Alteon Raises $2.5M to Develop Ultra-Long-Endurance Autonomous Aircraft

Bengaluru-based deep-tech aerospace startup Alteon has raised $2.5 million in a pre-seed funding round led by Lachy Groom, with participation from Together Fund.

The fresh capital will support offshore testing of Alteon's autonomous aircraft as the company works toward achieving dynamic soaring without propulsion. The startup also plans to expand its R&D efforts and deploy a fleet of ultra-high-endurance aircraft over the ocean.

Building Aircraft That Can Stay Airborne for Months

Founded in 2025 by Samay Sanghvi, Alteon is developing autonomous aircraft designed to remain airborne for extended periods by harvesting energy from the atmosphere.

The company's aircraft use a technique known as dynamic soaring, which allows them to extract energy from differences in wind speed and direction.

The concept is inspired by albatrosses, which can travel long distances over the ocean while using atmospheric energy rather than relying continuously on powered flight.

Testing Autonomous Flight Near the Ocean

A major challenge for Alteon is enabling its aircraft to perform dynamic soaring autonomously close to the ocean surface.

The company recently completed a flight test in which its aircraft demonstrated autonomous flight within one metre of the ocean's surface.

The test helped reduce technical risk around a key part of the manoeuvre required for the company's long-endurance flight system.

Alteon now plans to conduct offshore tests designed to demonstrate autonomous dynamic soaring without propulsion.

Moving Toward Propulsion-Free Flight

The company's long-term objective is to develop aircraft that can progressively harvest energy from wind gradients and eventually sustain flight without propulsion.

If successful, the technology could enable aircraft to remain airborne for significantly longer periods while reducing the energy requirements associated with conventional autonomous aircraft.

The startup is now working toward scaling its technology from individual tests to fleets of autonomous aircraft operating over the ocean.

Applications Across Ocean Monitoring and Defence

Alteon's aircraft are designed to carry payloads for a range of applications.

Potential use cases include mapping weather and ocean conditions, monitoring shipping and fishing activity, tracking critical infrastructure and supporting defence operations.

The aircraft could also be used for search and rescue, scientific research and industrial monitoring.

By operating continuously over large areas, Alteon believes its aircraft fleets could provide persistent intelligence and monitoring capabilities at a lower cost than traditional options such as ships, satellites and large offshore installations.

Scaling an Autonomous Aircraft Fleet

The new funding will allow Alteon to increase its research and development activities and move toward deploying multiple aircraft over the ocean.

The company is focused on developing autonomous systems capable of operating for extended periods with minimal human intervention.

Its approach combines aerospace engineering, autonomous flight systems and atmospheric energy harvesting into a specialized platform for persistent operations.

Growing Interest in India's Autonomous Aerospace Sector

Alteon's funding comes as investor interest in India's autonomous aircraft and aerospace ecosystem continues to grow.

Other Indian startups are also developing autonomous aircraft for applications ranging from delivery to defence and surveillance.

While dynamic-soaring aircraft remain an early and highly specialised technology, growing investment in autonomous flight and advanced aerospace systems is creating opportunities for startups developing alternatives to conventional aircraft and drone platforms.

With its focus on propulsion-free flight and long-endurance autonomous operations, Alteon is targeting a specialised segment of the emerging aerospace market.