This paper describes concepts of deployable open isogrid booms that may enable the development of space structures such as solar sails and large antennas to dimensions of hundreds of meters. The paper examines previous efforts funded by NASA developing deployable isogrid booms and describes their limitations. Several innovative ways of stowing and deploying isogrid booms are described and their advantages listed. light “gossamer” applications: the solid rod longeron truss, the isogrid tube, and the tube longeron truss, with structural efficiencies increasing from the first to the last in this list. A characteristic of all three is the use of continuous rod or tube longerons—no hinges— and while this provides high structural efficiency it also limits the booms’ practicality: the problem of storing the elongated structural elements in a compact package, and then deploying the booms, has limited both the elastic modulus of the materials and the diameters of the booms. The Naval Research Laboratory (NRL) has developed a design of a rod longeron truss 2 that allows the use of ultra-high modulus materials and unrestricted truss diameters. This advance is enabled by novel means both of stowing and of deploying the structure. This present paper shows concepts of an isogrid boom that uses the same stowage and deployment technique as the rod longeron boom.