# Philip Johnston

> Philip Johnston is the co-founder and CEO of Starcloud, the company putting AI data centers into orbit. In November 2025 his team flew an Nvidia H100 GPU to space aboard Starcloud-1, then trained the first large language model off-planet. Five months later the company raised a $170M Series A and became the fastest unicorn in Y Combinator history. A British applied mathematician and ex-McKinsey space-agency consultant, Johnston argues the cheapest place to build a gigawatt-scale data center is no longer Earth - it is low Earth orbit, where sunlight is free and the cold of space does the cooling.

- **Role:** Co-Founder & CEO at Starcloud
- **Organizations:** Starcloud, Opontia, McKinsey & Company
- **From:** Guildford, Surrey, United Kingdom
- **Nationality:** British
- **Education:** BSc Hons (First-class) Applied Mathematics, University of Nottingham, MA Applied Mathematics, Columbia University, MBA, The Wharton School, MPA National Security & Technology, Harvard Kennedy School
- **Known for:** Co-founded and leads Starcloud, the first company to operate a high-powered GPU and train an LLM in space, Launched Starcloud-1 (Nov 2025) with an Nvidia H100, ~100x more powerful than any prior space GPU, Built the fastest unicorn in Y Combinator history - $1.1bn just 17 months after the program

## Career timeline

- **2008-2010** — Software engineer working on high-frequency algorithmic trading; later venture capital work in South Africa
- **2019-2021** — Associate at McKinsey & Company, advising national space agencies on satellite programs
- **2021** — Co-founded Opontia, a digital brand aggregator; raised $20M seed and $42M Series A
- **2024** — Co-founded Starcloud (originally Lumen Orbit) to build orbital data centers
- **2024** — Completed Y Combinator (S24); raised a $21M seed round
- **2025-11** — Launched Starcloud-1 carrying an Nvidia H100 GPU - the most powerful GPU ever operated in space
- **2025-12** — Ran Google DeepMind's Gemma and trained Andrej Karpathy's nanoGPT in orbit - first LLM training in space
- **2026-03** — Raised $170M Series A; Starcloud hit a $1.1bn valuation, the fastest unicorn in Y Combinator history

## Achievements

- Co-founded and leads Starcloud, the first company to operate a high-powered GPU and train an LLM in space
- Launched Starcloud-1 (Nov 2025) with an Nvidia H100, ~100x more powerful than any prior space GPU
- Built the fastest unicorn in Y Combinator history - $1.1bn just 17 months after the program
- Raised a $170M Series A with backing from Nvidia, In-Q-Tel and Y Combinator
- Previously co-founded Opontia, ranked 12th on Forbes Middle East's Top 50 most-funded startups
- TED / TEDAI San Francisco 2025 speaker on AI data centers in space
- Student body president at Harvard Kennedy School

## Latest updates

- **2026-03** — Closed a $170M Series A and crossed a $1.1bn valuation, becoming YC's fastest unicorn.
- **2025-12** — Trained the first large language model in orbit and ran DeepMind's Gemma on Starcloud-1.
- **2025-11** — Launched Starcloud-1 with an Nvidia H100 GPU into low Earth orbit.

## Links

- Website: https://starcloud.com
- LinkedIn: https://www.linkedin.com/in/philipjohnst0n/
- Twitter/X: https://x.com/PhilipJohnst0n
- YouTube: https://www.youtube.com/watch?v=v_NhQkOGEPA
- Instagram: https://www.instagram.com/philipjohnst0n/

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Profile page: https://yespress.io/philip-johnston
Published by YesPress — https://yespress.io
Last updated: 2026-06-27