SpaceX has conducted a rollout of its giant Transporter/Erector strongback system at the Kennedy Space Center’s Pad 39A. The test rollout – from the company’s newly constructed Horizontal Integration Facility (HIF) – allowed engineers to conduct a variety of checks, in preparation for transporting the first Falcon Heavy rocket to the historic pad next year.
Pad 39A Test:
It has been a speedy turnaround of the former Shuttle launch complex since SpaceX took control of the pad on what is a 20 year lease.
Work on the site only began late in 2014, starting with the pile driving of the HIF foundations around the perimeter area of the pad.
During this work, Pad 39A’s Shuttle-specific hardware remained in a mothballed status.
SpaceX’s interim plan is to leave the Fixed Service Structure (FSS) and Rotating Service Structure (RSS) in place for the opening missions of the Falcon Heavy rocket.
“SpaceX is planning to keep the Rotating Service Structure for the time being,” noted SpaceX spokesman John Taylor to NASASpaceFlight.com earlier this year.
“No additional levels will be added to the Fixed Service Structure although we will make some structural reinforcements.”
By February of this year, steel columns – around 50 to 55 feet high – rose out of the foundations at the perimeter.
Estimates show the HIF structure outline to be around 285 feet long and 120 feet wide – although the official dimensions have not been released by SpaceX.
Work also began at the pad itself, focusing on the installation of a launch mount.
The kerosene tanks that will be used by SpaceX to fuel its rockets ahead of launch also arrived on site at 39A around this time.
With the skeleton of the structure complete, the skin of the building was then installed around the outer walls, along with the addition of SpaceX signage – which was also painted on the giant water tower and the Operations Building at the pad a few months ago.
Work then began on the famous 39A ramp which has previously hosted Saturn V and Shuttle stacks on the final leg to the pad.
The work included the installation of rails, which were laid out on the ramp after arriving at the pad complex, along with a collection of concrete sleepers and assorted equipment.
The HIF structure then received its doors, which will be opened to welcome Falcon stages that will arrive from SpaceX’s test site in McGregor, Texas – via trucks that will travel along the road next to the crawlerway.
The latest information noted the HIF now has its Air Conditioning (AC) system running, and the doors have been mainly closed over recent weeks to allow for internal outfitting work. Work is also being conducted on finishing the paving at the front of the building.
Pad 39A’s Flame Trench – which has been resurfaced with refractory concrete – has been largely reconfigured, allowing for all of the Merlin 1D exhaust to be directed North of the pad.
The entire South side of the Flame Trench has been filled in, resulting in a smooth/hard surface right up to the back side of the flame deflector.
Workers have been busy inside the HIF for some time, with overhead cranes installed, along with numerous arrivals of large structures on the back of a SpaceX truck that was seen ferrying equipment up the side of the Crawlerway.
Those large sections were parts of the Transporter/Erector – or TEL (Transport/Erector/Launch) – that was assembled inside the new HIF.
Sections of this hardware were seen arriving at 39A as welded subsections, taking the short trip from the S Hangar at KSC, where they had been worked on for the past several months.
Advancing the progress on the HIF’s operational status was the rollout of the Transport/Erector “Strongback” system late last week, a system that will host both Falcon 9 and Falcon Heavy launches from 39A.
Following closely to procedures for an actual rollout of the Falcon Heavy on the giant Transporter/Erector strongback system (outlined in L2), it was pushed out of the HIF using a semi-truck tractor, to the base of the pad ramp, to the start of the installed rail tracks.
The railroad tracks along the ramp incline are deemed as only guides and load supports for the system during rollout.
The procedures show that once it reaches the pad ramp, with a tug pulling the Transporter/Erector up the incline via two heavy winches located at the top of the pad.
Once the Transporter/Erector reaches the Launch Mount – guided into position by the railroad tracks – a pair of hydraulic cylinders extend rods into the structure from the Launch Mount.
These cylinder rods act as hinge pins that the Transporter/Erector pivots on, allowing it to be erected onto the Launch Mount.
Next, a pair of 15 foot long hydraulic cylinders are attached to the Transporter/Erector and are used to erect the system into the vertical position.
Once the Transporter/Erector is in the vertical position, another pair of hydraulic cylinders pin the Transporter/Erector into the vertical position, again using the cylinder rods as the lock pins.
Once vertical, the Falcon Heavy is mated to the Launch Mount Hold Down Posts (HDPs) via its Octoweb structure that hosts the engines. These HDPs are also hydraulically operated.
Prior to launch, the Transporter/Erector is retracted about 2.5 degrees away from the vehicle, similar to the process utilized for Falcon 9 launches.
However, for 39A operations, when the hold down post clamps are released, the Transporter/Erector will be fully retracted/lowered back to ground level.
As seen in photos of the test rollout late last week (both publicly and via a large collection in L2), the structure still has some work to be conducted on it, mainly cosmetic in nature. However, this was the first time the system had made the journey to the pad, marked by the lofting of a large American flag.
The first Falcon Heavy to be rolled out to the pad will undergo a Wet Dress Rehearsal (WDR), allowing for engineers to validate the pad systems.
That will be followed by the usual Static Fire test to check the health of the engines and pad systems, along with providing a final dress rehearsal for the launch team.
That first launch will be a demo mission, sometime in 2016. The current launch schedule is being evaluated following the loss of the Falcon 9 mission with the CRS-7 Dragon.
The first operational mission is with the Space Test Program-2 – as its primary payload – on a schedule that won’t be confirmed until after the demo flight has been successfully conducted.
The forward plan is to conduct further work on the pad ahead of crew launches with the Falcon 9 and Dragon 2 spacecraft.
(Images: via L2’s SpaceX 39A Update Section and L2 artist Nathan Koga – The full hi-res gallery of Nathan’s (SpaceX Dragon to MCT, SLS, Commercial Crew and more) L2 images can be *found here*)
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