The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

Daedalus, Project
One of the first detailed design studies of an interstellar
spacecraft. 30 Conducted from 1973 to 1978 by a group of
a dozen scientists and engineers belonging to the British
Interplanetary Society, led by Alan Bond, it demonstrated
that high-speed, unmanned travel to the stars is a
practical possibility. Certain guidelines were adopted: the
Daedalus spacecraft had to use current or near-future
technology, be able to reach its destination within a
human lifetime, and be flexible enough in design that it
could be sent to any of a number of target stars. These
guidelines ensured that the spacecraft would be practical,
that those who worked on the project might live to see it
achieve its goals, and that several stars could be investigated
using the same type of vehicle. The selected target
was Barnard’s Star, a red dwarf 5.9 light-years from the
Sun. Although the Alpha Centauri system is closer, evidence
available at the time (now considered unreliable)
suggested that Barnard’s Star might be orbited by at least
one planet. To reach Barnard’s Star in 50 years, the flighttime
allotted in the study, a spacecraft would need to
cruise at about 12% of the speed of light, or 36,000
km/s. This being far beyond the scope of a chemical
rocket, the Daedalus team had to consider less conventional
alternatives. The design they chose was a form of
nuclear-pulse rocket, a propulsion system that had
already been investigated during Project Orion. However,
whereas Orion would have employed nuclear fission,
the Daedalus engineers opted to power their
starship by nuclear fusion—in particular, by a highly efficient
technique known as internal confinement fusion.
Small pellets containing a mixture of deuterium and
helium-3 would be bombarded, one at a time, in the
spacecraft’s combustion chamber by electron beams and
thereby caused to explode like miniature thermonuclear
bombs. A powerful magnetic field would both confine
the explosions and channel the resulting high-speed
plasma out of the rear of the spacecraft to provide thrust.
By detonating 250 pellets a second, and utilizing a twostage
approach, the desired cruising speed could be
reached during an acceleration phase lasting four years.
Daedalus would be constructed in Earth orbit and
have an initial mass of 54,000 tons, including 50,000 tons
of fuel and 500 tons of scientific payload. The first stage
would be fired for 2 years, taking the spacecraft to 7.1%
of light-speed, before being shut down and jettisoned.
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Then the second stage would be fired for 1.8 years before
being shut down to begin the 46-year cruise to Barnard’s
Star. Since the design made no provision for deceleration
upon arrival, Daedalus would carry 18 autonomous
probes, equipped with artificial intelligence, to investigate
the star and its environs. The 40-m diameter engine
of the second stage would double as a communications
dish. On top of the second stage would be a payload bay
containing the probes, two 5-m optical telescopes, and
two 20-m radio telescopes. Robot “wardens” would be
able to make in-flight repairs. A 50-ton disc of beryllium,
7 mm thick, would protect the payload bay from collisions
with dust and meteoroids on the interstellar phase
of the flight, while an artificially generated cloud of particles
some 200 km ahead of the vehicle would help disperse
larger particles as the probe plunged into the
presumed planetary system of the target star.
En route, Daedalus would make measurements of the
interstellar medium. Some 25 years after launch, its
onboard telescopes would begin examining the area
around Barnard’s Star to learn more about any accompanying
planets. The information gathered would be fed
to the computers of the probes, which would be
deployed 1.8 to 7.2 years before the main craft entered
the target system. Powered by nuclear-ion drives and carrying
cameras, spectrometers, and other sensory equipment,
the probes would fly quickly past any planets
looking especially for any signs of life or conditions
favorable for biology.
Damblanc, Louis (1889–1969)
A civil engineer at the Institut des Arts et Métiers in Paris.
Between 1932 and 1935, he performed experiments with
black-powder rockets in order to develop better signaling
devices for the Coast Guard and others. He was among
the first to carry out methodical tests of the principle of
staging. 71
DARA (Deutsche Agentur für
Raumfahrtangelegenheiten)
The present German space agency, formed through consolidation
of the old West and East German space agencies.
While DARA is instrumental in establishing space
policy and goals and is the interface with ESA (European
Space Agency), DLR (the German Center for Aerospace
Research) conducts the technical and scientific research