Saturday, January 30, 2010
Just a sample of some of the cool images of this hypothetical interstellar spacecraft.
"Project Daedalus was a study conducted between 1973 and 1978 by the British Interplanetary Society to design a plausible interstellar unmanned spacecraft. A dozen scientists and engineers led by Alan Bond worked on the project, and settled on proposing a fusion rocket as its drive.
The design criteria had specified that the spacecraft had to use current or near-future technology and had to be able to reach its destination within a human lifetime (a flight time of 50 years was allocated). However, as noted above, it was not to be manned, being intended mainly as a scientific probe.
The target chosen was Barnard's Star, 5.9 light years away, which at the time was believed to possess at least one giant planet (the evidence on which this belief was based has since been discredited). However, the design was required to be flexible enough that it could be sent to any of a number of other target stars.
Project Daedalus is not considered feasible within the 21st century due to economic reasons."
Overall length: 190 meters
Propellant mass first stage: 46,000 metric tons (!)
Propellant mass second stage: 4,000 metric tons
First stage empty mass: 1,690 metric tons
Second stage empty mass: 980 metric tons
Engine burn time first stage: 2.05 years
Engine burn time second stage: 1.76 years
Thrust first stage: 7,540,000 newtons
Thrust second stage: 663,000 newtons
Engine exhaust velocity: 10,000,000 m/s (!)
Payload mass: 450 metric tons
This is a great project, but is likely to remain just a mental exercise. It is almost always better to put the money and effort into making larger and larger telescopes. Interstellar travel may offer large baseline parallax measurements, but other than that it is basically a matter of attempting something hard for the sake of doing something hard. That has certain intrinsic value to humans, but at this scale it is hard to justify the trillions of dollars and century or more of mission time. KM scale optical telescopes could probably get similar amounts of info about neighbor stars and solar systems for less money. And it only takes a few decades at most to build one of these, Daedalus would probably consume much of a century before even launching.