Pad 39B to gain new Flame Deflector and Trench upgrade

by Chris Bergin

One of the final upgrades to Kennedy Space Center’s Pad 39B will begin in earnest, following a deal between the Kennedy’s Ground Systems Development and Operations (GSDO) Program and J. P. Donovan Construction. The contract for a new Flame Deflector and associated Flame Trench work is required to help the pad deal with the immense thrust of the Space Launch System (SLS).

Pad 39B:

Both of KSC’s former Shuttle pads are in a transition phase, a process that began while the Space Shuttle was still flying.

While Pad 39B is prepared for a role in NASA’s Beyond Earth Orbit (BEO) exploration aspirations, Pad 39A is now deep into modifications to host SpaceX rockets – beginning with the Falcon Heavy.

Plans (L2) and Construction of the 39B TowersSigns of the new era could be seen as far back as 2007, when the giant Lightning Towers began to rise out of the ground inside 39B’s pad perimeter.

Those towers were designed to protect the Ares launch vehicle. However, despite the cancellation of the Constellation Program (CxP), the towers will be put to good use with SLS.

In fact, most of the pad work that was completed for Ares will be utilized by SLS, given both vehicles work with a “clean pad” scenario.

Pad 39B removal of the RSSControlled demolition of 39B’s Shuttle structures began in September, 2010 – with deconstruction work commencing on the Rotating Service Structure (RSS), ahead of the removal – block by block – of the Fixed Service Structure (FSS), rendering Pad B a clean pad for the first time in over 30 years.

With the removal of the Shuttle era structures, Pad 39B can now welcome the Mobile Launcher (ML) with SLS already hooked up to the associated umbilical connections via the Vehicle Assembly Building (VAB) integration flow.

The ML will arrive at 39B, ahead of being connected to power and fluid lines, with those pad facilities all but completed over recent years.

2015-02-06 03_26_02-Pad 39B transition making good progress ahead of SLS debutA test run – ahead of its current major modifications – saw the ML make the 4.2 mile journey to 39B in 2011, allowing for testing of the structural response of the ML during rollout, structural clearance, and HVAC (Air Conditioning) pressurization.

The ML was powered up via the pad’s power supplies, prior to being transported back to the park site via the Crawler Transporter – which is also being upgraded for SLS.

Under the guidance of the GSDO Program office, along with Center Operations at KSC, 39B now has a steel and concrete structure that houses two elevators and the associated machinery.

One of the final construction tasks to prepare 39B for SLS is the Flame Deflector and Trench, which were some of the first elements to be constructed when the pads were first built ahead of the Apollo program.

Flame Trench ConstructionHistorical photographs show earth movers building the pyramid base, prior to tons of concrete, bricks and support structures created the flame trench.

Once constructed, the trench proved its worth, ably deflecting the power and the plumes of the Saturn V’s five F1 engines during their ignition and launch.

The Shuttle flame trench – 490 feet long, 58 feet wide and 42 feet deep and built with concrete and refractory brick – bisected the pad at ground level.

The flame deflector system included an inverted, V-shaped steel structure covered with a high-temperature concrete material five inches thick that extended across the center of the flame trench.

One side of the ‘V’ received and deflected the flames from the main engines; the opposite side deflected the flames from the Solid Rocket Boosters (SRBs). There were two movable deflectors at the top of the trench to provide additional protection to hardware from the SRB plumes.

Work at Pad 39BWhile repair work was conducted on concrete slopes and surfaces around the pad, the flame trench became the focus of attention, as engineers worked to remove the legacy flame deflector that sat below and between the left and right pad surface crawlerway track panels, along with Apollo-era bricks from both walls of the flame trench.

The replacement, known as the “universal flame deflector” is tasked with accommodating SLS and other commercial launch vehicles, although only SLS is a confirmed future tenant of the pad at this time.

2015-02-06 03_30_39-Flame Deflector SLS - Google SearchFollowing simulations using NASA Ames’ supercomputer, a deflector design – that could withstand the high heat from plume exhaust, that did not result in plume blow-back, and whose surface pressure was within design margin limits – was selected.

This design is classed as similar to that used during the Apollo era.

Further design work on the new flame deflector continued through 2014, ahead of Thursday’s announcement that a contractor has been selected to conduct the installation of the new device.

“NASA has awarded a contract to J. P. Donovan Construction of Rockledge, Florida, to construct a new flame deflector and refurbish the flame trench for use in future launches of NASA’s new Space Launch System (SLS) rocket,” NASA announced.

“The firm-fixed price contract with two options begins Feb. 5. It has a maximum value of $24.9 million with a potential performance period of approximately one and a half years.”

An update on Pad 39A’s progress will be included in an upcoming Falcon Heavy update article.

(Images: Via L2 content from L2’s SLS specific L2 section, which includes, presentations, videos, graphics and internal – interactive with actual SLS engineers – updates on the SLS and HLV, available on no other site. Other images via NASA)

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