Definition
The Coleman-Sagan equation is used for establishing 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 \( {P}_{\mathrm{c}}={N}_0\;R{P}_{\mathrm{S}}\;{P}_{\mathrm{I}}\;{P}_{\mathrm{R}}\;{P}_{\mathrm{g}} \).
In planetary protection, the formulation is often used by determining the initial number of microorganisms (N 0) that could be present on or in a spacecraft and multiplying this number by an appropriately selected set of factors representing the probability this number could be reduced. The first reduction in proportion (R) is depending on various parameters, 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. The value P I describes the probability of the spacecraft to hit the planet. This value is ranging from 10−5for a...
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References and Further Reading
Sagan C, Coleman S (1965) Spacecraft sterilization standards and contamination of Mars. Astronaut Aeronaut 3(5):1–22
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© 2014 Springer-Verlag Berlin Heidelberg
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Conley, C.A. (2014). Coleman-Sagan Equation. In: Amils, R., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-27833-4_317-3
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DOI: https://doi.org/10.1007/978-3-642-27833-4_317-3
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Publisher Name: Springer, Berlin, Heidelberg
Online ISBN: 978-3-642-27833-4
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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