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Starcloud's Philip Johnston: Why the Cheapest Compute Will Be in Space

Sequoia CapitalMay 6, 202611m
Topics10
Introduction and Starcloud Overview0:01Starcloud 1 Deployment Video and Achievements0:30Energy Cost Comparison: Earth Solar vs. Space Solar2:01Constellation Concept Video and Scale3:00Q&A: Radiator Equation and Heat Dissipation4:31Q&A: Kessler Syndrome and Orbital Management6:30Q&A: Radiation and Bit Flips8:30Q&A: Compute Type9:015 GW Training Structure Video10:00Final Poll: When Cheaper to Run Compute in Space?11:01
In a Nutshell

Starcloud's CEO Philip Johnston demonstrates that space-based data centers, powered by 24/7 solar (8x more efficient than Earth, no land or battery costs), will deliver the cheapest compute once launch prices hit $500/kg via Starship ($10-20/kg target). Starcloud 1 already runs NVIDIA H100 GPUs in orbit, training nanoGPT and inference on Gemini/SAR data, with plans for an 88,000-satellite constellation adding 20 GW for inference workloads at $100B capex. Challenges like heat (solved via radiators and hotter Rubin chips), radiation (ground-tested), and orbits (low-risk dawn-dusk) are addressed, predicting space compute cheaper than Earth in 5-10 years.

AI-Generated Notes

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Philip Johnston, co-founder and CEO of Starcloud, builds data centers in space for energy advantages. Previous company also abused GPUs in unintended ways. Plans 5 minutes to explain why building data centers in space will soon make more sense than on Earth, followed by 5 minutes of questions.

Shows deployment video of Starcloud 1 with five NVIDIA GPUs, most significant being NVIDIA H100 chip. Separation confirmed. First to prove state-of-the-art terrestrial data center GPUs can run in space, overcoming thermal dissipation and radiation tolerance challenges (bit flips). Trained nanoGPT from Andrej Karpathy, ran version of Gemini, performed high-powered inference on SAR data (satellite data).

Compares solar project on Earth (cheapest Earth energy) to power data center vs. space:

  • Earth costs: permitted land (largest in North America), battery storage/backup (for ~4 hours peak/day), solar cells.
  • Space advantages:
    • No permitted land cost.
    • No battery storage (24/7 sun exposure).
    • 8x less solar cells needed (1 sqm space panel = 8x energy of 1 sqm Earth panel). Main space cost: launch. Break-even at ~$500/kg (10x reduction from today). Starship targets $10-20/kg.

Filed with SEC for constellation of 88,000 satellites, each ~200 kW, enabling 20 GW new compute capacity (for inference workloads: 3D video generation, back-office agents, code generation). Dawn-dusk sun-synchronous orbit: always in sun, 24/7 power, sub-50 ms latency to Earth, all optically linked. $100 billion capex (lower than terrestrial). Start of largest infrastructure project, Kardashev Type 2/3 (Dyson sphere) civilization.

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