SpaceX, Air Force assess more landing pads, Dragon processing at LZ-1
As SpaceX continues its efforts to press forward with Return To Flight later this month, a draft Supplemental Environmental Assessment report for Launch Complex 13 at the Cape Canaveral Air Force Station for construction of two additional landing pads to accommodate the simultaneous return of three core stages of a Falcon Heavy rocket has been released. The report also details the impact of construction of a temporary Dragon processing facility at LC-13 as well.
New pads for Falcon Heavy core stage landings:
In all, the draft Supplemental Environmental Assessment (SEA) report – acquired by a NASASpaceFlight.com member – covers a series of proposed actions that primarily include the construction of two concrete landing pads in addition to the one already present at LC-13 (also known as Landing Zone 1, or LZ-1) at the Cape Canaveral Air Force Station (CCAFS), Florida.
The landing pads themselves would be 85.96 m (282 ft) in diameter with an additional 15.24 m (50 foot) wide hard-packed soil apron surrounding them, for a total diameter of 116.44 m (382 ft) each.
The two new pads would be located on the north and south sections of LC-13 and would be approximately 18 inches thick with a specific design to withstand the weight and thrust of a landing Falcon 9 booster – the same way the current, main landing pad is designed.
However, these new landing pads would be considerably smaller than the main pad due to advancements/improvements in the landing technology (radar and Command & Control capabilities) used by SpaceX for its Falcon 9 first stage cores.
These improvements have come over the course of several years as SpaceX has continuously refined its landing systems for the Falcon 9 after each successive landing attempt – whether the attempt resulted in the successful return of a core stage or a Rapid Unscheduled Disassembly (RUD) of the stage upon “landing”.
Specifically, the need for this SEA stemmed from the fact that the two new pads would be constructed on “previously undisturbed land”, as stated by the draft release of the SEA report.
In total, ~23 acres of land would need to be cleared for the construction operations – including land for the two pads, the temporary Dragon processing facility, roads, crane paths, and stormwater management systems.
In contrast, the main pad required the clearing of 20 acres of land for the Falcon 9’s radar navigation system.
For the new pads, land clearing efforts would also permit the construction of two new short crane access paths from the existing crane path to the two new landing pads and would allow for the installation of a set of pedestals within the compacted apron of each new pad, similar to what is currently in use at the main landing pad, to allow for “parallel processing of landed boosters”.
In all, the northern area of construction, including the north landing pad and the temporary Dragon processing facility, “would require clearing approximately 11 acres and roller-chopping approximately two acres of vegetation just east of the site ditch,” notes the draft SEA report.
Clearing of the northern area in this manner would avoid the wetlands to the west and northeast of the landing pad – a critical part of the Merritt Island environment.
Likewise, the southern portion of the construction zone would have approximately 10 acres of vegetation cleared.
This would be accomplished in a manner that would avoid the wetlands to the south and the existing drainage ditch to the west.
Once the vegetation is removed, it would either be taken to an offsite facility for burial or burning or be burned onsite.
With the area cleared of vegetation, the locations of the two pads and connecting crane paths would then be graded in order to achieve a flat, compact area for construction. Current estimates for soil relocation and placement are 22,936 cubic meters (30,000 cubic yards) – which is considered moderate.
Construction and operation of the new pads would make use of the existing power systems already in place at LZ-1 – though these systems would have to be extended to the location of the new pads and Dragon processing facility.
According to the draft SEA report, “These utilities, along with water, video camera, and nitrogen gas lines would be contained within buried conduit in the immediate vicinity of the pad and traverse above ground throughout the rest of the site”.
Moreover, the new pads and Dragon processing facility would use a FireX system – as does the current landing pad.
Each pad would be constructed with “three or four remote controlled water cannons mounted on posts above ground to allow for remote firefighting capabilities,” states the draft SEA report.
The current FireX system would be supported by the addition of a new 45,424 litre (12,000 gallon) above ground water storage tank on the western edge of the landing zone.
Moreover, as with the main landing pad at LZ-1, the new landing pads would be built to direct all stormwater runoff to a retention basin so that contaminants are not introduced into the local water environment.
According to the draft SEA, “The exact location and size of the stormwater management infrastructure would be determined during final site design, and would consider avoiding or minimizing potential effects to wetlands and protected species”.
Dragon processing facility:
Currently, all Dragon missions for resupply efforts of the International Space Station return to Earth for a water landing in the Pacific Ocean, after which the capsules are loaded onto a ship, brought to San Diego, California, and then trucked halfway across the United States to McGregor, Texas, where they are deserviced.
