A Cost-Benefit Analysis of a Tethered Satellite System for Climate Change Monitoring in Very Low Earth Orbit

Spaceborne remote sensing plays a crucial role in addressing global sustainability challenges by providing critical data for climate monitoring and environmental management. In this study, we present a business case analysis for a novel Earth observation architecture based on a tethered satellite system operating in Very Low Earth Orbit (VLEO). The proposed system consists of two SmallSats connected by a tether, stabilized in a cross-track configuration. Along the tether, multiple low-frequency antennas are deployed, forming a Multi-Input Multi-Output (MIMO) Synthetic Aperture Radar (SAR) platform. This configuration allows the system to be used as a distributed radar sounder, integrating Synthetic Aperture Radar and Phased Array Beamforming techniques, achieving ground penetrating capabilities. The unique attributes of this architecture enable unprecedented monitoring of polar ice sheet structures a critical indicator of climate change. By operating at low frequencies, the system can inspect ice layers, providing valuable insights into subsurface structures. The combination of VLEO operation and the orientation of the tether that offers a large cross-track aperture offers significant advantages in terms of spatial resolution, signal-to-noise ratio and clutter noise improvement, surpassing the capabilities of monolithic or formation flying solutions. By integrating the data collected by this system with state-of-the-art numerical models, it would be possible to periodically refine existing predictions and enhance our understanding of the conditions in polar regions. This study presents a cost estimation for the proposed mission, examining key financial drivers such as satellite manufacturing, launch, deployment, and operational expenses. The business case analysis will also consider the costs associated with implementing the entire system, including operational expenses, data transmission to ground stations, and post-processing efforts required to extract meaningful insights from the collected data. The analysis compares the data retrieval capabilities of the proposed system with respect to the data currently available, assessing its potential value proposition. Our findings suggest that this innovative approach could offer a cost-effective alternative to traditional Earth observation platforms, while significantly enhancing our ability to monitor climate change