Read "Evans of the Earth-Guard" by Edmond Hamilton online for free on Textopian. Full text with search, annotations, highlights, and AI-powered reading aids.
_The present likelihood is that the first interplanetary flight will probably be by means of a rocket-propelled ship. As far as our knowledge goes the rocket seems to be the most feasible means of propulsion because it will reach its greatest efficiency in the vacuum of inter-stellar space._
_If the conditions on other planets, including our moon, are not too prohibitive, it is doubtless true that these planets will be explored for whatever mineral wealth or possibilities of life they may contain. The resulting interplanetary commerce will call into being a host of problems, such as the protection of cargo and passenger shipments against natural and human agents that might wish to destroy them._