Japan tried and failed to get its Akatsuki ("Dawn") probe into Venus' orbit back in 2010, and the spacecraft has been stuck orbiting the Sun ever since. However, the team is about to get another chance at completing its intended mission. Controllers plan to fire the ship's engines on December 7th at 9AM Japan time (December 6th 7PM ET), hopefully giving it just enough of a push to (eventually) get it circling around Venus. They'll know whether or not the burn worked properly within a few hours, but it'll take a few days before they know if they're in orbit.

Update: The attempt is happening in just a few minutes, for live updates you can watch a stream of the data and control center, or follow Emily Lakdwalla on Twitter.