NROL-44: Orion 10 (Mentor 8) – Delta IV-H [D-385] – Канаверал SLC-37B – 11.12.2020 01:09 UTC

[tnt22]

Aug 29, 2020 02:01

The flight control operational test is beginning for the Delta IV Heavy rocket. This test is known as flight slews, which will perform gimbal checks of the rocket's RS-68A engine nozzles on the vehicle, in a state prior to cryogenic fueling.

[tnt22]

Aug 29, 2020 02:15

MST Rolled Back

The Mobile Service Tower at Space Launch Complex-37 has been retracted and secured in the launch position, revealing the United Launch Alliance Delta IV Heavy rocket for the NROL-44 launch.

The MST reached the "harddown" milestone at 7:14 p.m.



The MST is a critical part of the launch complex, providing the primary access and weather protection to the rocket during its stay on the launch pad, and its overhead crane system serves a vital role in vertical integration of payloads onto the Delta IV rockets.

Rollback of the MST signals a major milestone at the start of launch day operations. Configuring launch pad systems and securing equipment will be completed over the next couple of hours before all personnel clear the site for fueling.

Activities remain on schedule for a liftoff at 2:04 a.m. EDT (0604 UTC).

[tnt22]

Aug 29, 2020 02:19

The flight control operational test has been completed successfully. This was an engine nozzle steering check performed prior to cryogenic fueling. A similar test wull be conducted after the rocket is loaded with super-cold propellant.

[tnt22]

Aug 29, 2020 02:30

The S-band system has been tested. This will be used for telemetry downlink during the flight.

[tnt22]

Aug 29, 2020 02:49

The initiation of gaseous nitrogen flow to the rocket is starting. This changes the environmental control system to supply conditioned nitrogen gas rather than air to Delta IV Heavy in preparation for the cryogenic fueling and in-flight environments.

[tnt22]

Aug 29, 2020 02:53


Photo by United Launch Alliance

[tnt22]

Aug 29, 2020 03:04

Delta 385

We are inside the final six hours until liftoff of Delta 385.

Today marks the 385th Delta launch, the 41st for Delta IV and the 12th in the Heavy configuration.
Activities remain on schedule for a liftoff at 2:04 a.m. EDT (0604 UTC).


Photo by United Launch Alliance

[tnt22]

Aug 29, 2020 03:42

The start of clearing all personnel from the danger area around the launch site is underway.

[tnt22]

Aug 29, 2020 03:46

Clear the Complex

The launch pad crew has completed its hands-on work to ready Space Launch Complex-37 for tonight's mission, and the launch conductor has given the instruction for personnel to depart the site in advance of fueling operations.

[tnt22]

Aug 29, 2020 03:52

Hold-fire checks are being conducted at this time. This verifies the circuitry used to stop the countdown if a safety concern arises.

[tnt22]

Aug 29, 2020 04:07

Pre-fueling tests has been performed to verify the proper functions of liquid oxygen and liquid hydrogen valves on both stages of the launch vehicle.

[tnt22]

Aug 29, 2020 04:10

Weather is GO for Fueling

This is Delta Launch Control at T-minus 4 hours, 24 minutes (L-4 hours, 54 minutes) and counting. In the pre-fueling weather briefing, conditions at Cape Canaveral are acceptable for proceeding into cryogenic tanking operations at Space Launch Complex-37.

Launch Weather Officer Will Ulrich from the Space Force's 45th Weather Squadron also reports that the weather outlook remains favorable for the flight of Delta IV Heavy this evening. The forecast calls for an 80 percent chance of allowable liftoff conditions, with the only possible concerns being cloud thickness and cumulus clouds.

All rules are green and "go" at the present time.

[tnt22]

Aug 29, 2020 04:19

Countdown Holding

This is Delta Launch Control at T-minus 4 hours, 15 minutes and holding. The countdown has entered the first of two planned, built-in holds that are scheduled in today's timeline. Each is a 15-minute block of time that gives the countdown some margin to resolve issues or catch up on work could be running behind.

This particular hold serves as a margin before fueling operations begin. At the present time, however, all activities are progressing well and no significant problems are being addressed by the launch team.
The final hold occurs at T-minus 4 minutes.

[tnt22]

Aug 29, 2020 04:23

Launch Conductor Scott Barney says that the launch team is not working any issues and is tracking to the scheduled timeline.

[tnt22]

Aug 29, 2020 04:31

GO for Fueling

A readiness poll of the launch team by Launch Conductor Scott Barney, with concurrence of ULA Launch Director Lou Mangieri, has authorized cryogenic tanking operations to begin as the countdown continues today. The Delta IV Heavy rocket will be loaded with approximately 470,000 gallons of liquid oxygen and liquid hydrogen over the next couple of hours.

[tnt22]

Aug 29, 2020 04:34

Countdown Resumes

This is Delta Launch Control at T-minus 4 hours, 15 minutes and counting. The next phase of today's launch countdown has been initiated for liftoff of the United Launch Alliance Delta IV Heavy rocket for the National Reconnaissance Office.

Preparatory steps for fueling are being kicked off, including liquid hydrogen storage tank pressurization and charging the high-pressure helium bottles on the common booster cores and second stage.

[tnt22]

Aug 29, 2020 04:48

The flight control operator is performing the ECU BIT test on the Delta IV Heavy rocket. This is the built-in test (BIT) of the engine control units (ECUs) that cycle hydraulically-actuated engine valves prior to the start of fueling operations.

[tnt22]

Aug 29, 2020 04:54

Valves on the Delta Cryogenic Second Stage are being opened and closed as part of the pre-loading purge cycle test.

[tnt22]

Aug 29, 2020 04:59

Chilldown Begins

A "go" has been given to start the cold gas chilldown conditioning of the liquid hydrogen system on the three common booster cores. This is the precursor step before filling the cores with propellant.


Photo by United Launch Alliance

The three common booster cores will be loaded with 330,000 gallons of super-cold liquid hydrogen that is chilled to minus-423 degrees Fahrenheit. The liquid hydrogen, along with the liquid oxygen to be loaded shortly as well, will be consumed by the three RS-68A main engines during the first minutes of the launch to exit Earth's atmosphere.

The port and starboard boosters will fire at full throttle for nearly four minutes and then separate. The center booster burns at partial thrust for most of that time in a fuel-conservation mode until the outer cores jettison, then its RS-68A engine revs up to full throttle for another minute-and-a-half of propulsion before staging.

[tnt22]

Aug 29, 2020 05:05

The first weather balloon of the countdown has been launched. A series of balloons will be set aloft over the next few hours to measure the speed and direction of upper level winds that the Delta IV Heavy will experience during flight.