Minimalist IAS
Science & technology

Prelims · Science & technology · 22 questions

Space technology

Every UPSC Prelims question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

Space technology questions per year: 2016: 2, 2017: 2, 2018: 3, 2019: 2, 2020: 1, 2021: 0, 2022: 1, 2023: 2, 2024: 2, 2025: 2, 2026: 2 Asked in 10 of 11 years · most in 2018 (3)

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UPSC syllabus: “General Science.” Sub-topics in the detailed syllabus →

निम्नलिखित कथनों में कौन-सा एक, जनसंचार-माध्यमों में बहुचर्चित “प्रभाजी कक्षीय बमबारी प्रणाली” के आधारभूत विचार को सर्वोत्तम रूप से प्रतिबिंबित करता है ?

Read this question in English

Which one of the following statements best reflects the idea behind the "Fractional Orbital Bombardment System" often talked about in media?

(a) A hypersonic missile is launched into space to counter the asteroid approaching the Earth and explode it in space. · (b) A spacecraft lands on another planet after making several orbital motions. · (c) A missile is put into a stable orbit around the Earth and deorbits over a target on the Earth. · (d) A spacecraft moves along a comet with the same speed and places a probe on its surface.

उत्तर और व्याख्या · explanation in English

Answer: (c) कोई मिसाइल पृथ्वी के परितः किसी स्थिर कक्षा में स्थापित किया जाता है और वह पृथ्वी पर किसी लक्ष्य के ऊपर कक्षा को त्यागता है ।

A Fractional Orbital Bombardment System (FOBS) sends a warhead into a low Earth orbit and brings it down over the target before it completes a full circuit — hence 'fractional'. Because it can approach from any direction, even over the South Pole, it is hard for early-warning radars to track. The Soviet Union built one in the 1960s, and it returned to the news in 2021 after reports of a Chinese test.

  • ✓ (c) FOBS places a weapon in orbit around the Earth and then deorbits it onto a target, instead of following the arcing path of an intercontinental ballistic missile.
  • ✗ (a) Deflecting or destroying an incoming asteroid is planetary defence (for example NASA's DART mission), not a bombardment system aimed at Earth.
  • ✗ (b) Orbiting a planet several times before landing describes a planetary landing mission, unrelated to weapons.

Remember · FOBS: nuclear warhead put into low partial Earth orbit, deorbited onto target — evades radars facing the usual ICBM routes; Soviet system banned under SALT II (1979).

Sources

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

यदि कोई मुख्य सौर तूफ़ान (सौर प्रज्वाल) पृथ्वी पर पहुँचता है, तो पृथ्वी पर निम्नलिखित में कौन-से संभव प्रभाव होंगे ?

  1. 1.GPS और दिक्संचालन (नैविगेशन) प्रणालियाँ विफल हो सकती हैं ।
  2. 2.विषुवतीय क्षेत्रों में सुनामियाँ आ सकती हैं ।
  3. 3.बिजली ग्रिड क्षतिग्रस्त हो सकते हैं ।
  4. 4.पृथ्वी के अधिकांश हिस्से पर तीव्र ध्रुवीय ज्योतियाँ घटित हो सकती हैं ।
  5. 5.ग्रह के अधिकांश हिस्से पर दावाग्नियाँ घटित हो सकती हैं ।
  6. 6.उपग्रहों की कक्षाएँ विक्षुब्ध हो सकती हैं ।
  7. 7.ध्रुवीय क्षेत्रों के ऊपर से उड़ते हुए वायुयान का लघुतरंग रेडियो संचार बाधित हो सकता है ।

नीचे दिए कूट का प्रयोग कर सही उत्तर चुनिए :

Read this question in English

If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?

1. GPS and navigation systems could fail.

2. Tsunamis could occur at equatorial regions.

3. Power grids could be damaged.

4. Intense auroras could occur over much of the Earth.

5. Forest fires could take place over much of the planet.

6. Orbits of the satellites could be disturbed.

7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.

Select the correct answer using the code given below:

(a) 1, 2, 4 and 5 only · (b) 2, 3, 5, 6 and 7 only · (c) 1, 3, 4, 6 and 7 only · (d) 1, 2, 3, 4, 5, 6 and 7

उत्तर और व्याख्या · explanation in English

Answer: (c) केवल 1, 3, 4, 6 और 7

Items 1, 3, 4, 6 and 7 are genuine effects of a strong solar storm: it disturbs GPS, damages power grids, brightens auroras, drags on satellites and blacks out high-frequency radio near the poles. Tsunamis (item 2) come from undersea earthquakes and forest fires (item 5) are not an effect of space weather, so they are ruled out.

  • ✓ 1. Solar-flare disturbances of the ionosphere range from errors of a few metres to complete loss of the GPS signal.
  • ✗ 2. A tsunami needs an earthquake tremor centred below the ocean; solar storms do not generate them, at the equator or anywhere else.
  • ✓ 3. Geomagnetic storms drive large ground currents (GICs) that can damage high-voltage transformers and have caused widespread power outages.
  • ✓ 4. The same storms create the aurora borealis and aurora australis, and a strong one can push the northern lights as far south as Florida.
  • ✗ 5. None of the recognised effects of space weather (radio, GPS, satellites, power lines, pipelines) is a ground-level fire hazard.
  • ✓ 6. A strong storm heats and expands the upper atmosphere, raising drag on low-Earth-orbit satellites, which can slow them or make them lose altitude.
  • ✓ 7. Near the poles, Earth's magnetic field funnels charged particles down. Severe space weather can cut radio contact with aircraft on transpolar routes, so they may need to reroute.

Remember · Solar storms hit technology: GPS, HF radio, satellites, power grids; and give auroras. They do not cause tsunamis or forest fires.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 3 (practise this chapter)

Sources

  • NOAA NESDIS, The Effects of Space Weather On Earth (Internet Archive copy) ↗ “The effects of solar flare disruptions can range from errors of a few meters to the complete loss of GPS signal. … GICs can flow into conductors such as power lines and damage high-voltage transformers. In the past, they have led to widespread power outages. … Extra drag can slow satellites in their orbit, or even cause them to lose altitude. … Planes flying on high-altitude transpolar routes must be aware of the space weather forecast before taking flight, as a loss of radio signal can prevent pilots from speaking with ground control. … a strong solar storm can cause the northern lights to appear as far south as Florida.”
  • NCERT Class 11 · Fundamentals of Physical Geography, Chapter 3 “The effect of tsunami would occur only if the epicentre of the tremor is below oceanic waters and the magnitude is sufficiently high.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

The Syllabus X-Ray of this topic

1 of its 4 sub-topics is Core

1 Core · 2 High · 0 Steady · 1 Rare

  • Core #28Satellites, orbits & navigation · 8 questions
  • HighIndia's launch vehicles & space missions · 5 questions
  • HighAstronomy & astrophysics · 4 questions

The X-Ray ranks all 928 sub-topics of the UPSC syllabus by what UPSC has asked since 2016. The 60 Prelims Core sub-topics are behind 51% of Prelims questions.

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The same topic in Mains

Read it in NCERT