Live coverage of the countdown and launch of a United Launch Alliance Atlas 5 rocket from Pad 41 at the 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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The United Launch Alliance’s fifth mission of the year is set for liftoff from Cape Canaveral during a 40-minute launch window that will open 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 will begin at 11:09 p.m. EDT Wednesday (0309 GMT Thursday) with rocket ignition, launcher guidance system checks and preparations to begin loading cryogenic propellants into 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 is 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 the Space Force’s Space-Based 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 about 10,700 pounds (4,850 kilograms) fully fueled for launch.
The first SBIRS payload in elliptical orbit was launched in 2006, and the Army launched the first SBIRS satellite in 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, the SBIRS satellites and remaining long-life DSP satellites provide global coverage to detect missile launches. Another infrared sensor can be aimed at specific regions of interest.
“There’s a fixed gaze sensor that can be pointed and looked at a fixed point,” said Michael Corriea, a Lockheed Martin vice president who oversees the SBIRS program. “So, for example, you can task it to look over China because maybe there was something you want to look at in a particular area, or North Korea.
A United Launch Alliance Atlas 5 rocket sits on its launch pad at the Cape Canaveral Space Force Station on Wednesday. Credit: Michael Cain / Spaceflight Now / Coldlife Photography
After a few hours of early countdown preparations, the ULA launch team at the Atlas Space Flight Operations Center in Cape Canaveral will give the go ahead for the start of the Atlas cryogenic tank 5 around 4:30 am EDT (0830 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 hydrogen-oxygen propellant mixture, and the Atlas first stage consumes liquid oxygen with 25,000 gallons of room-temperature kerosene fuel, which was loaded into the rocket Tuesday, shortly after ULA ground crews rolled the Atlas 5. launch pad from the nearby Vertical Integration Facility.
During the countdown, two built-in holds, one at T-minus 2 hours and one at T-minus 4 minutes, will occur before the final four-minute terminal countdown sequence to prepare for liftoff of the Atlas 5 rocket .
The rocket propellant tanks will be pressurized and the RD-180 engine ignites at T-minus 2.7 seconds. After accumulating thrust on the main engine, Atlas 5 sent the command to ignite two Northrop Grumman solid booster rockets to power the launcher off Pad 41 with 1.6 million pounds of thrust.
The launch-ready version of the Atlas 5 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 solid rockets and the third. figure the number of engines in the Centaure stage.
The SBIRS GEO 6 mission will mark the ninth and final flight of an Atlas 5 rocket in vehicle configuration 421, and the final launch from Cape Canaveral of an Atlas 5 rocket with the classic 4-meter (13-foot) conical program in diameter nose cone One more Atlas 5 with a 4-meter fairing is scheduled to launch later this year from California, while the rest will fly with the larger, 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 from Cape Canaveral to target geosynchronous transfer orbit on elliptic or oval shape of the mission.
The Atlas 5 will exceed the speed of sound in 49 seconds, then leave its belt boosters spent at T+ plus 2 minutes and 13 seconds.
The first stage RD-180 engine will fire up to T+plus 4 minutes and 12 seconds. Six seconds later, the first stage will separate from Atlas 5’s Centaur upper stage, which will fire its RL10 engine at T+ plus 4 minutes and 28 seconds. The shell-like payload fairing on top of the Atlas 5 will launch 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 planned before Atlas 5 releases the SBIRS GEO 6 satellite at T+plus 3 hours 1 minute.
The Atlas 5 guidance computer will aim to release the spacecraft into an altitude orbit between 3,242 miles (5,218 kilometers) and 21,956 miles (35,335 kilometers), with an inclination angle of 17.63 degrees with respect to the equator.
This cropped 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 continuously at an altitude of nearly 22,300 miles above the equator. In this orbit, the satellite’s speed will be locked with Earth’s rotation rate, giving the spacecraft’s infrared early warning sensors a constant view of the same part of the planet.
The satellite will also expand the power-generating polar panels and light shadows to begin tuning the performance of the 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)
MISSION: SBIRS GEO 6
PAYLOAD: SBIRS GEO 6 missile warning satellite
CLIENT: US Space Force
LAUNCH SITE: SLC-41, Cape Canaveral Space Force Station, Florida
LAUNCH DATE: August 4, 2022
LAUNCH WINDOW: 06:29-07:09 EDT (1029-1109 GMT)
WEATHER FORECAST: 80% chance of acceptable weather
BOOSTER RECOVERY: None
AZIMUTH LAUNCH: Est
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 with respect to the equator.
LAUNCH TIMELINE:
- T-00:00:02.7: Powering up RD-180
- T+00:00:01.1: take off
- T+00:00:06.0: The fitting/guidance maneuver begins
- T+00:00:48.9: Mach 1
- T+00:00:52.5: maximum aerodynamic pressure (Max-Q)
- T+00:02:13.3: Solid rocket launch
- T+00:04:12.4: Atlas booster engine cut (BECO)
- T+00:04:18.4: Separation of Atlas/Centaure scenarios
- T+00:04:28.4: Centaur main engine first start (MES-1)
- T+00:04:36.4: payload fairing ejection
- T+00:12:55.4: First cut of Centaur main engine (MECO-1)
- T+00:22:54.6: Centaur second main engine start (MES-2)
- T+00:27:38.8: Second Centaur main engine cut (MECO-2)
- T+02:57:40.5: Start of the third Centaur main engine (MES-3)
- T+02:58:38.4: Third Centaur main engine cut (MECO-3)
- T+03:01:27.4: Separation of the SBIRS GEO 6 spacecraft
MISSION STATISTICS:
- 677th launch of the Atlas program since 1957
- 378th launch of the Atlas from Cape Canaveral
- 266th mission of a centaur higher stage
- 243rd use of the Centaure by an Atlas rocket
- Production RL10 engine number 513 will be released
- 2nd RL10C-1-1 engine launched
- 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
- 18-19 GEM-63 solid propellant rockets flown
- 79th launch of an Atlas 5 from Cape Canaveral
- 5th Atlas 5 release of 2022
- 137th Flight of the Evolved Expendable Launch Vehicle
- 152nd United Launch Alliance flight overall
- 87th Atlas 5 under the United Launch Alliance
- United Launch Alliance’s 110th flight from Cape Canaveral
- 6th launch of a SBIRS GEO satellite
- 57th flight of the Atlas 5 400 series
- 9th Atlas 5 to fly in 421 configuration
- 106th launch from Complex 41
- 79th Atlas 5 to use Complex 41
- 33rd orbital launch overall from Cape Canaveral in 2022