Maarg Manthan · Topic 16.6

Hypersonic Glide Vehicles and Hypersonic Cruise Missiles

Science & Technology › Defence Technology and Missile Systems · Topic 16.6

Hypersonic weapons fly at speeds above Mach 5, five times the speed of sound, which is more than about 6,200 km per hour. There are two main types. A hypersonic glide vehicle is launched on a rocket to high altitude, is released, and then glides toward the target at hypersonic speed while manoeuvring in the upper atmosphere. A hypersonic cruise missile is powered by a scramjet, a supersonic combustion ramjet engine that burns fuel in air flowing through at supersonic speed, throughout its flight. Because they fly lower than ballistic missiles and can change course, they are hard to detect and intercept. India tested the Hypersonic Technology Demonstrator Vehicle on 7 September 2020 at Mach 6 and a long range hypersonic anti-ship missile in November 2024.

5 min read · UPSC Prelims · Science & Technology · Defence Technology and Missile Systems

At a Glance

Speed Above Mach 5
Type 1 Glide vehicle, rocket boosted
Type 2 Scramjet cruise missile
Indian test HSTDV, 7 September 2020
Challenge Heat, tracking, defence
Exam link UPSC Prelims, Science & Technology: Defence Technology and Missile Systems

Where Does It Fit?

This topic follows the account of anti-ballistic missiles. It covers weapons that are hard to defend against, and links to the earlier topics on missile classes and to the later topic on air defence. Previous topic: Anti-Ballistic Missile System. Next topic: Unmanned Aerial Vehicles (UAVs) and Drone Technology.

What Are Hypersonic Glide Vehicles and Cruise Missiles?

Type	Features
Hypersonic glide vehicle	A re-entry vehicle launched by a ballistic rocket that separates and glides at Mach 5 to 20 or more at 30 to 70 km altitude, flatter than a ballistic arc, with ability to manoeuvre. Examples: Russia’s Avangard, China’s DF-17 and the United States Army’s Dark Eagle
Hypersonic cruise missile	Powered by a scramjet throughout, flying at 20 to 30 km at Mach 5 to 10. Examples: Russia’s Zircon, and India’s HSTDV project
Scramjet	A ramjet in which air flows through the engine at supersonic speed. It needs a booster to reach speed first and has no moving compressor
Trajectory	Lower than ballistic missiles and not predictable, so radars on the ground see them late
Heat problem	Friction heats the surface to thousands of degrees, so special materials and cooling are needed
Guidance	Inertial, satellite and seeker based, with plasma around the vehicle disturbing signals
Differences from ballistic	Ballistic missiles are fast but follow a predictable arc and can be tracked

What Is India’s Position?

HSTDV: Hypersonic Technology Demonstrator Vehicle, tested on 7 September 2020 from Abdul Kalam Island, flew at about Mach 6 for 20 seconds with a scramjet
Scramjet ground test: DRDO reported an active cooled scramjet combustor test of about 1,000 seconds in April 2025 at Hyderabad
Long range hypersonic anti-ship missile: tested in November 2024 from Abdul Kalam Island with a range reported at over 1,500 km, with a payload of conventional and other warheads
BrahMos-II: a planned Mach 7 hypersonic version with Russia
Hypersonic wind tunnel: DRDO has test facilities and a hypersonic wind tunnel in Hyderabad
Mission: a mission to develop hypersonic technology for both defence and for reusable space vehicles
Global race: Russia, China and the United States have deployed or tested such weapons, and others including France, Japan, India and Australia have programmes
Caution: many test details are from official or media sources, and results should be checked

What Else Should You Remember?

Mach number: 5 times speed of sound, about 6,100 km per hour at altitude
High supersonic: Mach 3 to 5 is high supersonic
Pioneer X-43A: a NASA scramjet research aircraft that reached about Mach 9.6 in 2004
Waverider: an aircraft shape that rides its own shock wave, used for efficiency
Kinzhal: a Russian air-launched missile claimed to reach Mach 10, which is a modified ballistic missile
Avangard: Russia declared it operational in 2019
DF-ZF: a Chinese glide vehicle on the DF-17
Anti-ship use: a hypersonic weapon can strike moving aircraft carriers
Defence difficulty: existing interceptors are designed for predictable ballistic paths
Space sensors: satellite constellations that track hypersonic flights are being developed
Arms control: these weapons are not covered by older treaties
Strategic stability: short warning time may raise the chance of mistaken escalation
Dual use: scramjet technology could lower the cost of access to space
ISRO link: ISRO tested a scramjet engine in 2016 on an Advanced Technology Vehicle
Materials: carbon-carbon composites and ceramics resist heat
Link: speed classes are in Classification of Missiles: Ballistic vs Cruise Missiles
Link to BrahMos: the supersonic cousin is in BrahMos Missile System
Test infrastructure: ground test facilities for scramjets are costly, and flight tests give only short data
Plasma sheath: air around the vehicle becomes ionised and blocks radio signals, making control hard
Why pursue them: speed shortens the time an enemy has to react, which is the main military gain

Why Does It Matter for the Exam?

