Project Daedalus (1973-1978)

A 5-year study by the British Interplanetary Society (BIS) for an unmanned interstellar flyby probe powered by fusion. The first detailed engineering study of a fusion-powered starship.

Key Facts

  • Organization: British Interplanetary Society
  • Target: Barnard’s Star (5.96 ly)
  • Speed: 0.12c (36,000 km/s)
  • Travel time: ~50 years
  • Total mass: 54,000 tonnes (mostly fuel)
  • Payload: 450 tonnes
  • Fuel: Helium-3 / Deuterium pellets (He3 mined from Jupiter’s atmosphere)
  • Propulsion: Inertial confinement fusion — 250 fusion micro-explosions per second
  • Mission type: Flyby only (no deceleration)

Design Highlights

  • Two-stage design (like a rocket): Stage 1 burns for 2 years, Stage 2 for 1.8 years
  • Autonomous: 50-year flight with no human intervention; self-repairing via onboard robots
  • Sub-probes: 18 smaller probes deployed before arrival to study the target system from multiple angles during flyby
  • Designed with only near-term physics — no speculative technology, just scaled-up engineering

Legacy

  • Proved fusion-powered interstellar travel is physically feasible
  • Identified He3 mining from gas giants as a key enabler
  • Successor study: Project Icarus (2009-present, Tau Zero Foundation + BIS) — updating Daedalus with modern technology

See Also