- Why in news
- On May 9, 2026, DRDO's DRDL ran its actively cooled full-scale scramjet combustor for over 1,200 seconds at the SCPT facility in Hyderabad, up from over 700 seconds in January 2026.
- What it is
- A scramjet is a supersonic combustion ramjet, an air-breathing engine with no moving compressor. It takes oxygen from the atmosphere at hypersonic speed (above Mach 5) and burns fuel in supersonic airflow. DRDL, Hyderabad, is building it for India's Hypersonic Cruise Missile programme.
- Fuel
- The engine uses an indigenously developed liquid hydrocarbon endothermic fuel. Such a fuel absorbs heat, which helps cool the engine.
- Who built it
- DRDL designed and developed the combustor, and industry partners realised it.
- Purpose
- The test is a foundation for the Hypersonic Cruise Missile Development Program.
- Hypersonic speed
- Hypersonic means speed above Mach 5. A scramjet works only at such speeds and needs a booster to reach them.
Don’t confuse with Scramjet vs ramjet: A ramjet burns fuel in subsonic airflow after slowing the air. A scramjet burns it in supersonic airflow and works at higher Mach numbers.
Don’t confuse with Hypersonic cruise missile vs hypersonic glide vehicle: A cruise missile is powered by an air-breathing engine throughout flight. A glide vehicle is boosted by a rocket and then glides unpowered.
Science and technology: 57 Prelims questions since 2013; most test the concept behind the news, not the news itself. In Mains, 12 news-triggered questions.
Why it matters
- Sustained scramjet run-time is a key step towards operational hypersonic cruise missiles.
- It builds indigenous defence technology and involves industry and academia.
Problems
- Extreme heat and materials limits make long flights hard.
- Ground tests must still be turned into flight tests and then into reliable systems.
Way forward
- Move from ground tests to full-scale flight tests.
- Strengthen the test infrastructure and the industry supply chain.
Put in your answer
SCPT facility, Hyderabad: The Scramjet Connect Pipe Test facility validated the combustor design and the facility's own capability.
- 2022Prelims Q34Idea behind the Fractional Orbital Bombardment System missile concept.
- 2023Prelims Q58Ballistic versus cruise missile propulsion, and classifying Agni-V and BrahMos.
UPSC’s own questions that come close to this issue, from our Prelims and Mains banks.
Prelims practice · Single answer
Ours, not from a UPSC paper
Consider the following statements about the scramjet engine tested by DRDO in May 2026: 1. It burns fuel in a supersonic airflow inside the combustor. 2. It uses a multi-stage rotating compressor to compress the incoming air. 3. The combustor was designed and developed by DRDL and realised by industry partners. 4. It can produce thrust from a standstill without any booster.
How many of the above statements are correct?
True or false?
1 of 6
Statements the way Prelims prints them. Say first, then see the fact.
1.A scramjet engine burns fuel in a supersonic airflow inside the combustor.
True. Scramjet stands for supersonic combustion ramjet.
2.A scramjet engine uses a multi-stage rotating compressor to compress incoming air.
False. It has no rotating compressor; compression comes from the vehicle's high speed and the shape of the intake.
3.Hypersonic speed means speeds above Mach 5.
True. Hypersonic is defined as above Mach 5.
4.The combustor was designed and developed by the Indian Space Research Organisation with DRDO as testing partner.
False. DRDL, a DRDO laboratory, designed and developed it, and industry partners realised it.
5.The May 2026 run was longer than the earlier January 2026 test of over 700 seconds.
True. The May run exceeded 1,200 seconds.
6.A scramjet can produce thrust from a standstill without any booster.
False. A scramjet needs a booster to reach supersonic speed before it can operate.
Written by us from the release, not by UPSC; checked by a second model.
Worth revising until Prelims 2027: most news questions come within two years of the event.