Question 44 from UPSC CSE 2023 - S&T

Question

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?

IASCODEX · Accepted Answer

Correct Option: D. Neither 1 nor 2

Strategy: - Pinpoint technical inaccuracies regarding missile propulsion, trajectory, and classification.
- Clarify that ballistic missiles are rocket-propelled and atmospheric-exiting, contrasting with jet-propelled cruise missiles.
- Correctly identify Agni-V as an ICBM and BrahMos as a supersonic cruise missile, detailing their distinct characteristics.
- Leverage these factual corrections to invalidate both given statements.

Key Info: ## Ballistic Missiles
These missiles are powered by rocket engines only during the initial 'boost phase.' After burnout, they follow a high-arching, unpowered ballistic trajectory through and outside the atmosphere to their target. Examples include the Agni series (Agni-I to Agni-V), Prithvi, and Dhanush. They are characterized by long range (short-range to intercontinental) and can carry nuclear warheads. Agni-V is an Intercontinental Ballistic Missile (ICBM) with a range over 5,000 km, and is solid-fuelled.

## Cruise Missiles
These missiles are jet-propelled throughout their flight within the Earth's atmosphere, sustaining aerodynamic lift like a pilotless aircraft. They can be subsonic or supersonic. BrahMos is a supersonic cruise missile powered by a ramjet engine, with a range of about 400 km. Cruise missiles like BrahMos are not ballistic and do not have the range or flight profile of ICBMs.

## Propulsion Differences
Ballistic missiles follow a largely unpowered trajectory after boost, while cruise missiles are continuously powered by jet engines throughout most of their flight. The two classes differ fundamentally in guidance, propulsion, and trajectory.

## Key Indian Missiles
- **Agni-V** -- Intercontinental Ballistic Missile (ICBM), solid-fuel, ballistic missile
- **BrahMos** -- Supersonic cruise missile, ramjet propulsion

IASCODEX · Answer

Option A: 1 only

IASCODEX · Answer

Option B: 2 only

IASCODEX · Answer

Option C: Both 1 and 2