Phased control of multiple spacecraft during a low-thrust orbit transfer maneuver

A control system operable for controlling a phased transfer of multiple spacecraft from a separation orbit to a target orbit, the multiple spacecraft comprising a lead spacecraft and multiple follower spacecraft, the control system comprising:

• a processor;
• and
• a tangible, non-transitory computer readable storage medium on which is recorded an instruction set, wherein execution of the instruction set by the processor causes the control system to:
• while maintaining an in-phase relationship of the multiple spacecraft relative to each other within the separation orbit:
• compute respective desired trajectories for the lead spacecraft and the follower spacecraft to reach the target orbit;
• and
• establish a constant phase offset between the multiple spacecraft in mean anomaly of the separation orbit;
• and
• during a series of transfer orbits of the multiple spacecraft from the separation orbit to the target orbit, apply the respective desired trajectories such that the constant phase offset is maintained and the follower spacecraft are simultaneously transferred to the target orbit in-phase with the lead spacecraft.

A method for controlling a phased transfer of multiple spacecraft from a separation orbit to a target orbit, the multiple spacecraft comprising a lead spacecraft and multiple follower spacecraft, the method comprising:

• deploying the multiple spacecraft into the separation orbit from a single launch vehicle;
• while maintaining an in-phase relationship of the multiple spacecraft relative to each other within the separation orbit:
• implementing a compound steering control law via a control system, the compound steering law having a plurality of weight factors;
• computing, via the control system, respective desired trajectories for the lead spacecraft and the follower spacecraft to reach the target orbit;
• and
• establishing a constant phase offset between the multiple spacecraft in mean anomaly of the separation orbit;
• and
• during a series of transfer orbits of the multiple spacecraft from the separation orbit to the target orbit, applying the respective desired trajectories via the control system such that the constant phase offset is maintained and the follower spacecraft are simultaneously transferred to the target orbit in-phase with the lead spacecraft, including
• modifying an in-plane change in velocity (Δv) component of each of the multiple spacecraft in relation to an out-of-plane Δv component for each of the multiple spacecraft by manipulating a predetermined one of the weight factors over a duration of the series of transfer orbits to thereby control a mean motion of each of the multiple spacecraft.