US Shifts to Precision Gravity Bombs in Escalating Iran Campaign

The United States has announced a major tactical shift in its ongoing military campaign against Iran. US Defence Secretary Pete Hegseth stated that Iranian air defence systems have been significantly weakened after several days of operations. As a result, the US military plans to deploy precision-guided gravity bombs weighing 500, 1,000 and 2,000 pounds. The move indicates a transition from long-range “stand-off” weapons to direct aerial bombardment following the establishment of air superiority.

Earlier Reliance on Stand-Off Weapons

Until now, US forces had largely depended on stand-off munitions designed to strike targets from outside the range of enemy air defence systems. These weapons are launched from naval destroyers, stealth aircraft or drones to minimise risk to pilots. Cruise missiles such as the Tomahawk and unmanned combat systems like the Low-cost Unmanned Combat Attack System (LUCAS) have been widely used to target Iranian radar installations and surface-to-air missile systems. Such strikes aim to weaken enemy defences before direct aerial attacks are carried out.

Understanding Gravity Bombs

Gravity bombs, also known as free-fall bombs, are unpowered weapons that rely on gravity and aerodynamics after being released from an aircraft. Unlike cruise missiles, they do not contain engines or propulsion systems. Modern variants, however, have become highly accurate through the addition of Joint Direct Attack Munition (JDAM) kits. These kits include GPS guidance systems and steerable fins, enabling the bomb to glide towards precise coordinates. Gravity bombs have been widely used in modern conflicts including operations in Iraq, Afghanistan and Syria.

Conventional and Nuclear Variants

The bombs referenced in the current campaign are conventional weapons containing standard chemical explosives. They typically cost around $25,000 to $30,000 when fitted with a JDAM kit and are authorised for use by military commanders during operations. In contrast, the United States also maintains nuclear gravity bombs such as the B61 and B83 series. These weapons have significantly higher destructive yields, measured in kilotons or megatons of TNT, and their deployment requires direct authorisation from the US President.

Important Facts for Exams

• Gravity bombs are unpowered munitions that rely on gravity after release from aircraft.
• Joint Direct Attack Munition (JDAM) kits convert conventional bombs into GPS-guided precision weapons.
• The Mark 80 series is a major family of conventional gravity bombs used by the US Air Force.
• Air supremacy refers to a situation where one military controls the airspace with minimal opposition.

Mark 80 Series and Operational Use

The US arsenal of gravity bombs is centred on the Mark 80 series, which will be deployed with precision guidance systems. The 500-pound Mk-82 bomb is typically used against light vehicles, radar systems and exposed positions. The 1,000-pound Mk-83 is designed for stronger structures such as reinforced buildings and command centres. The largest variant, the 2,000-pound Mk-84, can penetrate hardened targets including underground facilities and large military installations. These bombs can be deployed by fighter aircraft such as the F-15E Strike Eagle and F-35, as well as strategic bombers like the B-52 Stratofortress.