Live coverage: Atlas 5 countdown and launch journal

Live coverage of the United Launch Alliance Atlas 5 rocket flight to deploy the WorldView 4 imaging satellite. Text updates will appear automatically below; there is no need to reload the page. Follow us on Twitter.

VIDEO: Previewing tomorrow's WorldView 4 launch from California atop Atlas 5 rocket https://t.co/FF5UuunZRE
(Lockheed Martin video) pic.twitter.com/IGsL1s6tf7

— Spaceflight Now (@SpaceflightNow) 11 de noviembre de 2016

LRR: Countdown clocks will begin ticking in the middle-of-the-night Friday morning to ready an Atlas 5 rocket at America's western spaceport to launch a commercial Earth-imagery observatory.

The Launch Readiness Review today formally gave approval to proceed into countdown operations at Vandenberg Air Force Base in California to deploy the WorldView 4 satellite for DigitalGlobe.

Friday's liftoff is targeted for 10:30 a.m. local time (1:30 p.m. EST; 1830 GMT) at the opening of a 15-minute launch opportunity.

A live launch webcast can be viewed on this page.

Air Force meteorologists, as of this morning, now give 90 percent odds that the weather will allow the launch to occur. High pressure has been dominant over the region for the past several days, keeping a weather system to the northwest. At launch time Friday, the forecast calls for mostly clear skies with just some high-level cirrus, light south‐southeasterly winds of 5 to 8 knots and temperatures between 67 and 72 degrees F.

"Team V is thrilled to be launching again following the devastating wildfires we experienced in September. We are excited to launch the Atlas 5 WorldView 4 mission from Vandenberg's Western Range and are looking forward to a safe and successful mission," said Col. Chris Moss, 30th Space Wing commander at Vandenberg and the launch decision authority.

It will be the 12th Atlas 5 to fly from Vandenberg.

The launch countdown begins at 2:30 a.m. local time for the start of an eight-hour sequence to prepare the launch pad and rocket for flight.

This is United Launch Alliance's 112th flight, the 9th just this year, and the company's 19th for a commercial client.

Live coverage: New space station crew counting down to liftoff

Live coverage of the Expedition 48 mission on the International Space Station

he three-person crew has boarded the Soyuz MS-01 spacecraft at Launch Pad No. 1 at the Baikonur Cosmodrome for liftoff at 0136:41 GMT (9:36:41 p.m. EDT).

The crew is led by Anatoly Ivanishin, a 47-year-old retired Russian Air Force fighter pilot who is making is second trip into space. Ivanishin was selected a cosmonaut in 2003 and completed initial training in 2005, then spent 165 days on the International Space Station in 2011 and 2012.

Ivanishin will occupy the capsule's center seat, with Japanese flight engineer Takuya Onishi and NASA astronaut Kate Rubins flanking him in the left and right couches.

Onishi will be the primary flight engineer, assisting Ivanishin with control duties during the launch and docking, which is set for 0412:02 GMT (12:12:02 a.m. EDT) Saturday.

Making his first spaceflight, the 40-year-old Onishi will become the 11th Japanese citizen to fly in space. Before his selection as an astronaut in 2009, Onishi was a Boeing 767 co-pilot for All Nippon Airways. He earned a Bachelor's degree in aeronautical and space engineering from the University of Tokyo in 1998.

NASA astronaut Kate Rubins, 37, is also launching on her first mission into orbit.

Born in Farmington, Connecticutt, and raised in Napa, California, Rubins received a Bachelor of Science degree in Molecular Biology from the University of California, San Diego, in 1999 and a Ph.D. in Cancer Biology in 2005 from Stanford University Medical School's Biochemistry Department and Microbiology and Immunology Department.

She worked for the U.S. Army Medical Research Institute of Infectious Diseases and the Centers for Disease Control and Prevention, and developed the first model of smallpox infection. Rubins later joined the Whitehead Institute for Biomedical Research at MIT, traveling to Africa to research therapies for the Ebola, Marbug and Lassa Fever viruses.

