Nasa is heading back to the moon, this time to explore its thin atmosphere and rough dust.
The robotic spacecraft Ladee will fly to the moon by way of Virginia's Eastern Shore.
Liftoff is set for late on Friday night from Nasa's Wallops Flight Facility.
Weather permitting, the soaring Minotaur rocket should be visible along much of the East Coast - as far south as South Carolina, as far north as Maine and as far west as Pittsburgh.
Ladee - short for Lunar Atmosphere and Dust Environment Explorer - will be the first spacecraft to be launched into outer space from Wallops. And it will be the first moonshot ever from Virginia in 54 years of lunar missions.
The unmanned Minotaur rocket consists of converted intercontinental ballistic missile motors. A peace treaty between the United States and Russia specifies the acceptable launch sites for those missile parts; Wallops is on that short list.
All but one of Nasa's approximately 40 moon missions - most memorably the manned Apollo flights of the late 1960s and early 1970s - originated from Cape Canaveral. The most recent were the twin Grail spacecraft launched two years ago this weekend. The lone exception, Clementine, a military-Nasa venture, rocketed away from Southern California in 1994.
Scientists involved in the 280 million US dollar, moon-orbiting mission want to examine the lunar atmosphere - yes, that's right, the moon's atmosphere.
"Sometimes, people are a little taken aback when we start talking about the lunar atmosphere because, right, we were told in school that the moon doesn't have an atmosphere," said Sarah Noble, Nasa programme scientist.
"It does. It's just really, really thin."