Good morning, and thanks for joining us for the countdown today. NASA’s Orbiting Carbon Observatory-2 is sealed at the top of a United Launch Alliance Delta II rocket at Vandenberg Air Force Base, aiming for liftoff from Space Launch Complex 2 at 2:56 a.m. PDT, 5:56 a.m. EDT. Today’s launch window extends for 30 seconds.
This is the second launch attempt for OCO-2. During the first attempt yesterday morning, the countdown was halted 46 seconds prior to liftoff when a valve that is part of the pulse suppression water system failed to function properly. The failed valve has been replaced and tested, and the team is ready to try again. Weather is 100 percent favorable for liftoff this morning.
The OCO-2 spacecraft will spend two years circling Earth in a polar orbit. From its vantage point more than 430 miles above Earth’s surface, the observatory will provide the first-ever global survey of atmospheric carbon dioxide, or CO-2. With OCO-2, scientists hope to learn more about the balancing act involved in the global carbon cycle — the give-and-take between the sources of CO2 and the areas that absorb it, called “sinks.”