The trio are scheduled to spend 115 days in orbit -- and 113 days on the space station -- before coming back to Earth on Oct. 30.

http://spaceflightnow.com

Live coverage: Falcon 9 launch scrubbed

Live coverage of the countdown and launch of a SpaceX Falcon 9 rocket from Cape Canaveral with the Thaicom 8 communications satellite. Text updates will appear automatically below; there is no need to reload the page. Follow us on Twitter

19:56

SpaceX chief executive Elon Musk says the issue being analyzed during this evening's countdown was with the Falcon 9's second stage Merlin engine

"There was a tiny glitch in the motion of an upper stage engine actuator. Probably not a flight risk, but still worth investigating," Musk tweeted

19:41 SCRUB

SpaceX has called off tonight's launch attempt and reset liftoff for no earlier than Friday at approximately 5:40 p.m. EDT (2140 GMT).

19:36 T-minus 60 minutes

One hour away from launch. SpaceX has not provided any more update on the nature of the issue that caused the delay from the opening of tonight's window, or if the data review is complete and satisfactory.

Chilldown of the pad's liquid oxygen system has started.

19:02

The SpaceX launch team just adjusted the target launch time four minutes earlier to 7:36 p.m. EDT (2336 GMT).

18:59 New launch time

SpaceX has reset tonight's Falcon 9 launch for 7:40 p.m. EDT (2340 GMT), at the end of tonight's window, assuming the issues that caused the earlier delay are resolved.

18:51

SpaceX has not yet set a new launch time this evening. The countdown remains in a hold at this moment.

18:23

SpaceX says the countdown clock is holding because the "launch team (is) finalizing review of vehicle data and check outs."

18:19

DELAY. The Falcon 9 rocket will not lift off as scheduled at 5:40 p.m. EDT (2140 GMT). The countdown is holding, but officials have not disclosed the reason for the pause.

This evening's launch window extends to 7:40 p.m. EDT (2340 GMT).

18:17

Fueling of the Falcon 9 rocket should have started more than 10 minutes ago, but SpaceX has not confirmed the milestone.

18:17

Fueling of the Falcon 9 rocket should have started more than 10 minutes ago, but SpaceX has not confirmed the milestone yet.

17:59 Falcon 9 targets "supersynchronous" orbit

SpaceX's Falcon 9 rocket will aim for an elongated "supersynchronous transfer orbit" on today's mission.

The Thaicom 8 satellite has a relatively light launch mass of 6,669 pounds (3,025 kilograms), according to its Bangkok-based owner.

The heavy-lifting capacity of the Falcon 9 allows the rocket to place it in an orbit with an apogee, or high point, of approximately 90,000 kilometers (nearly 56,000 miles) and a perigee, or low point, of 250 kilometers (124 miles), Thaicom tells Spaceflight Now.

17:52

T-minus 48 minutes. 

Coming up on several major milestones in the countdown, beginning with a poll of the launch team at T-minus 38 minutes and the start of propellant loading at T-minus 35 minutes.

17:38

SpaceX will attempt to land the 156-foot-tall first stage of the Falcon 9 rocket downrange aboard a recovery vessel, extending the company's experiments with rocket re-entry and reusability.

The drone ship, christened "Of Course I Still Love You," is positioned about 420 miles (680 kilometers) east of Cape Canaveral in the Atlantic Ocean.

SpaceX says a successful landing is challenging on this mission because of the higher speed the rocket needs to reach with the Thaicom 8 communications satellite, which is heading toward an orbit with a high point thousands of miles above Earth.

"Following stage separation, the first stage of Falcon 9 will attempt an experimental landing on the 'Of Course I Still Love You' droneship," SpaceX said in a statement. "As with other missions going to geostationary orbits, the first-stage will be subject to extreme velocities and re-entry heating, making a successful landing challenging."

SpaceX successfully landed a rocket on the drone ship for the first time April 8 after a launch from Cape Canaveral with a Dragon supply ship. That mission went into low Earth orbit on the way to the International Space Station.

