#Timeline: Atlas 5/NROL-79 launch events

Follow the unclassified portion of the Atlas 5 rocket’s ascent to space from California’s Vandenberg Air Force Base launch site with the U.S. National Reconnaissance Office’s NROL-79 satellite payload. Launch is scheduled for Wednesday at 9:50 a.m. local time (12:50 p.m. EST; 1750 GMT).

T+00:01.1: Liftoff

The United Launch Alliance Atlas 5 vehicle, designated AV-068, will lift off and begin a vertical rise away from Space Launch Complex 3-East at Vandenberg Air Force Base, California.

T+00:81: Mach 1 and Max Q

The Atlas rocket achieves Mach 1 some 81 seconds into the flight, then passes through the region of maximum dynamic pressure at 89 seconds.

T+04:03: Main Engine Cutoff

The RD-180 main engine completes its firing after consuming the load of RP-1 kerosene fuel and liquid oxygen supply in the Atlas first stage.

T+04:09: Stage Separation

The Common Core Booster first stage of the Atlas 5 rocket separates from the Centaur upper stage. Over the next few seconds, the Centaur engine liquid hydrogen and liquid oxygen systems are readied for ignition.

T+04:19: Centaur Ignition No. 1

The Centaur RL10 engine ignites to inject the Centaur stage and NROL-79 spacecraft into orbit.

T+04:27: Nose Cone Jettison

The two-piece, 14-foot-diameter payload fairing that protected the NROL-79 craft during the atmospheric ascent is separated to reveal the satellite to space.

The mission now enters a news blackout to perform the orbit-shaping and payload deployment for the National Reconnaissance Office in secrecy.

After performing its mission, the Centaur will be de-orbited into the South Pacific, west of Chile.

See earlier NROL-79 coverage.

Our Atlas archive.

from Spaceflight Now ift.tt/2mCfuuD

Leave a Reply

Your email address will not be published.

The CAPTCHA cannot be displayed. This may be a configuration or server problem. You may not be able to continue. Please visit our status page for more information or to contact us.

This site uses Akismet to reduce spam. Learn how your comment data is processed.