The nearly 1,000-pound observatory has been sealed inside the protective payload fairing atop the Delta II since Saturday, June 21. Fuel was loaded aboard the rocket’s second stage yesterday, wrapping up two days of hypergolic propellant loading activities. OCO-2’s onboard batteries will be charged today, followed by a powered health check tomorrow. NASA managers and launch officials will gather for the the Launch Readiness Review at 1 p.m. PDT on Sunday.
Launch is scheduled for July 1 at 2:56 a.m. PDT, 5:56 a.m. EDT. Our live countdown coverage begins right here at 12:45 a.m. PDT, 3:45 a.m. EDT.