Gravity and Space
We use artificial satellites for several reasons. Perhaps the first reason we would consider is for telecommunications - our mobile phones may use a satellite signal or have a GPS locator. Other satellites observe Earth and keep us safe by observing weather patterns or changing global conditions like sea levels or the area of Arctic ice. Some satellites are actually telescopes able to observe further into our universe without the distortions of Earth's atmosphere.
The cost of putting a satellite into orbit has reduced and there is a large number of artificial satellites currently orbiting Earth. In fact, it is hard to know exactly how many as some are used for spying and are kept secret. We now need to consider what could be done to clear up Earth's near space since old satellites become rubbish when they stop working. Can you imagine a space rubbish truck? Or maybe a big space broom?