Atlas V Starliner Updates

Atlas V stacked to receive Starliner capsule

Nov. 8, 2019 -- The stages and boosters have been joined together to form the Atlas V rocket that will launch the inaugural flight of Boeing's CST-100 Starliner spacecraft.

OVIstackedPhoto: United Launch Alliance

Stacking operations were completed today inside United Launch Alliance's Vertical Integration Facility (VIF) at the Cape Canaveral Air Force Station, Florida.

The work began Monday, Nov. 4 when the first stage was hoisted aboard the Mobile Launch Platform. The twin solid rocket boosters were attached on Wednesday, Nov. 6 and Thursday, Nov. 7 to opposite sides of the stage.

The OVI structure, which consists of the interstage, Dual Engine Centaur upper stage and Launch Vehicle Adapter, was lifted atop the first stage this morning to finish the initial buildup of the vehicle.

Applying power to the rocket, testing of the flight controls, checks of the engine steering profiles and a Combined Systems Test will occur over the next week to verify Atlas V is ready to flight.

That will clear the way for delivery of the Starliner capsule from Boeing's Commercial Crew and Cargo Processing Facility (C3PF) at the Kennedy Space Center to the nearby VIF at Space Launch Complex-41 for mating to the Atlas V in mid-November.

Launch remains targeted for Dec. 17.

Atlas V will propel Starliner off the pad at the exact moment the space station's orbital plane crosses over Space Launch Complex-41. The main engine and solids generate 1.6 million pounds of thrust to power the 172-foot-tall, 979,223-pound rocket skyward.

Starliner is headed for the International Space Station for its uncrewed Orbital Flight Test (OFT) as part of NASA's Commercial Crew Program.



Understanding rockets: What is LVOS?

Nov. 4, 2019 -- It is known as LVOS, a day that is celebrated in the life of every rocket destined to launch into space.

Today at the Cape Canaveral Air Force Station in Florida, this special occasion occurred for United Launch Alliance's Atlas V rocket that will launch Boeing's first CST-100 Starliner capsule on its historic Orbital Flight Test to the International Space Station in December.

oft_lvos1The Atlas booster arrives at the VIF. Photo: United Launch Alliance

Rocket engineers are fond of speaking in acronyms, but common folks can appreciate this event as the Launch Vehicle on Stand (LVOS) day, a milestone that officially begins the launch campaign and signals another mission is right around the corner.

The name is a blend of phrases from our heritage combined at United Launch Alliance. The Atlas program called this event Booster on Stand (BOS) while the Delta program used Vehicle on Stand (VOS). Now it is simply LVOS.

To accomplish LVOS for the Atlas V today, the common core booster first stage was moved from the holding bay at the Atlas Spaceflight Operation Center (ASOC) and hauled horizontally by semi-truck nearly four miles to the Vertical Integration Facility (VIF).

The stage will feed 25,000 gallons of RP-1 kerosene fuel and 49,000 gallons of liquid oxygen to the RD-180 main engine during the initial four-and-a-half minutes of the rocket's ascent into space.

oft_lvos4bThe Atlas is hoisted upright to launch OFT. Photo: United Launch Alliance

By sunrise this morning, the rocket was parked at the doorway to the VIF, which serves as our 30-story-tall vertical assembly building for the Atlas V at Cape Canaveral. Crews then went to work setting up ground handling equipment.

Two cranes grappled both ends of the 107-foot-long stage so that it could be lifted free from its carrier. Next, the aft portion was secured in a special dolly that rides rail tracks, allowing the rocket to be rotated from horizontal to upright by the overhead crane while also the rear inched closer to the VIF.

Once vertical, the aft structure was disengaged and the crane holding the forward end of the rocket slowly and carefully hoisted the stage into the VIF and positioned it aboard the Mobile Launch Platform (MLP).

oft_lvos8The Atlas booster goes vertical. Photo: United Launch Alliance

All the while, Air Force meteorologists from the 45th Weather Squadron monitored radar screens and anemometers to ensure no adverse storms were percolating that could cause a lightning warning and that winds were not too strong to interfere with the delicate work.

