Space weather can make it hard to predict satellite trajectories. Here's why that's a problem 

 Satellites in low Earth orbit can be hundreds of miles off their expected trajectories when bad space weather hits. 

https://cdn.mos.cms.futurecdn.net/xRMbHmiMhBvpHk5KRPcxoh.png

https://www.space.com/space-weather-unreliable-satellite-trajectory-predictions