Effects of the deployment and disposal of mega-constellations on human spaceflight operations in low LEO

The substantial space traffic changes occurred since the 2010s are having measurable repercussions even at the altitudes used for human spaceflight. These changes were mainly driven by the deployment of thousands of small satellites and cubesats below 600 km.After having evaluated how the situation evolved, from 2008 to 2021, at the altitudes of the International and Chinese space stations, and discussed the main aspects of the problem that may have an operational impact, the attention was focused on what might be expected in the 2020s, whether the current deployment plans for mega-constellations will be realized in whole or in part.Finally, the rationale for the introduction of a "human spaceflight protected region ", with the associated space traffic management recommendations, is presented and discussed.