The impact of ion propulsion on high energy interplanetary missions

Abstract

Interplanetary science missions often require a significant on-board propulsive capability, which results in the need to carry large quantities of propellant. This reduces possible payload mass, or increases the overall size, mass and cost of the mission. Ion propulsion offers an attractive means of avoiding these large propellant masses associated with chemical propulsion systems. Indeed, if a spiral orbit-raising approach is adopted for the mission, following deployment into low Earth orbit, a smaller launch vehicle can be used, allowing a dramatic reduction in cost to be achieved. The use of ion propulsion can also lead to the utilisation of small spacecraft for many missions, consistent with a low-cost philosophy. The paper considers three specific examples, in which the impact that this technology might have had on the Ulysses, Clementine and proposed Pluto missions is considered. In all cases, this would have had a major beneficial influence on capabilities and costs.