More Words, Deeper Hole

It is something of an open question as to whether vampires _have_ to sleep during the daytime. The O.G., Bram Stoker's Dracula, could get around on cloudy days, although under those conditions he couldn't use his Vampire Powers. The dirt requirement? I dunno how much is needed, and in any case a lot of fictional vampires don't seem to follow that rule. As for the "burning up" business, just keep the windows closed? It's not like spaceships are guided by looking out the window.