THURSDAY, MAY 22, 2014
Completing a pair of missions in one week's time, a feat also performed last month, United Launch Alliance sent an Atlas 5 rocket soaring Thursday morning.

Read our launch story.

1427 GMT (10:27 a.m. EDT)
MISSION SUCCESS. The Atlas 5 rocket has successfully delivered its clandestine payload into orbit today.

"Congratulations to all of our mission partners on today's successful launch of the NROL-33 mission! The ULA team is honored to deliver another critical national security asset to orbit together with the NRO Office of Space Launch and the Air Force," said Jim Sponnick, ULA vice president, Atlas and Delta Programs.

"Today's launch occurred six days after last week's GPS 2F-6 launch – the second time this year that this team has launched back-to-back missions within a week. Successfully launching at this tempo is a testament to the team's focus on mission success, one-launch-at-a-time, and continuous improvement of our launch processes.”

1314 GMT (9:14 a.m. EDT)
The United Launch Alliance Atlas 5 rocket has flown into a pre-arranged news blackout following jettison of the rocket's payload shroud. The veil of secrecy surrounding the launch of this clandestine satellite cargo means no further information about the progress of the ascent, upper stage engine firings or release of the payload will be announced in real-time.
1313 GMT (9:13 a.m. EDT)
T+plus 4 minutes, 35 seconds. The two halves of the four-meter-diameter Atlas 5 rocket nose cone encapsulating the spacecraft have separated.
1313 GMT (9:13 a.m. EDT)
T+plus 4 minutes, 24 seconds. Centaur has ignited! The RL10 engine is up and running at full thrust to power the vehicle into orbit.
1313 GMT (9:13 a.m. EDT)
T+plus 4 minutes, 12 seconds. The Atlas 5's Common Core Booster has been jettisoned, completing the first stage of flight, and the Centaur upper stage's liquid hydrogen and liquid oxygen systems are being readied for engine start.
1313 GMT (9:13 a.m. EDT)
T+plus 4 minutes, 7 seconds. BECO. Booster Engine Cutoff is confirmed as the RD-180 powerplant on the first stage completes its burn. Standing by to fire the retro thrusters and separate the spent stage.
1312 GMT (9:12 a.m. EDT)
T+plus 3 minutes, 45 seconds. Atlas now weighs just a quarter of what it did at liftoff.
1312 GMT (9:12 a.m. EDT)
T+plus 3 minutes, 45 seconds. Atlas now weighs just a quarter of what it did at liftoff.
1311 GMT (9:11 a.m. EDT)
T+plus 2 minutes, 45 seconds. Reaction control system has been activated.
1311 GMT (9:11 a.m. EDT)
T+plus 2 minutes, 35 seconds. Atlas continues tracking on course.
1311 GMT (9:11 a.m. EDT)
T+plus 2 minutes, 30 seconds. Atlas now weighs half of what it did at liftoff.
1311 GMT (9:11 a.m. EDT)
T+plus 2 minutes, 15 seconds. Vehicle systems looking good.
1310 GMT (9:10 a.m. EDT)
T+plus 1 minutes, 45 seconds. The RD-180 main engine continues to fire normally, burning a mixture of highly refined kerosene and liquid oxygen.
1310 GMT (9:10 a.m. EDT)
T+plus 100 seconds. Now passing through the region of maximum aerodynamic pressure on the vehicle as its accelerates through the dense lower atmosphere.
1310 GMT (9:10 a.m. EDT)
T+plus 85 seconds. All looks good aboard Atlas as it passes Mach 1.
1310 GMT (9:10 a.m. EDT)
T+plus 60 seconds. One minute into the ascent of NROL-33.
1309 GMT (9:09 a.m. EDT)
T+plus 40 seconds. The Atlas 5 is sending a thunderous roar across Florida's spaceport as it climbs into a clear night sky over Cape Canaveral.
1309 GMT (9:09 a.m. EDT)
T+plus 15 seconds. The Atlas 5 rocket has cleared the tower on 860,000 pounds of thrust from the RD-180 main engine. Pitch, yaw and roll maneuvers are underway to put the rocket on the proper heading.
1309 GMT (9:09 a.m. EDT)
LIFTOFF! Liftoff of the Atlas 5 rocket, supporting the National Reconnaissance Office with the practical benefits of space. And the vehicle has cleared the tower!
1308 GMT (9:08 a.m. EDT)
