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.
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.
NASA and SpaceX officials have said little this week about the apparent explosion of a Crew Dragon capsule Saturday during a ground test at Cape Canaveral, and members of a safety advisory panel said Thursday they will be patient as investigators review high-speed imagery, telemetry data and wreckage to determine the cause of the accident.
A NASA spacecraft under construction for launch in 2016 to retrieve samples from asteroid Bennu could benefit from an extra load of fuel, allowing an extended stay at the asteroid or a return to Earth a year early.
The U.S. Air Force this week awarded SpaceX a contract to launch a Global Positioning System satellite in early 2019, concluding the second of as many as 15 competitions the military plans to run over the next year to pit SpaceX against United Launch Alliance for rights to lift defense and intelligence-gathering payloads into orbit.
