A bioregenerative life-support system will be required in long manned
space flight, especially with several astronauts such as would be
required for a manned mission to Mars in the 1980 time period. While
almost 15 years is a long leadtime, the biological research and
engineering problems are formidable, and a system would have to be
developed at least 5 years before the mission.
The power and weight requirements for both chemical and biological
regenerative life-support systems were presented in table VIII. These
should be considered tentative best estimates based on present data.
The use of bioregenerative systems in spacecraft systems has been
studied by Bongers and Kok ([ref.175]) who put the
electrolysis-_Hydrogenomonas_ system in proper perspective with the
following statement:
The bioregenerative systems are more or less in a transitory
phase between research and development. The power data can be
considered fairly accurate, at least within ±20 percent. The
postulated weight data, however, represent approximations,
particularly with respect to auxiliary equipment and
construction materials. Also omitted are the weight penalties
most probably involved in the processing of the solid output of
the exchangers, elegantly defined as potential food. Further
research is required in this area to evaluate the regenerative
systems, especially the bacteria, with respect to this
potential. Furthermore, as yet there is no experimental proof
that the growth rates of the heavy bacterial suspensions can be
realized in a large design, determined on a relatively small
scale with fairly precise control of physiological conditions
and gas exchange. This aspect may affect considerably the weight
involved in a chemosynthetic balanced system. Nevertheless, at
present, this approach still seems most promising.