ULA Is Only Weeks Away From Vulcan’s First Launch!
Vulcan is an expendable two-stage heavy-lift rocket that has been in the development and testing phase since 2014. Its design combined with the use of brand-new hardware such as Blue Origin’s BE-4 engine, caused a host of delays during in its nearly decade-long development. Most recently an upper-stage explosion on the test stand pushed the flight back a few months.
Thankfully, these various issues have since been resolved and both the upper stage and booster are back at the launch site preparing to lift off. With an official launch date set for December 24th, this is the closest Vulcan has been to its first flight.
Between now and then, the company needs to complete one main test and integrate the payloads. Here I will go more in-depth into the final launch prep, why this first flight is such a big deal, its future with Dream Chaser, and more.
Back On The Pad
After fixing Vulcan’s upper stage, which had a weak point as revealed by a separate upper-stage explosion, ULA quickly shipped it back to the launch site in Florida. Just days ago on the 20th, ULA tweeted saying, “The Centaur V upper stage for the inaugural United Launch Alliance #VulcanRocket was integrated atop the booster on Sunday, completing initial buildup for the #Cert1 mission.” This included a few images of the process and integration. To be specific, the upper stage arrived from the factory at the Cape Canaveral Space Force Station launch site on Nov. 13 and was integrated atop the booster on Nov. 19.
With this step complete, ULA only needs to complete a handful of tests. This primarily has to do with the fact that they already completed a wet dress rehearsal and static fire earlier this year before the upper stage issue was discovered. Either way, the company said in a statement that “the assembled rocket will undergo combined testing of sub-systems and components over the next few weeks before rolling to Space Launch Complex-41 to undergo a Wet Dress Rehearsal to practice the countdown to launch.
This first mission, named Certification-1 or Cert-1. is the first of two flight tests required for ULA’s certification process with the U.S. Space Force. ULA has worked in close partnership with the Space Systems Command throughout the design, development, testing and production of our new rocket for assured access to space. The Space Force selected Vulcan as the No. 1 offeror and “best value” choice in the Phase 2 National Security Space Launch competition. Vulcan is trying to prove them right with a successful first flight.
However, that process is much easier said than done and a lot of new technology will be tested on launch day. The two BE-4 engines for example have never flown before and will be a first not only for ULA but also Blue Origin. They have performed well in testing but an actual launch exposes the engines to unique conditions.
In addition, solid rocket boosters will help propel the vehicle during first-stage flight. In regard to this, a pair of GEM 63XL solid rocket boosters were added to the sides of the first stage on Oct. 31 and Nov. 6. Together, they will provide nearly half of the 2 million pounds (8.9 kilo-Newtons) of thrust and augment the power generated by the two BE-4 methane-fueled main engines at liftoff.
With the exception of the upcoming wet dress rehearsal, one of the only other pre-launch steps is payload integration. The mission will send the commercial Astrobotic Peregrine lander to the Moon as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative and carry a Celestis memorial payload into deep space. The plan was also to launch a few Amazon Kuiper test satellites however delays among other factors moved that payload to an Atlas V mission instead.
With the Vulcan upper stage stacked, Mark Peller, ULA vice president of Vulcan Development commented, “We have worked diligently to develop this evolutionary rocket and certify the first vehicle for flight. This next-generation launch vehicle incorporates new technology at all levels, powered by American ingenuity to meet our nation’s need for expanding space missions” he said. Something the company is hoping to prove in just a few weeks from now.
Vulcan’s Future
As this first launch approaches, a handful of companies are waiting patiently and hoping for a perfect mission. Sierra Space, for example, the company developing the Dream Chaser spaceplane, needs this maiden flight to be successful. This is because the first-ever launch of Dream Chaser, will be on the second Vulcan mission. Earlier this month Sierra Space announced that the first test article named Tenacity, was officially complete and practically ready to launch. The goal was to launch in December but obviously, that’s not an option. Assuming Vulcan’s first flight next month works well, the question becomes how much time will ULA need to get the second Vulcan ready for another flight.