The weather never was a factor, and the stage was anchored to the three supports, called launch heads, protruding from the MLP's flame duct. Explosive bolts will be installed, which fire at liftoff to release the Atlas V to fly away from the pad.

Now that LVOS has been achieved, activities coming up will see the two solid rocket boosters brought to the VIF one-by-one and attached to the sides of the first stage, the Centaur upper stage will be hoisted atop the rocket and then the Starliner spacecraft will be mounted on the Atlas V.

The fully-assembled, 172-foot-tall rocket will be transferred aboard the MLP the one-third-of-a-mile from the VIF to the Space Launch Complex-41 pad in a few weeks for the Integrated Day-of-Launch Test (IDOLT), also known as a Wet Dress Rehearsal (WDR). The rocket will be returned to the VIF briefly after the countdown test to undergo final preps.

Launch of the Orbital Flight Test is targeted for no earlier than Dec. 17.



Go Atlas! Go Starliner!

June 13, 2019 -- Watch the latest episode when we learn about the Emergency Detection System -- unique technology developed for the Atlas V Starliner designers to protect the crew and monitor the health of the rocket.


Rocket delivered to launch Starliner's first astronauts

June 5, 2019 -- Another rocket shipment from the United Launch Alliance factory has arrived at Cape Canaveral Air Force Station, and this one is extra special.

av_082_marinerThe Mariner cargo vessel sails into Port Canaveral carrying the Atlas V booster and Centaur for the CFT launch. Photo: United Launch Alliance

The Mariner cargo ship has delivered the Atlas V booster stage and the Dual Engine Centaur upper stage that will write a new chapter in human spaceflight history by launching the first astronauts to the International Space Station aboard Boeing's CST-100 Starliner spacecraft for NASA's Commercial Crew Program.

The rocket delivered, designated AV-082, departed the factory in Decatur, Alabama, on May 23 for the journey that spanned rivers, the Gulf of Mexico and Atlantic Ocean to reach Port Canaveral for berthing at the unloading wharf.

The ship arrived at dawn Saturday, June 1. The cradle carrier holding Centaur rolled off the Mariner on Monday, June 3, followed by another truck pulling the Atlas stage today.

Now at the launch site, the Atlas V will undergo receiving checks and await the start of operations for its mission to send three astronauts to the station on the Crew Test Flight (CFT) of Starliner.


The Centaur exits the Mariner. Photo credit: ULA

As part of NASA’s Commercial Crew Program, the CFT mission carrying Boeing astronaut Chris Ferguson and NASA astronauts Mike Fincke and Nicole Mann will fully demonstrate Starliner and Atlas V’s ability to safely carry crew to and from the orbiting laboratory.

Ferguson, a retired Navy captain born in Philadelphia, flew on three space shuttle missions, serving as pilot on space shuttle Atlantis' STS-115 mission in 2006 that installed a solar power truss on the International Space Station, commander of space shuttle Endeavour's STS-126 mission in 2008 that brought up critical equipment to remodel the outpost's interior in preparation for doubling the size of its resident crews and commander of Atlantis' STS-135 mission that brought the shuttle program to completion, marking the most recent human spaceflight launch from U.S. soil in 2011. He has a master's degree in aeronautical engineering, has accumulated 5,700 hours of flight time in more than 30 types of aircraft and logged 40 days in space.

Fincke, a native of Pittsburgh, is a retired Air Force colonel with master's degrees in aeronautics and astronautics from Stanford and planetary geology from the University of Houston. In the Air Force, he was a test engineer and amassed over 1,900 flight hours in more than 30 different aircraft. He was the science officer for Expedition 9 in 2004 on the space station, commander of Expedition 18 in 2008-2009 and a spacewalker on STS-134, the next-to-last shuttle flight, in 2011.

