Elon Musk is making the rounds, speaking at the International Space Station R&D Conference which was on the heels of his talk at the National Governors Association. Though quite a bit of attention has been spent on Musk’s concerns regarding artificial intelligence, SpaceX’s progress on the Mars colonization front is still a high priority for many investors and other people. Though familiar obstacles, from physics and weather and technology and experimentation, have conspired to create a typical recursive process in the development of spacecraft, ultimately money might be the singular factor that prevents people from living on Mars.

First the tech. SpaceX is backing away from propulsion rockets because developers have determined the craft no longer needs a controlled descent to land on Mars. Replacement rockets are being designed and developed. Those will likely not be unveiled this year, but the highly anticipated Falcon Heavy inaugural flight is slated to occur later this year. The Falcon Heavy will likely not get far from the launch pad, despite the nine rockets strapped to the spacecraft. According to Musk, the design proved to be “way, way more difficult” than anticipated. The lift-off will provide some real world data that cannot be created in simulation. The slow-down on the design translates to a slow-down on capital.

TechCrunch reports that part of the SpaceX plan to colonize Mars is dependent on money generated from a smaller spacecraft capable of orbiting the Earth. Whether used for space tourism or government-backed missions, the earnings from the smaller spacecraft will fund the development of the larger craft and the Mars mission. It seems that even one of the world’s richest men needs to pay for his dreams.