📘 Q4. IAS Prelims 2022 — Science & Technology
🧷 Authentic Classroom Explanation by IAS Monk
📌 The Question
Which one of the following statements best reflects the idea behind the “Fractional Orbital Bombardment System (FOBS)”, 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.
✅ Answer
(c)
🧑🏫 Classroom Explanation
The Fractional Orbital Bombardment System (FOBS) is a strategic weapons delivery concept developed during the Cold War and revived in recent strategic discussions.
- In a FOBS, a missile payload is placed into a low Earth orbit, but unlike satellites, it does not complete a full orbit.
- Before completing one full revolution around the Earth, the payload is de-orbited using a retrograde burn and directed toward its target.
- This trajectory allows the weapon to approach from unexpected directions, bypassing conventional early-warning radar systems that are oriented for intercontinental ballistic missile (ICBM) paths.
Thus, the option that best captures the essence of FOBS is:
➡️ A missile is put into orbit and then deliberately de-orbited over a terrestrial target.
Hence, option (c) is correct.
🔍 Curiosity Raiser
Why would a nation prefer orbital deception over traditional ballistic missile trajectories in modern warfare?
📚 Enrichment Notes
- FOBS vs ICBM:
- ICBMs follow a predictable ballistic arc.
- FOBS exploits orbital mechanics to evade missile defence systems.
- Strategic concern:
- Reduced warning time
- Complicates space security and arms control treaties
- International relevance:
- Raises questions under the Outer Space Treaty (1967), which prohibits weapons of mass destruction in orbit.
- Current affairs linkage:
- Renewed debates on space weaponisation and hypersonic glide vehicles.
🪔 IAS Monk Whisper
“In modern warfare, the most dangerous weapon is not speed alone—but surprise written into the laws of physics.”