Application of Solar Electric Propulsion to Outer Planet Space Missions

Paper number

IAC-09.C4.8.8

Author

Prof. Garri A. Popov, RIAME, Russia

Coauthor

Dr. Vladimir Obukhov, RIAME, Russia

Coauthor

Mr. Gennady G. Fedotov, Moscow Aviation Institute, Russia

Coauthor

Prof. Mikhail S. Konstantinov, Moscow Aviation Institute, Russia

Coauthor

Dr. Viacheslav Petukhov, Russia

Year

2009

Abstract

Sequence of recent discoveries, including Io and Enceladus geological activity, Europa’s ocean, Titan’s lakes, leads to worldwide increasing of interest to the space missions to giant planets and their natural satellites. USA, Europe, Japan, and Russia are planning new space missions to outer planets.
Direct trajectories to outer planets (Jupiter, Saturn, and so on) require high velocity increment. Required velocity increment can be reduced using multiple gravity assist maneuvers, but it leads to drastically long transfer duration and to hard constraints on periodicity and duration of launch windows.
High specific impulse solar electric propulsion system (SEPS) reduces required propellant consumption. SEPS can be considered as alternate option to multiple flyby trajectories to increase payload mass and to decrease transfer duration. SEPS advantage in comparison with chemical propulsion is low propellant consumption, but SEPS has low thrust magnitude, its thrust decreases with heliocentric distance increasing and SEPS has relatively high dry mass, in particularity, due to high mass of electric power system.
Purpose of this study is analysis of SEPS usage efficiency for space missions to outer planets from the point of view payload increasing and decreasing of transfer duration. Within considered flight profile, conventional chemical upper stage inserts spacecraft into the earth escape trajectory. Heliocentric trajectory is shaped by SEPS and, if it is needed, by gravity-assist maneuvers. SEPS module separates from spacecraft before arrival to target planet and then bi-propellant propulsion system (BPPS) inserts spacecraft into orbit around the planet.
Main design parameters of SEPS are its electrical power, specific impulse, efficiency, lifetime, and specific mass of power and propulsion subsystems. These parameters selection is restricted by modern state-of-art (there are considered usage of stationary plasma thrusters and gridded radiofrequency ion thrusters) and it is close connected with trajectory optimization problem. Simultaneous optimization of trajectory and main design parameters is carried out using numerical techniques based on maximum principle and parametric analysis. As a result, in particularity, the SEPS specific impulse is optimized. There are compared results for SEPS and purely BPPS spacecrafts to find regions where SEPS usage leads to increasing of mission performance.
It is shown, in particularity, that 6-years trajectory to Jupiter using purely BPPS and 3 gravity-assist maneuvers (route Earth-Venus-Earth-Earth-Jupiter; this trajectory is accepted for prospective US and European missions to Jupiter) can be replaced by 4-years trajectory using combination of SEPS/BPPS and one earth gravity-assist maneuver and having launch windows every 13 months.

Abstract document

IAC-09.C4.8.8.pdf

Manuscript document

IAC-09.C4.8.8.pdf (🔒 authorized access only).

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