During axial thrusting maneuvers, spacecraft and rockets are often spin-stabilized to ameliorate the effect of undesired transverse torques from thruster offset and misalignment. The velocity-pointing errors due to these undesired torques are inversely proportional to the square of the spin rate. Recent work shows that the spin-stabilized axial thrust maneuver can be improved considerably by softening the ignition transient (for example, by increasing the thrust gradually from zero to maximum, rather than having a nearly instantaneous jump to maximum thrust). In previous work it is found that a linear-ramp thruster profile (for ignition and for burnout) provides a significant reduction in velocity-pointing errors. One advantage of this type of thrust profile is that it permits much smaller spin rates, which reduces the propellant mass required for spin up and spin down. We show that deviations from the linear thrust profile, such as a sinusoidal or an exponential profile, do not have significant effects on the inherent advantage of softening the ignition transient. However, increasing the duration of the thrust transient (in the profiles we examine) provides the greatest reduction in velocity-pointing errors.
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