Miraux Loïs
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Sci Total Environ. 2022 Feb 1;806(Pt 4):150862. doi: 10.1016/j.scitotenv.2021.150862. Epub 2021 Oct 9.
Space activities are now expanding at a fast pace and various ambitious projects have been proposed for the future, raising the question of their environmental sustainability. While the space debris situation has been widely recognized as a serious threat to space sustainability, other pressing environmental issues have received little attention yet, although they pose risks to the environment and actors of the space sector. Therefore, this paper first reviews the major environmental impacts of space activities and their potential growth, analyzed together in a comprehensive approach for the first time. The degradation of the orbital environment with space debris has already reached a threshold leading to a future increase of the number of objects even without additional launches, while the contribution of artificial space objects to night sky brightness may have already crossed the light pollution threshold defined by astronomers. Planned large constellations will likely deteriorate the situation significantly. In this context, the formulation of these thresholds within the planetary boundaries framework is proposed to support awareness-raising and policy-making. Furthermore, stratospheric ozone depletion and climate change resulting from rocket emissions could reach levels triggering regulatory responses in the next decades due to the coming surge in launch rates. This could also apply to particles from thousands of constellations' satellites burning while reentering Earth's atmosphere, although the magnitude of their effects is yet unknown. A common assumption is that limitations to the human enterprise in space are of a purely technical and economic nature. This paper challenges this assumption, by highlighting the existence of environmental limits to the currently planned development of space activities. Risks arising from these limits are explored, and the importance of ecodesign in the space sector is emphasized. Finally, the paper discusses the future sustainability of proposed space projects in the context of global ecological transition.
当前，太空活动正迅速扩张，各种雄心勃勃的未来项目纷纷被提出，这引发了其环境可持续性的问题。虽然太空碎片状况已被广泛认为是对太空可持续性的严重威胁，但其他紧迫的环境问题却很少受到关注，尽管它们对太空领域的环境和参与者构成风险。因此，本文首先回顾太空活动的主要环境影响及其潜在增长情况，首次以综合方法对其进行分析。太空碎片导致的轨道环境退化已达到一个阈值，即使没有额外发射，未来物体数量也会增加，而人造太空物体对夜空亮度的影响可能已经超过了天文学家定义的光污染阈值。计划中的大型星座可能会使情况显著恶化。在此背景下，建议在行星边界框架内制定这些阈值，以提高认识和支持决策。此外，由于未来发射率的激增，火箭排放导致的平流层臭氧消耗和气候变化可能在未来几十年达到引发监管回应的水平。这也可能适用于数千颗星座卫星在重新进入地球大气层时燃烧产生的粒子，尽管其影响程度尚不清楚。一个常见的假设是，太空人类活动的限制纯粹是技术和经济性质的。本文通过强调当前计划的太空活动发展存在环境限制，对这一假设提出了质疑。探讨了这些限制带来的风险，并强调了生态设计在太空领域的重要性。最后，本文在全球生态转型的背景下讨论了拟议的太空项目未来的可持续性。
