MONDAY, APRIL 18, 2011
The National Reconnaissance Office has successfully deployed vital replacement spacecraft over the past seven months to rejuvenate nearly all of its satellite constellations, most recently putting an ocean surveillance duo into orbit last week.
Read our full story.
THURSDAY, APRIL 14, 2011
A whirlwind of national security space launches over the past seven months using six rockets and four pads was completed successfully Thursday night when an Atlas 5 booster soared from California.
The worrisome weather forecast that gave low odds of launching faded from concern as the countdown ticked toward blastoff exactly on schedule at 9:24 p.m. local time.
Thundering from the Space Launch Complex 3-East pad at Vandenberg Air Force Base, the 19-story rocket maneuvered on a coast-hugging trajectory to the south.
A veil of secrecy was draped over the launch about five minutes into flight because of the classified payload being lofted for the National Reconnaissance Office, the agency responsible for designing and operating the country's fleet of intelligence-gathering satellites.
The NRO is marking its 50th year as America's eyes and ears in space to collect imagery and information.
Neither the identity nor the purpose of the new craft launched Thursday night has been revealed. It rode a 411-version of the Atlas 5 that's equipped with a four-meter-diameter nose cone, just one strap-on solid booster and a single-engine Centaur upper stage.
This capped a six-launch surge carrying new NRO satellites that began and ended with clandestine Atlas 5 flights from Vandenberg.
- An Atlas 5-501 on the NROL-41 mission launched from Vandenberg on Sept. 20
- A Delta 4-Heavy rocket for NROL-32 launched from Cape Canaveral on Nov. 21
- A Delta 4-Heavy rocket for NROL-49 launched from Vandenberg on Jan. 20
- A small Minotaur 1 rocket for NROL-66 from Vandenberg on Feb. 6
- A Delta 4-Medium+4,2 for NROL-27 from Cape Canaveral on March 11
- And this Atlas 5-411 for NROL-34 from Vandenberg
"It is fitting that NRO celebrates its anniversary in a few months, because today culminates one of the most aggressive launch schedules in our history," Col. Alan Davis, director of the NRO Office of Space Launch, said in a statement Thursday night.
"I am immensely proud of the contractor and government team who came together to support these missions. Their hard work and dedication ensures our nation's critical edge in space well into the next decade."
Five of the flights were conducted by United Launch Alliance and its combined family of Atlas and Delta vehicles. An Orbital Sciences Minotaur booster performed the other launch.
"Today's successful launch of the NROL-34 mission represents a tremendous accomplishment for our national security customer," Jim Sponnick, United Launch Alliance vice president for mission operations, said in a post-flight statement.
"Less than two years ago, this integrated team put in place a very challenging plan to launch five EELV/NRO missions in less than seven months. The combined NRO Office of Space Launch, U.S. Air Force Launch & Range and ULA teams have executed this plan flawlessly, culminating in today's successful launch aboard our 25th Atlas 5 rocket," he continued.
"With each of these incredibly important launches, we are reminded of the role we play in offering enhanced effectiveness and safety to the men and women protecting our country. Congratulations to the ULA team and our government, mission, and supplier partners for making these five successful NRO missions possible."
9:58 p.m. local (12:58 a.m. EDT; 0458 GMT Thurs.)
"The wind cooperated with us this evening enabling us to launch without compromising public safety," Col. Richard Boltz, 30th Space Wing commander, said in a post-launch release. "Without a doubt, every launch is a major feat, and I'm extremely proud of Team Vandenberg for yet another job well done."
9:55 p.m. local (12:55 a.m. EDT; 0455 GMT Thurs.)
Check out these great
streak shots from tonight's Atlas 5 rocket launch!
9:29 p.m. local (12:29 a.m. EDT; 0429 GMT Thurs.)
The Atlas 5 has flown into a scheduled news blackout with jettison of the rocket's payload shroud. The veil of secrecy surrounding the launch of this classified cargo means no further information about the progress of the ascent nor release of the payload will be announced in real-time.
9:28 p.m. local (12:28 a.m. EDT; 0428 GMT Thurs.)
T+plus 4 minutes, 33 seconds. The two-halves of the Atlas 5 rocket nose cone encapsulating the NRO spacecraft have separated.
9:28 p.m. local (12:28 a.m. EDT; 0428 GMT Thurs.)
