Most companies invest in potential projects until there are serious signs of non-viability. They spend millions on R&D for that purpose. Every project has the potential to become the next breakthrough in the field. As said above, if they can’t internally fund, they will usually look for grants or venture capitalists. However, these are usually for smaller companies. The bigger ones set aside a large portion of their budget for R&D, because they have the capital and resources to do so. No one gives up on a good idea just because they don’t have the money at first.