The Falcon 9's last launch May 6 ended with another successful landing at sea, with the booster surviving a scorching atmospheric re-entry after launching the JCSAT 14 communications satellite. That was the first Falcon 9 intact recovery on a geostationary mission.

The above photo of the drone ship was taken before a previous launch

17:17

The U.S. Air Force Eastern Range has finished hold-fire checks with the Falcon 9 rocket

The Falcon 9 countdown is significantly changed with the upgraded version of the rocket

While radio checks and flight termination system tests complete, fueling of the rocket with its propellant mixture of RP-1 rocket-grade kerosene and liquid oxygen will not begin until about a half-hour before the launch, instead of at about T-minus 3 hours on earlier Falcon 9s.

The upgraded Falcon 9 consumes a chilled propellant mix that allows engineers to load additional fuel into the rocket. The cryogenic liquid oxygen is chilled closer to its freezing point, from minus 298 degrees Fahrenheit to minus 340 degrees, while the RP-1 fuel is cooled from a more standard room temperature of about 70 degrees Fahrenheit to 20 degrees, according to SpaceX founder Elon Musk.

The change essentially permits the volume of the Falcon 9 fuel tanks, which are also slightly enlarged on this launch, to hold more mass of propellant, giving the rocket more performance.

The Merlin engines on the first and second stages will also produce more thrust. At liftoff, the nine-engine first stage will generate 1.5 million pounds of thrust, up from 1.3 million force-pounds on the Falcon 9's previous version.

The second stage engine is also modified with a bigger nozzle, and the stage separation system includes a new pusher device to help guide the first stage as it is jettisoned, ensuring no recontact.

Taken together, the modifications allow the Falcon 9 to carry heavier satellites into orbit and still attempt booster landings on the coast or on an ocean-going barge. This afternoon's launch will target a landing on a barge 420 miles (680 kilometers) offshore in the Atlantic Ocean.

17:05

The SpaceX launch team reports they have completed checks of the Falcon 9 rocket's flight termination system, which would be used to destroy the rocket if it flew off course.

16:41

A check of all SpaceX launch team stations at T-minus 2 hours indicates all is ready to proceed with tonight's flight.

Checks of the rocket's propulsion system are in work, and there are no open issues being tracked at this point in the countdown. The launch pad has also been cleared for this afternoon's liftoff.

16:05

SpaceX's launch crew is evacuating the pad at Cape Canaveral as the countdown ticks toward liftoff at 5:40 p.m. EDT (2140 GMT).

The launch window extends for two hours.

The launch team is on console at the launch control center this evening to run the Falcon 9 through prelaunch tests at the Complex 40 launch pad, then begin fueling the two-stage booster with super-chilled kerosene and liquid oxygen propellants about 35 minutes before liftoff.

Forecasters predict favorable weather during this evening's launch window, with a 90 percent chance conditions will be acceptable for liftoff.

Mostly sunny are in the forecast. Winds will be from the east-northeast at 17 to 22 mph, and the temperature at launch time is forecast to be 78 degrees Fahrenheit.

16:00 Processing photos

Thai communications satellite is fastened to the top of SpaceX’s 229-foot-tall Falcon 9 rocket for launch at 5:40 p.m. EDT (2140 GMT) Thursday.

See photos of the Falcon 9 rocket and Thaicom 8 satellite prepared for launch.

04:25 Launch timeline

The Falcon 9 rocket’s fifth flight of the year will take off from Cape Canaveral on Thursday, heaving the Thaicom 8 communications satellite into orbit on an easterly trajectory from Florida’s Space Coast.

It will take about 32 minutes to inject the approximately 6,800-pound (3,100-kilogram) spacecraft into a highly elliptical geostationary transfer orbit on the way to the satellite’s final perch 22,300 miles (35,700 kilometers) at 78.5 degrees east longitude over the equator.

See more details in this launch timeline.

03:48

SpaceX is counting down to the 25th launch of a Falcon 9 rocket Thursday at 5:40 p.m. EDT (2140 GMT). The commercial booster will haul up the Thaicom 8 television broadcasting satellite from Cape Canaveral and attempt another landing on SpaceX's recovery platform in the Atlantic Ocean.