Mann, born in Petaluma, California, is a lieutenant colonel in the Marine Corps. and Naval Aviator with 47 combat missions to her credit in Iraq and Afghanistan for Operations Iraqi Freedom and Enduring Freedom. She also earned a master's degree in mechanical engineering with a specialty in fluid mechanics from Stanford. CFT will be her first spaceflight after working closely with Boeing to develop Starliner spacecraft systems.

The three astronauts are currently in training for an extended duration stay at the station, contributing to life and work aboard the orbiting laboratory.


The Atlas first stage for CFT arrives at Cape Canaveral. Photo credit: ULA

CFT will be the second Starliner flight following the uncrewed Orbital Flight Test (OFT) targeted to launch to the station in August. The rocket for OFT, tail number AV-080, was brought to the Cape last year.

Both flights are key elements of NASA's Commercial Crew Program that returns the capability of launching astronauts into orbit on American rockets from U.S. soil.

Atlas rockets safely launched four human spaceflights in NASA's Project Mercury between 1962 and 1963, including the historic voyage of John Glenn to become the first American to orbit the Earth. The legacy of Mercury-Atlas is the foundation for the Atlas V rocket to launch astronauts in Starliner.


The CFT first stage enters the Atlas Spaceflight Operations Center. Photo credit: ULA




Atlas V departs factory for historic mission

May 23, 2019 -- The first Atlas V rocket to launch astronauts into space emerged from the United Launch Alliance factory today, rolling into a giant cargo ship for transport to Cape Canaveral.

av_082_roll-6The Atlas V booster and Centaur stages leave the Decatur factory today for CFT launch. Photo: United Launch Alliance

ULA built the Atlas V at the sprawling 1.6-million-square-foot manufacturing facility in Decatur, Alabama, taking raw materials and turning them into a rocket to launch the first crew of Boeing's CST-100 Starliner spacecraft.

After speeches celebrating the milestone by Alabama elected officials and ULA and Boeing dignitaries in attendance, ULA workers moved the Atlas V booster stage and Centaur upper stage down the road for loading into the Mariner vessel docked nearby.

The 312-foot-long ship is purpose-built to navigate both shallow waters of rivers and ocean travel to reach ULA's launch sites. It has been making the trek from Decatur to Cape Canaveral since 2001.


The Atlas first stage for CFT travels down the road the Decatur dock. Photo credit: ULA

This rocket, known as AV-082, will launch Starliner on the Crew Flight Test (CFT) to the International Space Station part of NASA's Commercial Crew Program. CFT will follow the maiden voyage of Starliner, the uncrewed Orbital Flight Test (OFT) targeted for August.

Aboard will be Boeing astronaut Chris Ferguson, a three-time space shuttle astronaut and commander of space shuttle Atlantis on the final shuttle mission; NASA astronaut Mike Fincke, a veteran of three spaceflights, including two long-duration stays on the International Space Station, and NASA astronaut Nicole Mann, a spaceflight rookie making her first trip into space.

Once at Cape Canaveral Air Force Station in Florida, the Atlas V will begin integrated operations and processing for the CFT launch.


Boeing's Rick Navarro and ULA's Gary Wentz addressed dignitaries and the news media in front of the CFT booster in the factory before rollout. Photo credit: ULA




Systems Engineer Greg Plettinck Honored With Silver Snoopy

May 1, 2019 -- Systems Engineer Greg Plettinck received NASA’s prestigious Silver Snoopy Award for outstanding support of NASA in his role as ascent room coordinator for the upcoming Atlas V Starliner missions.

2G4A2390ULA’s Greg Plettinck, receiving a Silver Snoopy award, is joined by (L to R): NASA astronauts Butch Wilmore, Josh Cassada and Suni Williams, ULA CEO Tory Bruno, astronaut Eric Boe, Plettinck, and CFT crew members Chris Ferguson, Mike Fincke and Nicole Mann. Photo: ULA

Plettinck received the award on April 30 from Eric Boe, chief of NASA’s astronaut office, and Boeing astronaut Christopher Ferguson during a town hall event in Denver. NASA’s Silver Snoopy Award is presented by astronauts to aerospace industry professionals for outstanding performance that contributes to mission success. Less than 1 percent of aerospace professionals are honored with the award annually, making it a special honor to receive this award.

