What Progress Has Been Made On SpaceX’s Florida Starship Site
SpaceX has been busy upgrading both Starship and the Boca Chica launch site in preparation for the launch vehicle’s second orbital test flight. Throughout Starship’s history, practically every major event and development has been made in Texas at Starbase. This being said, SpaceX has a different launch site in mind for primary future Starship operations.
Since 2019 work began at Launchpad 39A in Cape Canaveral to modify the existing site with additional capabilities to support Starship. By now, a full tower, catching arms, and the start of an orbital launch mount are present. At the same time, in recent months progress has slowed significantly in Florida as new developments are made.
While Boca Chica offers an incredible desolate testing location, LC-39A not only has another launch tower already installed but many other sites within close proximity. All of which contribute to the current site progress and SpaceX’s plans going forward. Here I will go more in-depth into the progress at LC-39A, the future plans for this site, what to expect in the coming months, and more.
Launch Complex 39A
Starting in 2019, SpaceX began substantial modification to LC-39A in order to begin work on phase 1 of the construction. The initial plan was to prepare the facility to launch prototypes of the large 9 m (30 ft) diameter methalox reusable rocket — Starship upper stage — from a launch stand. A second phase of the construction planned in 2020 was to build a much larger launch mount capable of launching the entire Starship launch vehicle, powered by 33 Raptor engines and producing a total of 72 MN (16,000,000 lbf) liftoff thrust when departing 39A.
Around the time when SpaceX proposed this addition to the already existing 39A launch site, the agency completed an environmental assessment. Here they outlined exactly what SpaceX planned to do at the site. SpaceX would construct an additional launch mount for Starship/Super Heavy at LC‐39A, adjacent to the existing mount used for the Falcon 9 and Falcon Heavy. A propellant farm would be built near the existing Falcon Rocket Propellant‐1 (RP‐1) farm similar in structure to the existing LOX farm. Site improvements would also include an interior transport road leading from the pad entrance gate up to the launch mount as well as several new high pressure gaseous commodity lines. A deluge water system and water cooled flame diverter would be installed and comprised of new water tanks capable of delivering the necessary water pressure.
Location options for Starship landings include Landing Zone 1 (LZ‐1) at Cape Canaveral Air Force Station (CCAFS) and downrange on a droneship (converted barge), both of which have been previously assessed for Falcon 9 booster landings (USAF 2017). Additionally, a new landing pad at LC-39A was being considered.
In late 2021, Elon Musk announced on Twitter that SpaceX has started construction of a Starship orbital Launchpad at the Cape. Last year in June, the first integration tower segment for the Starship orbital pad arrived at LC-39A. Most recently, SpaceX finished building a giant pair of steel arms, transported the arms to Pad 39A, attached them to a wheeled carriage, and installed the structure on Starship’s Florida launch tower. Also known as Chopsticks, the arms are integral to the “Mechazilla” system. Mechazilla refers to the combined launch tower and arms, which SpaceX has designed to grab, lift, stack, and fuel both stages of Starship.
Mechazilla’s simplest part is a third arm that is vertically fixed in place but capable of swinging left and right. The swing arm contains plumbing and an umbilical device that connects to Starship’s upper stage and supplies propellant, gas, power, and connectivity. The tower’s ‘chopsticks’ are far more complex. Giant hinges connect the pair of arms to a carriage that grabs onto three of the tower’s four legs with a dozen skate-like appendages. Those skates are outfitted with wheels, allowing the carriage to roll up and down tracks built into the tower’s legs.
Focusing on the overall project, by now, progress has somewhat come to a halt and for a few different reasons. The first has to do with NASA and its concerns related to the Dragon Spacecraft and crew launches. Currently, Pad 39A is the only qualified launch site available to the agency and SpaceX that can support a crewed Falcon 9 launch. With the extremely close proximity between the Starship tower and the Dragon rocket tower, a failure could easily damage the surrounding infrastructure and delay any crewed missions by quite a bit. While this issue isn’t necessarily stopping SpaceX, it’s not helping. The other reason for a halt in progress is the fact that SpaceX needs more testing.
