For a while they were under military contract for these, but the versions they built were expensive to maintain, but also much too loud. The military contract w

For a while they were under military contract for these, but the versions they built were expensive to maintain, but also much too loud. The military contract was removed, but i think as a result they worked towards making them more simple and more quiet. In the end though they're still building prototypes as R&D to try and find something that can be polished into a product. here's a video with commentary: https://www.youtube.com/watch?v=giS41utjlbU https://www.youtube.com/watch?v=giS41utjlbU