INS Aridhaman enters India’s naval fleet

Why in News?

India commissioned its third nuclear-powered ballistic missile submarine (SSBN) Aridhaman (S4). INS Arihant was the first vessel under the SSBN project, and was followed by INS Arighat. 

INS Aridhaman:

• INS Aridhaman is an advanced version of the Arihant-class submarines. 
• Built indigenously under the Advanced Technology Vessel programme.  
• Measures 125.4 metres and has a displacement of 7000 tons.
• Powered by an 83-MW pressurised light-water reactor with enriched Uranium. 
• The submarine features advanced indigenous sonar systems and acoustic suppression technologies, improving its underwater detection and survivability. 
• Can carry up to 24 K-15 Sagarika missiles with a range of 750 km, or eight K-4 missiles with a range of 3500 km, or K-5 missiles, which can be nuclear-tipped.

Significance of Arihant-class submarines:

• With the induction of INS Aridhaman, India has completed the nuclear triad, meaning it can launch a nuclear weapon from air, land and under the sea. SSBN’s ability to launch ballistic missiles from under the sea provides India with a secure second-strike capability, a crucial component of its nuclear deterrence strategy.
• Built under the Advanced Technology Vessel programme at Visakhapatnam, the submarine represents a key milestone in India’s indigenous defence capabilities.
• Places India among a select group of countries (the US, Russia, the UK, France, and China) that have nuclear-powered submarines. 

With India’s No-First-Use Nuclear Policy, SSBNs play a crucial role in nuclear deterrence due to their stealth capabilities and capability to execute retaliatory strikes.

Nuclear-Powered Submarines in India: 

Nuclear submarines can be classified into two categories: 

1. Submersible Ship Nuclear (SSN): 

• SSNs are nuclear-powered fast-attack submarines designed primarily for offensive combat roles. 
• Key Roles:
  • Anti-submarine warfare (ASW)
  • Anti-surface warfare (ASuW)
  • Intelligence, Surveillance and Reconnaissance (ISR)
  • Escorting aircraft carriers and SSBNs. 
• Capable of launching conventional weapons like torpedoes and cruise missiles.
• E.g., CHAKRA-II (deployed with the Eastern Naval Command)

2. Submersible Ship Ballistic Nuclear (SSBN):

• SSBNs are nuclear-powered submarines equipped with ballistic missiles that can carry nuclear warheads. They contribute to India’s nuclear deterrence capability.
• Key Characteristics:
  • Carry Submarine-Launched Ballistic Missiles (SLBMs).
  • Designed primarily for deterrence, and not for tactical attack missions.
  • Operate stealthily to avoid detection.
• E.g., Arihant-class submarines- Arihant, Arighaat, Aridhaman. 

Key Fact: Nuclear propulsion enables the submarines to remain submerged in oceans for extended periods. This is a significant advantage over conventional diesel-electric submarines, which need to surface regularly. 

Practice MCQ: 

Q. With reference to nuclear-powered submarines, consider the following statements:

1. Ship Submersible Nuclear (SSN) submarines are primarily designed for tactical attack roles such as anti-submarine warfare.

2. Ship Submersible Ballistic Nuclear (SSBN) submarines form the sea-based leg of the nuclear triad.

3. INS Aridhaman is equipped with ballistic missiles capable of carrying nuclear warheads.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only 

(d) 1, 2 and 3 

Answer: (d)

UPSC PYQ 2023

Q. Consider the following statements:

1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight.

2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (d)