A Transit-Assisted Orbital Tug: Propellant Saved on Standard Transfers by Partial Phase Advance

This paper presents a complete design study of a transit-assisted orbital tug that assigns part of each transfer to phase advance and the rest to a chemical stage, computed throughout from stated assumptions. On a transfer of 900 m per second with four tenths assigned to the transit system, the tug saves 1691.5 kg of propellant at an electrical cost of 38.88 GJ. The saving is 663.2 kg on a 400 m per second transfer and 3586.3 kg on a 1600 m per second transfer at the same assigned fraction, and raising the assigned fraction on the reference transfer to eight tenths saves 3203.1 kg for 77.76 GJ. Every figure is a computed result of the stated model and nothing was built or tested: the study is SIMULATED, NOT MEASURED, and its limits are stated as plainly as its performance.