Gossamer space structures are relatively large, flimsy, and lightweight. As a result, they are more easily affected or degraded by space thermal environments compared to other space structures. This study examines the structural integrity of a Three-Meter Ka-Band Inflatable/Self-Rigidizable Reflectarray Antenna under space thermal environments. Space thermal environments discussed by this paper include Earth, Mars, and Jupiter orbits. The most critical structural components of this antenna are the two Spring Tape Reinforced Aluminum Laminate Inflatable/Self-Rigidizable Booms. The effects of the thermal distortion of the booms to surface deviation of the Radio Frequency membrane are also investigated.