September 20, 2018

Launch timeline for Atlas 5’s mission with InSight


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A United Launch Atlas 5 rocket is set to dispatch NASA’s InSight lander toward Mars, kicking off an interplanetary journey from Vandenberg Air Force Base in California.

The 188-foot-tall (57-meter) rocket, propelled by an RD-180 main engine, is set for liftoff during a two-hour launch window Saturday that opens at 4:05 a.m. EDT (7:05 a.m. EDT; 1105 GMT).

The InSight mission will be the 78th flight of an Atlas 5 rocket, and the fourth Atlas 5 launch of 2018.

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.

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 Air Force Base, California, with 860,000 pounds of thrust.

T+0:01:17.8: Mach 1

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

T+0:01:26.9: Max-Q

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

T+0:04:04.3: 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+0:04:10.3: 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+0:04:20.3: Centaur Ignition 1

The Centaur RL10C-1 engine ignites for the first of three upper stage firings. This burn will inject the Centaur stage and the InSight spacecraft into an initial parking orbit.

T+0:04:28.3: 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+0:13:16.2: Centaur Cutoff 1

The Centaur engine shuts down after arriving in a planned low-Earth parking orbit. The vehicle enters a nearly 66-minute coast period before arriving at the required location in space for the second burn.

T+1:18:56.9: Centaur Ignition 2

Producing 22,900 pounds of thrust, the Centaur re-ignites to accelerate the InSight payload with enough velocity to escape Earth’s gravitational bond. This burn lasts 5 minutes, 23 seconds.

T+1:24:19.8: Centaur Cutoff 2

The second Centaur firing places the InSight payload on an Earth escape trajectory. After engine shutdown, the Centaur stage will begin re-orienting for deployment of InSight.

T+1:33:19.8: InSight Separation

The 1,530-pound (694-kilogram) InSight spacecraft deploys from the Centaur upper stage.

T+1:33:53.8: MarCO-A Separation

The first of NASA’s Mars Cube One satellites, designed to relay communications from InSight during its landing on Mars, releases from an aft bulkhead carrier on the Centaur stage.

T+1:34:41.8: MarCO-B Separation

The second of NASA’s Mars Cube One spacecraft is released from the Centaur’s aft bulkhead carrier.

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Follow Stephen Clark on Twitter: @StephenClark1.


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