Starship’s Tests
During Starship’s first orbital test flight, we saw the damage to the surrounding infrastructure and primarily the pad and concrete below which were destroyed. While SpaceX can get away with an explosive test like this in Boca Chica, similar results at the Florida Site would be significantly worse as surrounding sites could end up being damaged.
SpaceX knows this and has likely decided that before they continue work at the future Florida site, they need to figure out a way to consistently withstand the force of 33 Raptor engines firing at liftoff. Over the past few days, we have seen new images and development related to the steel plate and water deluge system being installed in Boca Chica. With a launch expected to happen in the next few months, this system will be put to the test. In reality, assuming it works very well on its first attempt, SpaceX will likely want to test it a few more times before creating and setting up a similar system in Florida.
It’s also important to point out that the LC-39A launch site is planned to be the future primary site for Starship. In the past Musk made comments that Boca Chica is an important test ground area and experimental launch site however the future is in Cape Canaveral. If this is the case, the launch site will not only need to support the occasional mission but frequent launches and even landings.
Not long after Starship’s first orbital test flight, SpaceX highlighted that prior to the launch they had already been planning to use a large water-cooled steel plate to deal with the flames and exhaust of the Raptors. At the time, Dr. Phil Metzger, a planetary scientist with quite a lot of experience, gave some insight into this process and how it could work. He commented that he used steel plates for some of the Morpheus launch locations so that they weren’t tied down to places with concrete. He analyzed the heating of the sheet and showed that the heat would redistribute fast enough that it would not locally melt on the surface, and that the steel plate was large enough to take the heat of the entire launch event without melting.
In reference to using this method for Starship, he was quoted saying, “For such a large rocket that much steel would be excessive. And ablative would not be enough to solve this, either. Would the ablative need to be 3 feet thick? He continued by saying, “But he said it will be water-cooled, which is an awesome idea. The water will be taking heat out of the steel in realtime so it won’t melt. Simple, and it should be effective.” This would also allow SpaceX to use much less steel as it won’t be needed to distribute the heat.
He then said, “So all that was just to say that I like the idea SpaceX is pursuing. I think it will work great to solve the plume erosion problem. It will *not* mitigate launch acoustics, however. The flat plate will reflect the sound back up along the sides of the vehicle, shaking the structure.” The very first “sound” that happens on launch is the shockwave from engine ignition. It bounces off the pad then runs up the sides of the vehicle, stressing everything. At NASA it is called the “Initial OverPressure” or IOP. To put in perspective the power of this, the IOP almost ruined the 1st Shuttle launch.
This is why the steel plate will need to be complemented by a significant water deluge system at Stage 0. On the first Space Shuttle launch the IOP deflected the elevons— the control surfaces on the wings — so far that the engineers were worried they could have snapped. So they added the water deluge system to absorb and break up the IOP shockwave. Considering the power of the Shuttle in comparison to Starship, it’s clear that during engine ignition as Starship was lifting off, it was producing immense sound waves that could have easily damaged it. Interestingly, one of the areas a lot people will be paying the most attention to during Starship’s next flight will be the launch pad. This will not only affect the launch attempt and future at the Boca Chica site, but also Florida and the future infrastructure at that location.
Starship is extremely powerful and it’s hard to compare it to other rockets within the industry. Combine this power with the various constraints at Boca Chica and you have a very unique pad design trying to withstand the force of 33 Raptor engines. Either way, SpaceX still has a lot of work left at both sites which we can expect to see more of in the coming weeks.
Conclusion
SpaceX is getting ready for Starship’s next launch as pad upgrades continue in conjunction with rocket improvements. After a fast start on the Florida site, it has since slowed down as SpaceX gets important tests out of the way in Texas that will give valuable insight into what works and what doesn’t. We will have to wait and see how it progresses and the impact it has on the space industry.