In the nomination, Boe articulated that Plettinck’s leadership and comprehensive training plan for the ascent team was critical in preparation for upcoming flight tests. In addition, Plettinck’s attention to detail and dedication has created a realistic training environment to sharpen the skills of both the ground teams and the astronauts.

“The flight crew recognize that the success of each mission is measured by the dedication to excellence and teamwork of people such as you,” said Boe. “Your efforts have demonstrated that you are a vital link in the success of our space programs and we thank you for your contributions.”

Plettinck accepted the Silver Snoopy pin along with a certificate and commendation letter in front of colleagues and said he was surprised and humbled to receive the prestigious award.

“I think of the flight crew as part of my family and conduct all of my tasks with them in mind. It feels like everything comes full circle. The last Space Shuttle mission I worked on was STS-133 before getting hired at ULA, the very flight that this Silver Snoopy pin flew on,” Plettinck said. “I am grateful to ULA, Boeing, and NASA for the opportunity to contribute to the safety and success of human spaceflight.



Atlas V rockets in production to launch astronaut crews

April 17, 2019 -- United Launch Alliance is finalizing production of the Atlas V rockets that will launch the first two crewed flights of Boeing's CST-100 Starliner to the International Space Station, known as the Crew Flight Test (CFT) and Post Certification Mission-1 (PCM-1).

cft_DECRL10 engines that will power CFT into space. Photo credit: ULA

At our factory in Decatur, Alabama, skilled technicians are putting the finishing touches on the CFT hardware before shipment to the Cape Canaveral launch site, and also working on the assembly and testing of the PCM-1 rocket.

These launches will be the second and third flights of the Starliner program. The first flight, the Orbital Flight Test (OFT), will be an uncrewed checkout mission to the International Space Station scheduled for August 2019. All Atlas V hardware for OFT is in Cape Canaveral and will soon begin processing for the first flight.

cft_firststageThe Atlas first stage for CFT is in final processing in Decatur. Photo credit: ULA

The CFT launch vehicle, designated AV-082, is in final processing in Decatur and will soon travel to Florida in the Mariner cargo ship. The Atlas V first stage and the Dual Engine Centaur (DEC) upper stage are fully assembled and now undergoing closeouts in preparation to depart the factory.

The PCM-1 rocket, designated AV-085, is making great strides in its manufacturing. The first stage tanks have been completed and the Dual Engine Centaur is in the final assembly cleanroom. The pictures below show the forward adapter that will hold the vehicle avionics being installed on the Centaur tank structure.

centaur_forwardThe Centaur for PCM-1 being assembled. Photo credit: ULA

For each Starliner launch, the Atlas V first stage will fire for four-and-a-half minutes before separating. The DEC then ignites its twin Aerojet Rocketdyne RL10 engines for a burn lasting more than seven minutes to put the spacecraft on the trajectory to reach the International Space Station.

CFT will carry Boeing astronaut Chris Ferguson and NASA astronauts Mike Fincke and Nicole Mann for an extended duration test flight to live and work aboard the station. The trio is undergoing training at the Johnson Space Center in Houston, learning the intricate details of Starliner's systems and operational information about the station facility. Fincke and Mann are training to conduct spacewalks at the station, while Ferguson is rehearsing his support role from inside the complex.

two_centaursBoth Centaurs for CFT and PCM-1 sit side-by-side in the Clean Room in the factory. Photo credit: ULA

PCM-1 will be NASA's first operational mission on Starliner, taking astronauts Suni Williams and Josh Cassada on a long duration expedition to the orbiting laboratory.

