All Aboard

While working on a new type of protective shield for missiles time travel is discovered. The "force field" protected the missile in a totally unexpected way, it send it back in time. Of course this was not the type of protection the researchers were looking for but they decided to take advantage of the opportunity presented to them. It took some effort and secret testing to prove to them it was what was happening but finally they knew beyond a shadow of a doubt.
Visiting the past is now possible, but should it be? The scientists who made the discovery want to use it but their benefactors don't agree. They believe it is too dangerous. What if going in the past effects the future? How could it not? What if someone gets stuck? There is just too many un answered questions.
To be a good scientist or researcher you have to be curious. Lord knows this group is. They just can't leave it alone so clandestinely they explore the past. Very carefully mind you. But explore they do.
They have questions of their own. What really happened? Are our history books accurate? Can you alter the future with time travel? Can you travel to the future?
So many questions!