T-minus 20 seconds. "Go Atlas" and "Go Centaur" was just called by launch team during a final status check.
1308 GMT (9:08 a.m. EDT)
T-minus 40 seconds. Centaur's liquid oxygen and liquid hydrogen tanks are stable at flight pressures.
1308 GMT (9:08 a.m. EDT)
T-minus 45 seconds. Range is green.
1308 GMT (9:08 a.m. EDT)
T-minus 1 minute. Now 60 seconds away from launch of NROL-33.
1307 GMT (9:07 a.m. EDT)
T-minus 90 seconds. The rocket's safety system has been armed.
1307 GMT (9:07 a.m. EDT)
T-minus 1 minute, 45 seconds. Liquid oxygen and liquid hydrogen propellant topping to the Centaur upper stage is being secured.
1307 GMT (9:07 a.m. EDT)
T-minus 1 minute, 55 seconds. The launch sequencer has been commanded to start.
1307 GMT (9:07 a.m. EDT)
T-minus 2 minutes. The Atlas first stage and Centaur upper stage are now switching from ground power to internal batteries.
1306 GMT (9:06 a.m. EDT)
T-minus 2 minutes, 30 seconds. The first stage RP-1 kerosene fuel tank and the liquid oxygen have stepped up to proper flight pressure levels.
1306 GMT (9:06 a.m. EDT)
T-minus 3 minutes. The Atlas first stage liquid oxygen replenishment is being secured so the tank can be pressurized for launch.
1305 GMT (9:05 a.m. EDT)
T-minus 3 minutes, 50 seconds. The ground pyrotechnics are enabled.
1305 GMT (9:05 a.m. EDT)
T-minus 4 minutes and counting. Clocks have resumed for the final minutes of today's countdown to launch the Atlas 5 rocket with a new spacecraft for the NRO from Cape Canaveral, Florida.
1304 GMT (9:04 a.m. EDT)
Standing by to pick up the count.
1303 GMT (9:03 a.m. EDT)
ULA launch director has given his respective final approvals to resume the countdown.
1302 GMT (9:02 a.m. EDT)
Polling of the team by Atlas launch conductor just occurred. All systems are "go" for a liftoff today at 2:48 p.m. EDT.
1301 GMT (9:01 a.m. EDT)
Standing by for the final readiness check to be conducted. The launch team will be polled for a "go" or "no go" to proceed with the count.
1258 GMT (8:58 a.m. EDT)
This will be...
1255 GMT (8:55 a.m. EDT)
The first stage liquid oxygen tank and Centaur's liquid oxygen and liquid hydrogen tanks are reported at flight level.
1251 GMT (8:51 a.m. EDT)
T-minus 4 minutes and holding. The countdown has entered the planned 14-minute hold to give the launch team a chance to review all systems before pressing ahead with liftoff. The hold is slightly longer to sync up with the new 9:09 a.m. EDT launch time.
1250 GMT (8:50 a.m. EDT)
T-minus 5 minutes. Standing by to go into the final built-in hold.
1244 GMT (8:44 a.m. EDT)
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1240 GMT (8:40 a.m. EDT)
The fuel-fill sequence for the first stage main engine is starting.
1239 GMT (8:39 a.m. EDT)
Just 30 minutes until liftoff time.
1236 GMT (8:36 a.m. EDT)
The final planned weather briefing to launch officials just occurred and the current observed conditions are GO, forecast GO and 100 percent chance of acceptable weather today.
1234 GMT (8:34 a.m. EDT)
Today marks the 46th flight for Atlas 5, born of the Air Force's competition to develop next-generation Evolved Expendable Launch Vehicles. In its previous 44 missions since debuting in August 2002, the tally shows 16 flights dedicated to the Defense Department, 11 for NASA, 9 commercial missions with communications spacecraft and 9 with spy satellites for the National Reconnaissance Office.
1224 GMT (8:24 a.m. EDT)
Now 45 minutes from liftoff.
1218 GMT (8:18 a.m. EDT)
Fast-filling of the first stage liquid oxygen tank has been completed. Topping mode is now underway.
1217 GMT (8:17 a.m. EDT)
The liquid hydrogen tank in the Centaur upper stage just reached the 96 percent level. Topping is now beginning.
1209 GMT (8:09 a.m. EDT)
Now 60 minutes from liftoff. Fueling of the Atlas rocket with cryogenic liquid oxygen and liquid hydrogen is progressing smoothly as the countdown continues on schedule for a liftoff at 9:09 a.m. EDT. Weather remains GO.