T+plus 4 minutes, 25 seconds. Centaur ignition! The Pratt & Whitney-made RL10 powerplant is up and running at full thrust.
9:28 p.m. local (12:28 a.m. EDT; 0428 GMT Thurs.)
T+plus 4 minutes, 11 seconds. The RD-180 main engine has completed its burn and shut down. And the Atlas 5's Common Core Booster first stage has been jettisoned!
9:28 p.m. local (12:28 a.m. EDT; 0428 GMT Thurs.)
T+plus 4 minutes, 5 seconds. The RD-180 main engine has completed its burn and shut down. And the Atlas 5's Common Core Booster first stage has been jettisoned!
9:27 p.m. local (12:27 a.m. EDT; 0427 GMT Thurs.)
T+plus 3 minutes, 45 seconds. The engine is throttling down to keep a constant 5'g acceleration.
9:27 p.m. local (12:27 a.m. EDT; 0427 GMT Thurs.)
T+plus 3 minutes, 30 seconds. The RD-180 main engine still firing normally, burning its mixture of highly refined kerosene and liquid oxygen.
9:27 p.m. local (12:27 a.m. EDT; 0427 GMT Thurs.)
T+plus 3 minutes. The Russian-designed RD-180 main engine continues to propel the rocket higher into the sky and further downrange from the launch site.
9:26 p.m. local (12:26 a.m. EDT; 0426 GMT Thurs.)
T+plus 2 minutes, 26 seconds. The Aerojet-made single solid rocket booster has been jettisoned from the Atlas 5 after completing its job of adding extra thrust for liftoff.
9:26 p.m. local (12:26 a.m. EDT; 0426 GMT Thurs.)
T+plus 2 minutes. After returning back to full throttle beyond Max Q, the main engine is easing back to 95 percent thrust.
9:25 p.m. local (12:25 a.m. EDT; 0425 GMT Thurs.)
T+plus 95 seconds. Booster burnout. The lone solid rocket booster has consumed all of its propellant, having provided the Atlas 5 an added kick during the initial climb away from the planet. The spent booster casing will be jettisoned shortly.
9:25 p.m. local (12:25 a.m. EDT; 0425 GMT Thurs.)
T+plus 65 seconds. Atlas has reached Mach 1.
9:25 p.m. local (12:25 a.m. EDT; 0425 GMT Thurs.)
T+plus 60 seconds. One minute into this nighttime ascent by the Atlas 5 from California.
9:24 p.m. local (12:24 a.m. EDT; 0424 GMT Thurs.)
T+plus 55 seconds. The RD-180 main engine is throttling down to 89 percent thrust for passage through the region of maximum aerodynamic pressure.
9:24 p.m. local (12:24 a.m. EDT; 0424 GMT Thurs.)
T+plus 30 seconds. The main engine firing at full throttle and the added thrust from the solid rocket motor generate a combined liftoff thrust of 1.2 million pounds.
9:24 p.m. local (12:24 a.m. EDT; 0424 GMT Thurs.)
T+plus 15 seconds. The 19-story launcher is maneuvering to its southerly trajectory to deliver a secret spy satellite into orbit for the National Reconnaissance Office.
9:24 p.m. local (12:24 a.m. EDT; 0424 GMT Thurs.)
LIFTOFF! Liftoff of the 25th Atlas 5 rocket and another mission dedicated to national service.
9:23 p.m. local (12:23 a.m. EDT; 0423 GMT Thurs.)
T-minus 20 seconds. "Go Atlas" and "Go Centaur" was just called by launch team during a final status check.
9:23 p.m. local (12:23 a.m. EDT; 0423 GMT Thurs.)
T-minus 40 seconds. Centaur's liquid oxygen and liquid hydrogen tanks are stable at flight pressures.
9:23 p.m. local (12:23 a.m. EDT; 0423 GMT Thurs.)
T-minus 1 minute. Now 60 seconds from launch at America's Western Spaceport.
9:22 p.m. local (12:22 a.m. EDT; 0422 GMT Thurs.)
T-minus 90 seconds. The safety system has been armed.
9:22 p.m. local (12:22 a.m. EDT; 0422 GMT Thurs.)
T-minus 1 minute, 50 seconds. Liquid oxygen and liquid hydrogen propellant topping to the Centaur upper stage is being secured.
9:22 p.m. local (12:22 a.m. EDT; 0422 GMT Thurs.)
