If there are many satellites orbiting earth, how do space launches not bump into any of them?
In: 2066
You’re underestimating just how large space is. Consider this, roughly 2% of Earth’s surface is covered by the United States (just using the US as an example because automobile stats are readily available). Each day, roughly 115 *million* cars drive on roads in the US each day. Earth’s surface is also effectively 2 dimensional for things like cars (i.e., cars don’t fly over or under each other, and yes, bridges and tunnels can change that, but for the most part, it’s true). Yet despite the fact that over 115 million vehicles operate in an area less than 2% of the Earth’s surface (even less considering cars only use roads, not the entire continent), we don’t have many major issues. We can operate our vehicles just fine and get things done that need to be done.
Now consider space. Low Earth Orbit (where most satellites operate) is not limited to just 2% of the surface area. Theoretically, they can make use of 100% of the sky and travel anywhere we want them to (practically though, it depends on the purpose of the satellite on what orbit they take). Space is also 3 dimensional, unlike Earth’s surface, so we can put some satellites higher or lower than others. Sometimes, this is only slightly higher or lower than others, maybe a mile or less. Other times, it’s vastly different. The James Webb Space Telescope, for example, orbits over 1 million miles away from the Earth. This means there is **FAR** more space (many orders of magnitude more) to keep satellites in than there is for cars to drive in the US. Yet, there’s only roughly 7,700 satellites in orbit compared to 115 million cars in the US. Quite frankly, considering these numbers, it’d be a miracle if satellites somehow *did* manage to collide.
But those are just the raw numbers on the scale of space. In practice, not only is space insanely large (even just Low Earth Orbit) but every satellite, and even significantly large random pieces of orbiting debris, are being tracked by space agencies to make sure no collisions happen regardless.
Despite the above, there is still a worry that space could eventually become so cluttered (especially if there’s an accident that causes a vast number of very small pieces of debris to scatter into orbit) that no new space craft could be launched without getting torn apart by orbiting debris. This phenomenon is called [The Kessler Syndrome](https://en.m.wikipedia.org/wiki/Kessler_syndrome) and would be detrimental not just to space exploration, but space based communication and systems like GPS. For that reason, space traffic is heavily monitored and regulated to prevent it. There’s also ongoing research on how to “clean up” space if the worst happens, and it *does* become a mess that prevents space travel. Many ideas simply boil down to a big space net that catches the debris and deorbits it.
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