UPSC Prelims Practice Questions — PARLIAMENT QUESTION: ACHIEVEMENTS OF ADITYA-L1 MISSION

Q1. The Sun-Earth Lagrange Point 1 (L1), where the Aditya-L1 spacecraft is stationed in a halo orbit, is best described as which one of the following?

  • A. A point about 1.5 million km from Earth, on the far side away from the Sun, where a spacecraft stays permanently shielded from all solar radiation
  • B. The unique point where the Sun's gravity exactly cancels the Earth's gravity, leaving any spacecraft placed there weightless and motionless in space
  • C. A point about 1.5 million km from Earth toward the Sun where the two bodies' combined gravity lets a spacecraft circle the Sun in step with Earth
  • D. A location in the Earth's outer magnetosphere where the incoming solar wind is fully deflected around a spacecraft parked there

Q2. Consider the following statements about the location of the Aditya-L1 spacecraft: 1. Aditya-L1 is placed in a halo orbit around the Sun-Earth L1 point, about 1.5 million km from Earth, roughly 1% of the Earth-Sun distance. 2. Like Aditya-L1, the James Webb Space Telescope is stationed at the Sun-Earth L1 point. 3. From its L1 halo orbit, the spacecraft can view the Sun continuously without being subjected to occultations or eclipses. Which of the statements given above is/are correct?

  1. Aditya-L1 is placed in a halo orbit around the Sun-Earth L1 point, about 1.5 million km from Earth, roughly 1% of the Earth-Sun distance.
  2. Like Aditya-L1, the James Webb Space Telescope is stationed at the Sun-Earth L1 point.
  3. From its L1 halo orbit, the spacecraft can view the Sun continuously without being subjected to occultations or eclipses.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q3. Aditya-L1 was placed in orbit by the PSLV-C57 flight. Which one of the following configurations of the PSLV was used for this launch?

  • A. PSLV-XL, with six extended strap-on motors
  • B. PSLV-Core Alone, with no strap-on motors
  • C. PSLV-DL, with two strap-on motors
  • D. PSLV-QL, with four strap-on motors

Q4. Approximately how many days does the Aditya-L1 spacecraft take to complete one revolution in its halo orbit around the L1 point?

  • A. About 88 days
  • B. About 178 days
  • C. About 365 days
  • D. About 687 days

Q5. Consider the following statements about the classification of Aditya-L1's payloads: 1. SoLEXS and HEL1OS are in-situ payloads that directly sample solar wind particles in the vicinity of L1. 2. Of the seven payloads, four are remote-sensing instruments and three are in-situ instruments. 3. VELC and SUIT are remote-sensing payloads, whereas ASPEX and PAPA are in-situ payloads. Which of the statements given above is/are correct?

  1. SoLEXS and HEL1OS are in-situ payloads that directly sample solar wind particles in the vicinity of L1.
  2. Of the seven payloads, four are remote-sensing instruments and three are in-situ instruments.
  3. VELC and SUIT are remote-sensing payloads, whereas ASPEX and PAPA are in-situ payloads.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q6. Aditya-L1 carries seven payloads, all developed indigenously. How many of these seven payloads were developed by ISRO, with the remainder built by Indian academic/research institutes in collaboration with ISRO?

  • A. Three
  • B. Four
  • C. Two
  • D. Five

Q7. In pursuit of its objective of studying solar flares, Aditya-L1's Solar Low Energy X-ray Spectrometer (SoLEXS) documented photospheric iron fluorescence across how many X-class solar flares during the 2024 peak of Solar Cycle 25?

  • A. 27 X-class solar flares
  • B. 47 X-class solar flares
  • C. 11 X-class solar flares
  • D. 63 X-class solar flares

Q8. Consider the following statements about the scientific scope of Aditya-L1: 1. Unlike ground-based solar telescopes, Aditya-L1 can observe near-ultraviolet solar radiation that is otherwise largely absorbed by the Earth's atmosphere. 2. Aditya-L1 studies the solar corona, the solar wind and the interplanetary magnetic field from its vantage point at L1. 3. Aditya-L1 is a formally classified space-weather forecasting mission whose sole purpose is issuing operational geomagnetic-storm warnings. Which of the statements given above is/are correct?

  1. Unlike ground-based solar telescopes, Aditya-L1 can observe near-ultraviolet solar radiation that is otherwise largely absorbed by the Earth's atmosphere.
  2. Aditya-L1 studies the solar corona, the solar wind and the interplanetary magnetic field from its vantage point at L1.
  3. Aditya-L1 is a formally classified space-weather forecasting mission whose sole purpose is issuing operational geomagnetic-storm warnings.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q9. With reference to India's planetary and solar science missions, consider the following: 1. Chandrayaan-1 — India's first mission to the Moon (2008). 2. Mars Orbiter Mission (Mangalyaan) — placed India in orbit around Mars in 2014 on its maiden attempt. 3. Aditya-L1 — India's first mission dedicated to the study of the Sun. 4. Aditya-L1 — India's first interplanetary mission, launched before both Chandrayaan and Mangalyaan. Which of the above is/are correctly identified?

  1. Chandrayaan-1 — India's first mission to the Moon (2008).
  2. Mars Orbiter Mission (Mangalyaan) — placed India in orbit around Mars in 2014 on its maiden attempt.
  3. Aditya-L1 — India's first mission dedicated to the study of the Sun.
  4. Aditya-L1 — India's first interplanetary mission, launched before both Chandrayaan and Mangalyaan.
  • A. 1, 2 and 3
  • B. 1, 2 and 4
  • C. 2, 3 and 4
  • D. 1 and 4 only

Q10. The Aditya-L1 mission, on whose achievements a written reply was tabled in the Rajya Sabha in July 2026, is executed by ISRO under which one of the following departments of the Government of India?

  • A. The Department of Space
  • B. The Department of Atomic Energy
  • C. The Department of Science and Technology
  • D. The Ministry of Earth Sciences

Q11. Consider the following statements about the release of Aditya-L1 scientific data to the community: 1. The first batch of Aditya-L1 scientific data was released on 6 January 2025, marking one year of the spacecraft in its halo orbit. 2. The first data release on 6 January 2025 coincided with the anniversary of the mission's launch. 3. A second batch of scientific data was released about five weeks later, on 14 February 2025. Which of the statements given above is/are correct?

  1. The first batch of Aditya-L1 scientific data was released on 6 January 2025, marking one year of the spacecraft in its halo orbit.
  2. The first data release on 6 January 2025 coincided with the anniversary of the mission's launch.
  3. A second batch of scientific data was released about five weeks later, on 14 February 2025.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3

Q12. Aditya-L1's data is made available to the community as a 'proposal-driven observatory'. In this context, the phrase most precisely means which one of the following?

  • A. The spacecraft autonomously proposes which solar regions to observe using onboard artificial intelligence
  • B. Observing time and data are allocated to scientists whose research proposals are selected through an announcement-of-opportunity process
  • C. Only ISRO's in-house scientists may propose observation targets, and external data requests are not entertained
  • D. The mission's continued operation depends on annual funding proposals being approved by Parliament