If you are heading out to the beach or Port Canaveral to watch the launch, sign up for our Twitter feed to get occasional countdown updates on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

And if you are need tips on picking a good viewing spot, check out this authoritative guide on where to go.

1207 GMT (8:07 a.m. EDT)
Centaur's liquid hydrogen tank is 30 percent full. The cryogenic propellant will be consumed with liquid oxygen by the stage's Aerojet Rocketdyne-made RL10 engine.
1158 GMT (7:58 a.m. EDT)
Chilldown of the liquid hydrogen system has been accomplished. The launch team has received the "go" to begin filling the Centaur upper stage with the supercold fuel.
1150 GMT (7:50 a.m. EDT)
First stage liquid oxygen tank is 40 percent full thus far. Chilled to Minus-298 degrees F, the liquid oxygen will be used with RP-1 kerosene by the RD-180 main engine on the first stage during the initial four minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket prior to today.
1143 GMT (7:43 a.m. EDT)
The first stage liquid oxygen tank has reached the 20 percent mark.
1141 GMT (7:41 a.m. EDT)
The Centaur liquid oxygen tank reached the 96 percent level. The topping off process is starting now.
1137 GMT (7:37 a.m. EDT)
The first stage liquid oxygen loading is transitioning from slow-fill to fast-fill mode.
1133 GMT (7:33 a.m. EDT)
The chilldown conditioning of liquid hydrogen propellant lines at Complex 41 is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket. The Centaur holds about 12,300 gallons of the cryogenic propellant.
1132 GMT (7:32 a.m. EDT)
Centaur liquid oxygen is 75 percent loaded.
1128 GMT (7:28 a.m. EDT)
The conditioning of the systems for the first stage liquid oxygen tank have been completed. And a "go" has been given to begin pumping supercold liquid oxygen into the Atlas 5's first stage.

The Common Core Booster stage's liquid oxygen tank is the largest tank to be filled today. It holds 48,750 gallons of cryogenic oxidizer for the RD-180 main engine.

1122 GMT (7:22 a.m. EDT)
Passing the 30 percent level on the Centaur upper stage's liquid oxygen tank.
1112 GMT (7:12 a.m. EDT)
Filling of the Centaur upper stage with about 4,100 gallons of liquid oxygen has begun at Cape Canaveral's Complex 41 following the thermal conditioning of the transfer pipes.

The liquid oxygen -- chilled to Minus-298 degrees F -- will be consumed during the launch by the Centaur's single RL10 engine along with liquid hydrogen to be pumped into the stage a little later in the countdown.

1111 GMT (7:11 a.m. EDT)
NEW LAUNCH TIME. Liftoff has been adjusted slightly to 9:09 a.m. EDT. The change was due to a COLA or Collision Avoidance cutout that prohibits liftoff at the opening of the window today.
1105 GMT (7:05 a.m. EDT)
The Centaur liquid oxygen pad storage area has been prepped. The next step is conditioning the transfer lines, which is now beginning to prepare the plumbing for flowing the cryogenic oxidizer.
1055 GMT (6:55 a.m. EDT)
T-minus 120 minutes and counting! The launch countdown has resumed for today's flight of the Atlas 5 rocket on the NROL-33 mission.

Clocks have one more built-in hold planned at T-minus 4 minutes. That pause will last 10 minutes during which time the final "go" for launch will be given. All remains targeted for liftoff at 9:05 a.m. EDT from Cape Canaveral's Complex 41.