Starliner, and the United Launch Alliance Atlas V rockets that will launch the spacecraft, are key elements of NASA's Commercial Crew Program to restore the capability to send astronauts into orbit from U.S. soil.



OFT team simulates launch day activities

Feb. 18, 2019 -- The joint team that will launch the United Launch Alliance Atlas V rocket and Boeing’s CST-100 Starliner on its Orbital Test Flight conducted a successful Integrated Crew Exercise (ICE) on Feb. 12.

ICE2 sim photo
Photo credit: ULA

ULA, Boeing, NASA and Air Force personnel executed a mock countdown that practiced fueling the rocket and operating on the unique launch day timeline that features a four-hour built-in hold at the T-minus 4 minute mark. The Blue Team entered Space Launch Complex-41 and took the Crew Access Tower elevator to the White Room for simulated work to ready the Starliner’s crew module for flight.

The team was given simulated issues with hardware and downrange assets to exercise troubleshooting, problem resolution procedures and the coordination that goes into adjusting the countdown as necessary. There were even simulated challenges from the weather, forcing officials to react to a changing weather conditions at the pad.

The exercise culminated with a successful liftoff and climb into space.

Participants were in various locations just like they will be on the day of launch, including Cape Canaveral Air Force Station and Kennedy Space Center in Florida, Denver, Colorado and Johnson Space Center in Houston, Texas.

Formal rehearsals like this one allow the combined organizations to practice as one team, demonstrate the roles and responsibilities of each team member and practice the countdown scripts.

Leading the Atlas V countdown were ULA Chief Launch Conductor Doug Lebo, ULA Launch Director Bill Cullen and ULA Anomaly Chief Dave McFarland. Key personnel leading CST-100 Starliner activities were Spacecraft Mission Director LeRoy Cain at the Cape, Spacecraft Launch Conductor Louis Atchison at Boeing Mission Control at NASA’s Kennedy Space Center and Flight Director Richard Jones in the Mission Control Center at NASA’s Johnson Space Center in Houston. Commercial Crew astronaut Mike Fincke also participated in the simulation.

The OFT will be the uncrewed test of the CST-100 Starliner spacecraft under NASA’s Commercial Crew Program. Starliner will launch to the International Space Station for an automated rendezvous and docking, complete a short stay and then return to Earth.



Go Atlas! Go Starliner!

Feb. 13, 2019 -- Watch the episode where a rocket scientist (Tory Bruno, ULA CEO and President) and an Astronaut (Chris Ferguson, Boeing Astronaut) discuss the Atlas V Starliner, Star Wars and Star Trek, favorite moments leading to launch, their excitement about launch day and more.


Atlas first stage delivered for Starliner launch

Dec. 11, 2018 -- All launch vehicle hardware has been delivered to Cape Canaveral for the United Launch Alliance Atlas V rocket to launch Boeing’s first CST-100 Starliner spacecraft on its uncrewed Orbital Flight Test.

Photo credit: NASA

The Atlas V first stage rolled off of the Mariner cargo vessel on Dec. 7 at the Cape Canaveral wharf for the short drive to the Atlas Spaceflight Operations Center for receiving inspections and checkout.

Mariner is the ocean-going vessel that ULA uses to transport rocket stages from the manufacturing plant in Decatur, Alabama to the launch sites. The Atlas stage departed the factory Nov. 28 for the journey of nearly 2,000 miles.

Early in 2019, the stage will move further north to the Vertical Integration Facility to be raised on the mobile launch platform. The twin solid rocket boosters will be mounted to the bottom of the first stage. Then, the top of the rocket stack, which consists of the interstage, Centaur upper stage and payload adapter, will be hoisted into position.

This delivery means all of the hardware that ULA needs to launch the first Starliner has been received at the launch site for final integration.



Centaur ready to launch first Starliner

Nov. 29, 2018 -- The dual-engine Centaur upper stage that will power Boeing’s first CST-100 Starliner crew capsule into space for its Orbital Flight Test is one step closer to launch.

