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Which one of the following statements best reflects the idea behind the "Fractional Orbital Bombardment System" often talked about in media ?
Explanation
The correct answer is Option 3. The Fractional Orbital Bombardment System (FOBS) is a strategic missile delivery method designed to strike targets from space.
- Mechanism: Unlike traditional Intercontinental Ballistic Missiles (ICBMs) that follow a high-arching parabolic trajectory, a FOBS weapon is launched into a low Earth orbit. It remains in a stable orbit for a "fraction" of a revolution before retro-rockets are fired to deorbit the warhead over its intended target.
- Strategic Advantage: Because the missile stays in low orbit, it can approach a target from any direction (e.g., over the South Pole), effectively bypassing early-warning radars and missile defense systems oriented toward North Polar trajectories.
Why other options are incorrect: Option 1 describes planetary defense, while Options 2 and 4 relate to space exploration and rendezvous missions. FOBS is specifically a military technology for Earth-to-Earth strikes via orbital space.
PROVENANCE & STUDY PATTERN
Guest previewThis is a classic 'Term in News' question derived from the 2021 media frenzy around China's hypersonic test. Static books (NCERT/PMF) explain 'orbits' and 'comets' to help you eliminate absurd options, but the specific definition came directly from The Hindu/Indian Express explainers. It tests awareness, not deep physics.
This question can be broken into the following sub-statements. Tap a statement sentence to jump into its detailed analysis.
Web source
Presence: 5/5
"A fractional orbital bombardment system is a payload that is delivered into low-Earth orbit but re-enters the atmosphere to bombard a target before completing a full orbit."
Why this source?
- Defines what a FOBS is: a payload placed into low‑Earth orbit that re‑enters to bombard a target before completing an orbit.
- This description indicates FOBS are used to strike terrestrial targets via deorbiting, not to intercept asteroids.
Web source
Presence: 5/5
"the Long March, a fractional orbital bombardment system (FOBS), launches the hypersonic glide vehicle into orbit before the hypersonic glide vehicle deorbits to its target."
Why this source?
- Describes a FOBS launching a hypersonic glide vehicle into orbit which then deorbits to its target.
- Shows the technology is used for space-to-Earth strike (global strike capability), not for asteroid interception.
Web source
Presence: 4/5
"As the name suggests, such systems complete a fraction of an orbit around the Earth before re-entering the atmosphere."
Why this source?
- States such systems 'complete a fraction of an orbit around the Earth before re-entering the atmosphere,' reinforcing the Earth‑strike role.
- Passage discusses use with nuclear payloads and global strike, further indicating intent against terrestrial targets rather than asteroids.
- Defines what a FOBS is: a payload placed into low‑Earth orbit that re‑enters to bombard a target before completing an orbit.
- This description indicates FOBS are used to strike terrestrial targets via deorbiting, not to intercept asteroids.
- Describes a FOBS launching a hypersonic glide vehicle into orbit which then deorbits to its target.
- Shows the technology is used for space-to-Earth strike (global strike capability), not for asteroid interception.
- States such systems 'complete a fraction of an orbit around the Earth before re-entering the atmosphere,' reinforcing the Earth‑strike role.
- Passage discusses use with nuclear payloads and global strike, further indicating intent against terrestrial targets rather than asteroids.
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > UPSC Prelims 1998] Consider the following statements regarding asteroids: > p. 32
Strength: 4/5
“[UPSC Prelims 1998] Consider the following statements regarding asteroids:
• 1. Asteroids are rocky debris of varying size orbiting the sun• 2. Most of the asteroids are small, but some have diameters as large and 1000 km”
Why relevant
Defines asteroids as rocky debris of varying size orbiting the Sun, establishing what a target would be.
How to extend
A student could combine this with basic orbital-distance facts to judge whether a missile could realistically reach typical asteroid orbits for interception.
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > UPSC Prelims 2011] What is difference between asteroids and comets? > p. 36
Strength: 5/5
“• 2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.• 3. Comets show a perceptible glowing tail, while asteroids do not.”
Why relevant
States most asteroids are found between Mars and Jupiter, clarifying typical asteroid orbital zones.
How to extend
Use a simple solar-system map to compare those orbital distances with the range/altitude implied by 'hypersonic missile into space' to assess feasibility.
