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EDITOR’S NOTE: Updated Feb. 27, 2020, with artist’s rendering and dimensions of the mobile gantry.

With construction already underway at Kennedy Space Center’s launch pad 39A on facilities for SpaceX’s next-generation Starship vehicle, another new fixture could soon rise at the seaside launch complex to satisfy U.S. military requirements to vertically integrate sensitive top secret spy satellites with Falcon 9 and Falcon Heavy rockets.

SpaceX is finalizing plans to build the new moveable tower at pad 39A, company officials said. Its function will be similar to mobile gantries in use at other launch pads, such as service towers used by United Launch Alliance at the company’s Delta 4 launch pads at Cape Canaveral and Vandenberg Air Force Base, California.

The 284-foot-tall (86-meter) tower will have 11 floors and doors to surround Falcon 9 and Falcon Heavy rockets at pad 39A, shielding the vehicles from storms and high winds and providing a controlled environment for ground crews to hoist heavy satellites and mount them on top of the launch vehicles in a vertical configuration.

At its base, the gantry will measure 118 feet by 108 feet (36 meters by 33 meters).

SpaceX currently installs satellites, already cocooned inside their payload shrouds, onto Falcon 9 and Falcon Heavy rockets horizontally inside hangars near the company’s launch pads. But some of thee U.S. government’s most sensitive intelligence-gathering satellites, some of which come with billion-dollar or higher price tags, are designed to be mounted on their launch vehicles vertically.

SpaceX officials said the vertical integration capability is required for participants in the National Security Space Launch Phase 2 Launch Service Procurement. The U.S. Air Force’s Space and Missile Systems Center — now part of the U.S. Space Force — released a request for proposals for the Phase 2 Launch Service Procurement last May.

The military plans to select two companies later this year to launch the Pentagon’s most critical satellite missions from 2022 through 2026. The military’s incumbent National Security Space Launch providers — United Launch Alliance and SpaceX — are competing for the lucrative contracts with newcomers Northrop Grumman and Blue Origin for the Phase 2 contracts.

ULA is seeking an anchor customer for the company’s new Vulcan Centaur rocket, scheduled to debut in 2021, while Northrop Grumman is developing the OmegA booster and Blue Origin is working an orbital-class rocket named the New Glenn. The new launch vehicles proposed by ULA, Northrop Grumman and Blue Origin have not yet flown.

The winning companies will share rights to launch roughly 30 Pentagon space missions over a five-year period starting in 2022.

SpaceX submitted a proposal to use the company’s Falcon 9 and Falcon Heavy rockets — made by combining three Falcon 9 first stage cores — to launch the military’s communications, navigation, early warning and reconnaissance satellites.

Gwynne Shotwell, SpaceX’s president and chief operating officer, said the company did not propose to use the company’s next-generation Super Heavy and Starship vehicles to deliver the Pentagon’s payloads to orbit.

“It’s Falcon 9 and Falcon Heavy, no Starship,” Shotwell said last month. “We bid to meet every requirement. The only modifications we need are an extended fairing on the Falcon Heavy, and we are going to have to build a vertical integration capability. But we are basically flying the rockets that they need.

“There are more data requirements they’re asking for, some additional inspection, some additional stuff that’s new to Phase 2,” she said. “I believe some of the reference orbits have slightly more mass to each orbit. But Falcon 9 and Falcon Heavy are beasts as they are.”

An artist’s illustration of the new mobile gantry at pad 39A seen by Spaceflight Now in December indicated it will stand taller than the launch pad’s fixed service structure. Like other elements of the pad, the mobile tower will be covered in black and white cladding.

SpaceX did not initially release an artist’s concept of the mobile gantry for publication, but an illustration of the tower was released in February in a draft environmental assessment published by the Federal Aviation Administration (The artist’s concept was added to this story Feb. 27).

Officials did not say when construction will begin on the new rocket enclosure. The build-up of the structure will have to be scheduled around launch operations at pad 39A, including crew missions to the International Space Station that will take off from the same site.

The mobile tower will be positioned on the north side of the Falcon 9 and Falcon Heavy launch mount at pad 39A, opposite the new Starship launch facility under construction on the southeast side of the pad.

SpaceX will continue to assemble the rockets inside a hangar near the southern perimeter of the historic launch pad, which NASA previously used Apollo moon missions and space shuttle flights.

After rolling the rockets up the ramp to the launch pad, SpaceX crews will raise the launchers vertical and then move the mobile gantry into place around the vehicles. If payloads needs to be mounted vertically, ground teams will hoist the satellites using cranes and bolt them on top of their rockets.

“It comes up and kind of circles around,” Shotwell said. “It’s got to be out there during a Category 5 hurricane, fully enclosed. The whole rocket has to be encapsulated. It’s got huge hurricane clamps on it that clamp it to the ground.”

Fitted with four transport wheel assemblies at the corner of the structure, the gantry will move away from the rocket to a distance of around 130 feet (39 meters) before launch.

Shotwell said SpaceX could also build a similar gantry at its launch pad at Vandenberg Air Force Base in California, the primary U.S. launch site for polar orbit missions.

