Elon Musk of SpaceX has announced his spacecrafts could soon be returning to Earth and landing on platforms.

During a conversation at MIT's AeroAstro Centennial Symposium on Friday, Musk said he plans to have his Falcon 9 rockets land on football field-sized floating platforms in the Atlantic Ocean as soon as December. He hopes to one day land the rockets back where they were launched.

"Imagine if an aircraft were single-use. Then how many people would fly?" Musk said. "The fly rate would be really low. To buy a 747 is like $250 million, or maybe $300 million, and you'd need two of them for a round trip." Musk joked that people would just go places by boat if the airplane industry worked that way, and he believes using reusable rockets that can leave Earth and return to Earth to be used again will save money and make space travel more accessible.

He spoke about how lowering costs can make it more likely humans can colonize other planets or the Moon. He said estimates for the cost of a Mars mission usually hover around $100-200 billion, and he believes there could be a "10,000 fold reduction" of that cost.

In April, SpaceX successfully tested launching a Falcon 9 rocket into space and landing it on a stage in the Atlantic Ocean.