Currently scheduled to launch on Friday, Oct. 4, the United Launch Alliance’s (ULA) heavy-lift Vulcan rocket is ready to fly on its second certification mission for the United States Space Force. The mission, named Certification Flight 2 or simply Cert-2, is expected to launch from Space Launch Complex 41 (SLC-41) at the Cape Canaveral Space Force Station in Florida during a three-hour launch window that opens at 6:00 AM EDT (10:00 UTC).
Assuming a successful launch into orbit, Vulcan will be certified by the United States Space Force (USSF) to carry national security payloads, some of which are already featured on Vulcan’s manifest. Vulcan was originally intended to loft Sierra Space’s Dream Chaser spaceplane named Tenacity to the ISS; however, Sierra Space and ULA announced earlier this year that Dream Chaser teams would need more time for testing and flight preparations. Now, Vulcan will be launching with a mass simulator payload, as well as experiments and technology demonstrations that may be incorporated into future missions
Vulcan arrived at Cape Canaveral on July 27 aboard ULA’s cargo ship Rocket Ship from the company’s factory in Decatur, Alabama. Vulcan’s first stage is 5.4 m in diameter and 33.3 m in length and is constructed of orthogrid aluminum barrels and spun-formed aluminum domes with a common bulkhead. The modular stage is powered by two cryogenic methane and liquid oxygen-powered BE-4 engines manufactured by Blue Origin.
For this mission, Vulcan will fly in the two solid rocket booster (SRB) configuration and loft the mass simulator into low-Earth orbit atop the Centaur V upper stage. After performing maneuvers to exercise Centaur V’s delta-V, endurance, and attitude control, Centaur and its payload will be safely disposed of into a graveyard orbit. The payload will not be released from the stage.
“This mission design will inject into a circular mid-inclination low-Earth park orbit followed by a second burn to inject the inert payload into a hyperbolic orbit such that it will never return to Earth,” ULA said, who has described the flight profile as “Cert-2 Earth Escape.” Tori Bruno later confirmed in a message to Jonathan McDowell that the orbit would be heliocentric, citing a late change to ULA plans.
Assuming that this certification flight is successful and Vulcan is granted certification by the USSF, Vulcan will launch USSF-106 and USSF-87, two critical national security missions, into orbit later this year. Vulcan’s first launch was on Jan. 8 of this year, sending the Peregrine Mission One spacecraft to the Moon. The Vulcan’s first flight was deemed to be a complete success.
Vulcan streaks into the sky on its first mission in January. (Credit: Stephen Marr for NSF)
Vulcan was transported to the Vertical Integration Facility G (VIF-G) at SLC-41 on Aug. 10, where it was maneuvered into a vertical position atop the Vertical Launch Platform (VLP) — an integrated launch pad and tower — before being mated with the two Graphite Epoxy Motors (GEM) 63XL SRBs. The two strap-on boosters add almost one million pounds of thrust to that generated by the two BE-4 engines on Vulcan’s first stage.
The Centaur V upper stage, which is 11.7 meters tall and 5.4 meters in diameter, was stacked atop the first stage on Aug. 20. Centaur provides guidance and flight management to the booster throughout the flight and also provides the payload interface. Powered by two RL10C-1-1A engines, each providing 23,825 pounds of thrust, Centaur is fueled by liquid hydrogen and liquid oxygen.
The encapsulated mass simulator payload was stacked atop Centaur on Sep. 21. ULA’s CEO Tory Bruno indicated that even at this late in the launch process, experiments and instruments were still being added to the payload. This was a consequence of the late decision to carry a mass simulator that required no data channels and gave ULA additional bandwidth for monitoring the rocket and engines. The payload will be encapsulated in the standard 15.5-meter-long fairing configuration.
“We have several experiments that are technology demonstrations and measurements that are associated with ULA’s high performance, longer duration version of Centaur V that ULA will be introducing in the future. These help speed up Centaur V development,” said Bruno.
