A United Launch Alliance Delta IV is set to lift off at 3:39 a.m. PST (6:39 a.m. EST) from Vandenberg Air Force Base carrying the National Reconnaissance Office’s NROL-45. If there are clear skies, the launch will be visible for hundreds of miles.
ULA will webcast the launch at http://www.ulalaunch.com.
SpaceX is planning to be back in action two weeks later with a planned Feb. 24 launch of its upgraded Falcon 9 booster. The rocket will carry SES-9 communications satellite for SES S.A. of Luxembourg. SpaceX will conduct the launch from the Cape Canaveral Air Force Station in Florida.
“In order to minimise the impact of moving the launch from late last year, SpaceX is supporting a mission modification,” SES said in a press release. “The changed mission will reduce the time needed for SES-9 to reach its orbital slot, keeping the Operational Service Date (OSD) in the third quarter of 2016, as previously foreseen….
“SES-9 will use a chemical bi-propellant apogee motor to quickly achieve a 24h synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity at 36,000 kilometers over the equator,” the company added. “Subsequent on-orbit manoeuvres will be executed with electric propulsion.”