Abstract: A telescopic boom system provides an extensible boom that may be used in spacecraft applications including supporting photovoltaic panels, communication antennas, instrumentation, and so forth. A stowed configuration is volumetrically compact, including the boom and actuators such as a motor. During deployment, threaded nuts for each nested section of the boom are self-aligning with respect to a leadscrew driven by the motor. Sections are staged for extension in staged sequence by a flexure arm engaging a ramp feature on a portion of the nested section. Extension failure mitigation is enhanced by allowing partial retraction of some sections during extension. Once fully extended, tension of the boom may be later adjusted, modifying the structural fundamental frequency. A ratchet may be engaged with extension of a final nested section to prevent retraction of the extended boom.