Muratore: Safety and efficiency went hand-in-hand in rebuild of SLC-40
CAPE CANAVERAL, Fla. — SpaceX hosted a briefing to members of the media on Friday, Dec. 8, 2017, to provide an overview of work that has been done to return to service Cape Canaveral’s Space Launch Complex 40 (SLC-40) after the Sept. 1, 2016, explosion of a Falcon 9 rocket caused severe damage to the site. According to John Muratore, director of SLC-40, the NewSpace firm tied safety and efficiency to improve the effectiveness of launch operations at SLC-40.
When asked, Muratore noted that the accident which caused the total loss of the $185 million Amos 6 satellite, the Falcon 9 rocket, and much of the launch site was used as an opportunity to remake SLC-40 to improve it.
“From the very start, after we kind of dusted off ourselves after the accident, we really looked at this as an opportunity to not only rebuild the pad but [also] to make it better. We’ve gone in and done a lot of work reinforcing the structures, improving the ground systems, and making the systems common with our other pads so that people and tools can be used across all the pads in SpaceX,” Muratore noted in response to a query by one of the media. “It’s important to remember that SLC-40 originally started its design work before the first Falcon 1 had ever flown, so it was put together with only an initial idea of how Falcon 9 operations are going. What we’ve done is taken this opportunity, having 30 or more missions under our belt when we started this redesign, we’ve been able to take advantage of all of those lessons learned and integrate them into the pad, and then also taken what we’ve learned from the designs of [KSC] Pad 39 and at Vandenberg and dialed them in. So it’s been formed by all that experience. Our focus has been to make it safe and reliable as possible.”
According to Muratore, SpaceX focused the rebuild of Canaveral’s SLC-40 on safety, efficiency, and longevity, stating:
“The big thing about safety is the safer a pad is, the more operationally efficient it is. If every time we do something, we have to come up with a special platform, special stairs, special rigging, or special personal protection equipment, that makes the pad less operationally efficient. With safety as our primary driver, we drove to the most efficient pad possible. We’re really excited about how it’s worked out, and you see on this pad really superior access for people to get in and out. Lots of remote operation, lots of redundancy, so if we have a problem or a failure with a piece of equipment, we can move on, and we’re really excited about that.
“On top of that, we were working with legacy pad and physical infrastructure, and we really stripped it down to the barest part and verified the strength of all those components. And then we built reinforcing on top of that and made the pad a lot more robust structure. It’s a structure that will easily last us many years,” Muratore said. He went on to note that the experience the Hawthorne, California-based company gained renovating one of the U.S.’ most historic sites has helped them when it became necessary to rebuild SLC-40.
With the work originally done to make SLC-40 ready to support flights of the Falcon 9, as well as Vandenberg’s SLC-4E (East), Kennedy Space Center’s Launch Complex 39A and its new Texas launch site in Boca Chica Village located near Brownsville, Texas, SpaceX has acquired extensive experience in getting launch pads operational.
Muratore said: “With lessons we learned at [LC-]39, we learned that 39 has been able to do the fastest turns we’ve done at SpaceX. We’ve looked at all the improvements we’ve put in 39—for blast protection. The dog houses, which are the enclosures, we put them on hold-downs. On the strongback/throwback, which is the mechanism by which at launch we start moving the strongback away from the rocket so that it doesn’t get toasted by the rocket as it flies out, we have a really augmented water system because we found that a lot of water really protects the pad. And then we’ve obviously had to put in a lot of provisions to protect all the equipment on the pad from all the water we put on there. The most exciting thing for us is that we put in the flame trench—we’ve always struggled with erosion of the concrete in the flame trench—and we’ve gone and reworked the concrete many times on both pads. We put a water-cooled diverter on this pad. It consists of pipes running down the pad, and we run a large amount of water through it, and that enables long static-fires without any damage to the pad. And that’s critical to our rapid flight strategy.
