An interesting — if sketchy — report from the website of futurist Ray Kurweil about a joint DARPA-NASA project on interstellar travel:
NASA Ames Director Simon â€œPeteâ€ Worden revealed Saturday that NASA Ames has â€œjust started a project with DARPA called the Hundred Year Starship,â€ with $1 million funding from DARPA and $100K from NASA.
Near-lightspeed nano spacecraft might be close: Researchers creating the tiny engines that could drive mini-starships
The solution to interstellar space exploration may lie in the use of micro or nano-sized spacecraft that can be accelerated to incredible speeds. Protons in a particle accelerator can reach near-lightspeed because they are so small and light. Similarly, very small unmanned space probes could be light enough to reach the speeds necessary for interstellar space exploration.