发表机构
Space Physics Laboratory, Vikram Sarabhai Space Centre; Indian Institute of Space Science and Technology（空间物理实验室，维克拉姆·萨拉巴hai航天中心; 印度空间科学与技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过轨道重建和热层密度模拟，发现微小轨道差异经热层阻力与空间天气耦合放大，导致范艾伦探测器A轨道衰减加速并提前再入，而探测器B仍在轨。
AI 中文摘要
范艾伦探测器被发射到几乎相同的轨道，并经历了相同的太阳和地磁环境，然而它们任务后的寿命却出现了巨大差异。探测器A经历了快速加速的轨道衰减，并于2026年3月重返大气层，而探测器B仍留在轨道上。我们利用重建的轨道轨迹、模拟的热层密度以及低空停留时间和大气阻力指标来研究这种差异的原因。我们发现，轨道演化的微小差异逐渐增加了探测器A在低热层中的停留时间，而低热层陡峭的密度梯度使得额外的低空暴露变得愈发重要。地磁活动期间热层密度的增强进一步放大了这一差异，导致更大的阻力，并加速了探测器A的轨道衰减。我们的结果表明，轨道演化的微小差异如何通过热层阻力和空间天气的耦合效应被放大，即使对于初始轨道几乎相同的双胞胎航天器，也会产生截然不同的轨道寿命。
英文摘要
The Van Allen Probes were launched into nearly identical orbits and experienced the same solar and geomagnetic environment, yet their post-mission lifetimes diverged dramatically. Probe A underwent rapidly accelerating orbital decay and reentered the atmosphere in March 2026, while Probe B remains in orbit. We investigate the cause of this divergence using reconstructed orbital trajectories, modeled thermospheric densities, and measures of low-altitude residence and atmospheric drag. We find that small differences in orbital evolution progressively increased Probe A residence time in the lower thermosphere, where the steep density gradient made additional low-altitude exposure increasingly important. Enhanced thermospheric density during periods of geomagnetic activity further amplified this difference, leading to greater drag and accelerating orbital decay of Probe A. Our results show how small differences in orbital evolution can be amplified through the coupled effects of thermospheric drag and space weather, producing substantially different orbital lifetimes even for twin spacecraft sharing nearly identical initial orbits.
