# Agile Stage-Gate Approach for Design, Integration, and Testing of a 1U CubeSat
## 2 Materials and Methods
### Gates of the Project  
The development of AztechSat-1 began on May 2017, when the official kickoff took place. During this month, the mentoring team from NASA validated the first stage of the project. The AztechSat-1 project followed the recommended best practices for success. During the project, AztechSat-1 passed through six important gates at NASA and two internal gates, summarized in the following:  
Mission Concept Review/System Requirements Review (MCR/SRR): This was the first gate of the project after the kickoff meeting. In this stage, a review was carried out by NASA to ensure that the system requirements were identified. At this point, the concept had been properly established as a requirement by the stakeholders, and the construction of the clean room was completed. The mission requirements were established, and the proposed objectives were defined. Even though this stage presented two reviews, both were held at the same time given the nature of the project.  
Preliminary Design Review (PDR): The second gate of the project was to build a prototype for the module to enable intersatellite communication. A technical review by NASA was also completed successfully, and all technical subsystems were able to demonstrate a good understanding of the project. The first engineering model with no spatial capacities was presented. From this point, verification testing was conducted.  
Critical Design Review (CDR): The second gate was split to demonstrate the maturity of the project. The second part of the second stage was also evaluated by NASA, and the engineering unit for the nanosatellite was built. Intersatellite communication and ground-to-satellite communication were successfully proven. A technical review ensured that most of the AztechSAT-1 subsystems could proceed. However, three subsystems were given the task of improving the performance in order to pass the review.  
Delta Critical Design Review (Delta CDR): The Integration and Testing team was re-evaluated, and then the project was able to proceed as defined with minimal changes; this stage mostly focused on the sequence of testing.  
System Integration Review (SIR): The success of the system integration review ensured that all elements of the project such as modules, components, subsystems, and the system were integrated. It identified facilities, planning for integration, documented procedures, and external support as needed. After the third gate of the project was successfully completed and the nanosatellite was fully assembled, validation testing began.  
Flight Readiness Review (FRR): This gate validated the readiness to initiate and conduct the flight. In this stage, the nanosatellite was tested at the NASA Ames Research Center, and all previously conducted environmental testing was approved.  
Post-Launch Review: Students and professors presented a review that evaluated the status of the on-board system. The Mission Operation team assumed the main role from this point onward.  
Results: In the final stage of the project, results and learned lessons were documented for future projects.