Photo credit: United Launch Alliance

Inside a ULA launch site test cell, the Centaur has been hoisted upright and attached to the interstage adapter that supports the stage atop the Atlas V rocket’s first stage during the initial minutes of launch. The Launch Vehicle Adapter (LVA) was mated to the forward end of Centaur and provides the mechanical interface to attach Starliner.

This three-piece combined element is called the OVI stack, or Off-site Vertical Integration, for the Atlas V rocket’s launch campaign. It will be driven to the Vertical Integration Facility and lifted atop the first stage when the time comes.

The Atlas V program evolved to OVI stacking operations in 2015 to improve launch processing techniques and enable schedule efficiencies. This process eliminates several days of lifting operations at the VIF that would require acceptable weather to stack each structure separately.

The Centaur was built at ULA’s manufacturing facility located in Decatur, Alabama. It arrived at Cape Canaveral aboard the Mariner cargo ship on Oct. 19 and spent two weeks undergoing receiving activities at the Atlas Spaceflight Operations Center before the short drive to the Delta Operations Center to begin the OVI assembly sequence. The LVA arrived at the Cape on Nov. 12.

Centaur will separate from the interstage adapter during in-flight staging before igniting its twin RL10A-4-2 engines more than four minutes after liftoff. Starliner will be released from the Launch Vehicle Adapter when the spacecraft separates from the Atlas V to conclude the launch.



ULA’s VALOR ensures astronaut safety during launch

Nov. 15, 2018 -- An elite group of United Launch Alliance (ULA) specialists will serve as an ascent flight control team during launches of Boeing’s Starliner spacecraft aboard Atlas V rockets.

Stationed in the Vehicle Ascent and Launch Operations Room (VALOR) at ULA’s Denver headquarters, this dedicated team will monitor the health and performance of the Atlas V rocket during every Starliner capsule’s climb to space.

The safety of astronauts is paramount in the return of human spaceflight launch capabilities to the United States, and ULA’s VALOR team takes this responsibility seriously. The highly trained engineers staffing the consoles will provide real-time status of the Atlas V vehicle and assist in making real-time decisions with Boeing’s flight director at Mission Control in Houston.

“This ULA Ascent Team in the VALOR is Boeing’s and the flight crew’s insight into the launch vehicle during ascent. If you compare it to the space shuttle program, we are equivalent to the BOOSTER position in Mission Control,” said Gregory Plettinck, the Ascent Room Coordinator (ARC).

VALOR is located in the Denver Operations Support Center, which provides engineering expertise during all ULA launches. This new room is isolated to ensure no distractions to the engineers’ work that goes beyond the normal level of ascent data monitoring.

Console positions will monitor all critical systems, like avionics, the engines, fuel tanks and the vehicle navigation. They also will be supplying confirmation of launch ascent events to Mission Control in Houston, such as engine ignitions, throttling events and cutoffs, and the jettisoning of the twin solid rocket boosters, the first stage, aeroskirt and Starliner itself.

“The team undergoes extensive training and all members must be certified to properly carry out their roles on day of launch. The safety of the flight crew depends on them,” said ULA Mission Manager Caleb Weiss.

In addition, VALOR will offer situational awareness of any off-nominal launch vehicle data in the telemetry stream from the rocket and prompt the engineers to report flight rule violations if they occur.

“In the event of a developing anomaly, the team will provide a recommendation to the flight director in Houston on the course of action to best keep the crew safe,” Weiss said.

The VALOR will be available to support other missions that use an Ascent Team such as the ULA-made Interim Cryogenic Propulsion Stage on NASA’s Space Launch System.



More Launch Gear Arrives for the Orbital Flight Test

Nov. 12, 2018 –The Launch Vehicle Adapter (LVA) that will attach Boeing’s first Starliner spacecraft to the Atlas V launch vehicle arrived at Cape Canaveral from the United Launch Alliance factory today.

