I live in a Maryland suburb of Washington, D.C., and the weatherman thought we'd be able to see a rocket launched from Wallops Island (alas, it blew up instead) which by car is 166 miles away. Assuming that I have a clear view of the horizon (I don't really, but perhaps I could go to a nearby 19-story apartment building), and clear skies, how far from the launch pad would the launch be visible to the naked eye?
Here's a map that shows the general visibility for Antares launches (that was the rocket the weatherman was talking about, although it won't be flying again until 2016):
I once watched a Minotaur V launch from Wallops down on Brighton Beach in New York. It was clearly visible. It was also a night launch, it probably wouldn't have been visible during daytime. Minotaur V is less powerful than Antares, so if you had a clear view of the horizon, you should definitely be able to see an Antares launch from DC.
Also, it's not a NASA rocket. The Antares (and the Minotaur V) is built by Orbital Sciences Corporation. Currently all manifested missions of the Antares are under contract with NASA.