“When we meet real tragedy in life, we can react in two ways – either by losing hope and falling into self-destructive habits, or by using the challenge to find our inner strength.” -Dalai Lama
Orbiting at hundreds of miles above Earth’s atmosphere, you’d think the Hubble Space Telescope would be safe and stable for a long time. But despite our definitions, Earth’s atmosphere doesn’t “end” and space doesn’t “begin” when we get 60 miles (100 kilometers) up. Instead, Earth’s atmosphere continues, albeit tenuously, for incredible distances, until it eventually merges with the solar wind. It’s the fourth (of five) layers that contains the Hubble Space Telescope: the thermosphere.
Although each oxygen molecule might travel for a kilometer before striking another, the presence of these molecules is enough to slowly produce a drag on Hubble. Over the timespan of years and decades, it loses altitude and begins to fall. If we do nothing, then by the late 2020s to the mid-2030s, it will uncontrollably de-orbit on its own. Our greatest optical observatory will be lost, and there are no plans to save it.