## 6 Conclusions  
This study demonstrates the value of small satellite constellations, including Uvsq-Sat (2021-2024) and Inspire-Sat (2023-2024), for advancing continuous monitoring of the Earth's radiation budget and Energy Imbalance at different solar local times. This approach helps capture the complex feedbacks--linked to greenhouse gases, clouds, aerosols, and solar variability--that govern Earth's energy balance. It is worth noting that the current absolute accuracy of Uvsq-Sat and Inspire-Sat, on the order of a few \(\mathrm{Wm}^{-2}\), exceeds the \(<\)0.5 \(\mathrm{Wm}^{-2}\) threshold typically required for quantitative climate research on Earth's radiative fluxes. However, this level of accuracy is well suited to the demonstrator nature of these missions, which focus on relative measurements and broad radiative flux variations rather than absolute climate-grade precision--a requirement that becomes particularly important when multiple satellites are conducting absolute measurements simultaneously. With more resources and time, ground calibration procedures for satellites like Uvsq-Sat could be refined to further reduce uncertainty. Looking ahead, calibration improvements--including onboard degradation monitoring and cross-calibration between satellites--are planned to enhance data quality. Although such measures are complex, they will be essential for future small satellite constellations designed to meet the absolute stringent requirements. By measuring both reflected solar radiation and outgoing longwave radiation, Uvsq-Sat and Inspire-Sat provide data that complement CERES observations. While Wide Field-Of-View measurements do not replace Narrow Field-Of-View observations, they extend angular coverage and offer a broader radiative perspective. The integration of Wide Field-Of-View Earth's radiation budget instruments within a constellation frame work enables improved monitoring frequency, enhanced data reliability, and increased resilience. This approach offers a transformative path for tracking Earth's radiative energy budget--essential for improving climate model validation, deepening the understanding of climate feedbacks, and informing policy decisions to address climate change. Our analysis reveals a generally good agreement between Uvsq-Sat and CERES data for Earth's energy imbalance from 2021 to 2024. Over this period, EEI derived from Uvsq-Sat averaged +0.87 \(\pm\) 0.23 Wm\({}^{-2}\), closely matching the recent CERES trend. Both datasets indicate a peak in EEI around mid-2023, followed by a decline throughout 2024, likely reflecting stabilizing feedbacks triggered by the 2023 El Nifro event. All authors formulated and directed the methodology and results analysis. All authors have read and agreed to the published version of the manuscript. This work received funding from Agence Nationale de la Recherche (ANR, France), Academie de Versailles (78, France), Communaute d'Agglomeration de Saint-Quentin-en-Yvelines (SQY, France), and Centre Paris-Saclay des Sciences Spatiales (CPS3, France). This work was also supported by State funding, managed by the French National Research Agency under the 'Academie Spatiale IdF' initiative, as part of France 2030, with the reference ANR-23-CMAS-0001. The Uvsq-Sat data derived in this work are available at [[http://bdap.ipsl.fr/uvsqsat/](http://bdap.ipsl.fr/uvsqsat/)]([http://bdap.ipsl.fr/uvsqsat/](http://bdap.ipsl.fr/uvsqsat/)) and [[http://nahla.projet.latmos.ipsl.fr--accessed](http://nahla.projet.latmos.ipsl.fr--accessed)]([http://nahla.projet.latmos.ipsl.fr--accessed](http://nahla.projet.latmos.ipsl.fr--accessed)) on 14 July 2025. We thank the International Satellite Program in Research and Education (INSPIRE) team for their continued collaboration in advancing space research and the deployment of small satellites dedicated to science.