However, it has always been a stated goal for SpaceX to streamline post-flight processing by servicing Dragons in the post- and pre-flight periods at the CCAFS (i.e., the Dragons’ launch site).
Streamlining of the process is expected, among other things, to eventually result in Dragons, both uncrewed and crewed, returning to Earth for water landings off the coast of Florida in the Atlantic Ocean before eventually transitioning to propulsive landings at the CCAFS.
To this end, “SpaceX initiated a facility assessment process with the Air Force in May 2016 in an attempt to locate an existing site capable of accommodating Dragon capsule processing requirements,” notes the draft SEA report.
The initial assessment resulted in an understanding that it would be quicker for SpaceX to meet its immediate mission requirements by building a temporary Dragon processing facility inside of LZ-1 while long-term CCAFS planning for a permanent Dragon facility is undertaken.
LZ-1 ended up being a perfect location for a temporary facility because of all the equipment and servicing systems already in place to support returning Falcon 9 core stages – which can easily support Dragon post-fight propellant unloading, propellant servicing, refurbishment, checkouts and closeouts, and pre-flight propellant load and servicing operations.
Moreover, it was found that LZ-1 would be a prime location for the Dragon capsules to undergo periodic static fires of their SuperDraco launch abort and landing system thrusters.
The static fire events would take place on the northern edge of the north landing pad and would be carried out by connecting a Dragon capsule to a portable test stand that, while not permanently installed at the landing pad, could be easily erected between Falcon 9 core stage landings at the site.
In all, the temporary Dragon processing facility would be 39.6 m (130 ft) long, 30.5 m (100 ft) wide, and 9.1 m (30 ft) high, would incorporate all of the lessons SpaceX has learned from its Dragon processing facility at the company’s McGregor, Texas, facility, and would be allowed to accommodate a maximum amount of hypergolic propellant in the quantities of 1,160.2 kg (2,558 lbs) of Monomethylhydrazine and 1,906.4 kg (4,203 lbs) of nitrogen tetroxide.
Environmental impacts of construction:
In short, the draft SEA report notes that all of this proposed activity – including operational use of the new facilities at LZ-1 – would “likely not cause any significant cumulative impacts to resource areas”.
This assessment was reached by a thorough examination of 15 resource areas, including: land use/visual resources; noise; biological resources; cultural resources; air quality; climate; hazardous materials/hazardous waste; water resources; geology and soils; transportation; utilities; health and safety, socioeconomics; environmental justice; and Section 4(f) properties.
In total, 10 of these 15 resource areas were found to fall into the “no impacts” or “none identified” categories, including: 4(f) properties, environmental justice, health and safety, utilities, transportation, geology and soil, climate, historical and cultural resources, land use/visual resources, and water resources (under nominal operational conditions, with Spill Prevention, Control, and Countermeasures in place to “reduce the potential for adverse impacts to water resources”).
In terms of noise, the draft SEA report found that minor impacts to the CCAFS and surrounding communities are expected, primarily from the noise generated by a landing Falcon 9 core stage – which is approximately 33% of the noise generated by a Falcon 9 launch.
Nonetheless, given numerous calls to emergency dispatch from people in Central Florida scared by the sonic booms generated from the CRS-9 returning core stage, the draft SEA report notes that “Central Florida, within an approximate 60-mile radius, may hear sonic booms.
“During a multiple stage landing event, two sonic booms may occur for each returning stage several seconds apart. Public awareness and notification plans would reduce surprise and increase the public’s knowledge of the potential sonic boom events”.
Additionally, construction is anticipated to have a temporary negative impact on air quality while operational use of the new facilities would produce a “not significant” impact to local air quality.
Likewise, while not completely preventable, handling of hazardous materials/waste is found to have a “not significant” impact on the local environment if proper procedures are followed.
Nonetheless, the most significant, negative, impact during construction will occur to wildlife.
“Clearing of land would impact approximately 23 acres of scrub-jay habitat and would also impact southeastern beach mouse, indigo snake, and gopher tortoise habitat”.
However, once operational, the facilities would not be expected to have a daily impact on the local wildlife if, as the draft SEA report recommends, a “Light Management Plan [is] developed and … [approved] by the USAF and the USFWS to reduce or eliminate night-time impact to the sea turtle nesting/hatchling process”.
Positively, though, there are no anticipated or identified effects on marine life from construction and operational use of the new facilities, and no effect to wildlife is expected from the sonic booms of the returning core stages.
Moreover, the one net positive gain identified by the draft SEA report relates to the local economy, which would be buoyed by construction efforts and the hiring of local construction workers and construction-related purchases.
(Images: Patrick Air Force Base; SpaceX; and L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to MCT, SLS, Commercial Crew and more) L2 images can be *found here*)