Project Daedalus is the name of an extremely large (54,000 tons) interstellar spacecraft, designed as part of a proof-of-concept exercise. Project Daedalus was also the name of that study, conducted between 1973 and 1978 by the British Interplanetary Society. Project Daedalus continues to feature in discussions of interstellar travel. One of its requirements was that it could only be built using the current or near-future technology of the time. Daedalus was never built of course, and maybe never will be, but it helps set an interesting data point for brainstorming about interstellar travel.
The target star of Daedalus was Bernard's Star, located 5.9 light years away. At the time it was thought to have at least one planet, but the evidence this was based on has since been tossed out. Daedalus was to be unmanned, and require only 50 years to reach the target system. It was expressly designed to make it to its target in less than a human lifetime.
At its huge weight and size (190 meters), Daedalus would have needed to be constructed in orbit. Daedalus was to be powered by helium-3/deuterium pellets, the nuclei of which would be fused together by an inertial confinement laser. Fusing 150 pellets per second, large amounts of superheated plasma would be released, which would then be accelerated out the rear of the craft using a magnetic nozzle. Firing like this for about three years, Daedalus could reach 10% of the speed of light. The fuel for slowing down would weigh the craft down too much, so it wasn't included. The craft would simply fly through the Bernard's star system at 10% of lightspeed, making observations along its way, and continue forward for as long as it could avoid falling into another star or a black hole.
Some of the project specifications:
- Overall length: 190 meters
- Propellant mass first stage: 46,000 metric tons
- Propellant mass second stage: 4000 metric tons
- First stage mass empty mass: 1690 metric tons
- Second stage empty mass: 980 metric tons
- Engine burn time first stage: 2.05 years
- Engine burn time second stage: 1.76 yeard
- Thrust first stage: 754,000 Newtons
- Thrust second stage: 663,000 Newtons
- Engine exhaust velocity: 10,000km/s
- Payload mass: 450 tons
Daedalus would be an amazing craft to see built, and would return the first-ever close-up images of another stellar system. Perhaps it will be built one day, as the cost of the requisite technologies, such as space launches, come down.