So ready feel the rumble of BE-4's and GEM-63 XL's firing in tandem again. @ulalaunch's Vulcan Centaur is poised & ready at SLC-41 for tomorrow morning's showtime – launch window is open from 6a – 9a EDT for the Cert-2 mission.
📸 – @NASASpaceflight
👓 -… pic.twitter.com/OaPd7wbUQp
— Max Evans (@_mgde_) October 3, 2024
Following the rocket’s successful stacking at the VIF-G, Vulcan was rolled out to SLC-41 on the VLP, carried on a pair of diesel-electric-powered railroad trains running on parallel tracks, on Sept. 30. Once at SLC-41, the VLP was lowered onto its support pads and secured, allowing the trains to withdraw.
On Tuesday, Oct. 1, ULA performed a wet dress rehearsal (WDR) with Vulcan at the pad at SLC-41. During the WDR, the rocket was fully fuelled and prepared as if for launch, running the countdown procedure right down to the point just before the engines ignite. This test was also part of the certification process and is the last major hurdle to be cleared before the rocket is ready to fly.
Following the WDR, ULA announced on Oct. 2 that the tests had been successful and that Vulcan and ULA teams are on track for a Friday launch. Teams will also conduct a launch readiness review, which will give Vulcan the final “go” for launch.
Timelapse of @ulalaunch teams performing a Wet Dress Rehearsal on the Vulcan Centaur VC2S at SLC 41 at the Cape Canaveral Space Force Station, ahead launch on the Cert-2 flight, currently scheduled for Friday October 4th.@NASASpaceflight
Space Coast Live https://t.co/BEepgAJYUG pic.twitter.com/DJ6gda28ML— Elisar Priel (@ENNEPS) October 2, 2024
Unlike Falcon 9 and Falcon Heavy, Vulcan is not currently reusable, and there are no plans to return any of the rocket’s components flying on this mission. However, ULA is continuing to pursue SMART reuse with Vulcan, and Bruno recently stated that a preliminary design review regarding SMART reuse was completed at the beginning of the year. Additionally, Bruno said that ULA is likely one to two years away from the first Vulcan flight with SMART reuse.
After completing the launch readiness review, ULA started the countdown as planned and commenced fuelling Vulcan. Late into the count, an issue was identified with ground systems data collection which led to a prolonged hold before a new lift-off target of 6:30 AM EDT (11:30 UTC).
A second unscheduled hold was called less than two minutes before the new T-0 time. ULA reported that this hold was also related to data collection systems. A new T-0 of 7:25 AM EDT (11:25 UTC) was established and the countdown restarted.
Lift off was successful on this occasion and the two SRBs appeared to burn to exhaustion after almost two minutes, separated, and fell away from the booster, which continued to burn until five minutes after lift-off.
Yeah, that's not nominal. pic.twitter.com/xBJp1lqU4j
— Chris Bergin – NSF (@NASASpaceflight) October 4, 2024
The Centaur V separated and fired both RL-10 engines successfully, commencing a ten-minute burn to reach orbit. This burn lasted for 20 seconds longer than expected, as a result of an anomaly with one of the two SRBs during ascent leading to slightly less performance. The Centaur V entered a coast phase for 15 minutes before the second burn commenced, the RL-10s burning for a further four minutes to place the vehicle and the inert payload into its planned orbit.
Following the burn, the stage adjusted its attitude and performed a simulated spacecraft separation.
Tory Bruno confirmed during the official launch broadcast that SRB #1 did experience an “observation”, but the mission continued nominally and that the initial aims have all been achieved. Video footage showed that there was what appeared to be a burn-through above the nozzle of the SRB, causing the nozzle to detach in a shower of sparks and debris. The Vulcan’s BE-4 engines quickly gimballed to address the change in thrust, and the booster continued on course.
ULA later confirmed that the payload had been delivered to the precise “bullseye” orbital insertion point, and the FAA issued a statement that no investigation would be required following this anomaly.
(Lead image: ULA’s Cert-2 Vulcan launches from SLC-41. Credit: Sawyer Rosenstein for NSF)