Despite the early financial support from wealthy investors and the backing of well-known space-exploration researchers, Planetary Resources faces many technical questions and uncertainties about costs and the technology required to extract materials from asteroids.

WSJ: Planetary's Plan to Mine an Asteroid

At present, British government policy specifically bars any public programmes connected with human spaceflight, and it has directed that any monies instead go towards the robotic exploration of space - for example in Earth observation and unmanned planetary probes.

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