The most common particle separation techniques used in terrestrial mineral processing, such as froth flotation and dense medium separation, rely heavily on water, gravity and in many cases, air. This demand for water is a serious logistical and environmental issue on earth, and its absence, and potentially the partial or total lack of gravity, make these traditional separation technologies impractical in extraterrestrial environments such as the moon. On the other hand, some separation technologies that are limited to mostly niche applications on earth, such as electrostatic and magnetic separation, are relatively little-hampered by low gravity and lack of air and water. Indeed, some technologies, such as triboelectric separators, are likely to work better and more reliably under these conditions than on earth. Here, electrostatic separation technologies will be reviewed, then discussed in terms of their applicability under low gravity and in vacuum. Changes in design for optimal operation under these conditions will be proposed. Finally, some separator configurations are introduced that are impractical on earth but will come into their own in extraterrestrial applications.