Definition: above Mach 5
Types: glide vehicle versus scramjet cruise
Indian tests: HSTDV 2020, anti-ship 2024
Current affairs link: new tests and global deployments
Common errors: calling ballistic missiles hypersonic weapons or BrahMos hypersonic

As an analytical point, hypersonic weapons reduce warning time and challenge missile defence. India’s work aims at a basic capability, and the key challenges are materials, engines and testing.

Why Is This Topic Important?

Types HGV and HCM
Engine Scramjet
India HSTDV

What Came Next?

The next topic covers unmanned aerial vehicles and drone technology. Next topic: Unmanned Aerial Vehicles (UAVs) and Drone Technology.

Key People and Terms

HGV Hypersonic glide vehicle
HCM Hypersonic cruise missile
Scramjet Supersonic combustion ramjet
HSTDV Hypersonic Technology Demonstrator Vehicle
Waverider Shape riding its shock wave
Plasma blackout Signal loss during hypersonic flight

Exam Corner

Points to Remember

Hypersonic: above Mach 5.
HSTDV test: 7 September 2020, about Mach 6.
Scramjet needs a booster.
Avangard: Russia, 2019.
Anti-ship hypersonic test: November 2024.

Do Not Confuse With

HGV and HCM Glider on a rocket versus scramjet powered
Ramjet and scramjet Subsonic combustion versus supersonic combustion
Ballistic and hypersonic Predictable arc versus manoeuvring

Memory Hook

Mach five is the line; glide or scram; HSTDV flew in twenty-twenty.

Mains Angle

Questions ask for definitions and Indian tests. These points help.

Threat Short warning
Tech Materials
India Programme

A Question You May Face

An original practice question, not a past paper question.

“What are hypersonic weapons? Discuss the challenges they pose to missile defence and India’s capability.”

How to Answer

Define Mach 5.
Types Two.
Challenge Defence.
India HSTDV.

GS Relevance

Prelims: hypersonic definition, HGV versus HCM, scramjet, HSTDV, countries. GS Paper 3: defence technology.

Frequently Asked Questions

What is a hypersonic missile?

A hypersonic missile is one that flies faster than Mach 5, five times the speed of sound, and can usually manoeuvre during flight. It may be a glide vehicle launched by a rocket or a cruise missile powered by a scramjet engine, and it is difficult to detect and intercept because of its speed and flat path.

What is a scramjet engine?

A scramjet, or supersonic combustion ramjet, is an air-breathing engine in which air flows through at supersonic speed and fuel burns in that fast stream. It has no compressor or turbine, and works only above about Mach 4, so a booster is needed. India tested one in the HSTDV in 2020.

What is the HSTDV?

The Hypersonic Technology Demonstrator Vehicle is a DRDO project to prove scramjet technology for hypersonic flight. It was tested successfully on 7 September 2020 from Abdul Kalam Island, flying at about Mach 6 for about 20 seconds, making India the fourth country to demonstrate such a vehicle.

How is a hypersonic glide vehicle different from a ballistic missile?

A ballistic missile follows a predictable high arc after the boost and mostly cannot change course. A hypersonic glide vehicle is released from a rocket at high altitude and then glides in the upper atmosphere at hypersonic speed on a flatter path, changing direction, which makes it harder to predict and intercept.

Which countries have hypersonic weapons?

Russia, which declared Avangard operational in 2019 and has used Kinzhal and Zircon, and China, with the DF-17, are the leading users. The United States has tested several systems, and India, France, Japan, Australia and others have programmes. The exact status of each system changes quickly.

PYQ Practice — Statement Analysis

1 Hypersonic speed means above Mach 5.

True

Five times the speed of sound.

2 A scramjet engine has a rotating compressor.

False

It has no moving compressor.

3 HSTDV was tested in 2020.