WGS-9 – Delta IV-M+(5,4) – Канаверал SLC-37B – 19.03.2017 – 00:18 UTC

[tnt22]

SMC Commander‏ @SMC_CC 47 мин назад
 
#WGS9 on #DeltaIV sits on the pad; @AF_SMC & mission partners @ulalaunch @BoeingDefense @45thSpaceWing continue prep for tonight's mission
 

[tnt22]

03/18/2017 21:24  Weather forecast now better than 90% GO

In the pre-fueling weather update, all conditions are favorable at Cape Canaveral for liftoff of the United Launch Alliance Delta 4 rocket.

The odds of acceptable weather for an on-time launch this evening at 7:44 p.m. EDT (2344 GMT) are "greater than" 90 percent. The outlook calls for just a few clouds, acceptable winds and a temperature of 66 degrees F.

Development of cumulus clouds is the only real concern, but meteorologists say it is unlikely with today's atmospheric conditions.

Spaceflight Now‏ @SpaceflightNow 2 мин. назад
 
The odds of acceptable weather for today's Delta 4 launch of #WGS9 improved to "greater than" 90 percent GO https://spaceflightnow.com/2017/03/17/d377_journal/ ...
 

[tnt22]

03/18/2017 21:28  Countdown in built-in hold

T-minus 4 hours, 15 minutes and holding. The countdown has entered a 30-minute-long built-in hold, a pre-planned pause designed to give the team time to catch up on any work that could be running behind schedule. Once the clocks resume ticking, the main countdown for this evening's launch operation will begin.

[tnt22]

03/18/2017 21:49  'Man stations for cryogenic tanking'

The launch team is reporting on station for the start of fueling operations. Some 170,000 gallons of cryogenic liquid hydrogen and liquid oxygen will be loaded today.

[tnt22]

Spaceflight101 LIVE‏ @S101_Live 36 сек. назад
 
The first several hours of the countdown are filled with hands-on work at the pad – propellant loading preparations & vehicle close-outs.

[tnt22]

Заправка началась!

03/18/2017 21:57  GO to fuel

Team is GO to begin fueling operations right on schedule.

Spaceflight Now‏ @SpaceflightNow 59 сек. назад
 
Launch team is GO to load 170,000 gallons of fuel into Delta 4 this afternoon for #WGS9 https://spaceflightnow.com/2017/03/17/d377_journal/ ... (@scriptunasphoto pic)
 

[tnt22]

03/18/2017 21:59  Countdown has resumed

T-minus 4 hours, 15 minutes and counting. The team is ready for cryogenic fueling as the countdown is underway for today's opportunity to launch the Delta 4 rocket with the Wideband Global SATCOM satellite.

A final 30-minute planned hold is scheduled into the countdown at the T-minus 4 minute mark.
Liftoff remains targeted for 7:44 p.m. EDT (2344 GMT).

Spaceflight101 LIVE‏ @S101_Live 57 сек. назад
 
T-4 Hours 15 Minutes & Counting. Clocks are now ticking as Terminal Countdown Ops for today's Delta IV launch start. #WGS9

[tnt22]

Spaceflight101 LIVE‏ @S101_Live 32 сек. назад
 
The first step is the activation of Delta IV's RIFCA – Redundant Inertial Flight Control Assembly, the heart of the Flight Control System.

[tnt22]

ULA‏Подлинная учетная запись @ulalaunch 21 сек.назад
 
#DeltaIV #WGS9 cryogenic fueling operations underway! Launch at 7:44pmEDT; broadcast at 7:24pmEDT. http://bit.ly/div_wgs9

[tnt22]

03/18/2017 22:23  Fueling ops underway

A "go" has been given to start the cold gas chilldown conditioning of the liquid hydrogen system. This is the precursor to filling the vehicle with propellant.

[tnt22]

/r/ULA‏ @_r_ULA 3 мин. назад
 
.@AerojetRdyne @OrbitalATK The 5-meter diameter Delta Cryogenic Second Stage is powered by a single @AerojetRdyne RL10B-2 engine.
 
  /r/ULA‏ @_r_ULA 4 мин.4 минуты назад

The first stage is powered by an @AerojetRdyne RS-68A engine with four @OrbitalATK GEM-60 solid rocket motors.

