This chapter is intended to contribute to the development of an integrated small-size antenna system for 1 U CubeSats. Dipole antennas require deployable subsystems for 1 U CubeSats that have a small volume margin for redundant systems inside the box, and hence, the antenna deployment subsystem can be a single point of failure. In this letter, a 50 Ω coplanar waveguide strip line fed the integrated patch antenna, and this antenna used the 1 U CubeSats structure itself as support. This study aims to design a high-stiffness 1 U CubeSat body integrated patch antenna that can achieve performances suitable for unlimited lifetime CubeSat missions at low power consumption. The whole antenna configuration is optimized using the Quasi Newtonian Method and gives peak gain higher than 10.5 dBi, wide HPBW, and very low losses around an operating frequency of 13.4 GHz. In addition to that, the developed antenna configuration presents high return loss, whereas it occupies less than 8% of 1 U CubeSat face at the same operating frequency. Moreover, the proposed metallic antenna system is lightweight, low-cost, and presents a very high stiffness configuration for operation in the outer space. These achievements result in the ability to target high-altitude satellite missions using 1 U CubeSat configurations at low cost and low-power consumption for an unlimited period of operation.