Running more than three months late, a United Launch Alliance Delta 4-Heavy rocket took off Thursday and carried a U.S. government spy satellite into an orbit thousands of miles above Earth in the first mission from the newly-renamed Cape Canaveral Space Force Station.
The 235-foot-tall (71-meter) rocket lifted off from pad 37B at Cape Canaveral at 8:09 p.m. EST Thursday (0109 GMT Friday) with thrust from three hydrogen-fueled RS-68A engines producing 2.1 million pounds of thrust, equivalent to 51 million horsepower.
The orange and white launch vehicle — the most powerful in ULA’s fleet — soared into a starry sky over Florida’s Space Coast, targeting a trajectory toward the east from Cape Canaveral over the Atlantic Ocean.
A classified payload for the National Reconnaissance Office, owner of the U.S. government’s spy satellite fleet, was secured inside the Delta 4-Heavy’s nose cone for the rocket’s climb away from pad 37B.
The rocket’s three Aerojet Rocketdyne RS-68A engines steered the Delta 4-Heavy on an easterly course. The two side booster cores shut down and jettisoned to fall into the Atlantic ocean around four minutes after liftoff.
The Delta 4-Heavy’s center core stage throttled up its engine to full power after running in a fuel-saving partial thrust mode for the early minutes of the mission. Just before exhausting its propellant supply, the RS-68A center engine shut down and the core stage separated, leaving the second stage’s RL10 engine — also made by Aerojet Rocketdyne — to perform multiple firings to place the NRO’s newest spy satellite into orbit.
The launcher’s payload shroud separated about six-and-a-half minutes into the mission. The rest of the launch sequence occurred in secret due to a government-imposed new blackout intended to keep certain mission details under wraps — a standard practice for missions with NRO satellites.
ULA’s live broadcast ended at that point, and the company remained silent about the progress of the multi-hour launch sequence until around 2:20 a.m. EST (0720 GMT) Friday, when ULA issued a press release confirming a successful conclusion to the Delta 4-Heavy mission.
“We are honored to launch the first payload from the newly-renamed Cape Canaveral Space Force Station. I want to thank our mission partners for their collaboration and teamwork as we worked through technical challenges that culminated in the launch of this critical national security payload,” said Gary Wentz, ULA vice president of government and commercial programs.
The Florida launch base, formerly known as Cape Canaveral Air Force Station, was officially renamed Wednesday during a visit by Vice President Mike Pence. Nearby Patrick Air Force Base was also renamed as Patrick Space Force Base, and the two facilities are the first in the Defense Department to get a new Space Force designation.
The new names reflect the next step in the evolution of the U.S. Space Force, which was established nearly a year ago to take over most of the Air Force’s space operations.
“The Delta 4-Heavy again demonstrated its success as the nation’s proven heavy lift vehicle, through its unique capability to deliver this mission to orbit due to a combination of performance and fairing size,” Wentz said in a statement.
The NRO published no details about the payload on the Delta 4-Heavy mission, which officials designated NROL-44.
But independent analysts say publicly-known parameters such as the rocket’s capabilities, its launch azimuth, and the launch window suggested the Delta 4-Heavy was carrying a signals intelligence satellite into geosynchronous orbit more than 22,000 miles (nearly 36,000 kilometers) above Earth and closely hugging the equator.
Reaching such an orbit required the rocket to follow one of the most challenging flight profiles in the launch business, with three burns expected by the Delta’s upper stage to deploy its satellite payload at the targeted altitude.
Four previous Delta 4-Heavy launches in 2009, 2010, 2012 and 2016 followed similar trajectories after taking off from Cape Canaveral, each carrying a classified cargo for the National Reconnaissance Office. Independent analysts believe all delivered top secret NRO eavesdropping satellites to space.
In a “press kit” released before the launch, the NRO said the NROL-44 mission supports the agency’s “overall national security mission to provide intelligence data to the United States’ senior policy makers, the intelligence community and Department of Defense.”
But the satellite is likely related to the NRO’s fleet of “Advanced Orion” or “Mentor” signals intelligence stations flying in equatorial geosynchronous orbits. The Advanced Orion-series satellites began launching on Titan 4 rockets in 1995, following a pair of earlier NRO Orion payloads that launched in the 1980s on space shuttle missions.
The NRO began using Delta 4-Heavy rockets for the Advanced Orion missions in 2009, following the retirement of the Titan 4 booster.
Like the previous Delta 4-Heavy launches with Advanced Orion satellites, the launch time moved around four minutes earlier each day.
