Daily Current Affairs Quiz: December 31, 2025

Answer: C [It allows restart and fine control during later stages.]
Explanation:

Liquid fuel is preferred in the upper stages of launch vehicles primarily because it offers the ability to restart and precisely control thrust during flight. This capability is essential for conducting complex maneuvers such as orbital insertion, trajectory correction, and satellite positioning. Unlike solid fuel, which burns continuously once ignited and cannot be stopped or adjusted mid-flight, liquid fuel engines can be throttled, shut down, and reignited as needed. This fine control makes liquid fuel ideal for the later stages of space missions where accuracy is critical.

Answer: A [1 only]
Explanation:

Statement 1 is correct: The Rohini series of sounding rockets were among ISRO’s earliest launch vehicles. The stretched versions (SR-56/57) were capable of carrying payloads of about 100 kg, marking an important milestone in India’s space program.

Statement 2 is incorrect: The PSLV actually uses solid propellant in the first and third stages, and liquid propellant in the second and fourth stages. The statement reverses the propellant usage.

Answer: B [It is designed to launch heavier communication satellites into Geosynchronous Transfer Orbit (GTO).]
Explanation:

The GSLV Mk III, now known as LVM3, is ISRO’s heaviest launch vehicle and was specifically developed to be capable of launching heavier communication satellites, such as those in the INSAT series, into Geosynchronous Transfer Orbit (GTO). Its predecessors had limitations in lifting capacity for such heavy payloads. Unlike earlier vehicles, it uses a combination of liquid and cryogenic propellants in its upper stages and solid propellants in its boosters, not solely solid propellants. It is versatile and capable of launching various types of satellites, including communication and navigation satellites. ISRO has indigenously developed its core propulsion systems, including the Vikas engines and the high-efficiency cryogenic engine.

Answer: D [1 and 3 only]
Explanation:

Statement 1 is correct: SSLV has been designed to meet the growing demand for on‑demand and dedicated launches of small satellites. It provides flexibility, quick turnaround, and cost‑effective access to space for small payloads.

Statement 2 is incorrect: SSLV does not use solid propellant for all stages. While the first three stages are solid‑propellant based, the fourth stage (Velocity Trimming Module) uses liquid propellant for precise orbital insertion.

Statement 3 is correct: Compared to PSLV, SSLV requires fewer launch preparations and reduced ground support systems. This makes SSLV suitable for rapid deployment and minimal infrastructure, enabling faster and more efficient satellite launches.

Answer: C [Both 1 and 2]
Explanation:

Statement 1 is correct: Reusable Launch Vehicles (RLVs) are designed to reduce the cost of space missions by reusing major components such as boosters or winged bodies. This reusability minimizes manufacturing expenses and makes launches more economical.

Statement 2 is correct: RLVs function as rockets in space but rely on aerodynamic principles like lift and drag while re‑entering Earth’s atmosphere. Their winged design allows controlled descent and landing, similar to aircraft, ensuring safe recovery for reuse.