Joint Replenishment Strategy for Multiple Satellite Constellations with Shared Launch Opportunities

TL;DR

The paper addresses maintaining multiple satellite constellations with shared launch opportunities and parking orbits by developing a multi-echelon inventory model. It combines an in-plane $(s,Q)$ policy with a parking-orbit $(U,\mathbf{S})$ policy under stochastic failures and lead times, integrating RAAN-alignment dynamics and transfer times. Centralized and decentralized decision frameworks are introduced, with case studies showing measurable cost savings from sharing launches (e.g., around 3.6% in a three-constellation example) and highlighting sensitivity to parameter heterogeneity across constellations. The work provides a rigorous, practically oriented framework for coordinating spare-satellite logistics across constellations and sets the stage for future contracts and substitution mechanisms to further improve efficiency.

Abstract

This paper proposes a novel replenishment strategy that can jointly support multiple satellite constellations. In this approach, multiple constellations share launch opportunities and parking orbits to address the operational satellite failures and ensure the desired service level of the constellations. We develop an inventory management model based on parametric replenishment policies, considering the launch vehicle's capacity and the shipping size of satellites. Based on this model, we introduce two decision-making scenarios and propose their corresponding solution frameworks. We conduct two case studies to provide valuable insights into the proposed strategy and demonstrate its applicability to supply chain management for maintaining multiple satellite constellations.

Figures (6)

• Figure 1: Order cycle representation with an $\left(s,Q\right)$ policy ($s=1$, $Q=4$)
• Figure 2: Example MC: The number of SKUs is 2 ($m = 2$) with shipping sizes of 1 ($a_1=1$) and 2 ($a_2=2$) for each SKU; both the SROP ($U$) and the transportation capacity ($A$) are set to 5
• Figure 3: Overview of the proposed inventory model with ground analogy
• Figure 4: Solution procedure for decentralized scenario, $m=2$
• Figure 5: TESSAC reduction obtained by joint replenishment strategy