###### Abstract  
Satellite networks show the development trend in global coverage, flexible access, and reliable transmission. They are the key to building a wide coverage, massive connection, three-dimensional, all-round, all-weather, space-, air- and ground-integrated information network. Due to its high frequency and large bandwidth, the laser inter-satellite link (ISL) is easily interfered with by sunlight. When sun outage occurs, the laser inter-satellite link will be interrupted for a long time. Most of the existing satellite link failure-routing algorithms are distributed and have poor load balancing capabilities. The centralized algorithm calculates paths independently for different services, and the effect is not ideal. In this paper, a local pre-rerouting algorithm (LPRA) is proposed. The center node collects the link information from the limited area before sun outage and the service information in the link that is about to be interrupted, and reroutes these services before sun outage occurs. After the occurrence of sun outage, services that originally needed to go through the failed link are forwarded according to the path calculated in advance, thereby avoiding link congestion and reducing the packet loss rate. Simulation results show that the proposed algorithm performs better than existing algorithms in terms of packet loss ratio, total delay and load balancing capabilities. L +
Footnote †: journal: Applied  
**Citation:** [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] A Local  
Pre-Rerouting Algorithm to Combat Sun Outage for Inter-Satellite Links in Low Earth Orbit Satellite Networks. _Appl. Sci._**2024**, 14, 1625. [[https://doi.org/10.3390/app14041625](https://doi.org/10.3390/app14041625)]([https://doi.org/10.3390/app14041625](https://doi.org/10.3390/app14041625))  
Academic Editors [PERSON]  
and [PERSON]  
Received: 29 November 2023  
Received: 12 February 2023  
Accepted: 16 February 2024  
Published: 17 February 2024  
**Copyright**\(\copy\) 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([[https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)]([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/))). **Copyright**\(\copy\) 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons. Solar noise is a broadband noise, and the radiation intensity increases with the frequency. Therefore, the impact of sun outage on the received signal-to-noise ratio depends on the size of the solar noise, the frequency bandwidth and the operating frequency. The sun outage interference is the greatest during the peak period of solar activity. The wider the working frequency band, the more noise is received, and the solar interference is relatively serious; the higher the working frequency, the greater the noise intensity received in the corresponding frequency band [4]. Due to its high frequency and large bandwidth, the laser inter-satellite link is extremely susceptible to interference from the sun outage phenomenon. When the laser link is collinear with sunlight, the laser link will be interrupted for a period of time [5]. The impact of sun outage on the satellite transmission network is very significant, especially when it occurs in the direct link of the satellite at the edge of the ground station's visible area, because it carries a large amount of traffic from the satellite terminal to the core network, and the failure time is long and cannot be recovered, so load balancing in the failure area is very necessary. As a network topology change, sun outage failure is predictable. For predictable topology changes, the algorithm can perform route calculations in advance, so it can support a certain algorithm complexity and calculation time.