UPSC Prelims Practice Questions — India's New-Age Space Technologies

Q1. With reference to air-breathing scramjet propulsion, consider the following statements: Which of the statements given above is/are correct?

  1. In a scramjet, the incoming air is slowed to subsonic speed before combustion, whereas in a ramjet combustion takes place in a supersonic airflow.
  2. A scramjet cannot produce thrust from rest, so a vehicle using it must first be accelerated to high speed by another propulsion system.
  3. A dual-mode engine can work as a ramjet at lower flight speeds and switch to scramjet operation at higher hypersonic speeds.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 1, 2 and 3
  • D. 2 and 3 only

Q2. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. A scramjet engine cannot propel a vehicle once the vehicle has left the Earth's atmosphere.
  2. A scramjet carries only fuel on board and draws its oxidiser from the oxygen in the incoming air.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q3. With reference to NavIC, India's satellite navigation system, consider the following statements: Which of the statements given above are correct?

  1. Its Standard Positioning Service is the encrypted service reserved for authorised strategic users.
  2. Its satellites are placed in geostationary and inclined geosynchronous orbits, so they stay over a fixed band of longitudes.
  3. Like GPS and Galileo, it is designed to provide positioning to users anywhere on Earth.
  4. Its service area includes the region around the Indian landmass, not only India itself.
  • A. 1, 2 and 4 only
  • B. 2 and 4 only
  • C. 1 and 3 only
  • D. 2, 3 and 4 only

Q4. Consider the following statements: Which of the following is correct in respect of the above statements?

  1. A civilian user in India can obtain a position fix from NavIC without being issued any authorisation or decryption key.
  2. NavIC's Restricted Service is encrypted and is available only to authorised users.
  • A. Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
  • B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  • C. Statement-I is correct, but Statement-II is incorrect
  • D. Statement-I is incorrect, but Statement-II is correct

Q5. With reference to the NASA–ISRO Synthetic Aperture Radar (NISAR) mission, consider the following statements: Which of the statements given above is/are correct?

  1. As an active sensor, its radar illuminates the ground with its own microwave pulses instead of depending on sunlight.
  2. Its longer-wavelength radar penetrates vegetation more deeply than its shorter-wavelength radar, so the two together give complementary information about the surface.
  3. ISRO supplied the L-band radar and NASA supplied the S-band radar, while the spacecraft bus came from NASA.
  • A. 1 and 2 only
  • B. 2 and 3 only
  • C. 1, 2 and 3
  • D. 1 only

Q6. With reference to reusable launch vehicles, consider the following statements: Which of the statements given above is/are correct?

  1. Recovering and reflying a stage reduces the amount of hardware discarded on each launch, which is the main way reusability lowers cost per kilogram to orbit.
  2. A launcher flown in its reusable configuration delivers a larger payload to low Earth orbit than the same launcher flown as an expendable vehicle.
  3. Recovering a stage requires autonomous guidance and precision landing, capabilities that ISRO's Pushpak landing experiments were designed to demonstrate.
  • A. 2 only
  • B. 1 and 2 only
  • C. 1 and 3 only
  • D. 2 and 3 only

Q7. With reference to electric propulsion for satellites compared with conventional chemical propulsion, consider the following statements: Which of the statements given above are correct?

  1. Electric propulsion achieves a much higher specific impulse, so it uses propellant far more efficiently.
  2. Electric thrusters give high thrust, which makes them suitable for lifting a launch vehicle off the Earth's surface.
  3. Because its thrust is low, raising a satellite to geostationary orbit with electric propulsion takes much longer than with chemical propulsion.
  4. Because a satellite using electric propulsion needs less propellant mass for the same manoeuvres, it can carry more payload or stay in service longer.
  • A. 2, 3 and 4 only
  • B. 1 and 2 only
  • C. 1, 3 and 4 only
  • D. 1, 2 and 3 only

Q8. Consider the following assertion: ISRO's semicryogenic engine, which burns liquid oxygen with rocket-grade kerosene (ISROSENE), is considered a cleaner propulsion option. Which of the statements given below support/supports the above assertion?

  1. Liquid oxygen and kerosene are non-toxic and non-hazardous propellants.
  2. Kerosene, unlike liquid hydrogen, can be stored at ambient temperature instead of at cryogenic temperature.
  3. The semicryogenic stage is expected to raise LVM3's payload capability to geosynchronous transfer orbit from about 4 tonnes to about 5 tonnes.
  • A. 1 only
  • B. 2 and 3 only
  • C. 1, 2 and 3
  • D. 1 and 2 only