原题
Space Debris: A Growing Concern
The Kessler Syndrome, proposed by NASA scientist Donald J. Kessler in 1978, hypothesizes a cascading effect in low Earth orbit (LEO) in which collisions between satellites and debris—defunct satellites, spent rocket stages, and fragments from earlier collisions—generate more fragments, exponentially increasing the likelihood of further collisions. This feedback loop could render certain orbital regions unusable for decades. While the model is compelling, some assumptions merit scrutiny. For instance, it presumes a uniform distribution of debris and constant collision probability, yet orbital mechanics suggest that debris clusters in specific altitudes and orbital paths, potentially limiting the scope of cascading events.
Moreover, technological advancements in debris tracking and active removal may mitigate the risk more effectively than Kessler originally envisioned. Critics argue that the syndrome underestimates the resilience of orbital infrastructure and overstates the inevitability of runaway collisions. Alternative explanations for observed debris growth include a greater number of satellite launches and fragmentation from aging spacecraft, rather than a self-sustaining cascade.
Nonetheless, the Kessler Syndrome remains a valuable heuristic for space policy, emphasizing the need for international cooperation and sustainable orbital practices. Its cautionary implications are profound—especially as commercial constellations dramatically increase the number of active satellites in LEO.
The word "resilience" in the passage is closest in meaning to
Astrength
Bthreat
Cknowledge
Dsupervision
正确答案：A
解题思路
老师暂未填写解题思路。