“If it ends up being required at Vandenberg, we will put one in at Vandenberg,” Shotwell said. “It depends on the mission manifest that they have.”

The other change SpaceX must introduce to meet the Phase 2 Launch Service Procurement requirement is a larger payload envelope on top of its Falcon 9 and Falcon Heavy rockets.

The clamshell-like payload fairing currently flown by SpaceX measures around 17 feet (5.2 meters) in diameter, with a height of about 43 feet (13.1 meters). The U.S. government’s biggest spy satellites, such as those with huge Earth-pointing telescopes, won’t fit inside SpaceX’s current fairing.

The class of large intelligence-gathering satellites that require vertical integration and an enlarged fairing currently fly on ULA’s Delta 4-Heavy rocket.

An official familiar with SpaceX’s bid for the Phase 2 Launch Service Procurement said the company proposed flying a larger fairing, with a width of 17.7 feet (5.4 meters) and a height of around 61 feet (18.6 meters), to satisfy the military’s payload shroud requirement for spacecraft that require the extra room.

The official said SpaceX is considering two options for the larger fairing.

One possibility is for SpaceX to purchase the fairing hardware from RUAG Space, a Swiss company the produces 5.4-meter fairings for ULA’s Atlas 5 and Vulcan rockets, and Arianespace’s Ariane 5 and Ariane 6 launchers.

ULA and Arianespace are rivals of SpaceX in the launch business, and ULA has reportedly blocked the sale of a new, lower-weight, less expensive 5.4-meter fairing it has partnered with RUAG to produce at the Atlas and Vulcan rocket factory in Decatur, Alabama.

RUAG’s other current fairing production line in Switzerland supplies 5.4-meter payload shrouds based on a previous design for Atlas 5 and Ariane 5 rockets. The availability of the older fairing model to SpaceX remains uncertain.

Tory Bruno, ULA’s CEO, said last year the ULA and RUAG spent “many millions of dollars” designing an improved fairing for the Vulcan rocket. The shroud will also be compatible with ULA’s Atlas 5 rocket, which the Vulcan Centaur will eventually replace.

“Our partnership with RUAG is not exclusive beyond ULA’s actual intellectual property,” Bruno wrote in a post on Reddit. “RUAG remains a supplier to Ariane. They are free to design and build new fairings for others, as well.

“This is a great example of the benefits of competition,” he wrote. “Companies innovate, invest their own money, improve performance and lower costs in order to do better in the marketplace.

“Obviously, we hope to recover the money we spent by having improved future Vulcan sales as a result.”

If SpaceX is unable to purchase the bigger fairings from RUAG for the handful of missions expected to require them, the company could opt to produce the payload shrouds in-house, according to an official familiar with SpaceX’s planning.

The Phase 2 Launch Service Procurement is the most recent round in a multi-phase Air Force-led program to reintroduce competition to the military’s launch contracting, and end the Pentagon’s reliance on Russian-made rocket engines, which power the first stage of ULA’s Atlas 5 rocket.

The Air Force in 2016 awarded rocket engine development contracts to several companies, including SpaceX, ULA, and Orbital ATK, now part of Northrop Grumman.

In 2018, the Air Force awarded contracts with a combined maximum value of some $2.2 billion to ULA, Northrop Grumman and Blue Origin to develop launch system prototypes.

Shotwell said SpaceX changed its strategy after being passed over by the Air Force in 2018.

“Sometimes we learn,” she said.

SpaceX filed a lawsuit last year protesting the Air Force’s selection of three other companies over SpaceX, arguing it unfairly forced SpaceX to self-fund infrastructure projects to support the Phase 2 requirements, presumably including the vertical rocket enclosure at pad 39A.

The Air Force says the Phase 2 Launch Service Procurement is a fully open competition.

Blue Origin won a protest decision from the Government Accountability Office in November, ruling that the Air Force’s evaluation criteria — which stated military officials should pick two proposals that, “when combined,” offered the best value to the government — was not reasonable. The Air Force said it would move to remove the language from the evaluation criteria, and evaluate bids on their own.

“I can’t predict how they will decide this,” Shotwell said. “I think we’re in a good position. We met all their requirements We think we put in a competitive bid. And we’re flying the rockets that we bid, now, with lots of heritage on the rockets that we bid.”

“ULA, for sure, has some advantages. They’ve been processing and flying these national security space payloads. So at least they have that experience, even if they don’t have a rocket,” Shotwell said. “So they have an advantage over the other two competitors. But I don’t know. I have no idea how this is going to go. I really don’t.”

Even if SpaceX does not win a Phase 2 Launch Service Procurement contract, Shotwell said the company’s launch business is in good shape.

“One of the reasons why we look for commercial, civil, international and national security space payloads is to make sure that our business is strong regardless of the bumps in the road in the various market sectors,” she said. “It would be a very unhappy day at the company (if we don’t win), for sure, but we will survive. Absolutely. We have a large business base, and it’s not just launching national security space payloads.”

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Follow Stephen Clark on Twitter: @StephenClark1.