Rocketry Startups funded by Y Combinator (YC) 2026

Elodin creates flight software, simulations, and hardware for drones, satellites, and defense.

Tesseract is a provider of cost effective propulsion components and systems for in-space applications spanning commercial Earth-orbiting satellites, robotic exploration missions, and human spaceflight.

Relativity is building humanity’s multiplanetary future. We invented a new approach to design, build, and fly our own rockets, starting with Terran 1 – the world’s first entirely 3D printed rocket, and Terran R, our next generation medium-heavy lift fully reusable launch vehicle. As a vertically integrated technology platform, Relativity is at the forefront of an inevitable shift toward software-defined manufacturing. By fusing 3D printing, artificial intelligence, and autonomous robotics, we are pioneering the factory of the future. Disrupting 60 years of aerospace, Relativity offers a radically simplified supply chain, building a rocket with 100x fewer parts in less than 60 days. We believe in a future where interplanetary life fundamentally expands the possibilities for human experience. Our long-term vision is to upgrade humanity’s industrial base on Earth and on Mars.