There is a long history of planetary protection used by space programs. The SALEGOS group of specialists discussed the possibility of using experience gained from such protection for developing a framework for constructing a procedure for the defense of Lake Vostok against contamination. It is considered that the challenges faced by subglacial lake exploration resemble those of planetary exploration. The essential goal of planetary protection is to prevent contamination by foreign organisms during exploration for life - the goal in subglacial lake exploration is the same. The U.S. National Research Council program entitled "Preventing the Forward Contamination of Europa" may be used as an example because their procedures are beneficial toward understanding the applicability to Lake Vostok.
NASA recommends that components of the equipment should be cleaned often and individually using different techniques depending on the durability of the component. Current Mars mission protection requires that missions not carrying life detection experiments must be cleaned to ensure that the total "bioload" does not exceed 300,000 spores and the "density" of the spores on the surface does not exceed 300 spores per square meter. Missions comprised of life detection experiments should be put through additional cleaning to ensure that the total "bioload" does not exceed 30 spores. Efficiency of these cleaning operations depends on the types and numbers of micro-organisms, their resistance to treatment, and comparability between the device being cleaned and technique being used. In our example there is a conclusion that for each future mission to Europa the probability of contamination of a subglacial ocean of Europa by viable micro-organisms brought from the Earth should be less than one in ten thousand. Problems of biological contamination connected with Europa are discussed in detail by Richard Greenberg in his book Europa, the Ocean Moon. The group of specialists on planetary studies suggested a procedure for a calculation to determine whether each particular Europa mission met the mission's requirements and a group of specialists on the study of subglacial lakes (SALEGOS) should do the same.
The group was unable to reach complete agreement on cleanliness standards for "bioloads" for subglacial lake studies. The agreed basic concept is that "... the 'bioload' on any instrument package should be at such a level that incidental transport of organisms into the study site is reduced to a sufficiently low probability" (Kennicut, 2001). However, this declaration means nothing, because we still have no idea about specifying ''such a level'' in quantitative form. The author's point of view is closer to the view of the minority of the SALEGOS group, which thinks that organisms, which can be introduced into the Lake Vostok environment by contamination due to penetration into the lake, have a very low probability of surviving and multiplying in the lake's truly alien environment (Kennicut, 2001).
Was this article helpful?