“It’s critical in two ways: the obvious one is if you don’t take damage on the pad, you can fly more often; but the not-so-obvious one is as we reuse rockets more and more, we’ll run into problems where we have to change an engine out, just as they change engines out in airplane hangars. With the water-cooled diverter, we can run very long static fires, so we can change an engine out, take it to the pad, and run for much longer periods of time. For our very first time out, we ran seven seconds, which is pretty much the longest we’ve run on any pad. And so that enables us to be able to do all the work we need to do whenever we turn a rocket or do maintenance on the rocket to really make sure it’s good for flight. That’s a really important technology improvement we’ve put in.”
SpaceX has made the strongback more rigid so as to make it more able to handle the high winds it is likely to encounter along Florida’s Space Coast. Some of the other modifications to the site included the addition of six actuators to lift Falcon 9s to the pad. In the past, this would take between 20 to 30 minutes. With these upgrades, Muratore stated that the rockets can be raised within 5 minutes and lowered within 3 minutes (lowering the rocket took about a half hour in the past). Streamlining by having fewer components in place and fewer parts that could encounter a problem means that there are fewer things that could go wrong.
“We also made the systems really redundant. The old pad had all the wires from all the sensors and controls going to a central point under the pad. What we did is we put a distributed data acquisition system in, and there are ten nodes all around the pad. And wires go from the pieces of hardware [that] we want [to be] measured or controlled and they go right to that node. So it goes analog from where we’re taking or sending the commands to that node, which is typically a very short wiring run, and then it gets on a dual-redundant fiber-optic network,” Muratore noted. “That has the advantage of we don’t have to run wire pairs everywhere. If we have a maintenance problem and we go out to deal with that long wire run, and furthermore we don’t have the potential for noise. On a network that’s fiber, there’s no way to contaminate that with electrical noise because it’s just light running down a glass fiber. The place where you can pick up noise is between the end item and the hardware, so we’re really reduced the noise on this pad, and that’s also given us a more reliable operation.”
Muratore also stated that the LOX [liquid oxygen] densification system was rebuilt and redesigned to densify LOX much faster. Meanwhile, some elements of the “old” infrastructure at SLC-40, such as the concrete diverter that was used for Titan launches, was left in place. Rebar was placed into the concrete diverter which used 12 inches (30 cm) of Fondag, a special concrete that has aluminum particles in it. Fondag is a very high-pressure and very high-temperature concrete that sets faster than normal concrete.
It was asked if SLC-40 could be used to support eventual Falcon Heavy flights, Muratore suggested that the infrastructure in place at SLC-40 is not currently designed to support the Falcon Heavy launch vehicle which is scheduled to launch from LC-39A early next year (2018).
According to Muratore, SpaceX invested approximately $50 million in restoring SLC-40. When asked, he stated that before-and-after images of the changes to the site were not likely to be released due to International Traffic in Arms Regulations (ITAR) restrictions. SpaceX spokesperson John Taylor noted at this point that some images could be released during a future webcast and reiterated that ITAR and proprietary concerns would guide which images were released.
According to Muratore, SpaceX paid special attention to what had gone before at SLC-40. A great deal of infrastructure had to be put into place to support future flights SpaceX is planning to send to orbit from the same launch site that, in the past, supported launches of Titan IIIC, Titan 34D, and Titan IV rockets.
“We built a giant underground pit where all of the equipment that used to be on the top of the pad is now in this pit and it’s got concrete over it. Then on the east and west side of the pad, we have patio-cover decks—these giant steel enclosures that protect a few of the pieces […],” Muratore said, going on to note what was required to restore SLC-40. “In the end, you have to come out of the concrete at some point to get to the interfaces to the transporter-erector. So we’ve done a really serious job of putting all of the support equipment under concrete and steel. We also moved equipment farther away. We mapped out after the accident where every piece of hardware went. And we mapped out where all the damage was. We’ve moved as much equipment as possible out beyond that boundary. And then we put concrete walls up to support that. We also built a couple of concrete buildings where we put a bunch of support equipment. We certainly don’t ever want a tragedy like that to happen again, but right now the only thing that’s really exposed is the transporter-erector itself, which holds the rocket, and the equipment that’s immediately next to it. All the other support equipment has been moved back out of the area where we saw blast damage on 40.”
