Atlas 5 rocket ready for blast off at dawn Thursday – Spaceflight Now

Live coverage of the countdown and launch of a United Launch Alliance Atlas 5 rocket from Pad 41 at Cape Canaveral Space Force Station in Florida. The mission will launch the US Space Force’s SBIRS GEO 6 missile warning satellite into geosynchronous orbit. Text updates will automatically appear below. follow us on Twitter.

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United Launch Alliance’s fifth mission of the year is scheduled to lift off from Cape Canaveral during a 40-minute launch window opening at 6:29 a.m. EDT (1029 GMT). An Atlas 5 rocket will launch on a $1.2 billion mission with a US Space Force missile warning satellite.

The countdown is set to begin at 11:09 p.m. EDT Wednesday (03:09 GMT Thursday) with rocket power-up, launch vehicle guidance system checks and preparations to begin loading cryogenic thrusters into the Atlas. 5.

The mission will be the fifth Atlas 5 flight of the year and the 95th launch of an Atlas 5 rocket overall. It is one of 22 Atlas 5s remaining in ULA’s inventory before the rocket was retired. ULA, a 50-50 joint venture between Boeing and Lockheed Martin, is developing the next-generation Vulcan Centaur rocket to replace the Atlas and Delta rocket families.

The payload for Thursday’s mission is SBIRS GEO 6, the latest satellite in Space Force’s Space Infrared System. SBIRS satellites carry infrared sensors to detect heat plumes from missile launches, warning US military forces and government leaders of a potential attack.

Built by Lockheed Martin, the SBIRS GEO 6 satellite weighs approximately 10,700 pounds (4,850 kilograms) fully fueled for launch.

The first SBIRS payload into elliptical orbit was launched in 2006, and the Army launched the first SBIRS satellite into geosynchronous orbit in 2011. The SBIRS program replaced the Army’s Defense Support Program, a series of 23 missile warning satellites launched between 1970 and 2007.

One of the infrared cameras on each SBIRS GEO satellite scans the spacecraft’s coverage area in a U-shaped pattern. With a fleet positioned around the world, SBIRS satellites and long-lived DSP satellites remaining provide global coverage to detect missile launches. Another infrared sensor can target specific regions of interest.

“There’s a fixed sensor that can be pointed and fixed at a fixed point,” said Michael Corriea, Lockheed Martin vice president overseeing the SBIRS program. “So, for example, you can ask him to watch China because maybe there was something you wanted to look at in a particular region, or in North Korea.

A United Launch Alliance Atlas 5 rocket stands on its launch pad at Cape Canaveral Space Force Station on Wednesday. Credit: Michael Cain / Spaceflight Now / Coldlife Photography

After a few hours of preparation for the countdown, the ULA launch team at the Atlas Spaceflight Operations Center in Cape Canaveral will give the “go” for the start of cryogenic tanking of Atlas 5 at approximately 4:30 a.m. EDT ( 08:30 GMT).

Nearly 66,000 gallons of liquid hydrogen and liquid oxygen will be loaded into the two-stage Atlas 5 rocket. The Aerojet Rocketdyne RL10 engine in the Centaur upper stage burns the propellant mixture of hydrogen and oxygen, and the Atlas first stage burns liquid oxygen with 25,000 gallons of room temperature jet fuel, which has was loaded into the rocket on Tuesday, shortly after ULA ground crews rolled the Atlas 5 off the launch pad of the nearby Vertical Integration Facility.

Two built-in takes will occur in the countdown, one at T-minus 2 hours and another at T-minus 4 minutes, before the final four-minute terminal countdown sequence to prepare for liftoff of the Atlas 5 rocket.

The rocket’s propellant tanks will be pressurized and the RD-180 engine is set to fire at T-minus 2.7 seconds. After building up thrust on the main engine, the Atlas 5 sent the command to ignite two Northrop Grumman strapped solid rocket boosters to supply the pad 41 launch vehicle with 1.6 million pounds of thrust.

The version of the Atlas 5 ready for launch on the SBIRS GEOE 6 mission is known as the “421” configuration, with the first number indicating the size of the payload fairing, the second number representing the number of thrusters at solid rocket and the third figure the number of engines on the Centaur stage.

The SBIRS GEO 6 mission will mark the ninth and final flight of an Atlas 5 rocket in the 421 vehicle configuration, and the final launch from Cape Canaveral of an Atlas 5 rocket with the classic 4-meter (13-foot) taper diameter of the Atlas program. nose cone. Another Atlas 5 with a 4-meter fairing is slated to launch later this year from California, while the others will fly with the larger, more bulbous 5-meter payload fairing.

After liftoff, the 194-foot-tall (59-meter) Atlas 5 rocket, designated AV-097 for this mission, will head east of Cape Canaveral to target the mission’s elliptical or oval geosynchronous transfer orbit.

