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 investment follows a major offshore flight test in which the company's aircraft autonomously flew within one metre of the ocean surface. Alteon is developing a new class of autonomous aircraft that can stay airborne for months by harvesting energy from wind gradients, without the need for conventional refuelling or landing.
Flight Test Validates Core Technology
The announcement follows an early August test that marked a critical technical milestone for the company. During the offshore flight, the prototype executed multiple consecutive loops less than one metre above the open ocean. This demonstrated the aggressive low-altitude manoeuvre that underpins Alteon's autonomous high-endurance flight strategy in real-world conditions.
Alteon's aircraft use dynamic soaring, a method inspired by albatrosses that extracts energy from wind gradients near the ocean surface. This approach removes the need for conventional refuelling and landing by keeping the aircraft aloft for extended periods. A key engineering challenge is enabling the aircraft to perform this energy-harvesting manoeuvre autonomously and reliably close to a moving ocean surface.
Founder Journey and Investor Confidence
Samay Sanghvi founded Alteon in 2025 after starting work on the concept in 2023 straight out of high school. He noted that building aircraft that fly for over a year requires solving difficult engineering problems across autonomy, structures, and aerodynamics rather than relying on one breakthrough. Without a formal engineering degree, he taught himself by building and crashing radio-controlled aircraft, and the company now has a team of 20 with early backing from Emergent Ventures and 1517.
Lead investor Lachy Groom, co-founder of Physical Intelligence, described the team's progress as remarkable and said success could put millions of aircraft essentially parked in the sky. Shubham Gupta, co-founder of Together Fund, said the ocean is the largest unwatched surface, and endurance has always been the bottleneck because every aircraft has had to land. He added that Alteon removes this assumption with aircraft that fly themselves, charge themselves from the wind, and stay up for months.
Funding Applications and Market Momentum
The new capital will support Alteon's transition from the August milestone toward achieving autonomous dynamic soaring without propulsion. The company also plans to scale research and development to deploy a fleet of long-endurance aircraft over the ocean. These aircraft could carry a range of payloads for weather and ocean mapping, ship tracking, critical infrastructure monitoring, and coordination of autonomous systems for defence and industry.
Alteon's raise comes as investor interest in India's autonomous aircraft ecosystem grows, with Airbound recently raising $37 million for lightweight autonomous delivery aircraft. The company envisions a continuous real-time layer of ocean capabilities at a fraction of the cost of ships, satellites, and large offshore installations. Persistent fleets could support authorities in detecting illegal fishing, drug trafficking, and national security threats, including those exposed by the 26/11 Mumbai attacks, through continuous observation.
By removing the endurance limits of conventional aircraft, Alteon aims to create a persistent autonomous presence over the ocean. The pre-seed funding provides resources to prove that wind-powered dynamic soaring can sustain flight without propulsion and to move toward a deployable fleet. If successful, the technology could transform maritime surveillance, enable faster responses to security threats, and create a new layer of continuous ocean intelligence at significantly lower cost.