite Launch Vehicle (SLV)?

A Satellite Launch Vehicle (SLV) is a rocket-powered vehicle that transports satellites or spacecraft from Earth's surface into space.

It is designed to overcome Earth's gravitational pull and deliver payloads into various orbits, such as Low Earth Orbit (LEO) or Geostationary Orbit (GEO).

How do Launch Vehicles Work?

Launch vehicles work based on the principles of rocket propulsion, which involve action and reaction (Newton's Third Law). The vehicle’s propulsion system generates the necessary thrust to lift off the ground.

It consists of multiple stages that drop off as the vehicle ascends. These stages contain their own engines and propellants. The payload is protected by a fairing during launch, and once the vehicle reaches space, the fairing is jettisoned, allowing the satellite to be inserted into orbit.

What is ISRO's Contribution to Launch Vehicles?

ISRO has played a key role in advancing India's space capabilities. From launching its first satellite, SLV-3, in 1980, to developing more advanced launch vehicles like PSLV, GSLV, and GSLV Mk III, ISRO has significantly contributed to satellite deployments. These vehicles have launched various satellites for communication, Earth observation, and scientific research.

What are the Different Stages in a Launch Vehicle?

Launch vehicles generally have multiple stages. Each stage is designed to provide a certain amount of thrust to carry the vehicle further into space.

• First stage: Solid rocket motor for initial thrust.
• Second stage: Liquid rocket engine to maintain momentum.
• Third stage: High-thrust solid or liquid motor.
• Fourth stage: Earth-storable liquid engines for final insertion into orbit.

Types of Launch Vehicles Developed by ISRO

• SLV (Satellite Launch Vehicle): India's first experimental launch vehicle, used to place payloads into LEO.
• ASLV (Augmented Satellite Launch Vehicle): A five-stage vehicle designed to place 150 kg payloads into orbit.
• PSLV (Polar Satellite Launch Vehicle): Known as the "workhorse" of ISRO, it can carry satellites to various orbits, including LEO and Sun-synchronous polar orbits.
• GSLV (Geosynchronous Satellite Launch Vehicle): Designed for launching heavier communication satellites into GTO, GSLV uses a cryogenic upper stage for better thrust.
• GSLV Mk III: The next-generation vehicle capable of placing heavier payloads into geostationary transfer orbits and LEO.

Foreign Launch Vehicles Used by ISRO

• Ariane 5 (ESA): Used for launching heavier satellites like INSAT-3D and GSAT-30.
• Falcon 9 (SpaceX): A reusable launch vehicle that has been used by ISRO for various payloads.
• Space Launch System (NASA): A heavy-lift rocket capable of carrying 70 metric tons to LEO, used for lunar missions.
• Soyuz 5 (Russian Space Agency): A powerful launch vehicle capable of launching 17 metric tons to LEO.

What are Sounding Rockets and Their Role in Space Research?

Sounding rockets are short-range, one or two-stage solid-propellant rockets used to explore the upper atmosphere and conduct space research. ISRO began using sounding rockets in 1965, and they continue to provide valuable data for atmospheric research.

Notable Active Launch Vehicles of ISRO

• PSLV: A reliable, four-stage vehicle capable of launching payloads up to 1,750 kg into a 600 km altitude Sun-synchronous orbit.
• GSLV: A three-stage vehicle designed for placing satellites in GTO, capable of lifting payloads up to 6 tonnes into LEO.
• LVM3 (GSLV Mk III): ISRO's most powerful launch vehicle, capable of placing 4-tonne satellites into GTO and 8,000 kg payloads into LEO.

Satellite Launch Vehicles Under Development by ISRO

• Human Rated Launch Vehicle (HRLV): A modified version of the LVM-3, capable of launching manned missions into low Earth orbit.
• Small Satellite Launch Vehicle (SSLV): Designed for launching small satellites (up to 500 kg) into planar orbits.
• Reusable Launch Vehicle Technology Demonstrator (RLV-TD): A reusable launch vehicle similar to an aircraft, with the aim to reduce space mission costs.
• Scramjet Engine Technology: ISRO's scramjet engine, tested in 2016, uses hydrogen as fuel and atmospheric oxygen for combustion at hypersonic speeds.

ISRO is also working on human-rated launch vehicles and reusable technology to reduce costs in future space missions.

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Source: 

INDIAN EXPRESS