在 Rebecca Heilweil 的分析中，国际空间站（ISS）最危险的事故是穿透。轨道上的碎片有数百万块，包括废弃火箭体、碎裂卫星和微陨石，常速约17,000英里/小时（约27,000公里/小时）。NASA估计，0.6厘米孔可留出约14小时处置时间，而20厘米孔不足1分钟。规避依赖军方的太空监视网“pizza box”；若碰撞概率达到1/100,000，ISS会用推进器机动躲避。自1998年起已被反复采用，该系统大约只跟踪45,000个大碎片，且传感器存在噪声。防护并不均衡：Whipple Shield主要应对约1立方厘米碰撞，而追踪通常覆盖体积≥10立方厘米的碎片。
若发生泄漏，宇航员可以封堵并隔离受损舱段，但当压力降到约490 mm Hg时，关键任务系统和低氧风险会快速上升。NASA在2017年给出的最坏情况概率是121分之一；到2025年底估计任意六个月去压缩风险为36分之一到170分之一。治理框架覆盖欧洲航天局23个国家成员，以及日本和加拿大；俄罗斯承诺持续到2028年并参与应急去轨。优选处置方式是美国Dragon飞船，2024年后备方案改用Progress。若 ISS 缓慢下沉可节省推进剂，但远程控制、姿态与供电可能退化；受控去轨仍依赖通信、供电与航电，其中部分尚未验证可在减压环境下工作。
在最极端的连锁中，舱压丢失会损坏航电，进而影响电力、热控与数据处理，再到冷却和推进控制，ISS可能失控下落1–2年。专家警告，失控碎片可能达到汽车到火车尺寸，并造成全球公共风险。历史上还没确认有人死于空间站碎片；2024年有一块与ISS相关碎片击中佛罗里达屋顶且无人受伤。寿命延长受推进剂限制：将ISS提升640公里约可再飞行100年需至少18.9吨推进剂，1000年需36吨，即约2,000件航空托运行李，但目前没有运载器可完全运输；Starship也许可分担部分，但对接口困难。
In Rebecca Heilweil’s analysis, the ISS’s worst accident is a puncture. Orbital debris is in the millions—including spent rocket bodies, fragmented satellites, and micrometeoroids—often moving around 17,000 mph (about 27,000 km/h). NASA estimates a 0.6 cm hole leaves about 14 hours to respond, while a 20 cm hole leaves under 1 minute. Avoidance relies on the military Space Surveillance Network “pizza box”; if collision odds reach 1 in 100,000, ISS thrusters maneuver away. Used often since 1998, the system tracks roughly 45,000 large objects, and sensors have noise. Defense is uneven: the Whipple Shield is for roughly 1 cm³, while tracking usually covers debris ≥10 cm³.
If a leak occurs, crews can patch and isolate sections, but when pressure drops to about 490 mm Hg, critical-system failure and hypoxia risk rise quickly. NASA gave a 1 in 121 worst-case probability in 2017; by late 2025, risk in any six-month period was estimated at 1 in 36 to 1 in 170. Governance includes 23 ESA member countries plus Japan and Canada; Russia is pledged through 2028 and assists in contingency deorbiting. Preferred disposal is the US Dragon vehicle, with a 2024 fallback to Progress. Slow descent can save propellant, but remote-control, attitude, and power may degrade; controlled deorbit still requires communications, power, and avionics, some not yet verified for decompressed operation.
In the extreme cascade, loss of cabin pressure damages avionics, then power, thermal, and data handling, then coolant and propellant control, potentially causing uncontrolled descent for 1–2 years. Experts warn uncontrolled fragments could reach car-to-train size and pose global public risk. History is not fully reassuring: no confirmed deaths from station debris, and a 2024 ISS-related fragment hit a Florida roof with no injuries. Extension is propellant-limited: lifting ISS by 640 km for 100 years needs at least 18.9 metric tons, and 1,000 years needs 36 t, about 2,000 airline carry-ons, but no current launch vehicle can deliver that fully; Starship might carry part, yet docking remains difficult.