Space Science & Exploration

✅ Pair I: International Year of the Woman Farmer : 2026 — Correct
*The UN designated 2026 to honor the vital role of women in agriculture and to address gender inequalities in farming globally.* ✅ Pair II: International Year of Sustainable and Resilient Tourism : 2027 — Correct
*2027 is proclaimed to promote tourism that supports sustainable development and resilience against climate and health challenges.* ✅ Pair III: International Year of Peace and Trust : 2025 — Correct
*The year 2025 focuses on fostering global peace, trust, and cooperation among nations and communities.* ✅ Pair IV: International Year of Asteroid Awareness and Planetary Defence : 2029 — Correct
*2029 marks the UN’s focus on asteroid awareness and planetary defense, coinciding with asteroid Apophis’s close approach.* Therefore, all four pairs are correctly matched.

✅ I. Axiom-4: Correct
Axiom-4 is a private crewed ISS mission focused on micro-gravity research through scientific experiments. ✅ II. SpaDeX: Correct
SpaDeX, ISRO’s autonomous docking tech demo, also supports micro-gravity research during its mission. ✅ III. Gaganyaan: Correct
India’s first human spaceflight, Gaganyaan, promotes micro-gravity research by enabling experiments in space. Therefore, all three missions support and encourage micro-gravity research.

✅ Statement I: Correct
*GAGAN is an Indian SBAS developed by ISRO and AAI to enhance GPS accuracy and integrity, crucial for aviation safety.* ✅ Statement II: Correct
*It improves GPS reliability and accuracy, enabling better air traffic management and safer, efficient navigation.* ❌ Statement III: Incorrect
*GAGAN’s benefits extend beyond aviation to railways, roadways, maritime, agriculture, and disaster management.* Correct Answer: Only Statements I and II are correct.

* Statement-I is incorrect: Giant stars do not live much longer than dwarf stars. In fact, giant stars have shorter lifespans compared to dwarf stars because they burn through their nuclear fuel at a much faster rate. * Statement-II is correct: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions. This is correct as giant stars are more massive and have higher pressures and temperatures in their cores, leading to faster nuclear fusion rates.

* Statement 1: Incorrect. RTGs (Radioisotope Thermoelectric Generators) are not miniature fission reactors. Fission reactors use nuclear fission, a process of splitting atoms to release a tremendous amount of energy. RTGs, on the other hand, utilize the natural radioactive decay of isotopes to generate heat, which is then converted to electricity through a process called thermoelectricity. * Statement 2: Correct. RTGs are indeed a reliable power source for spacecraft, especially those venturing far from the sun where solar panels become ineffective. They provide consistent, low-level electric power for extended periods, making them ideal for probes, satellites, and rovers in deep space. * Statement 3: Correct. Plutonium-238 is a common isotope used in RTGs due to its long half-life (the time it takes for half of the material to decay) and its ability to generate a steady heat output from its decay process. While it can be a byproduct of weapons development, there are also alternative ways to produce Plutonium-238 specifically for peaceful applications like RTGs.

* Pair 1 is incorrect: Cepheids are actually stars that brighten and dim periodically, not giant clouds of dust and gas.  * Pair 2 is incorrect: Nebulae are giant clouds of dust and gas in space, not stars that brighten and dim periodically. Thus, the first two pairs are reversed.  * Pair 3 is correct: Pulsars are rapidly rotating neutron stars that are formed when massive stars exhaust their fuel and collapse.  * So out of the 3 pairs given, only 1 pair (pair 3) is correctly matched.

* Neither of the statements about ballistic missiles and cruise missiles is accurate. * Ballistic missiles: These are rocket-powered weapons that follow a high, arcing trajectory after a brief powered ascent. They travel at supersonic speeds throughout most of their flight due to inertia. * Cruise missiles: These are jet-propelled weapons that fly at relatively low altitudes and can manoeuvre throughout their flight path. They can be subsonic, supersonic, or hypersonic depending on the design. * Agni-V: This is a long-range intercontinental ballistic missile (ICBM) developed by India. It is not a medium-range cruise missile. * BrahMos: This is a supersonic cruise missile jointly developed by India and Russia. It is not a solid-fueled ICBM. BrahMos uses a ramjet engine for sustained supersonic flight after a booster rocket launch.

* Satellite navigation is based on the use of range measurements between navigational satellites and the user. Information about the satellite's coordinates is given to the user through a navigation signal. Range measurements are based on the calculation of the receiving signal time delay compared with the signals generated by the user equipment. * Currently, there are four global systems viz., GPS from the USA, GLONASS from Russia, Galileo from the European Union, and BeiDou from China. In addition, there are two regional systems viz., NavIC from India and QZSS from Japan. * Global navigation system caters to the users in the entire world, whereas the regional navigation system caters to the users in the limited service area. Hence, option (D) is the correct answer.

Out of the listed effects of a major solar storm, the most likely ones are Statement 1 is correct. A solar storm can disrupt the Earth's ionosphere, which can affect the signal transmission of GPS and other radio-based navigation systems. Statement 3 is correct. Strong currents induced by the solar storm in power grids can damage transformers and cause widespread blackouts. Statement 4 is correct. Solar storms can energize particles in the Earth's magnetosphere, leading to spectacular auroras at lower latitudes than usual. Statement 6 is correct. The drag from a solar storm can alter the orbits of satellites, especially those in lower Earth orbit. Statement 7 is correct. Similar to GPS, radio communication can be affected by disturbances in the ionosphere. Statement 2 is incorrect. Tsunamis are caused by underwater earthquakes or volcanic eruptions, not solar storms. Statement 5 is incorrect. While a solar storm could potentially ignite some fires through electrical sparks, this is not a widespread effect. Therefore, codes 2 and 5 should not form the part of answer.

It is a delivery system that uses a low Earth orbit to bypass early warning systems and deliver warheads on targets very quickly. FOBS launches a warhead into a low Earth orbit trajectory instead of a full ballistic missile arc. These systems are typically designed to detect missiles launched on high ballistic trajectories. A FOBS warhead in a low orbit might be harder to detect until it re-enters the atmosphere for its final approach to the target. Due to the orbital path, the time between re-entry and target impact can be shorter compared to a traditional ballistic missile attack.