Pad 39B transition making good progress ahead of SLS debut

by Chris Bergin

Kennedy Space Center’s Pad 39B is fast returning to the status of an active launch pad, with new elevator towers now visible on the surface of the former Shuttle launch site. The “clean pad” will be able to launch a number of vehicles, although its primary role will be the launch pad for the Space Launch System (SLS).

Pad 39B:

Shuttle Discovery was the last crewed vehicle to launch from Pad 39B, as she rose into the Florida night sky during her STS-116 launch at the end of 2006.

With all the remaining Shuttle missions reverting to the use of Pad 39A, engineers began converting 39B for the Constellation Program (CxP), with the first notable change relating to the construction of three giant lightning protection system towers.

Plans (L2) and Construction of the 39B TowersLocal firm Ivey Construction of Merritt Island, Florida won the $28m contract to build the three 600 ft high towers that were intended to surround 39B and reduce the probability of a direct lightning strike to the Ares I and Ares V vehicles and associated launch equipment during processing and other activities prior to flight.

The self-supporting structural steel towers and an overhead wire system with associated conductors rose out of the ground as huge pylons, with five levels for worker access – the highest being Level E at 482ft – rising yet further to a total height of 594ft.

Access to the five levels can be reached by stairs or via the ‘man lift’ that travels up the side of the tower.

Along with the towers are nine large downconducters, placed around the complex, which act as anchor points for the massive cables that stretch across the lightning towers.

Following the work on the foundations of the towers, the pylons began to rise out of the ground, with one of the world’s largest cranes – the Manitowoc 21000, costing $1m a month to hire – dominating the space coast skyline, as it hoisted segments next to the pad.

STS-125 launches as Endeavour sits inside the RSS on 39BThe towers were completed ahead of one final swansong with a Shuttle stack, as Endeavour paid a short visit to 39B during her STS-400 role as the Launch On Need (LON) support for Atlantis’ STS-125 mission to service the Hubble Space Telescope.

This was the only post-RTF mission not to include the “safe haven” of the International Space Station (ISS) – as such, Endeavour was tasked with being ready to launch within days of a major issue being found with Atlantis during her mission.

With Endeavour sat on pad as Atlantis successfully launched on her flagship mission to Hubble from 39A, this period marked the 39B’s final role with Shuttle. Endeavour eventually launched from 39A on her STS-127 mission, following the standdown from her rescue support requirement.

Ares I-X from 39B, via L2Pad 39B then transitioned into the Constellation Program, marked by Ares I-X rolling to the pad out for its test launch in 2009.

This was supposed to be the first of two test launches (I-X and/or I-X Prime, I-Y), ahead of the debut of the Ares I missions. However, Ares was cancelled via the demise of CxP.

With the realignment towards the Space Launch System, most of the Pad’s past and future transition proved to be a nice fit for the Heavy Lift Launch Vehicle (HLV), with the giant towers ably protecting all variants of SLS along with the “clean pad” scenario allowing for the monster rockets to roll up to the pad just as Ares had planned.

However, Pad-B’s Shuttle configuration still stood in contrast to the forward-looking plan of the now-defunct Constellation Program as well as a building plan for LC-39B: the desire to render it a clean surface pad with the long-term goal of being able to support multiple vehicles and missions – an idea that fits into the overall KSC infrastructure update plan for a 21st Century launch complex.

Pad 39B removal of the RSSWith this in mind, controlled demolition of Pad B’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, back when the pad hosted the giant Saturn V launch vehicles.

Preparations for the modern day Saturn V – the SLS – have proceeded to plan, allowing for a mix of the old and the new, as renovations took place on infrastructure such as the Water Tower – which is used to holds hundreds of thousands of gallons of water, in turn providing the required rush of water to supply the Sound Suppression System, used to protect the launch vehicle from acoustical energy reflected from the platform during lift-off.

SLS ML arrives at 39B, via L2SLS’ new Mobile Launcher – a platform and FSS that is being converted from its Ares I role to that required for the HLV – made 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.

39B Clean Pad, via L2Following the visit of the ML, work has continued at the pad, with structures starting to rise out of the clean pad’s surface once again.

Under the guidance of the Ground Systems Development and Operations (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.

These elevators will provide access from the pad surface to the “0” level, or deck, of the new ML. The two new traction elevators replaced a single old hydraulic elevator was left on the pad surface from the Shuttle days.

Pad 39B has also enjoyed modifications to the Pad Terminal Connection Room, replacing the old Halon fire system with a new sprinkler system, and removal of Shuttle’s hypergolic fuels and the oxidizer farms – although the the liquid hydrogen and liquid oxygen spheres remain. They have undergone repairs, sandblasting and have been repainted.

SLS hooked up at 39B, vla L2Interfaces on the ML’s utility platform were modified, with evaluations continuing on the configuration of the array of connections that will hook up between the ML and the SLS rocket.

While repair work was conducted on concrete slopes and surfaces around the pad, the iconic flame trench – which still contains some of the bricks that were scorched from Saturn V launches – will also be upgraded via a new design that will be worked on in 2015.

Future work at the Pad may still include the installation of a roller coaster, built in-situ at 39B.

The Roller Coaser EES as it was with Ares I, vla L2 This option won the trade study for Ares I’s Emergency Egress System (EES) – required to transport astronauts and/or pad crews to safety in the event of a serious problem with the launch vehicle.

No decision has been made on SLS’ EES at this time, although the roller coaster option was designed with the Ares – now SLS – ML in mind, with the ability for the ML to roll up to the pad, prior to hooking up with the massive structure that would use enclosed cars to race astronauts and/or pad crews to a protective bunker.

Other work that is set to take place includes refurbishing or modifying the piping that will interface with the ML and replacing the water lines and unused piping beneath the pad, in an area called the catacombs.

The liquid hydrogen, liquid oxygen and other interfaces on the pad or pad structures will be updated, while the pad structure in the Environment Control Room, ducts will be removed, and a new system will be designed and built to replace the old Shuttle-related equipment.

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

(L2 is – as it has been for the past several years – providing full exclusive SLS and Exploration Planning coverage. To join L2, click here:

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