Introduction

The main difference between supersonic and hypersonic missiles lies in their speed and the physical effects they encounter during flight.

Speed

Supersonic missiles travel faster than the speed of sound (Mach 1) but not faster than Mach 5. Most supersonic missiles operate at speeds between Mach 2 and Mach 3, which is approximately 1,500-2,300 mph (2,400-3,700 km/h).

Hypersonic missiles, on the other hand, travel at speeds of Mach 5 and higher - at least five times faster than the speed of sound. This translates to speeds of around 3,836 mph (6,174 km/h) or more.

Physical Effects

The key distinction between supersonic and hypersonic missiles is not just their speed, but the physical phenomena they encounter

Heat generation

Hypersonic missiles generate extreme heat due to air friction, which poses significant engineering challenges.

Air chemistry

At hypersonic speeds, the air molecules around the missile begin to break down, forming a plasma sheath that can interfere with communications and sensors.

Maneuverability

Hypersonic missiles, particularly hypersonic glide vehicles (HGVs), can maneuver within the atmosphere, making them more unpredictable and harder to intercept.

Types

Supersonic missiles are typically traditional cruise missiles or shorter-range ballistic missiles.

Hypersonic missiles come in two main types

Hypersonic cruise missiles (HCMs)

These maintain a constant hypersonic speed throughout their flight using advanced propulsion systems like scramjets.

Hypersonic glide vehicles (HGVs)

These are launched on ballistic missiles and then glide to their targets at hypersonic speeds.

Technological Challenges

Hypersonic missiles present far greater technological challenges than supersonic missiles.

These include

Developing materials that can withstand extreme temperatures

Creating sophisticated guidance systems that can function in a plasma environment

Designing engines capable of sustained hypersonic flight (for cruise missiles)

Strategic Implications

Hypersonic missiles are considered more strategically significant due to their potential to evade current missile defense systems and their shorter time to target, which compresses decision-making windows for military leaders.

Conclusion

Supersonic and hypersonic missiles exceed the speed of sound, hypersonic missiles operate in a different regime of speed and physics, presenting unique challenges and strategic implications that set them apart from their supersonic counterparts.