SpaceX chief Elon Musk has tweeted two photos that give us a peek into the company's Martian dreams. One of the images shows the BFR, the massive rocket SpaceX is developing for deep space missions, while the other shows the BFR and what he called "Mars Base Alpha." It's no secret that the private space corporation wants to build a human settlement on the red planet. Back in 2017, it announced its plans to launch two BFR cargo missions to Mars by 2022 to prepare for the arrival of the first Martian settlers by 2024. Before any of that can happen, though, SpaceX has to be able to start testing its BFR system in the first half of 2019.