Launch timeline for Atlas 5’s mission with Landsat 9

A United Launch Atlas 5 rocket is set for launch with the Landsat 9 satellite, a joint project between NASA and the U.S. Geological Survey, and four small CubeSat rideshare payloads.

The 194-foot-tall (59-meter) rocket, propelled by an RD-180 main engine, is set for liftoff during a 30-minute launch window Monday that opens at 11:12 a.m. PDT (2:12 p.m. EDT; 1812 GMT).

The Landsat 9 mission will be the 88th flight of an Atlas 5 rocket, and the second Atlas 5 launch of 2021.

The Atlas 5 rocket will lift off from Space Launch Complex 3-East at Vandenberg Air Force Base, flying in the “401” configuration with no solid rocket boosters and a four-meter-diameter payload fairing.

Read our mission preview story for details on the launch.



The Atlas 5 launch profile with the Landsat 9 mission. Credit: United Launch Alliance

T+0:00:01.1: Liftoff

After igniting its RD-180 main engine at T-minus 2.7 seconds, the Atlas 5 rocket climbs away from Space Launch Complex 3-East at Vandenberg Space Force Base, California, with 860,000 pounds of thrust.

T+0:01:19.6: Mach 1

The Atlas 5 rocket exceeds the speed of sound, flying to the south from Vandenberg Space Force Base.

T+0:01:27.2: Max-Q

The Atlas 5 rocket passes through the region of maximum dynamic pressure during ascent through the lower atmosphere.

T+0:04:02.7: Booster Engine Cutoff

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

T+0:04:08.7: 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+0:04:18.6: Centaur Ignition 1

The Centaur RL10C-1 engine ignites for the first of four upper stage firings. This burn will inject the Centaur stage and the Landsat 9 spacecraft into orbit.

T+0:04:26.7: Payload Fairing Jettison

The Atlas 5’s 4-meter-diameter (13-foot) payload fairing separates in a clamshell-like fashion once the rocket climbs into the rarefied upper atmosphere.

T+0:16:30.3: Centaur Cutoff 1

The Centaur engine shuts down after arriving in a planned low Earth orbit with a perigee of 414 miles (666 kilometers), an apogee of 422 miles (679 kilometers), and an inclination 98.22 degrees. The vehicle enters a 64-minute coast period before arriving at the required location in space for deployment of the Landsat 9 spacecraft.

T+1:20:40.4: Landsat 9 Separation

The 5,975-pound (2,710-kilogram) Landsat 9 spacecraft, built by Northrop Grumman, deploys from the Centaur upper stage to begin its environmental monitoring mission.

T+1:50:43.2: Centaur Ignition 2

The Centaur’s RL10 engine ignites for a 10-second to begin maneuvering into a lower orbit for release of four CubeSat secondary payloads.

T+2:10:53.5: Centaur Ignition 3

A third burn by the Centaur upper stage’s RL10 engine begins. This 10-second burn will place the rocket in the correct orbit for CubeSat deployments.

T+2:14:05.3: Begin CubeSat Deployments

Four CubeSats deploy from a carrier on the Centaur upper stage. There are two NASA-sponsored CubeSats: The Cusp Plasma Imaging Detector, or CuPID, which will study the boundaries of Earth’s magnetic field, to see how energy from the sun can break through our planet’s magnetic shield. The Colorado Ultraviolet Transit Experiment, or CUTE, will train its telescope on planets outside our solar system to study how quickly their atmospheres are escaping. There are also two military-sponsored CubeSats to test advanced communication technology.

T+2:57:44.1: Centaur Ignition 4

The Centaur upper stage’s RL10 engine fires a fourth time for a deorbit burn to steer the spent rocket back into Earth’s atmosphere for a destructive re-entry over the Pacific Ocean. This ensures the rocket does not generate any new space junk.

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