“The use of the Delta 4-Heavy, the eastward trajectory, and the four minute per day earlier time of liftoff, point to the launch of the eighth Advanced Orion satellite,” said Ted Molczan, an authoritative skywatcher who tracks satellite activity.k “This signals intelligence spacecraft is so large, that when seen from Earth, it shines with the brightness of an 8th magnitude star, making it easily visible with small binoculars.”
Before the launch in 2010 of a suspected Advanced Orion satellite, then-director of the NRO Bruce Carlson called the payload the “the largest satellite in the world.” The satellites are believed to carry giant antennas that unfurl to a diameter of up to 100 meters, or 328 feet, once in space.
The antenna can likely be tuned to listen in on telephone calls, collect data transmissions, and eavesdrop on other communications among U.S. adversaries.
The geographic coverage area for the satellite launched Thursday night is unknown, but the Advanced Orion spacecraft span the world, flying at just the right altitude to orbit the Earth at the same rate the planet rotates. That allows the satellites to remain fixed over the same region of the planet.
It’s also not known whether the new satellite will replace an aging member of the Advanced Orion fleet, or expand the network’s coverage.
In that orbit, the satellite is expected to unfurl a giant football field-sized antenna to eavesdrop on telephone calls and other data traffic from U.S. adversaries.
The Advanced Orion satellites require the combination of the Delta 4-Heavy rocket’s lift capability, long-duration upper stage, and huge 65-foot-long (19.8-meter) trisector payload fairing.
ULA set Sept. 26 a 50-50 joint venture between Boeing and Lockheed Martin, first tried to launch the Delta 4-Heavy rocket and the NROL-44 mission in late August.
The launch company’s original launch date for the NROL-44 mission was Aug. 26, but the NRO requested a one-day delay before the countdown could begin. A pneumatics issue prevented the rocket from launching Aug. 27, and the Aug. 29 countdown stopped when the automated launch sequencer detected a problem with a pressure regulator on the launch pad designed to flow helium gas to spin up rocket’s center engine for ignition.
ULA set Sept. 26 as the target launch date for the NROL-44 mission, but officials delayed the mission again to investigate a concern with the swing arm retraction system at the Delta 4-Heavy’s seaside launch complex at Cape Canaveral. The swing arms, which feed liquid propellants and conditioned air to the vehicle, are designed to quickly retract away from the rocket at liftoff.
Bad weather and a hydraulic leak in hardware associated with the launch pad’s mobile gantry forced ULA officials to call off a pair of launch attempts in late September.
Another launch attempt Sept. 30 was halted at T-minus 7 seconds, just before ignition of the rocket’s three hydrogen-fueled RS-68A main engines. Engineers traced that problem to a bad sensor reading involving a valve position inside one of the RS-68A engines.
While that problem was resolved, ULA encountered deeper issues with the swing arms at pad 37B.
Tory Bruno, ULA’s president and CEO, tweeted that technicians drained 2,000 gallons of oil from the hydraulic swing arm retraction system. Teams replaced several dozen valves and “several other important items” before recharging the system with fresh hydraulic fluid, Bruno tweeted.
“Mission success is the priority,” he added.
The repeated problems with different parts of the Delta 4-Heavy’s launch pad have raised questions about aging infrastructure at pad 37B, which was originally built to support Saturn rocket launches in the 1960s, then mothballed until Boeing took over the facility in the 1990s for the Delta 4 program.
Boeing built the towering mobile gantry for the Delta 4 rocket, along with a then-new fixed umbilical tower with the three huge retractable swing arms.
ULA is retiring the Delta 4 rocket family after four more launches — two more from Cape Canaveral and two from Vandenberg Air Force Base in California. The company’s next-generation Vulcan Centaur rocket, scheduled to debut in the second half of next year, will replace ULA’s existing Delta 4 and Atlas 5 launch vehicles.
Vulcan Centaur rockets will sell for a fraction of the price of a Delta or Atlas 5, according to ULA.
While SpaceX’s Falcon Heavy rocket is significantly less expensive and can lift heavier payloads into low orbits, the Delta 4-Heavy has demonstrated an ability to inject satellites directly into high-altitude circular geosynchronous orbits more than 22,000 miles (nearly 36,000 kilometers) above Earth.
The Delta 4-Heavy also has a larger payload fairing than the Falcon Heavy, and the mobile shelters at Cape Canaveral and Vandenberg allow ground crews to mate satellites to the rocket in a vertical orientation. SpaceX plans to offer an enlarged payload shroud on the Falcon Heavy and build a vertical integration hangar at the Kennedy Space Center to support future national security missions that can currently only fly on the Delta 4-Heavy.
The launch Thursday night was the 41st flight in the history of the Delta 4 rocket program, and thee 12th to use the Delta Heavy rocket configuration.
Follow Stephen Clark on Twitter: @StephenClark1.