The 229-foot-tall (70-meter) rocket will be making its fifth flight of the year, and second launch for Thaicom, a Bangkok-based satellite operator providing television broadcast and data services over the Asia-Pacific.

Thursday evening's liftoff is also the second Falcon 9 flight this month for SpaceX.

The weather outlook issued Wednesday by the U.S. Air Force's 45th Weather Squadron indicates a 90 percent chance of acceptable conditions during the two-hour launch window.

http://spaceflightnow.com

Live coverage: Soyuz launch from French Guiana delayed to Saturday

Live coverage of the countdown and launch of a Soyuz rocket from French Guiana with Europe’s Sentinel 1B radar Earth observation satellite, France’s Microscope relativity probe and three CubeSats from Belgium, Italy and Denmark

13:59 SCRUB

Bad weather over the Guiana Space Center will keep the Soyuz rocket on the ground today, officials said.

Unacceptable high-altitude winds over the spaceport exceeded safety constraints for today's flight with five European satellites.

The launch has been rescheduled for 2102 GMT (5:02 p.m. EDT; 6:02 p.m. French Guiana time) Saturday, when weather conditions are forecast to be better.

07:34 Five European satellites ready for Soyuz flight to custom orbits

The term “direct flight” will go to new heights Friday with a four-hour flight by a Soyuz rocket and its Fregat upper stage to deliver five satellites to three distinct orbital destinations hundreds of miles above Earth.

The Russian Soyuz booster — crowned by a Fregat upper stage — is set for liftoff at 2102:13 GMT (5:02:13 p.m. EDT) Friday from the Guiana Space Center, a European-run spaceport on the northern shore of South America.

07:33 Norsat 1 grounded

Officials from the Norwegian Space Center are looking for another launch opportunity for a microsatellite designed to track ship traffic and study space weather after engineers determined it could not safely be attached to a Soyuz rocket set for liftoff Friday.

Officials decided to keep the Norsat 1 spacecraft on the ground earlier this month. Such a decision is rare so close to a launch.

http://spaceflightnow.com

Falcon 9 rocket poised for launch Friday

launch of a Falcon 9 rocket from Cape Canaveral with SpaceX’s eighth operational Dragon resupply flight to the International Space Station

#ICYMI, @SpaceX #Dragon is headed to @Space_Station w/ habitat prototype, medical research: https://t.co/ZpU8qIR8Y3https://t.co/hIOQt7aJym

— NASA (@NASA) 8 de abril de 2016

A Falcon 9 rocket sits on its launch pad this week awaiting liftoff Friday at 2043 GMT (4:43 p.m. EDT). Credit: SpaceX

SpaceX ready to return to the space station

Ground crews loaded time-critical experiments, including 20 mice to help scientists study muscle atrophy, into SpaceX’s commercial Dragon cargo capsule Thursday, a day before a launch planned from Cape Canaveral toward the International Space Station.

The last-minute additions to the Dragon spacecraft’s pressurized cabin also include fresh food and other goodies for the space station’s six-man crew. The rocket will be rotated vertical on its launch pad overnight.

Liftoff is set for 4:43:32 p.m. EDT (2043:32 GMT) from Cape Canaveral’s Complex 40 launch pad, roughly the moment the plane of the space station’s orbit passes over the Central Florida rocket facility.

The two-stage, 213-foot-tall rocket will release the Dragon spacecraft in orbit about 10 minutes later, then the supply ship will extend two power-generating solar array wings and begin pursuing the station, aiming for arrival early Sunday.

NASA astronaut Jeff Williams and European Space Agency flight engineer Tim Peake will grapple the gumdrop-shaped Dragon capsule around 7 a.m. EDT (1100 GMT) Sunday as it flies in formation just underneath the orbiting research complex.

The commercial delivery by SpaceX will be the fourth mission to fly to the space station in three weeks, coming after the arrival of a fresh three-man crew on a Soyuz capsule, and resupply flights by Russia’s Progress refueling freighter and Orbital ATK’s Cygnus cargo carrier.