T-minus 1 minute, 55 seconds. The launch sequencer has been commanded to start.
9:22 p.m. local (12:22 a.m. EDT; 0422 GMT Thurs.)
T-minus 2 minutes. The Atlas first stage and Centaur upper stage are now switching from ground power to internal batteries.
9:21 p.m. local (12:21 a.m. EDT; 0421 GMT Thurs.)
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.
9:21 p.m. local (12:21 a.m. EDT; 0421 GMT Thurs.)
T-minus 3 minutes. The Atlas first stage liquid oxygen replenishment is being secured so the tank can be pressurized for launch.
9:20 p.m. local (12:20 a.m. EDT; 0420 GMT Thurs.)
T-minus 3 minutes, 50 seconds. The ground pyrotechnics have been enabled.
9:20 p.m. local (12:20 a.m. EDT; 0420 GMT Thurs.)
T-minus 4 minutes and counting. Clocks have resumed for the final minutes of tonight's countdown to launch the Atlas 5 rocket carrying a clandestine payload for the National Reconnaissance Office. Liftoff is set to occur at 9:24 p.m. local.
9:19 p.m. local (12:19 a.m. EDT; 0419 GMT Thurs.)
Countdown clocks will resume in one minute.
9:18 p.m. local (12:18 a.m. EDT; 0418 GMT Thurs.)
The launch director and the mission director each have given their approval to press onward with the countdown as well.
9:17 p.m. local (12:17 a.m. EDT; 0417 GMT Thurs.)
All systems are reported "go" to continue with the countdown for liftoff at 9:24 p.m. tonight!
9:16 p.m. local (12:16 a.m. EDT; 0416 GMT Thurs.)
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.
9:12 p.m. local (12:12 a.m. EDT; 0412 GMT Thurs.)
Here's a look at some stats about today's mission. This will be:
- The 607th launch for Atlas program since 1957
- The 288th Atlas to occur from Vandenberg AFB since 1959
- The 37th Atlas to use Space Launch Complex 3
- The 25th launch of an Atlas 5 since 2002
- The fourth Atlas 5 to occur from Vandenberg
- The 17th Atlas 5 under United Launch Alliance
- The third Atlas 5 to fly in the 411 configuration
- The 12th Department of Defense mission on Atlas 5
- The fifth National Reconnaissance Office use of Atlas 5
- The second Atlas launch of 2011
9:10 p.m. local (12:10 a.m. EDT; 0410 GMT Thurs.)
T-minus 4 minutes and holding. The countdown has entered the planned hold to give the launch team a chance to review all systems before pressing ahead with liftoff. Today's launch time is aimed for 9:24 p.m. PDT.
9:09 p.m. local (12:09 a.m. EDT; 0409 GMT Thurs.)
T-minus 5 minutes. Standing by to go into the final built-in hold.
All three cryogenic tanks are reported at flight level.
9:08 p.m. local (12:08 a.m. EDT; 0408 GMT Thurs.)
Weather conditions are acceptable for liftoff at 9:24 p.m. PDT. Although winds have been a worry throughout the countdown, they have eased and are within limits now.
9:04 p.m. local (12:04 a.m. EDT; 0404 GMT Thurs.)
Twenty minutes from liftoff now. The countdown clocks are heading to the T-minus 4 minute mark where a planned 10-minute hold will occur. Launch of Atlas 5 remains scheduled for 9:24 p.m. PDT.
8:58 p.m. local (11:58 p.m. EDT; 0358 GMT)
The fuel-fill sequence for the first stage main engine is underway.
8:55 p.m. local (11:55 p.m. EDT; 0355 GMT)
Tonight's mission for the National Reconnaissance Office is named Odin and the rocket itself is called Frigga.
"The rocket is named Frigga. She is the wife of Odin in Norse mythology. We're continuing our tradition of naming West Coast launches after important mythological or historical women," Lt. Col. Jenns Robertson, the Air Force launch director, said in a pre-flight interview.
8:45 p.m. local (11:45 p.m. EDT; 0345 GMT)
The United Launch Alliance Atlas 5 rocket flying tonight arrived at Vandenberg Air Force Base last autumn to be readied for the NROL-34 mission.
"This particular rocket has been doing quite well in its launch processing. We started processing in late fall when the rocket arrived here on base," Lt. Col. Jenns Robertson, 4th Space Launch Squadron operations officer and the Air Force launch director, said in a recent pre-flight interview.
