Indian Space Missions and ISRO Programmes

Chandrayaan-1 (2008, PSLV): India's first lunar mission; its Moon Impact Probe and the Moon Mineralogy Mapper (NASA payload) confirmed water/hydroxyl molecules on the lunar surface. Chandrayaan-2 (2019, LVM3): Orbiter (still functioning), Vikram lander (crash-landed), Pragyan rover. Chandrayaan-3 (2023, LVM3): Successful soft landing on 23 August 2023 near the lunar South Pole — making India the FIRST country to land near the South Pole and the 4th to soft-land on the Moon. Lander = Vikram, Rover = Pragyan; payloads ChaSTE (thermal), ILSA (seismic), RAMBHA (plasma). Memory aid: 'C-3 = South Pole, 23 Aug (now National Space Day).' Chandrayaan-1 → water; Chandrayaan-3 → South Pole soft landing.

Mars Orbiter Mission (MOM/Mangalyaan, 2013, PSLV): made India the FIRST country to reach Mars orbit on its first attempt and the first Asian nation to reach Mars; entered orbit 24 Sep 2014; notably low-cost. Aditya-L1 (2023, PSLV): India's first solar mission, placed in a halo orbit around the Sun–Earth Lagrange point L1 (~1.5 million km from Earth), giving continuous unobstructed view of the Sun. Key payload: VELC (Visible Emission Line Coronagraph) studies the solar corona. L1 is favoured because gravitational forces balance there, allowing a satellite to 'hover' with minimal fuel. Memory aid: 'Aditya = Sun god → L1 Sun-watcher.' Lagrange points: L1, L2, L3 unstable; L4, L5 stable.

Gaganyaan: India's first crewed spaceflight programme, aiming to send astronauts ('Gagannauts'/Vyomanauts) to LEO (~400 km) aboard LVM3 with indigenous crew escape system. NavIC (IRNSS): regional navigation system of 7 satellites (mix of GEO and inclined geosynchronous orbits) covering India and ~1500 km around it; uses L5 and S-band; civilian (SPS) and restricted services. GAGAN: GPS-aided augmentation for aviation. INSAT/GSAT: communication satellites in GEO for broadcasting, telephony, weather (INSAT carries VHRR/meteorological payloads). Memory aid: 'NavIC = regional GPS, 7 satellites; GAGAN = aviation booster.' Bhuvan is ISRO's geo-platform; NISAR is the upcoming ISRO–NASA radar imaging satellite.

Cover the answer, recall, then check. 12 cards on must-know facts for UPSC Prelims.

Q1. What was India's first satellite?
A1. Aryabhata, launched in 1975 (on a Soviet rocket) — named after the ancient Indian astronomer.

Q2. What was the first satellite launched by an Indian-made rocket?
A2. Rohini (RS-1), placed in orbit by the SLV-3 in 1980, making India a space-launch capable nation.

Q3. What was Chandrayaan-1's major discovery?
A3. It confirmed the presence of water molecules / hydroxyl on the lunar surface (2008–09).

Q4. Why was Chandrayaan-3 (2023) historic?
A4. India became the 4th country to soft-land on the Moon and the 1st to land near the lunar south pole (lander Vikram, rover Pragyan).

Q5. Why was Mangalyaan (Mars Orbiter Mission) significant?
A5. India became the first nation to reach Mars orbit on its very first attempt, and the first Asian nation to reach Mars (2013–14).

Q6. What does Aditya-L1 study, and from where?
A6. India's first solar observatory, in a halo orbit around the Sun-Earth L1 point, studying the Sun's corona, solar wind and flares.

Q7. What is NavIC?
A7. Navigation with Indian Constellation (IRNSS) — India's own regional satellite navigation system covering India and ~1,500 km around it.

Q8. What is the Gaganyaan mission?
A8. India's first human spaceflight programme, aiming to send crew (gaganyatris) to low-Earth orbit and return them safely.

Q9. Who is regarded as the father of the Indian space programme?
A9. Dr. Vikram Sarabhai. ISRO was established in 1969; its HQ is in Bengaluru.

Q10. From where does ISRO launch its rockets?
A10. Satish Dhawan Space Centre (SDSC-SHAR), Sriharikota, Andhra Pradesh.

Q11. What was notable about XPoSat (Jan 2024)?
A11. India's first dedicated X-ray polarimetry satellite — making India only the second country (after the US) with such a mission.

Q12. Which ISRO satellites are for communication versus earth observation?
A12. INSAT/GSAT series = communication (geostationary); Cartosat/RISAT/Resourcesat = earth observation (polar/Sun-synchronous).

Worked Example

Problem/Question: Consider the following pairs of Indian space missions and their objectives:

1. Chandrayaan-3 — soft-landing near the lunar south pole
2. Mangalyaan (MOM) — India's first interplanetary (Mars) mission
3. Aditya-L1 — a mission to study Jupiter from a halo orbit
   How many of the above pairs are correctly matched?
   (a) Only one (b) Only two (c) All three (d) None

Solution/Model answer:

• Pair 1: Chandrayaan-3 (2023) achieved a soft landing near the lunar south pole. Correct.
• Pair 2: Mangalyaan/MOM (2013-14) was India's first Mars mission, making ISRO the first agency to reach Mars on its first attempt. Correct.
• Pair 3: Aditya-L1 studies the Sun from the Sun-Earth L1 point, not Jupiter. Incorrectly matched.
  Two pairs (1 and 2) match; eliminate (c) and (d). Answer is two.

Answer/Takeaway: (b) Only two.