Explained: What Are Hypersonic Missiles And Why Countries With Nukes Need Them

India successfully tested its first long-range hypersonic missile earlier today (November 16, 2024) from Dr APJ Abdul Kalam Island, Odisha. Developed by DRDO, the missile can carry multiple payloads and has a range of over 1,500 km.

Hypersonic missiles are a class of advanced weapon systems that travel at speeds greater than Mach 5, or five times the speed of sound.

While such speeds have been associated with ballistic missiles for decades, what sets hypersonic weapons apart is their use of aerodynamic lift to manoeuvre within the atmosphere, significantly enhancing their capabilities compared to traditional ballistic missiles.

Historically, ballistic missiles follow a predictable, parabolic trajectory, launched into space and then re-entering the atmosphere in a high-speed arc toward their target. While these missiles can achieve hypersonic speeds during their descent, they lack the ability to change course once launched.

In contrast, the new generation of hypersonic weapons utilizes “boost-glide” technology. After being launched by a rocket booster, these vehicles re-enter the atmosphere at hypersonic speeds and are guided towards their target using aerodynamic lift. Unlike ballistic missiles, which follow a fixed trajectory, boost-glide vehicles can perform evasive maneuvers during flight, making them extremely difficult to intercept.

The ability to maneuver at such high speeds under the guidance of aerodynamic lift significantly reduces the time it takes to reach their targets, making them harder to track and intercept with current missile defense systems.

The ranges of boost-glide hypersonic weapons can extend into the thousands of kilometers, effectively making them equivalent to intercontinental ballistic missiles (ICBMs). This capability makes them attractive to nations with nuclear arsenals, as they offer a potential way to bypass existing defense mechanisms and ensure that nuclear deterrence remains credible.

Scramjet propulsion allows the missile to maintain hypersonic speeds without the need for traditional rocket propulsion, making it more efficient for long-range attacks. This type of missile offers the same speed and maneuverability benefits but uses a different engine architecture.

The significance of hypersonic missiles, especially for countries with nuclear capabilities, lies in their ability to defeat modern missile defense systems. Ballistic missile defense systems, such as those designed to intercept ICBMs, are built to track and intercept missiles following predictable, high-altitude trajectories.

However, the maneuverability and speed of hypersonic missiles render these defense systems ineffective, as they are unable to adjust quickly enough to counter the missile’s evasive actions.

For nuclear-armed nations, hypersonic missiles offer an additional layer of security by ensuring that their nuclear weapons remain viable even in the face of advanced defense systems. The ability of these missiles to change course mid-flight and fly at extreme speeds makes them a strategic asset that could potentially overwhelm or avoid interception. This new class of weapons, therefore, not only improves offensive capabilities but also strengthens the credibility of a nation’s nuclear deterrent.

The development of hypersonic missiles is a technical challenge due to the extreme conditions they face during flight. The high speeds generate intense heat due to atmospheric friction, requiring advanced materials capable of withstanding these temperatures, such as carbon-carbon composites or heat-resistant alloys.

Additionally, the propulsion systems—whether scramjets or rocket boosters—need to operate efficiently at such extreme velocities, further complicating the engineering. The guidance systems also need to be precise, relying on advanced inertial navigation and possibly even artificial intelligence to adjust the missile’s course in real time.