United Launch Alliances Delta Heavy IV rocket launch from Space Launch Complex-37 at Cape Canaveral Space Force Station in Florida for the final time. The rocket carries the NROL-70 mission for the National Reconnaissance Office.
Credit: ULA
Credit: ULA
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TechTranscript
00:00 [ Music ]
00:03 To mitigate the fireball created
00:05 by the hydrogen-burning Delta IV Heavy rocket,
00:08 the staggered engine start sequence begins with ignition
00:11 of the launch table HBOs,
00:12 burning off the excess hydrogen injected into the flame duct.
00:18 Next, the starboard Delta IV roving lights,
00:20 igniting its RS-68A engine.
00:23 Then the center and port RS-68A engines ignite
00:27 and generate more than 2.1 million pounds of total thrust
00:31 to lift the 1.6 million pound triple core rocket off the pad.
00:35 Shortly after liftoff, Delta begins a pitch
00:42 over to attain the proper flight path while minimizing the
00:45 pressure the vehicle experiences during flight.
00:47 Delta then reaches Mach 1, the speed of sound,
00:52 followed by the rocket reaching maximum dynamic pressure
00:55 as it travels through Earth's atmosphere.
00:57 With propellant depleted in the port and starboard boosters,
01:04 the engines shut down and the boosters jettison
01:07 to shed their weight.
01:08 The remaining booster engine then throttles to full power
01:11 to maximize performance against gravity losses.
01:14 Once propellant levels deplete in the center booster,
01:18 the engine shuts down and the booster is jettisoned
01:21 from the second stage.
01:22 The vehicle now weighs approximately 6%
01:25 of what it did at liftoff.
01:26 Following jettison of the center booster,
01:32 the Delta Cryogenic Second Stage,
01:35 or DCSS, main engine ignites.
01:38 During ascent, NROL-70 is protected inside a 5-meter
01:42 diameter metallic payload fairing.
01:44 After traveling through the densest part
01:47 of Earth's atmosphere, the payload fairing is jettisoned.
01:49 The Delta IV Cryogenic Second Stage carries the last payload
01:56 to launch on a Delta IV rocket to its final orbital destination,
01:59 where it will begin its national security mission.
02:02 [ Sound Effects ]
02:06 [ Silence ]