Concept:Liquid Oxygen-Methane (LOX-Meth) is a propellant combination that balances performance, reusability, and cost for modern launch vehicles.
Explanation:Assertion (A) is true: India's Next-Generation Launch Vehicle (NGLV), being developed by ISRO, uses LOX-Methane as its preferred propellant.
Reason (R) is also true and directly explains the choice. Methane burns cleaner than kerosene, leaving little carbon deposit, which is essential for reusability of engines. Compared to LOX-Hydrogen, LOX-Methane is easier to handle because methane boils at a higher temperature (-161.5°C vs -253°C), reducing cryogenic complexity. Operational costs are lower than kerosene because the engine needs less refurbishment after each flight, and tank designs are simpler. These advantages make LOX-Methane the ideal choice for a reusable, cost-effective launch vehicle like NGLV.
Thus, R correctly explains why A is true.
Answer:Both A and R are true, and R is the correct explanation of A.