[jeffreyw]

Navigational devices need to take into account the relativistic effects of near luminal velocities. The internal structures of the craft need to account for rapid changes in acceleration which will be possible (meaning inertia cancellation). As well, high speed propulsion needs technology more advanced than rockets (that's obvious). As well, there needs to be some type of protection of the vessel and its occupants of interstellar radiation (which is quite damaging). 

Just simply studying them and the eyewitness accounts is beyond the pride of most "scientists". They just dismiss all of it out of spite, unfortunately UFO's signal the eventual technological advances we as a species will become familiar with over time.

It is suggested to read the many tens of thousands of reports of UFO's. A good collection of them (many quite recent) are available on www.nuforc.org. I would be skeptical of the reports, but it should be of serious note, only ONE of them needs to be an actual craft from another place in the galaxy to show that we are being visited by people from other worlds. In that case, they are not UFO's anymore, but extraterrestrial craft. This of course is laughable to those who can't stomach the truth, but only time will tell.