Furlable sail devices, systems, and methods are provided in accordance with various embodiments. For example, some embodiments include a system and/or device that may include: a furlable boom; a furlable sail coupled with a distal end of the furlable boom; and/or a shear take-up mechanism coupled with a root end of the furlable sail. In some embodiments, the shear take-up mechanism applies tension to the furlable sail. The shear-take up mechanism may include one or more springs coupled with the root end of the furlable sail. In some embodiments, the furlable sheet includes a structural sheet. The structural sheet may include one or more areas with bending stiffness. The structural sheet may be fabricated to be self-supporting. In some embodiments, the furlable boom includes a slit-tube boom. Some embodiments may be configured as deorbit sails.