Bengaluru. Alteon, a deep-tech aerospace company building aircraft designed to remain airborne for months at a time, on September 01 announced – $2.5 million in pre-seed funding led by Lachy Groom, with participation from Together Fund. The round follows a milestone flight test in which Alteon’s aircraft demonstrated its ability to autonomously fly within a metre of the ocean’s surface. The test derisked a key part of the manoeuvre, Alteon’s autonomous high-endurance flight rests on.
Aviation has continually pushed the limits of aircraft performance, but one constraint has remained: aircraft still have to land for refuelling, maintenance and recovery. Alteon has spent more than a year developing an aircraft engineered to remain airborne for months.
Alteon is developing autonomous dynamic soaring vehicles that extract energy from wind gradients, as albatrosses do, to remain airborne for extended periods. One of the key engineering challenges is performing this autonomously close to the surface of a moving ocean.
In an early August offshore flight test, Alteon’s aircraft autonomously flew multiple consecutive loops less than a metre above the open ocean. The test cleared a major technical hurdle on the path to sustained dynamic soaring, demonstrating the aircraft could fly the aggressive manoeuvre in real offshore conditions.
“Today we already know that it is possible to gain energy from the wind using dynamic soaring. Building aircraft that fly for over a year using it, is not a matter of a single technical breakthrough but a matter of solving a range of challenging engineering problems across autonomy, structures, aero and more. As we go from measuring flight time in hours to months, the standard everything has to meet goes up with it. Ultra high endurance is downstream of ultra high efficiency, precision and reliability. Day in day out we put our aircraft in the air and learn from every build, every flight and every failure to get closer to building aircraft that can stay airborne for more than a year,” said Samay Sanghvi, Founder of Alteon.
Alteon’s next phase of testing will focus on harvesting energy from the wind until the aircraft can sustain flight without propulsion, much like the albatross.
Samay Sanghvi, started working on what would become Alteon in 2023, straight out of high school. Without a formal engineering degree teaching himself engineering by building, and crashing, radio-controlled aircraft before developing early prototypes. He received early backing from Emergent Ventures, and 1517, and formally founded Alteon in 2025. Today Alteon is a growing team of 20, based in Bengaluru.
“Samay and team are making remarkable progress toward building an airplane that can stay aloft for more than a year at a time. If they get this right, we could soon have millions of them — essentially parked in the sky — doing things that today require large ships, crews and huge amounts of infrastructure. From observing the oceans in real time and forecasting weather to science and defence,” said Lachy Groom, investor and co-founder of Physical Intelligence.
This funding will take Alteon from August’s milestone offshore test toward accomplishing autonomous dynamic soaring without propulsion, while scaling R&D toward deploying a fleet of these aircraft over the ocean.
The objective is not simply to make aircraft fly longer. It is to make continuous, autonomous presence over the ocean possible. These fleets can carry a range of payloads for applications, from mapping weather and ocean conditions, tracking ships and fishing activity to monitoring critical infrastructure, and coordinating autonomous systems across defence, search and rescue, science and industry.
Together they will create a continuous, real-time layer of capabilities over the ocean at a fraction of the cost of ships, satellites or large offshore installations.
“The ocean is the biggest unwatched surface on the planet, and the bottleneck has always been endurance: every aircraft ever built has had to land. Alteon removes that assumption entirely, with an aircraft that flies itself, charges itself from the wind, and stays up for months. We’re proud to back Samay, all of 19 when we invested, whose rare mix of engineering depth and commercial instinct convinced us he’s the one to build this,” Shubham Gupta, Co-founder, Together Fund.
A fleet that can stay airborne for months, can observe activity continuously rather than through periodic patrol. It can help authorities detect and deter activity, such as illegal fishing, drug trafficking and potentially help authorities intervene and respond to national security threats such as those exposed by the 26/11 Mumbai attacks.
