India’s Solar-Powered Aircraft: Capable of 90-Day Nonstop Flight

The platform developed by the National Aerospace Laboratories (NAL) in Bengaluru is known as a High-Altitude Platform (HAP). It is a solar-powered autonomous unmanned aircraft designed to continuously monitor enemy territory at stratospheric levels. The HAP can operate day and night at altitudes of 17-20 km with an endurance of months.

Additionally, a HAP with a payload is referred to as a High-Altitude Pseudo Satellite (HAPS). Another prototype with a 24-hour endurance has also been developed by a startup in Bengaluru called New Space Research and Technologies. During times of conflict, HAPS can address the perpetual theatre and strategic air asset shortfall, particularly during force mobilisation, filling strategic and tactical roles of Intelligence, Surveillance, Reconnaissance (ISR) and providing battlefield communications.

The aircraft can also play an additional role in directing operations when utilized by air defense services. Currently, the only functional HAPS in the world is the Airbus Zephyr, which has demonstrated a 64-day continuous flight in the Arizona desert in the US. Many efforts are ongoing worldwide to develop such platforms, including in the US, United Kingdom, Germany, and New Zealand.

The Council of Scientific and Industrial Research-National Aerospace Laboratories (CSIR-NAL) has been testing the capabilities of the HAP. CSIR-NAL carried out a series of flight trials on the solar-secondary battery subscale High Altitude Platform vehicle at the Defence Research and Development Organisation’s aeronautical test range (ATR) at Challakere, Karnataka. The aircraft has a wingspan of nearly 12 meters and a weight of less than 22 kg when fully equipped.

Other requirements include a service ceiling of 23 km, a payload carrying capacity of 15 kg, and the ability to take off from a field with a length of 150-200 meters. NAL is aiming to achieve 90 days of HAPS operations, with plans for the final version to have a wingspan as wide as an Airbus 320 but weigh only as much as a regular motorcycle. The biggest advantage of HAPS is its ability to continuously monitor enemy territory, day or night, once equipped with the right sensors, making it a unique bird in the sky that can observe neighboring countries.