"We've really seen an increase in processing speed with the past several launches. This is fourth launch of an Atlas 5 from Vandenberg. As the team gains the experience and the expertise of launching these things, they get familiarity with the processes they are running and the way the equipment works and what they have to do to get the job done, you see efficiency gains left, right and center. So we're really proud of how fast this rocket has been processed."
8:40 p.m. local (11:40 p.m. EDT; 0340 GMT)
The liquid hydrogen tank in the Centaur upper stage just reached the 97 percent level. Topping is now beginning.
8:32 p.m. local (11:32 p.m. EDT; 0332 GMT)
The Centaur liquid hydrogen tank is half-way loaded so far. The cryogenic propellant will be consumed with liquid oxygen by the stage's Pratt & Whitney-made RL10 engine.
8:29 p.m. local (11:29 p.m. EDT; 0329 GMT)
Fast-filling of the first stage liquid oxygen has been completed at the tank's 97 percent mark. Topping mode is now underway.
8:24 p.m. local (11:24 p.m. EDT; 0324 GMT)
Now 60 minutes from launch. All activities are proceeding smoothly toward a liftoff at 9:24 p.m. Pacific Time.
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8:20 p.m. local (11:20 p.m. EDT; 0320 GMT)
Chilldown of the liquid hydrogen system is now complete, allowing the super-cold rocket fuel to begin filling the Centaur upper stage.
8:10 p.m. local (11:10 p.m. EDT; 0310 GMT)
First stage liquid oxygen tank is passing the half-full mark. 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 minutes of flight today. The 25,000 gallons of RP-1 were loaded into the rocket earlier.
8:08 p.m. local (11:08 p.m. EDT; 0308 GMT)
Liquid oxygen on Centaur has reached flight level.
8:04 p.m. local (11:04 p.m. EDT; 0304 GMT)
Centaur engine chilldown sequence is being initiated.
8:02 p.m. local (11:02 p.m. EDT; 0302 GMT)
The Centaur liquid oxygen tank reached the 95 percent level and the topping off process is starting.
7:57 p.m. local (10:57 p.m. EDT; 0257 GMT)
The chilldown conditioning of liquid hydrogen propellant lines is starting to prepare the plumbing for transferring the Minus-423 degree F fuel into the rocket. The Centaur holds about 13,000 gallons of the cryogenic propellant.
7:56 p.m. local (10:56 p.m. EDT; 0256 GMT)
The Centaur liquid oxygen tank is 75 percent full now.
7:54 p.m. local (10:54 p.m. EDT; 0254 GMT)
Now 90 minutes from liftoff. There are no reports of technical troubles from the launch team and fingers remain crossed that the winds will end up being just fine tonight.
7:52 p.m. local (10:52 p.m. EDT; 0252 GMT)
The first stage liquid oxygen loading is switching from slow-fill to fast-fill mode as the countdown continues as planned.
7:51 p.m. local (10:51 p.m. EDT; 0251 GMT)
Half of the Centaur liquid oxygen tank has been filled so far.
7:45 p.m. local (10:45 p.m. EDT; 0245 GMT)
The Centaur liquid oxygen tank is nearing a quarter full already.
7:35 p.m. local (10:35 p.m. EDT; 0235 GMT)
Filling of the Centaur upper stage with about 4,300 gallons of liquid oxygen is beginning at Vandenberg's Space Launch Complex 3 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 loaded into the stage a little later in the countdown.
7:29 p.m. local (10:29 p.m. EDT; 0229 GMT)
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 about 50,000 gallons of cryogenic oxidizer for the RD-180 main engine.
7:23 p.m. local (10:23 p.m. EDT; 0223 GMT)
The Centaur liquid oxygen system's 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.
7:14 p.m. local (10:14 p.m. EDT; 0214 GMT)
T-minus 120 minutes and counting! The launch countdown has resumed for this evening's flight of the Atlas 5 rocket following the planned half-hour built-in hold.
Clocks have one more hold scheduled 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 9:24 p.m. local time (12:24 a.m. EDT; 0424 GMT) from Vandenberg Air Force Base, California.
7:11 p.m. local (10:11 p.m. EDT; 0211 GMT)
The launch team and all systems are "ready" to proceed with the countdown and begin fueling the Atlas 5 rocket this evening as planned.
