The United Launch Alliance rocket, equipped with two strap-on solid-propellant boosters for added performance, will launch the clandestine NROL-61 payload for the U.S. National Reconnaissance Office from Cape Canaveral.
Liftoff is planned for 8:37 a.m. EDT (1237 GMT).
The booster was wheeled out aboard a mobile launcher platform, emerging from the hangar where the rocket’s two stages and the payload were integrated over the past three weeks.
The slow drive from the 30-story Vertical Integration Facility to the launch pad used a pair of specially-made “trackmobiles” to carry the rocket’s 1.4-million pound launching platform along rail tracks for the 1,800-foot trip.
The rocket is flying the 421 vehicle configuration. The version features two stages, two solids and a 14-foot-diameter nose cone. It is powered off the launch pad by an RD AMROSS RD-180 main engine and Aerojet Rocketdyne solids. The Centaur upper stage has an Aerojet Rocketdyne RL10C-1 cryogenic engine.
Photo credit: United Launch Alliance
See earlier NROL-61 coverage.
Our Atlas archive.
from Spaceflight Now ift.tt/2aeB8yF