SpaceX, make Falcon rockets. SpaceX is a private American aerospace company. They carry out missions for NASA, the USA military, and commercial companies. 

Can I see satellites from Earth?

Yes! You can see satellites for the same reason we can see the Moon and planets – they reflect light from the Sun. 

Satellites are useful in lots of ways. They look at the Earth as well as space. They also help us in our the daily lives.