The proposal is specifically targeted to the NASA applications highlighted in the X5.02 solicitation. The proposed lightweight polybenzoxazine composites are potentially relevant to the following NASA applications: Space transportation vehicles; International Space Station Modules; Micrometeoroid and Orbital Debris Shielding; and Thermal protection structures. The developed composites can be applied to broad commercial aerospace use due to ease of processing and advantageous property profiles. Very recently, Airbus has qualified use of benzoxazine-based composites for interior and exterior applications using the first generation benzoxazine chemistry. The benzoxazine chemistry proposed in this SBIR proposal is a further advanced system that may be termed as the second and third generation benzoxazines. Thus, the benzoxazine technology that has already been accepted in the demanding aerospace arena can further be advanced. Another potential area of application is the very fast land-based transportation systems, such as magnetic levitation trains, where light-weight, high mechanical performance, and fire safety are extremely important.