# Agile Stage-Gate Approach for Design, Integration, and Testing of a 1U CubeSat
## 4 Discussion  
Despite Agile representing a key revolutionary element in the software industry, hybrid models applying the Agile Stage-Gate methodology are only now becoming popular in different sectors. By mixing Agile and Stage-Gate systems, this model offers new possibilities to carry out complex projects by accelerating team-based collaboration and interactions. In this work, the design, integration, and testing approach of the first Mexican nanosatellite deployed from the ISS is described, including verification of the nanosatellite at a university and validation at NASA. The development process of a 1U CubeSat is proposed for a scientific and technological payload. The goal of this study was to design, build, verify, and validate a 1U CubeSat through testing. The results showed good satellite and intersatellite communication. We agree that the Agile Stage-Gate approach improved both team communication and task prioritization. Even though an Agile culture was not previously implemented in our institution, there was no evidence of delays derived from resistance. Stakeholder approval was granted in each stage. Moreover, rapid sprints were adapted among teams, including design process and product tasks. Quantitative metrics used in the project considered team velocity for burndown points, lead time, cumulative flow diagrams, and resource allocation. The first and most important aspect of the present work is the successful development of a final product by Mexican students following a hybrid approach based on the Agile Stage-Gate method as well as the correct process for integration and testing of a 1U CubeSat using the same approach. AztechSat-1 is working correctly as data can be sent and received. In addition, both vibration and thermal tests were carried out by experts from NASA. AztechSat-1 was delivered and integrated into the Dragon capsule and was successfully sent into orbit, fulfilling its main mission objective by returning successful data from orbit within 40 min after deployment. AztechSat-1 is the first Mexican-designed and integrated nanosatellite deployed from the ISS. The proposed design and the assembled system were verified and validated, ensuring that the CubeSat was ready to fly and fulfil all mission requirements. Through this study, data were obtained for future projects, and the concept of intersatellite communication was proposed for the first time to improve communication between satellites by sharing Earth stations. AztechSat-1 was launched aboard the 19 th SpaceX Commercial Resupply Services contract mission for NASA on 5 December 2019 and delivered to the ISS. The satellite was deployed from the space station on 19 February 2020 [30], NORAD ID: 45261. One of the main challenges to overcome in the proposed model was finding human and material resources to support the hybrid methodology. Agile sprints and deliverables are difficult to realize, especially when all members are widely distributed; for example, many students and professors belonged to different departments. Writing--review and editing, E.R.G.-S.; supervision J.C.-L.; project administration H.S.V.-M.; methodology F.C.-G. and E.R.G.-S. All authors have read and agreed to the published version of the manuscript. This study was mainly supported by a sectoral fund for Research, Technological Development, and Innovation in Space Activities AEM-CONACYT. Project number: 292767 under the title \"Diseño y construccion del modulo de enlace interstalital AztechSat-1--GlobalStar\", a Council of Science and Technology of the State of Puebla (CONCYTEP) fund. Project number 08 Bis/2018 under the title \"Disefo y construccion del Modulo de Enlace Intersateiltal \"AzTechSat-1\"--GlobalStar\", an internal budget from UPAEP, a non-profit university located in Puebla, Mexico, from 2017 to 2019, as part of a continuing education project for students from the Electronics department for CubeSat subsystem acquisition, development, and manufacturing. **Data Availability Statement:** Publicly available datasets were analyzed in this study.