The OCO-2 spacecraft is running on internal power and configured for launch.
Final Built-in Hold Begins
Clocks are holding at T-4 minutes. This is a 10-minute built-in hold and the last one planned in today's countdown.
T-15 Minutes and Counting
Countdown clocks are ticking again. There will be one more built-in hold at the T-4 minute mark.
Weather Still Looking Good
Launch Weather Officer Joseph Round just briefed the launch team on the current and forecast weather conditions, but there were no surprises. We're still "green" on all launch agency and range safety constraints.
T-15 Minutes and Holding
The countdown has paused temporarily at the T-15 minute mark. This is a planned hold lasting 20 minutes. There are no issues being worked in the countdown and liftoff remains scheduled for 2:56 a.m. PDT/5:56 a.m. EDT.
Engine Slews in Progress
The rocket's second-stage engine is going through a series of steering checks called "slews." The first-stage engine check is up next.
One Hour until Launch
Today's launch window opens in an hour. The countdown continues to go smoothly and weather remains favorable.
LOX Loading Complete
The Delta II rocket is fully fueled for launch following the completion of LOX loading activities.
Measuring Earth’s CO2 – and Solving a Mystery
The hexagon-shaped OCO-2 spacecraft was built by Orbital Sciences Corp. and weighs in at almost 1,000 pounds. Two 10-foot-long solar arrays will power all the observatory's systems — including its only scientific payload. This instrument comprises three spectrometers that will break the sunlight reflected up from Earth's surface into its component colors, then focus on …