In the next couple of minutes, chilldown thermal conditioning of the mobile launch platform upon which the rocket stands will begin. This is meant to ease the shock on equipment when supercold cryogenic propellants start flowing into the rocket.

1052 GMT (6:52 a.m. EDT)
All console operators have reported GO status during the pre-fueling readiness poll. The ULA launch director also voiced his approval for moving forward with the countdown as scheduled today.

Loading of cryogenic liquid oxygen and liquid hydrogen into the Atlas 5 rocket will be getting underway a short time from now.

1050 GMT (6:50 a.m. EDT)
The ULA launch conductor at the Atlas Spaceflight Operations Center is briefing his team on procedures before entering into the final two hours of the countdown.
1040 GMT (6:40 a.m. EDT)
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1025 GMT (6:25 a.m. EDT)
T-minus 2 hours and holding. The countdown has just entered the first of two planned holds over the course of the day that will lead to the 1:45 p.m. EDT launch of the Atlas 5 rocket.

This initial pause was designed to give the team some margin in the countdown timeline to deal with technical issues or any work that could fall behind schedule before fueling starts. But all is going smoothly today, with officials not reporting any troubles in the count.

The final hold will occur at T-minus 4 minutes.

0930 GMT (5:30 a.m. EDT)
The hazard area roadblocks around the launch site's safety perimeter have been established. Also, the launch team is configuring the pad's water deluge system.
0700 GMT (3:00 a.m. EDT)
In today's first weather briefing to mission managers, all current conditions are observed GO for launch of the Atlas 5 rocket and odds for the 9:05 a.m. EDT liftoff time stand at 90 percent favorable.
0650 GMT (2:5- a.m. EDT)
The Atlas-Centaur rocket has been powered up at Complex 41 and guidance system testing is getting started for today's launch, as the countdown progresses as planned.
0605 GMT (2:05 a.m. EDT)
The countdown begins now for the mid-day launch of the Atlas 5 rocket to deploy the National Reconnaissance Office's NROL-33 satellite for intelligence-gathering.

Clocks are picking up the seven-hour sequence of work that will prepare the booster, payload and ground systems for blastoff at 9:05 a.m. EDT (1305 GMT).

Soon the launch team will begin powering up the rocket to commence standard pre-flight tests. Over the subsequent few hours, final preps for the Centaur's liquid oxygen and liquid hydrogen systems will be performed, along with a test of the rocket's guidance system and the first stage propulsion and hydraulic preps, internal battery checks and testing of the C-band system used to track the rocket as it flies downrange, plus a test of the S-band telemetry relay system. The Complex 41 site will be cleared of all personnel at 6:10 a.m.

A planned half-hour hold begins at 6:25 a.m. when the count reaches T-minus 120 minutes. Near the end of the hold, the team will be polled at 6:53 a.m. to verify all is in readiness to start fueling the rocket for launch.

Supercold liquid oxygen begins flowing into the Centaur upper stage around 7:12 a.m., followed by the first stage filling around 7:25 a.m. Liquid hydrogen fuel loading for Centaur will be completed a short time later.

A final hold is scheduled at the T-minus 4 minute mark starting at 8:51 a.m. That 10-minute pause will give everyone a chance to finish any late work and assess the status of the rocket, payload, Range and weather before proceeding into the last moments of the countdown.

The launch window opens at 9:05 a.m. EDT (1305 GMT).

WEDNESDAY, MAY 21, 2014
Under siege in recent weeks by critics of its main engine and pricing, an Atlas 5 rocket plans to persevere Thursday with a mid-morning blastoff carrying a classified intelligence cargo into orbit.

Read our launch preview story.

1750 GMT (1:50 -.m. EDT)
The weather outlook for Thursday morning's launch of an Atlas 5 rocket from Cape Canaveral has improved to 90 percent favorable.

"On launch day, high pressure persists over Central Florida with fair weather conditions, a loose pressure gradient, and light winds. Although slight, the primary concern for launch is Cumulus Clouds," Air Force forecasters report.

