PARIS to Hektor, A Mission to the Jovian Trojan Asteroids

PARIS (Planetary Access with Radioisotope Ion-drive System) spacecraft enable a new class of missions to the outer solar system. The high power-to-mass ratio of new radioisotope power systems enables New-Frontiers class missions that carry a significant a science payload to new destinations. The PARIS spacecraft take advantage of the high-efficiency of Stirling radioisotope generators (SRGs) or new thermoelectric converters to provide the power for an electric propulsion system. These low-thrust missions launched to a high C3 are especially effective for exploring objects in shallow gravity wells. The Jovian Trojan asteroids are very primitive bodies located near the Jovian L4 and L5 Lagrange points and are discussed as targets in the Solar System Decadal Survey. There are estimated to be more than 105 Jovian Trojans greater than 1 km in diameter. We consider a PARIS mission that can reach the asteroids in less than 5 years, orbit 624 Hektor, the largest of the Jovian Trojans, and go on to orbit at least one other nearby object. The candidate payload for this mission includes wide-field and narrow-field cameras, a UV-Vis-IR spectrograph, gamma-ray and neutron spectrometers, and plasma and energetic particle spectrometers. About 900 W of power are required. The launch mass would be slightly less than 1000 kg. The < 5 year trip time is dependent on having the next generation power sources with a specific power of > 8W/kg.