Mariner sailed into Port Canaveral on Nov. 11. Photo credit: United Launch Alliance

The Mariner cargo vessel brought the LVA and two stages of a Delta IV rocket from our manufacturing plant in Decatur, Alabama. The ship, which was purpose-built to transport the large diameter Delta IV stages to Florida and California launch sites, set sail on Nov. 3 and traveled nearly 2,000 miles, arriving Nov. 11.

Technicians unloaded the elements today and they were transported for the LVA to begin integrated operations with the Centaur upper stage.

The LVA is the specially-designed structure that will be fitted to the top of Centaur. It will soon be attached to the Centaur during pre-launch stacking operations and eventually support the Starliner spacecraft during launch of the Orbital Flight Test next year.

Also part of the LVA is the aeroskirt, which ULA designed in collaboration with Boeing and NASA for added aerodynamic stability during the flight. This metallic orthogrid structure will smooth the air flow over the Starliner-Atlas V vehicle, and will be nominally jettisoned after the first stage of flight. The aeroskirt also has provisions for venting in the event the Starliner abort engines are fired.

OFT, the precursor to Boeing’s Crew Flight Test, is being performed in partnership with NASA’s Commercial Crew Program to return the nation’s human spaceflight launch capability.

The LVA is seen here readied for shipping from Decatur. Photo credit: United Launch Alliance


The crated LVA rolls off Mariner. Photo credit: United Launch Alliance



Wilmore visits Centaur

Oct. 25, 2018 -- Barry “Butch” Wilmore, the NASA astronaut who piloted shuttle Atlantis’ STS-129 flight and commanded Expedition 42 on the International Space Station, stopped by ULA today to check out the dual-engine Centaur upper stage and engage with employees working on the Commercial Crew Program.

Photo credit: United Launch Alliance



Centaur arrives at Cape Canaveral

Oct. 19, 2018 -- The dual-engine Centaur upper stage that will launch Boeing's first Starliner spacecraft on its uncrewed Orbital Flight Test to the International Space Station has arrived at Cape Canaveral for final processing by United Launch Alliance technicians.

The Centaur is prepared to exit the Mariner. Photo by NASA

The stage arrived Oct. 19 aboard the Mariner cargo ship, the ocean-going vessel that ULA uses to transport rocket stages from the manufacturing plant in Decatur, Alabama to the launch sites.

Wrapped in a protective covering for the transit, the Centaur was offloaded at the Port Canaveral wharf and driven on a specialized trailer to ULA's Atlas Spaceflight Operations Center for initial arrival checks.

Later, it will move to the Delta Operations Center to be raised vertically, mounted onto the interstage structure and fitted with the adapter that will support Starliner atop the rocket. That combined stack will then be ready for mating to the Atlas V first stage at the Vertical Integration Facility next year.

The Centaur heads for ULA's Cape Canaveral facilities. Photo by NASA

Mariner left Decatur on Oct. 10 for the journey of nearly 2,000 miles.

The venerable Centaur will resume flights in a dual-engine configuration -- which was once commonplace -- for this inaugural launch of Starliner. The last Centaur stage to utilize two engines was an Atlas IIAS rocket launch in 2004.

The Atlas V has needed only single-engine Centaurs to perform all of its launches to date to deliver payloads to their intended destinations, but the Starliner mass along with the need to shape the trajectory to limit astronaut accelerations and optimize ascent abort performance in case of a vehicle failure necessitates the thrust of two engines.

The Centaur enters the Atlas Spaceflight Operations Center. Photo by NASA

For the OFT launch, the Centaur will be powered by a pair of Aerojet Rocketdyne RL10A-4-2 cryogenic engines, burning liquid oxygen and liquid hydrogen to generate nearly 45,000 pounds of thrust.

Centaur flew for the 250th time on Oct. 17 in launching the Air Force's AEHF-4 protected communications satellite. Two-thirds of those previous launches were dual-engine configurations.

The high-energy stage has launched spacecraft to every planet in our solar system, plus the moon, Pluto and solar observatories, and critical national security, communications and weather satellites.