Loading of cryogenic liquid oxygen and liquid hydrogen into the Atlas 5 rocket will be getting underway a short time from now.
7:09 p.m. local (10:09 p.m. EDT; 0209 GMT)
The Atlas launch conductor is briefing his team on procedures before entering into the final two hours of the countdown. A readiness check of the team members is next.
7:04 p.m. local (10:04 p.m. EDT; 0204 GMT)
Check out
some photos of the Atlas 5 rocket taken during tower rollback today.
6:55 p.m. local (9:55 p.m. EDT; 0155 GMT)
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6:44 p.m. local (9:44 p.m. EDT; 0144 GMT)
T-minus 2 hours and holding. The countdown has just entered the first of the planned holds over the course of the evening that will lead to the 9:24 p.m. PDT (12:24 a.m. EDT) launch of the Atlas-Centaur rocket.
This initial pause lasts 30 minutes, giving the team some margin in the countdown timeline to deal with technical issues or any work that is running behind. The final hold is scheduled to occur at T-minus 4 minutes.
Workers have left the pad area in advance of this evening's propellant loading and launch of the Atlas 5 rocket.
6:29 p.m. local (9:29 p.m. EDT; 0129 GMT)
With all the hands-on work now finished at the pad, technicians are clearing Space Launch Complex 3 for the remainder of the countdown.
6:19 p.m. local (9:19 p.m. EDT; 0119 GMT)
The pad crew reports the gantry is parked, closed up and ready for launch.
5:50 p.m. local (8:50 p.m. EDT; 0050 GMT)
The mobile service tower is being secured in its launch position. The ground crew will get its doors closed, plus finish final buttoning up of pad equipment over the next half-hour before all workers clear the pad for the remainder of the countdown.
Today's launch will be the fourth Atlas 5 rocket to fly from Vandenberg's Space Launch Complex 3-East pad. The site underwent an extensive overhaul, with construction occurring in 2004 and 2005, to accommodate the larger and more powerful Atlas 5 family of rockets. Some of the major modifications included:
- 30-foot extension to mobile service tower
- 20-foot exhaust duct depth increase
- 250-ton Fixed Launch Platform installed
- Significant ambient and cryogenic fluid ground system modifications
- Complete replacement of the Ground Command/Control/Communication system
- New and refurbished Launch Control/Mission Support Centers
5:40 p.m. local (8:40 p.m. EDT; 0040 GMT)
Preps for the Atlas first stage liquid oxygen system and pneumatics have been completed. Other work that occurs at this portion of the countdown include Centaur liquid oxygen and liquid hydrogen system final preps, internal battery checks, testing of the C-band system used to track the rocket as it flies downrange and tests of the S-band telemetry links.
5:30 p.m. local (8:30 p.m. EDT; 0030 GMT)
The weather odds remain only 30 percent favorable for launching tonight due to the high winds. But the launch team is going to give it a shot and hope the winds cooperate when the time comes.
5:22 p.m. local (8:22 p.m. EDT; 0022 GMT)
The tower is clear of the vehicle as it continues to slowly roll away. The structure's internal crane was instrumental in bringing the rocket stages, solid motor and payload together. And now the fully assembled Atlas 5 has been unveiled for its 25th launch.
5:11 p.m. local (8:11 p.m. EDT; 0011 GMT)
At the Space Launch Complex 3 pad, the mobile service gantry has been configured for its retraction away from the Atlas 5 rocket this afternoon. Approval has been given to wheel the 8-million-pound tower to its launch position a short distance from the 19-story-tall booster.
4:55 p.m. local (7:55 p.m. EDT; 2355 GMT)
Despite they windy weather on the Central Coast, conditions are acceptable for rolling the mobile service tower and pressing ahead with the countdown for a launch attempt tonight at 9:24 p.m. PDT.
4:24 p.m. local (7:24 p.m. EDT; 2324 GMT)
Now entering the final five hours in this countdown to launch. Centaur's helium bottles have been charged. The flight control preps are complete and the operational test is underway.
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3:50 p.m. local (6:50 p.m. EDT; 2250 GMT)
And the Centaur upper stage now has been pressurized to the proper levels to handle the high winds once the mobile service tower is rolled back.
3:24 p.m. local (6:24 p.m. EDT; 2224 GMT)
Out at Space Launch Complex 3-East, the pad crew is working through its checklist to ready the mobile service tower for rollback later this afternoon. The gantry is the massive building on wheels that is used for assembling the rocket and payload, provides workers full access to the vehicle during the pre-flight campaign, then retracts a few hours before liftoff time to reveal the Atlas.