The Atlas 5 will exceed the speed of sound in 49 seconds, then shed its worn strap boosters at T+ plus 2 minutes, 13 seconds.

The first stage RD-180 engine will fire for up to T+plus 4 minutes, 12 seconds. Six seconds later, the first stage will separate from the Centaur upper stage of Atlas 5, which will fire its RL10 engine at T+plus 4 minutes, 28 seconds. The shell-like payload envelope above Atlas 5 will jettison at T+ plus 4 minutes and 36 seconds, once the rocket flies above the thick lower layers of the atmosphere.

Three RL10 engine burns are expected before Atlas 5 releases the SBIRS GEO 6 satellite at T+ plus 3 hours, 1 minute.

The Atlas 5’s guidance computer will aim to release the spacecraft into an orbit whose altitude is between 3,242 miles (5,218 kilometers) and 21,956 miles (35,335 kilometers), with an inclination angle 17.63 degrees from the equator.

This cutaway graphic shows the “421” variant of the Atlas 5 rocket used to launch the SBIRS GEO 6 satellite. Credit: United Launch Alliance

The SBIRS GEO 6 spacecraft will use an onboard propulsion system to steer into a circular geosynchronous orbit that is permanently at an altitude of nearly 22,300 miles above the equator. In this orbit, the satellite’s speed will be fixed with the Earth’s rotation rate, giving the craft’s early-warning infrared sensors a constant view of the same part of the planet.

The satellite will also expand energy-generating pole panels and lightweight shades to begin fine-tuning the performance of its heat-seeking sensors.

SBIRS GEO 6 should be ready to enter operational service in early 2023, according to Space Force officials. The satellite is designed for a 12-year mission. Read our mission preview story for more details on SBIRS GEO 6.

ROCKET: Atlas 5 (AV-097)


PAYLOAD: SBIRS GEO 6 missile warning satellite

CUSTOMER: US space force

LAUNCH SITE: SLC-41, Cape Canaveral Space Force Station, Florida

RELEASE DATE: August 4, 2022

LAUNCH WINDOW: 6:29 a.m. to 7:09 a.m. EDT (10:29 a.m. to 11:09 a.m. GMT)

WEATHER FORECAST: 80% chance of having an acceptable time



TARGET ORBIT: Perigee of 3,242 miles (5,218 kilometers); Apogee of 21,956 miles (35,335 kilometers); Angle of inclination of 17.63 degrees relative to the equator.


  • T-00:00:02.7: RD-180 ignition
  • T+00:00:01.1: Takeoff
  • T+00:00:06.0: Beginning of the pitch/yaw maneuver
  • T+00:00:48.9: Mach 1
  • T+00:00:52.5: Maximum air pressure (Max-Q)
  • T+00:02:13.3: Solid Rocket Booster Release
  • T+00:04:12.4: Atlas booster motor shutdown (BECO)
  • T+00:04:18.4: Separation of the Atlas/Centaur floors
  • T+00:04:28.4: First Centaur Main Engine Start (MES-1)
  • T+00:04:36.4: Payload fairing jettison
  • T+00:12:55.4: Centaur First Main Engine Shutdown (MECO-1)
  • T+00:22:54.6: Start Centaur Second Main Engine (MES-2)
  • T+00:27:38.8: Centaur second main engine shutdown (MECO-2)
  • T+02:57:40.5: Centaur Third Main Engine Start (MES-3)
  • T+02:58:38.4: Centaur Third Main Engine Shutdown (MECO-3)
  • T+03:01:27.4: SBIRS GEO 6 spacecraft separation


  • 677th launch of the Atlas program since 1957
  • Launch of the 378th Atlas from Cape Canaveral
  • 266th mission of a Centaur upper stage
  • 243rd use of the Centaur by an Atlas rocket
  • Launch of the 513th production RL10 engine
  • Launch of the 2nd RL10C-1-1 engine
  • 101st flight of an RD-180 main engine
  • 95th launch of an Atlas 5 since 2002
  • 37th US Air Force/Space Force use of an Atlas 5
  • 18th-19th GEM-63 solid rocket boosters stolen
  • 79th launch of an Atlas 5 from Cape Canaveral
  • 5th launch of the Atlas 5 of 2022
  • 137th Evolved Expendable Launcher Flight
  • 152nd United Launch Alliance flight overall
  • 87th Atlas 5 under United Launch Alliance
  • 110th United Launch Alliance flight from Cape Canaveral
  • 6th launch of an SBIRS GEO satellite
  • 57th Atlas 5 400 series flight
  • 9th Atlas 5 to fly in 421 configuration
  • 106th launch of Complex 41
  • The 79th Atlas 5 will use Complex 41
  • 33rd total orbital launch from Cape Canaveral in 2022

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