Definition
The Coleman-Sagan equation is a method for estimating the probability of contaminating another planetary body by Earth microorganisms and was first published by S. Coleman and C. Sagan in 1965.
This formula can be written as Pc = N0 R[PS] PI PR Pg.
In planetary protection, the formulation is often used by first determining the initial number of microorganisms (N0) that could be present on or in a spacecraft (the bioburden), and then multiplying this number by an appropriately selected set of factors representing the amount by which this number could be reduced. The first reduction in proportion (R) is dependent on parameters that would reduce the number of surviving organisms, including conditions to which the spacecraft is exposed both before and after launch. Then, while present on the spacecraft, the microorganisms have to reach the surface of the planet (or other solar system target). The value PIdescribes the probability of the spacecraft to hit the planet. This value...
References
Sagan C, Coleman S (1965) Spacecraft sterilization standards and contamination of Mars. Astronaut Aeronaut 3(5):1–22
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Conley, C.A. (2022). Coleman-Sagan Equation. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-27833-4_317-4
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DOI: https://doi.org/10.1007/978-3-642-27833-4_317-4
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Coleman-Sagan Equation- Published:
- 15 March 2023
DOI: https://doi.org/10.1007/978-3-642-27833-4_317-4
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Coleman-Sagan Equation- Published:
- 02 May 2015
DOI: https://doi.org/10.1007/978-3-642-27833-4_317-3