In preparation for exposing the rocket to the weather, the launch team does plan to implement available "high wind procedures" to ensure the vehicle can safely withstand the gusty conditions at Vandenberg today.
3:03 p.m. local (6:03 p.m. EDT; 2203 GMT)
The Atlas first stage and Centaur upper stage have been powered up as the early portion of the countdown activities rolls onward. Guidance system testing is about to begin now.
1:44 p.m. local (4:44 p.m. EDT; 2044 GMT)
Launch-minus 7 hours, 40 minutes and counting! Clocks have begun ticking for tonight's flight by the Atlas 5 rocket from the western spaceport.
As the countdown gets underway, the launch team will power up the rocket to conduct standard pre-flight tests and ready the vehicle for this national security satellite deployment mission.
Rollback of the mobile service tower from around the rocket is expected about three hours from now, weather permitting. Once the gantry is removed, crews at the pad will make preparations to systems and equipment before the site is cleared of all personnel for fueling.
A planned 30-minute hold begins when the count reaches T-minus 120 minutes at 6:44 p.m. local time. With five minutes remaining in the hold, the team will be polled to verify all is in readiness to start loading propellant into the rocket for launch.
Supercold liquid oxygen begins flowing into the Centaur upper stage around 7:30 p.m. local, followed by the Atlas first stage. Liquid hydrogen fuel loading for Centaur will be completed a short time later.
A final hold is scheduled at 9:10 p.m. when clocks hit the T-minus 4 minute mark. That will give the team 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.
Liftoff remains targeted for 9:24 p.m. local time (12:24 a.m. EDT; 0424 GMT).
11:00 a.m. local (2:00 p.m. EDT; 1800 GMT)
Launch day has arrived for the NROL-34 mission aboard an Atlas 5 rocket from Vandenberg Air Force Base, California. The countdown sequence begins about seven hours before tonight's 9:24 p.m. PDT launch. Watch this page for live updates throughout the evening.
WEDNESDAY, APRIL 13, 2011
For its 25th launch Thursday night, the Atlas 5 rocket takes an unconventional shape that's not too strong and not too weak, but provides just the right amount of power for its payload.
Read our preview story.
TUESDAY, APRIL 12, 2011
With strong winds in the forecast, weather experts aren't gushing with optimism for an on-time launch of the Atlas 5 rocket Thursday night from Vandenberg Air Force Base in California.
Meteorologists are predicting a 70 percent chance that the windy weather will violate the strict launch rules and keep the booster grounded on the pad.
Similar odds are given for the backup launch opportunity available Friday night as well.
A secretive payload for the National Reconnaissance Office is riding aboard the rocket to Earth orbit. The NRO operates the country's fleet of spy satellites to support intelligence gathering and security.
Liftoff time Thursday night is 9:24 p.m. local from Vandenberg's Space Launch Complex 3. The booster will head southward over the Pacific Ocean on the power of its kerosene-fueled main engine and single strap-on solid motor. A cryogenic Centaur upper stage then injects the cargo into desired orbital perch.
Final readiness reviews are planned for Wednesday to give approval to enter into Thursday's countdown operation.
"Our engineering teams are going over the rocket and all the paperwork with a fine-tooth comb to make sure that everything is right and there's nothing that would put the mission at risk," said Lt. Col. Jenns Robertson, 4th Space Launch Squadron operations officer and the Air Force launch director.
"The most important thing for us is we deliver a healthy payload to its intended orbit...So we're going to make sure we do everything right to get there."
The first hurdle the weather will pose Thursday is retracting the mobile service gantry away from the Atlas rocket around 4:30 p.m. local time. The forecast is calling for northwesterly winds of 20 to 25 knots with gusts as high as 35 knots. The limit for rolling the tower is 25 knots, meteorologists report.
The winds are supposed to ease after sunset, dropping to 15-20 knots with gusts of 25 knots by liftoff time. The precise launch limit depends upon the exact direction, but winds can't be greater than 27 knots, officials say.
Otherwise, the outlook includes good visibility, just a few high cirrus clouds and temperatures in the 50s F. It's just a matter of whether the winds will be low enough for the countdown to proceed safely.
Watch this page for live updates during the count and launch!
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