[tnt22]

Spaceflight101 LIVE‏ @S101_Live 2 мин. назад
 
The Range Countdown Sequence is now starting at the Morrell Operations Center as controllers monitor range assets & corridor clearance #WGS9

[tnt22]

03/18/2017 22:55  CBC LH2 tanking begins

The cold gas chilldown conditioning of the liquid hydrogen system has been accomplished. Liquid hydrogen propellant will begin to flow into the Common Booster Core in "slow-fill" mode. That is sped up to "fast-fill" after a small portion of the tank is loaded.

Chilled to Minus-423 degrees Fahrenheit, the liquid hydrogen will be consumed by the RS-68A main engine along with liquid oxygen during the first four minutes of the launch.

Spaceflight Now‏ @SpaceflightNow 2 мин. назад
 
Fueling starting! Loading 110,000 gallons of liquid hydrogen for Delta 4 first stage underway at the Cape for #WGS9 https://spaceflightnow.com/2017/03/17/d377_journal/ ...

[tnt22]

03/18/2017 23:00  CBC LOX chilldown

And now the chilldown of the liquid oxygen system on Delta's Common Booster Core is starting. This preps the tank and pumping to guard against shock when the supercold oxidizer begins flowing into the rocket a short time from now. The first stage will be loaded with 40,000 gallons of supercold LOX.

[tnt22]

03/18/2017 23:11  Upper stage LH2 chilldown

The launch team is preparing to start fueling the Delta 4 rocket's upper stage. And with that the "go" has been given to start the chilldown conditioning of the upper stage liquid hydrogen system.

[tnt22]

03/18/2017 23:20   CBC LOX tanking

The CBC liquid oxygen chilldown is complete. "Slow-fill" mode is beginning to load a small percentage of the tank. The process then speeds up to the "fast-fill" mode until the tank is nearly full.

Spaceflight Now‏ @SpaceflightNow 1 мин. назад
 
Delta 4's Common Booster Core first stage now being filled with 40,000 gallons of liquid oxygen to launch #WGS9 https://spaceflightnow.com/2017/03/17/d377_journal/ ...
 

Spaceflight101 LIVE‏ @S101_Live 2 мин. назад
 
Prop load is underway on the Common Booster Core, receiving 29,500kg of -253°C Liquid Hydrogen & 172,500kg of -183°C Liquid Oxygen. #WGS9

[tnt22]

https://spaceflightnow.com/2017/03/18/hotos-launch-pad-gantry-retracted-from-delta-4-rocket/

Photos: Launch pad gantry retracted from Delta 4 rocket
 March 18, 2017     Justin Ray

The 330-foot-tall mobile service tower is rolled away from the United Launch Alliance Delta 4 rocket at Cape Canaveral's pad 37B in the hours before the scheduled liftoff. The 9-million-pound gantry was retracted the length of a football field in preparation for launch of the Air Force's WGS 9 communications satellite into Earth orbit.

Спойлер

Photo credit: United Launch Alliance

[свернуть]

[tnt22]

03/18/2017 23:37  Upper stage LOX chilldown

The "go" has been given for the upper stage liquid oxygen chilldown in advance of filling that tank.

[tnt22]

03/18/2017 23:39  Upper stage LH2 tanking

After chilldown of the upper stage liquid hydrogen system, the clear was given for loading the rocket's tank with 14,000 gallons. The launch team is actively filling the upper stage's liquid hydrogen tank with propellant for the RL10 engine.

[tnt22]

03/18/2017 23:44  L-3 hours and counting

Now three hours till launch. The Delta 4 rocket is being loaded with supercold liquid oxygen and liquid hydrogen as the countdown rolls on for launch at 7:44 p.m. EDT (2344 GMT).

Complex 37 has two giant sphere-shaped fuel tanks to store the cryogenic liquid oxygen and liquid hydrogen. The LOX tank holds 250,000 gallons and LH2 sphere about 850,000 gallons.

The cryogenics are fed from the storage tanks through pipelines to the pad. For the Common Booster Core, the propellants are routed up to the launch table upon which the rocket sits. Tail service masts, the large box-like structures at the base of the vehicle, feed the oxygen and hydrogen to the booster via separate umbilicals.

The upper stage receives its cryos from the middle swing arm that extends from the Fixed Umbilical Tower to the front-side of the rocket.