A year since the “first-last” mission by a member of the United Launch Alliance (ULA) Delta IV fleet, one of the most powerful rockets in the world must wait at least another 24 hours, following Thursday morning’s scrubbed launch attempt of the Delta IV Heavy. Scheduled to fly at 2:12 a.m. EDT, the mission was scrubbed due to an issue and review of a critical ground pneumatics control system. “Working an issue with power redundancy on a ground system,” tweeted ULA CEO Tory Bruno. “Ran out of time in the window. Best not to rush this sort of thing.”
Liftoff of the triple-barreled booster—laden with the highly secretive NROL-44 payload on behalf of the National Reconnaissance Office—is now targeted for no earlier than 2:04 a.m. EDT Saturday from Space Launch Complex (SLC)-37B at Cape Canaveral Air Force Station, Fla.
Ready to embark on the 12th mission of its career, the Delta IV Heavy is powered off the launch pad by three Common Booster Cores (CBCs), each equipped with a single Aerojet Rocketdyne-built RS-68A engine and with a total propulsive yield at liftoff in excess of 2.1 million pounds (1.1 million kg). Until the arrival on the scene of SpaceX’s Falcon Heavy two years ago, this made the Delta IV Heavy the most powerful operational launch vehicle in the world.
Atop the central CBC is the Delta Cryogenic Second Stage (DCSS), equipped with Aerojet’s RL10-B-2 engine, and the stack was topped-off by the large payload fairing housing NROL-44. All told, it has the muscle to put 63,470 pounds (28,790 kg) into low-Earth orbit and 31,350 pounds (14,220 kg) into geostationary transfer orbit, offering a hint at the size, scale and energy requirement demanded by NROL-44.
Unsurprisingly, little detail has emerged about the exact nature of the payload, with the exception of its cryptic mission patch, emblazoned with a howling wolf. “The wolf’s howl represents a warning to the pack as the first point of detection of signs of trouble,” the NRO noted with characteristic ambiguity in its description of the patch. “The wolf’s voice, in this representation, is directed toward space, where NRO spacecraft are operating the agency’s overhead collection mission in support of both defense and intelligence operations.”
Behind the howling wolf, though, four other shadowed wolves offer a clue. “The five wolves show the solidarity across the FVEY community,” the NRO continued, “and the pack represents the solidarity of the nation in leveraging and supporting the warning sentry.” The Five Eyes (FVEY) is the five-nation intelligence alliance incorporating Australia, Canada, New Zealand, the United Kingdom and the United States, all of whom are parties to multilateral treaties for joint signals-intelligence collaboration.
But the critical importance of this mission could not be denied. “The NROL-44 launch was deemed mission-essential to perform during the COVID-19 national emergency,” noted ULA in its pre-launch update. “Personnel involved in the launch are following health guidelines such as wearing face coverings, adhering to physical distancing while on console and using virtual connections when possible.”
To date, the Delta IV Heavy has flown 11 times since December 2004, all but once with total success. Its initial test flight suffered a premature CBC shutdown, but since then it has successfully launched seven reconnaissance/intelligence satellites, one early-warning satellite, NASA’s Parker Solar Probe and the first mission by the Orion spacecraft on Exploration Flight Test (EFT)-1.
And of those missions, a total of four—launched between January 2009 and June 2016—are suspected to have been Advanced Orion (alternatively codenamed “Mentor”) signals-intelligence satellites, weighing up to 11,500 pounds (5,200 kg) and bound for geostationary orbit, some 22,600 miles (35,900 km) above the planet. It is possible that today’s mission might represent another Advanced Orion/Mentor.
“The Northrop Grumman satellite has a Harris mesh antenna spanning about 330 feet (100 meters),” AmericaSpace explained in its NROL-37 launch report. “The overall spacecraft was substantially upgraded starting in 2009 with the NROL-26 flight carrying the first Advanced Orion/Mentor.” The lifting capability of the Delta IV Heavy’s upgraded RS-68A engines is also believed to afford the satellites additional “maneuvering, life-extending and eavesdropping intelligence capabilities”.
The Launch Readiness Review (LRR) was conducted under the auspices of ULA Launch Director Lou Mangieri on Monday morning. It produced a unanimous “Ready” status from all participants, although later that evening the mission customer requested a 24-hour postponement of the launch from Wednesday to Thursday.
Although the “launch window” extended from 1:50 a.m. through 6:25 a.m. EDT, liftoff was precisely targeted for 2:12 a.m. Countdown operations began crisply at sunset Wednesday and the Delta IV Heavy was powered up and put through initial avionics tests. At 6:47 p.m.—after hydraulic jacks had slightly elevated the Mobile Service Tower (MST)—the 300-foot-tall (100-meter) structure was wheeled on rail-tracks away from the giant rocket at a glacial pace of 0.25 mph (0.4 km/h). It reached its launch position and was declared “hard-down” at 7:40 p.m.
“The sun is setting on the Florida Space Coast on a beautiful summer evening,” noted ULA at the conclusion of the MST rollback. Indeed, conditions were predicted to be 80-percent-favorable, with only a slight chance of violation of the Cumulus Cloud Rule.
“Pockets of drier air embedded within deep easterly flow will bring below-normal rain chances through early Thursday, with only a small chance for onshore-moving showers,” noted the 45th Weather Squadron at Patrick Air Force Base in its L-1 briefing early Wednesday. “The primary concern during the launch window Thursday morning remains the Cumulus Cloud Rule.”
With the 235-foot-tall (72-meter) Delta IV Heavy thus exposed to the elements, pre-launch testing commenced in earnest. “Hold-fire” tests of the circuitry needed to stop the countdown were completed, the guidance system was tested and the cryogenic tanks were readied for fueling.
Shortly before 9:30 p.m., as planned, the countdown entered the first of two built-in holds at T-4 hours and 15 minutes. The hold was due to last 15 minutes, ahead of the Go/No-Go decision for fueling, but as circumstances transpired it was extended to an hour ultimately remained in place until a scrub was called.
Just before 10 p.m., the first indications of a problem arose in the form of a heater issue and personnel were deployed to the rocket. Within a couple of hours, the problem was declared cleared by Anomaly Chief Dave McFarland and the pad was cleared by midnight. However, at the same time, ULA announced that its engineers were working on “a precautionary data review of pressure measurements”. It added that teams would hold off on picking up the countdown until the review of a critical ground pneumatics control system had been concluded.
By 1:20 a.m., less than an hour before the scheduled 2:12 a.m. launch—but with clocks still holding at T-4 hours and 15 minutes—Mr. McFarland reported to the Mission Management Team that more time was required to attend to the pneumatics review. As the available time to launch the NROL-44 mission ebbed away, Mr. Mangieri declared a scrub for the night. Another attempt is set for Sat., Aug. 29 at 2:04 a.m. EDT, after taking additional time to validate an appropriate path forward with the ground pneumatics control system.
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