Extract scarce minerals such as asteroid platinum is a project still unpublished, but that threatens to become a reality. Several companies have spent years investigating and investing to achieve, one day, scenes such as the one that Bruce Willis punch stars in hand. Armageddon stop belonging to the field of science fiction. A recent study reviewed by the MIT Technology Review reveals that, if achieved, it would be doing a good favor to the environment.
The work led by the researcher at the University of Paris-Saclay (France) Andreas Hein and his colleagues are the first to be concerned with calculating greenhouse gas emissions from asteroid extraction operations and comparing them with the harmful gases that are released on Earth with these activities.
The study starts by calculating the huge amounts of greenhouse gases that the space rockets expel during their ascent. It must be borne in mind, however, that the consumed fuel that remains inside the atmosphere is included (the first stage of the ascent, which spends the most): the externalities of the energy already consumed in space (second and third stage) ) do not pollute the Earth …
Hein's team also takes into account the large amount of harmful gases, such as nitrous oxide, that are released with the decomposition in the upper atmosphere of part of the mass of the rocket discarded when it returns to Earth.
The results of the study are clear: a kilogram of platinum mined in space implies about 150 kilos of CO2 for the atmosphere. The work also indicates that economies of scale could contribute to reducing the figure to 60 kilos.
Is 150 kilos a lot or a little? A lot, compared to what it costs to extract the same amount of that metal on Earth, mainly because of the amount of energy involved in the process: for every kilogram of platinum about 40,000 carbon dioxide is released.
The imbalance is evident. Although to achieve a more realistic comparison, one should also take into account the implications of space launches on the ozone layer or the gases released during the construction of rockets, spatial control bases, and so on.
The calculation is, however, a first step to assess the suitability of an economic sector that experts believe will flourish this century. It also serves to put into perspective the extent to which it contaminates conventional mining, a more mundane issue of which we are less concerned than we should be.