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 3: Geological Time Scale The Evolution of The Earths Surface > 3.1. Hadean Eon (4,540 mya to 4,000 mya) > p. 41
Strength: 3/5
“• The Hadean eon represents the time before a reliable (fossil) record of life. Temperatures are extremely hot, and much of the Earth was molten because of frequent collisions with other bodies, extreme volcanism, and the abundance of short-lived radioactive elements.• A giant impact collision with a planet-sized body named Theia (approximately 4.5 billion years ago) is thought to have formed the Moon. The moon was subjected to Late Heavy Bombardment (lunar cataclysm – 4 billion years ago).• During the LHB phase, a disproportionately large number of asteroids are theorised to have collided with the early terrestrial planets in the inner Solar System, including Mercury, Venus, Earth, and Mars.• Volcanic outgassing probably created the primordial atmosphere and then the ocean.”
Why relevant
Describes that many asteroids have collided with terrestrial planets during the Late Heavy Bombardment, showing asteroids can intersect planetary paths.
How to extend
Combine with orbital mechanics basics to consider whether an incoming asteroid would be in near-Earth space (more interceptable) or in main-belt orbits (farther, harder to reach).
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Hadean Eon (4,540 – 4,000 mya) > p. 270
Strength: 3/5
“• Volcanic outgassing created the primordial atmosphere. Outgassing from volcanism, supplemented by gases produced during the late heavy bombardment of Earth, produced the next atmosphere.• During the Late Heavy Bombardment (4 billion years ago), a disproportionately large number of asteroids collided with the early terrestrial planets including earth.• Over time, the Earth's surface solidified leaving behind hot volatiles which resulted in a heavy CO2 atmosphere with hydrogen, nitrogen, inert gases, and water vapour.• After the formation of oceans, dissolving in ocean water removed most CO2 from the atmosphere. Some CO2 reacted with metals to form carbonates that were deposited as sediments.• The early atmosphere contained almost no oxygen.”
Why relevant
Reinforces that asteroid impacts on Earth have occurred, indicating the practical problem such a system would aim to solve.
How to extend
A student could infer that intercepting an Earth-bound asteroid requires timing and trajectory considerations beyond merely 'launching a missile into space.'
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 5: Earths Magnetic Field (Geomagnetic Field) > Explanation: > p. 78
Strength: 3/5
“• Thumba Equatorial Rocket Launching Station (TERLS) near Thiruvananthapuram was built to launch sounding rockets (two-stage solid propellant rockets used for space research) in the 1960s and 70s. The presence of a strong equatorial electrojet (current flowing eastward in the equatorial region of the Earth's ionosphere) current over Thumba, which was also very close to the geomagnetic equator, made it an ideal site for the launch of sounding rockets.• The Axis of the earth's magnetic field is inclined at 11° to the geographic axis of the earth. The North Magnetic Pole (86.50°N and 164.04°E) lies to the north of Ellesmere Island in northern Canada and is rapidly drifting towards Siberia.”
Why relevant
Notes existence of rocket launch infrastructure (sounding rockets launched from Thumba), showing national capability to send vehicles into near-space.
How to extend
Extend by comparing the documented sounding-rocket role to the much greater requirements of reaching asteroid distances/orbital rendezvous to evaluate whether a hypersonic missile launch is analogous.
Defines asteroids as rocky debris of varying size orbiting the Sun, establishing what a target would be.
A student could combine this with basic orbital-distance facts to judge whether a missile could realistically reach typical asteroid orbits for interception.
States most asteroids are found between Mars and Jupiter, clarifying typical asteroid orbital zones.
Use a simple solar-system map to compare those orbital distances with the range/altitude implied by 'hypersonic missile into space' to assess feasibility.
Describes that many asteroids have collided with terrestrial planets during the Late Heavy Bombardment, showing asteroids can intersect planetary paths.
Combine with orbital mechanics basics to consider whether an incoming asteroid would be in near-Earth space (more interceptable) or in main-belt orbits (farther, harder to reach).
Reinforces that asteroid impacts on Earth have occurred, indicating the practical problem such a system would aim to solve.
A student could infer that intercepting an Earth-bound asteroid requires timing and trajectory considerations beyond merely 'launching a missile into space.'
Notes existence of rocket launch infrastructure (sounding rockets launched from Thumba), showing national capability to send vehicles into near-space.
Extend by comparing the documented sounding-rocket role to the much greater requirements of reaching asteroid distances/orbital rendezvous to evaluate whether a hypersonic missile launch is analogous.
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