According to Muratore, the delay in making SLC-40 operational again was caused by a wide variety of reasons. Environmental remediation, unexpected discoveries, and requirements at other launch sites crept in to push SLC-40’s return to service.
Muratore said: “In any large construction project like this with upgrades or you’re building a launch site, it’s really hard to predict from the start what’s going to happen. As we were digging up, we ran into problems. This pad was built in the 1960s, and the documentation on it reflected the fact that that was 50 years ago. So we dug in and found all sorts of things in places we didn’t expect them to be. Of course, whenever you make a projection like that, and you buy a tremendous amount of equipment and you make best-case assumptions based on that. It’s sort of a combination of things we discovered along the way that slowed us down combined with, as we got into it, we saw opportunities to really improve the pad. Like the water-cooled diverter. That was a major upgrade that we think is going to play very well with our mission reuse strategy and our pad refurbishment strategy.
“So it was a combination of things we discovered along the way and didn’t expect combined with opportunities to make the pad even more awesome than it was. All in all, we really didn’t start working on the pad until the February time frame because the pad was still on lockdown from the accident through late November / early December and then we had to do some environmental remediation to clean the pad up. At the same time, we were activating SLC-4 East at Vandenberg and 39A, so we really got the full launch organization focused on 40 in February. It’s truly been a ten-month build, which considering the large civil component and a complete rebuild of the entire electrical system. The electrical high-voltage system here was put in place in the ‘60s—we had panels on them from Bechtel they put them in the early 1960s when they built this pad. We had to redo all of the fluids except for the LOX and fuel farm, which were untouched. It really is a fast build in ten months.”
When all was said and done, SpaceX was left with a facility that it believes can support a launch a week. That would exceed what SpaceX has been able to demonstrate at 39A, with Muratore noting that the best turnaround time between launches at 39A was 12 days. With all of the work that has been done to get SLC-40 ready to resume operations, SpaceFlight Insider asked what was the biggest challenge when it came to restoring the historic launch site.
“To me, the greatest challenge period was the simple […] engineering. It was stripping everything out, and digging all the concrete up, and replacing the concrete. As a matter of fact, that’s kind of frustrating because it can only move at a certain speed. Many of those operations are limited to daylight operations, and you’re really impacted by weather,” Muratore told SpaceFlight Insider. “And of course we didn’t talk about it, but the entire time from the accident to today we’ve had two major hurricanes hit here at the Cape, and we had two tropical depressions float through. We really couldn’t get started putting all the systems in while we were doing all of that concrete work and all that civil work.
“So to me that was the biggest challenge: getting to the transition from [civil?] work where we could do the pad outfitting because it kind of went civil work, pad outfitting, and then activation and test. There were three distinct phases of it, and it was really hard to work on phase 2 until phase 1 was completed. In the end, we were very clever and broke the pad up into different areas so that we could get the [civil] work and then we started doing the activating and installation work there. But that was the really challenging part, was trying to find ways to get work done on the activation to get work done on the fluids and electrical, and the command-and-control systems while we were still tearing it up for concrete.”
The first flight from the rebuilt SLC-40 is currently scheduled to be the launch of NASA’s CRS-13 mission which is set to take to the skies on Tuesday, Dec. 12, with the instantaneous launch window slated to open at 11:46 a.m. EST (16:46 GMT). If everything goes as planned, this will be the 26th launch of a Falcon 9 from SLC-40 since the U.S. Air Force leased the complex to SpaceX in 2007. Also, it will be the 17th flight of the rocket in 2017 with an 18th launch scheduled for December 22 from Vandenberg SLC-4E in California.
Bart Leahy is a freelance technical writer living in Orlando, Florida. Leahy's diverse career has included work for The Walt Disney Company, NASA, the Department of Defense, Nissan, a number of commercial space companies, small businesses, nonprofits, as well as the Science Cheerleaders.