Every year, NASA uses the “NASA Innovative Advanced Concepts” program (NIAC) to finance interesting projects that might someday become a reality. Projects in Phase 1 are subject to a nine-month study on their general feasibility, while in Phase 2, projects receive a two-year grant to develop their designs in detail. At the end, they aren’t required to be commercially marketable just yet – the transition to that level of development is done in Phase 3.
Currently, the list includes two projects whose destination is Venus, Earth’s hellish little sister.