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

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

Answer: (c) A missile is put into a stable orbit around the Earth and deorbits over a target on the Earth.

Fractional Orbital Bombardment System (FOBS)
  • A Fractional Orbital Bombardment System (FOBS) is a warhead delivery system that uses a low Earth orbit towards its target destination.
  • The Soviet Union first developed FOBS as a nuclear-weapons delivery system in the 1960s. It was one of the first Soviet efforts to use space to deliver nuclear weapons. In August 2021, the People’s Republic of China tested a weapon that combined a FOBS with a hypersonic glide vehicle.
  • Salient features of FOBS
    • Most important feature is its capability to attack from any direction and can hide the target destination till the payload was dropped.
    • It has no fixed trajectory as it can use thrusters to change
      • This is a serious problem for the US as its defence system relies on the detection of an ICBM launch which follows an arcing trajectory.
      • Also, most of  North America’s early warning systems are pointed towards the North pole but the FOBS target the South pole which will again make it the nation difficult to early detection of FOBS missiles.
    • It has no range limit and can be targeted at any point on the earth.

Hypersonic Missile

  • A hypersonic missile is a weapon system that flies at least at the speed of Mach 5 i.e. five times the speed of sound and is maneuverable.
  • The maneuverability of the hypersonic missile is what sets it apart from a ballistic missile as the latter follows a set course or a ballistic trajectory. Thus, unlike ballistic missiles, hypersonic missiles do not follow a ballistic trajectory and can be maneuvered to the intended target.
  • The two types of hypersonic weapons systems are Hypersonic Glide Vehicles (HGV) and Hypersonic Cruise Missiles.
    • The HGV is launched from a rocket before gliding to the intended target while the hypersonic cruise missile is powered by air-breathing high-speed engines or ‘scramjets’ after acquiring its target.