Update: Successful launch! Follow the mission's progress on Twitter.
In this season of solar sailing (Japan's IKAROS is still going strong), another ship is about to leave the harbor.
NASA's modest solar sail demonstrator, Nanosail-D, is due to launch tonight on a Minotaur 4 rocket from Alaska. You can watch Spaceflight Now's live feed from the Kodiak Launch Complex. Liftoff is scheduled for 8:24 p.m. Eastern time.
Nanosail-D is just one of more than a dozen experiments and technology demos onboard the Minotaur, and will be NASA's first orbital deployment of a solar sail.
It's more an experiment in packaging than propulsion. The Nanosail engineers want to see if the sail can deploy cleanly from its shoebox-size container. If it does, it won't do much actual sailing; there's still enough atmosphere in its low orbit to exert drag on the thin material.
Read about the project here. This video shows how the sail will unfold: