UPSC Prelims Practice Questions — ISRO conducts successful test of modified PSLV third stage

Q1. With reference to the stage architecture of India's Polar Satellite Launch Vehicle (PSLV), consider the following statements: Which of the statements given above is/are correct?

  1. The PSLV-XL, PSLV-QL and PSLV-DL variants are distinguished chiefly by the number of strap-on motors attached to the first stage.
  2. The second stage of PSLV is powered by the Vikas engine, which burns liquid hydrogen and liquid oxygen.
  3. The fourth stage of PSLV is powered by two liquid-propellant engines.
  • A. 1 only
  • B. 2 and 3 only
  • C. 1 and 3 only
  • D. 1, 2 and 3

Q2. With reference to satellite orbits used for Earth observation, consider the following statements: Which of the statements given above is/are correct?

  1. A satellite in geostationary orbit can continuously observe the same region of the Earth's surface.
  2. A satellite in a Sun-synchronous orbit passes over a given location at the same local solar time on each pass.
  3. A geostationary satellite must orbit in the plane of the Earth's equator.
  • A. 1 and 2 only
  • B. 1, 2 and 3
  • C. 1 and 3 only
  • D. 2 and 3 only

Q3. Compared with an imaging satellite in a low Sun-synchronous orbit, an imaging satellite in geostationary orbit generally offers which of the following?

  • A. Finer spatial resolution and frequent coverage of the whole globe
  • B. Finer spatial resolution and continuous viewing of one fixed region
  • C. Coarser spatial resolution and coverage of the whole globe at fixed solar time
  • D. Coarser spatial resolution and continuous viewing of one fixed region

Q4. Consider the following facts: After two consecutive PSLV failures in its third stage, ISRO revised that stage's design margins, raw material acceptance criteria and assembly procedures, and the modified stage then passed a ground static test. PSLV's return to flight was made conditional on implementing corrective actions recommended by a National Level Expert Committee. Which of the following inferences can validly be drawn from the above facts?

  1. ISRO is treating the third-stage problem as one that could arise from manufacturing and quality-control processes, and not from design alone.
  2. The successful static test shows that PSLV has completed its validation for return to flight.
  3. The root cause of the failures has been conclusively traced to defective raw material supplied by vendors.
  • A. 1 only
  • B. 1, 2 and 3
  • C. 1 and 2 only
  • D. 2 and 3 only

Q5. With reference to India's space-sector institutional framework, consider the following statements: Which of the statements given above is/are correct?

  1. NewSpace India Limited (NSIL) is the single-window agency that authorises space activities of private companies.
  2. IN-SPACe authorises and promotes space activities carried out by non-governmental entities.
  3. Under the Indian Space Policy 2023, ISRO is to concentrate on research and development of new space technologies, while mature operational systems move progressively to industry.
  • A. 1 and 2 only
  • B. 2 and 3 only
  • C. 1, 2 and 3
  • D. 3 only

Q6. Which of the following capabilities is generally available in a liquid-propellant rocket stage but not in a conventional solid-propellant rocket motor?

  • A. Producing thrust that varies with the pressure in the combustion chamber
  • B. Carrying its own oxidiser so that combustion needs no atmospheric air
  • C. Expelling hot combustion gases through a nozzle to generate thrust
  • D. Shutting down the engine in flight and re-igniting it later

Q7. With reference to the propulsion systems of India's launch vehicles, consider the following statements: Which of the statements given above is/are correct?

  1. The third stage of PSLV, like its second stage, uses liquid propellant.
  2. The upper stage of GSLV burns cryogenic liquid hydrogen with liquid oxygen.
  3. The core of PSLV's first stage is a solid-propellant motor, not a liquid stage.
  • A. 2 and 3 only
  • B. 1 and 2 only
  • C. 1, 2 and 3
  • D. 3 only

Q8. With reference to launching satellites towards geostationary orbit, consider the following statements: Which of the statements given above is/are correct?

  1. For a given launch vehicle, the payload mass it can place in geosynchronous transfer orbit is lower than the mass it can place in a low Earth orbit, because reaching the higher orbit needs more energy.
  2. A satellite placed in a geosynchronous transfer orbit usually uses its own onboard propulsion to raise and circularise its orbit to geostationary altitude.
  3. Launching eastward from a site near the equator lowers the energy needed because the Earth's rotational surface speed is lowest at the equator.
  • A. 1 only
  • B. 2 and 3 only
  • C. 1 and 2 only
  • D. 1 and 3 only