In late 2015, DSI received venture funding[10] to begin the development of a propulsion system and spacecraft capable of traveling from low Earth orbit (LEO) to deep space on its own.

[15] Comet is a launch-safe electrothermal propulsion system designed for orbit raising, life extension, and de-orbit.

It uses water as a propellant, and is scalable from CubeSats to micro-satellites, with a flexible interface suitable for a wide range of spacecraft.

Several comet systems were sold to various customers and flew as part of various satellites built for HawkEye 360,[16] Astro Digital,[17] and Capella Space;[18] production is ongoing in Luxembourg under new ownership.

[5] However, DSI responded to these statements by stating that the majority of the materials mined — principally water — would be destined for use in space, thus avoiding the enormous fuel costs of repeatedly returning to and escaping from Earth's gravitational field, and additionally, that servicing communications satellite constellations could earn the company $5 to 8 million per month.

In particular, Planetary Resources did not release information on their intentions for processing, power generation, or in-space manufacturing hardware and equipment.