The California-based company has a lucrative contract with NASA to bring cargo to the station.

Additionally, the firm has customers from the private sector, military and non-governmental entities to launch cargo into space. As the company makes its money from launch services, SpaceX is firmly focused on developing technology for future space exploration. 

The company is developing what will be the world's most powerful rocket if completed: the Falcon Heavy. Additionally, founder Elon Musk has publicly speculated about the possibility of Mars colonies.

Musk made his fortune very early in life: by age 30, in 2002, he had accumulated a reported $300 million and was looking for his next big venture.

According to the New York Times, his money came from the sale of two companies: Zip2, which was bought for $307 million in 1999, and PayPal, which eBay purchased for $1.5 billion in 2002.