DRDO’s indigenous High-Altitude Platform System (HAPS) during its successful flight test at stratospheric altitude.
The Defence Research and Development Organisation (DRDO) has successfully flight-tested an indigenously developed High-Altitude Platform System (HAPS), taking the experimental platform to an altitude of 21 km above mean sea level.
The platform remained at an altitude of around 20 km for more than 30 minutes before it was commanded to descend. It was subsequently recovered successfully, while the flight performance data was analysed.
The system has been designed and developed by DRDO’s Aerial Delivery Research and Development Establishment (ADRDE), Agra, as a lighter-than-air platform for long-endurance operations in the stratosphere.
What happened during the test?
During the experimental flight, the HAPS reached a maximum altitude of 21 km and demonstrated its ability to maintain an altitude of 20 km for over 30 minutes.
Real-time video and other vehicle parameters were transmitted from the airborne platform to a Ground Control Station throughout the flight. According to the Defence Ministry, the data received during the flight indicated that the system performed as intended.
The platform carried several instrumentation and control systems, including an inertial measurement unit, GPS receiver, onboard cameras and an altitude-control mechanism, along with other instrumentation and control systems.
The trial was conducted in coordination with the Indian Air Force, Centre for Military Airworthiness and Certification (CEMILAC), Directorate General of Civil Aviation (DGCA), Airports Authority of India (AAI) and other civil authorities.
What is HAPS?
HAPS stands for High-Altitude Platform System.
It is an unmanned platform designed to operate at very high altitudes, generally in the stratosphere, much higher than conventional aircraft.
Unlike satellites, which orbit Earth, a HAPS operates within the atmosphere. Unlike conventional aircraft, it is designed to operate at high altitude for extended periods while carrying sensors, instruments or other equipment.
DRDO’s tested platform is specifically a lighter-than-air system, meaning it uses buoyancy to remain airborne rather than relying entirely on aerodynamic lift. In simple terms, it can be understood as a stratospheric airship designed to operate at very high altitude.
Because HAPS platforms are designed for long-duration operation at high altitude, the technology can potentially support applications such as persistent aerial surveillance and other missions requiring long-duration observation, depending on the platform’s configuration and payload.
Why is the 21-km altitude significant?
The stratosphere begins above the troposphere, where most commercial aviation and weather activity takes place. Operating at around 20 km puts the platform well above the normal operating altitudes of commercial aircraft.
At this height, a HAPS can potentially provide a wide-area view while remaining within the atmosphere rather than operating in space. This can make the technology useful for missions that require persistent observation over an area.
The latest trial is significant because it demonstrated that the indigenous platform could reach the stratosphere, maintain an altitude of around 20 km for more than 30 minutes and transmit real-time data while carrying onboard systems.
India’s HAPS development
This is not DRDO’s first test of its stratospheric airship technology.
In May 2025, ADRDE conducted the maiden flight trial of its Stratospheric Airship Platform from the Sheopur trial site in Madhya Pradesh. That platform reached around 17 km altitude, carried an instrumental payload and remained airborne for approximately 62 minutes.
The latest test takes the platform to a higher demonstrated altitude and provides further flight data for the continued development of India’s indigenous high-altitude airship technology. The two trials had different flight profiles and objectives, so the results should not be treated as a direct performance comparison.
Defence Minister Rajnath Singh congratulated DRDO, the Indian Air Force, public sector undertakings and industry partners involved in the trial. He described the successful test as an important milestone towards developing a long-endurance stratospheric airship in India.
The successful flight therefore marks another step in India’s development of indigenous high-altitude platforms that could eventually support long-duration surveillance and other missions from the stratosphere.
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