The specifics include a few low clouds, scattered high clouds, good visibility, southwesterly winds of 6 to 10 knots and a temperature 73-76 degrees F.

TUESDAY, MAY 20, 2014
1510 GMT (11:10 a.m. EDT)
A photo gallery of today's rollout is posted here.
1437 GMT (10:37 a.m. EDT)
The Atlas 5 rocket stands atop its launch pad at Cape Canaveral for blastoff Thursday morning to deploy a classified satellite for the U.S. National Reconnaissance Office.

Thursday's available launch opportunity begins at 9:05 a.m. EDT.

The United Launch Alliance booster was rolled out to the Complex 41 pad shortly after 10 a.m. EDT today aboard a mobile platform, emerging from the assembly building where the rocket's two stages and the payload were integrated over the past month.

The 19-story-tall rocket is flying the 401 vehicle configuration for the 22nd time in 46 flights. The version features just two stages, no solid rocket boosters and a four-meter-diameter nose cone. It is powered off the launch pad by an RD AMROSS RD-180 main engine and the Centaur upper stage is equipped with an Aerojet Rocketdyne RL10.

Weather forecasters continue to project an 80 percent chance of favorable conditions for liftoff.

A reminder that if you will be away from your computer but would like to receive occasional countdown updates, sign up for our Twitter feed to get text message updates on your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

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1404 GMT (10:04 a.m. EDT)
The United Launch Alliance Atlas 5 rocket's rollout to the pad is underway!

This slow half-hour drive from the 30-story Vertical Integration Facility to Cape Canaveral's Complex 41 pad uses a pair of specially-made "trackmobiles" to carry the rocket's 1.4-million pound mobile launching platform along rail tracks for the 1,800-foot trip.

The 20-story-tall satellite booster is moving to Cape Canaveral's Complex 41 for launch of the NROL-33 mission.

The two-stage rocket and the payload were put together inside the assembly building over the past month in preparation for this rollout event. The Atlas 5 is designed to spend minimal time at the launch pad, which does not include a service gantry like other sites.

For tips on taking pictures of the launch, see our photography guide.

For details on where the best spots are to see the launch, see the viewing guide.

And if you will be away from your computer but would like to receive occasional updates, sign up for our Twitter feed to get text message updates sent to your cellphone. U.S. readers can also sign up from their phone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)

MONDAY, MAY 19, 2014
The Launch Readiness Review was held today and reported all systems are GO for liftoff of the Atlas 5 rocket on Thursday.

Liftoff is planned for 9:05 a.m. EDT. The unclassified "launch period" extends until 10:15 a.m. EDT.

The rocket will be rolled from its assembly building to the launch pad at Cape Canaveral's Complex 41 on Tuesday morning at 10 a.m. EDT. The countdown begins Thursday morning at 2 a.m. EDT, followed by the start of fueling at 7 a.m. EDT.

The weather forecast calls for an 80 percent chance of acceptable conditions, with a slight chance of coastal showers.

SUNDAY, MAY 18, 2014
The outlook for Thursday morning's launch of an Atlas 5 rocket from Cape Canaveral is favorable with an 80 percent chance of acceptable conditions.

"Relatively dry conditions and favorable weather expected through the week," Air Force forecasters report.

"For MLP roll on Tuesday, there is a small threat of an isolated coastal shower. Light winds from the northeast during the roll period are expected with a gradual increase through the afternoon with gust in the upper teens.

"Weather remains favorable on Wednesday during the exposure with on-shore winds in the mid-teens and a small coastal shower threat.

"On launch day, high pressure and fair weather persists over Central Florida with a loose pressure gradient and light winds. Although slight, the primary concern for launch is Cumulus Clouds associated with coastal showers with on-shore winds in the low levels of the atmosphere."

The specifics include a few low clouds, scattered high clouds, good visibility, southwesterly winds of 6 to 10 knots and a temperature 72-74 degrees F.

"In the event of a 24-hour delay, similar conditions persist with high pressure and fair weather over Central Florida. The primary concerns for a 24-hour delay are Cumulus Clouds coming in off the Atlantic," forecasters say.