NASA is working on plans to build houses on the moon using 3D printers. The houses will be constructed using 'lunar concrete' made from the moon's surface. However, challenges involving the harsh lunar environment and testing the equipment must first be overcome. Marshall Space Flight Center is collaborating with universities and enterprises to develop prototypes for space-friendly furniture. NASA is also exploring using these for establishing sustainable lunar habitats. NASA says these homes could be built as early as 2040. If successful, this project could pave the way for moon neighborhoods and, eventually, similar endeavors on Mars.