SpaceX may be the only private outfit currently shepherding cargo to the International Space Station, but Orbital Sciences, which is the second party in NASA's Commercial Orbital Transportation Services effort, is taking a step towards its own ISS resupply missions. Today, the firm's Antares rocket will undergo its very first test flight, taking off from the space agency's Wallops Flight Facility on Wallops Island, Virginia. Liftoff is slated for sometime between 5PM and 7PM, with an 80 percent chance of favorable weather, as opposed to the 45 percent odds and high-altitude winds that foiled its initial attempt yesterday. To watch Antares embark on its maiden voyage, hit the jump for a live video feed.

Update: Antares blasted off at a hair past 5PM and successfully separated from its mock payload. The live stream has wrapped up, but we'll slot in a video of the launch as soon as we get ahold of one.

Update 2: NASA just posted its footage of the rocket taking off, and we've placed the video after the break for your viewing pleasure.

[Image credit: NASA, Flickr]