Submitted by **remorsefulDownfall** t3_12511v8
in **explainlikeimfive**

How do the scientists that launch things into space predict that what they're launching isn't going to end up in the orbit of, or even crash into, another body in space like a planet or a star? Is it a calculation they do? (If so I would like to know the calculation as well).

TheJeeroniant1_je1wvdz wroteThere is an extraordinary amount of math involved. They plan out the exact path of the vessel, as well as the paths of all planets involved.

The approximate path of the vessel is calculated with conic sections (ellipses and hyperbolas) around a planet or star.

The best way to predict a path, albeit with an extraordinary amount of math, is actually very simple. We use the conic sections to predict planets' orbits, since they don't tend to change much, and then we do a very simple calculation to see how much they each tug on the vessel. We then add all of these tugs together and see what direction it is pulled overall. We move it a tiny forward, and repeat the calculation again. Move it again. Calculate, move, calculate. Over and over ten billion times to get a good prediction of the path the vessel will follow. Computers are great for that.