DEFINITION
A "Bracewell probe" is a hypothetical concept for an autonomous spaceraft dispatched by a civilisation for the express purpose of communicating with other (alien) civilizations. It was proposed by the physicist and radio astronomer in a 1960 paper, as an alternative to interstellar radio communication between widely separated civilizations.
BRACEWELL PROBES
A Bracewell probe would be an autonomous robotic space probe with some degree of intelligence and it would contain information that its originating civilisation might wish to communicate with any other technological civilisation it might encounter.
It would seek out other civilisations or monitor other stellar systems where it felt there was a reasonable chance of technological civilisations arising. Once it encountered such a civilisation it would attempt to communicate with it axchange information over much shorter time scales and larger information band widths than would be possible using direct radio communication between stellar systems.
The Bracewell probe would thus act as a local ambassador of their home civilisation and would act as the primary point of contact between the two cultures.
EXAMPLES IN SCIENCE FICTION
RONALD BRACEWELL
Ron Bracewell was an Australian scientist and engineer. He lived from 1921 to 2007. His last position was as Lewis M Terman Professor of Electrical Engineering at the Space, Telecommunications and Radioscience Laboratory at Stanford University in the USA. He returned to Australia after his 'retirement'.
The Galactic Club was a term coined by Ron Bracewell to describe a Galaxy-wide communicty of advanced technological civilisations - that only admitted other civilisations when they had developed a sufficient level of proficiency in technology.
REFERENCES
1 Bracewell, R. N. . Communications from Superior Galactic Communities. Nature. 186 (4726): 670–671 (1960).
2 Bracewell, Ronald N., The Galactic Club: Intelligent Life in Outer Space, Stanford Alumni Association (1974)
Australian Space Academy