At this point, we know the company has already been working to mass-produce this vehicle in preparation for a busy launch schedule. Back on November 3rd, Tory Bruno tweeted saying, “Wow. That kind’a looks like 4 Centaur V’s in flow at the Rocket Factory…” Here you could see all the upper stages with varying progress in the factory. By now the next Vulcan booster and upper stage should be practically complete. If so, they would need to ship to the Florida launch site, complete a wet dress rehearsal, then static fire, and launch Dream Chaser.
In the grand scheme of things, Vulcan has a very busy future planned out. Project Kuiper for example, Amazon’s satellite service, selected Vulcan for 38 launches. By 2026, Amazon’s FCC license requires that at least half of the satellites are in orbit and operational. This suggests that a majority of Vulcan’s launches will be expected to happen before 2026. To add to this, in 2019, it was announced that all six Dream Chaser CRS-2 flights would be carried into orbit by ULA’s Vulcan launch vehicle. Combine this with additional contracts and we are expected to see Vulcan flying very regularly.
In preparation for this expected demand, we have not only seen ULA busy but also Blue Origin. Since Vulcan is expendable, every launch means two more BE-4 engines are needed. It’s possible the total 38 launches require 76 BE-4 engines. The one exception is the fact that ULA plans to reuse Vulcan’s BE-4 engines in the future. However, this plan is meant for the future and Tory Bruno has pointed out that they won’t work on this system until Vulcan has begun flying consistently.
In response, Blue Origin has been working in overdrive trying to pump out BE-4 engines. Besides comments from Tory, even videos from the company show tens of BE-4 engines in production with nozzles littering the factory floor. This highlights the future demand the company has. However, as partially mentioned prior, not a single BE-4 engine has flown, yet they are being produced in mass at the factory. This is because assuming things somewhat stay on schedule for Vulcan and New Glenn, once these vehicles start flying, they are going to keep flying very frequently. The Vulcan in particular will need a lot of these engines in the next few years.
Focusing on the design and build of Vulcan, the two BE-4 engines use liquefied natural gas (LNG) / methane, each producing 550,000 pounds (2,400 kN) of sea level thrust. The Centaur avionics system, provides guidance, flight control and vehicle sequencing functions during the booster and Centaur phases of flight. The booster is 17.7 ft (5.4 m) in diameter and 109.2 ft (33.3 m) in length. The booster’s tanks are structurally rigid and constructed of orthogrid aluminum barrels, spun-formed aluminum domes and intertank skirts.
Moving up the rocket you have the interstage, and then the Centaur upper stage. The Centaur V second stage is 17.7 ft (5.4 m) in diameter and 38.5 ft (11.7 m) in length. Its propellant tanks are pressure-stabilized and constructed of corrosion-resistant stainless steel. Centaur is a cryogenic vehicle, fueled with liquid hydrogen and liquid oxygen, powered by two RL10C-1-1A engines producing 23,825 pounds (106 kilo-Newtons) of thrust. The cryogenic tanks are insulated with a combination of helium-purged blankets, radiation shields and spray-on foam insulation (SOFI). After the explosion of this upper stage on the test stand, the company launched an investigation. The investigation found that the leak originated in the forward dome of the tank, which is made of very thin stainless steel, near a door at the top of the structure. A very detailed finite element model of that part of the tank revealed a “stress riser,” or intensification of loads, because of the complicated geometry around that part of the dome.
This has since been fixed both on the upper stage preparing for flight and subsequent stages. Finally, at the very top, the spacecraft is encapsulated in a 5.4-m- (17.7-ft-) diameter payload fairing (PLF), a sandwich composite structure made with a vented aluminum-honeycomb core and graphite-epoxy face sheets. The bisector (two-piece shell) PLF encapsulates the spacecraft. The payload attach fitting (PAF) is a similar sandwich composite structure creating the mating interface from spacecraft to second stage and payload fairing. On the first flight, this will help protect the moon lander and additional payloads.
Conclusion
United Launch Alliance is just weeks away from the first flight of the Vulcan Centaur. This mission has been a very long time in the making and will determine the schedule of a few important future launches. We will have to wait and see how it progresses and the impact it has on the space industry.