“One of the biggest things from an on-orbit operations point-of-view is the fact that this will bring to a close a very busy season of visiting vehicles,” said Kirk Shireman, NASA’s space station program manager at the Johnson Space Center in Houston. “When Dragon arrives on Sunday morning, it’ll close a series of four visiting vehicles in four consecutive weeks.”

For managers in charge of keeping the space station stocked with supplies, the rapid-fire cadence of visiting spaceships is welcome news.

“It’s very important to have a very regular supply chain, not only from a consumables standpoint, but even more importantly from the standpoint of research and utilization,” Shireman said. “It’s critical that we have a constant supply chain coming up and coming back down.”

For SpaceX, the launch marks the Dragon’s first flight since a rocket failure in June 2015 destroyed a cargo carrier heading for the space station. The last Dragon mission to reach the outpost was in April last year.

File photo of a Dragon spacecraft during a rendezvous with the International Space Station. Credit: NASA

The space station’s other two principal resupply vessels — the Cygnus and the Progress — were lost in launch failures in the months preceding SpaceX’s mishap last year. Astronauts and cosmonauts had to delve into their food reserves while the spaceships were grounded, but Shireman said the research lab is now in the best shape it’s been in since the rash of cargo launch failures disrupted the supply chain.

“This flight in particular is important to our overall research program on the ISS,” said Julie Robinson, NASA’s program scientist for the International Space Station. “SpaceX is a workhorse for us, carrying many late-load payloads. This capability allows us to conduct important biological research with live animals.”

Another much-needed capability only offered by SpaceX’s Dragon is its capacity to bring back research specimens, such as urine and blood samples from the astronauts, and plant and animal tissue from other biological experiments.

“Not only will we be carrying an enormous amount of cargo up to the International Space Station, we’ll bring down critical science samples as well as failed hardware from the ISS, as well as removing some trash,” Shireman said.

The Dragon spaceship will launch with 6,913 pounds (3,136 kilograms) of cargo.

Nearly half of the supply load’s weight comes from a novel experimental habitat built by Bigelow Aerospace, an entrepreneurial firm based in North Las Vegas, Nevada.

Founded by real estate investor Robert Bigelow, the company has aspirations to build a commercial space station in Earth orbit using expandable modules that can launch inside tight volumes, then deploy and inflate to full size in space.

The Bigelow Expandable Activity Module, or BEAM, will ride to the station inside the Dragon cargo craft’s rear trunk section. After arrival, the space station’s robotic arm will grab the module and move it to an attach point on the complex.

The soft-sided module will be inflated and pressurized in late May or early June for a two-year test run to see how well it withstands the harsh environmental of space with extreme temperature swings and the threat of impacts by micrometeoroids and tiny fragments of space junk.

Technicians install the Bigelow Expandable Activity Module into the trunk of the Dragon spacecraft. Credit: SpaceX

More than 1,400 pounds of science experiments will fly to the station inside the Dragon spaceship’s internal compartment.

They include a habitat with 20 female mice for an experiment developed by Eli Lilly, the Indiana-based pharmaceutical firm, to investigate how an antibody made in the company’s laboratories might inhibit muscle loss.

“This experiment has implications for spaceflight and longer-term space missions, but for us, the interest is because of patients on Earth who have muscle-wasting diseases,” said Rosamund Smith, Eli Lilly’s principal investigator for the muscle atrophy experiment. “This can be things ranging from ALS, muscular dystrophy, some types of cancer and even the frail elderly undergo muscle-wasting, and there are many similarities between the muscle-wasting that occurs on Earth in those disaseaes and that (which) occurs in space.”

Astronauts will help collect data on the function of the mice’s muscles, then euthanize the specimens and prepare tissue samples for return to Earth aboard the Dragon spacecraft when it comes home May 11.

The returning Dragon will also come back with blood and urine samples collected from astronaut Scott Kelly, who completed a nearly year-long expedition on the space station in early March.

NASA hopes to study how the 340-day mission affected Kelly’s physiology in preparation for even longer voyages to Mars.

SpaceX targets drone ship for Falcon 9 booster landing

SpaceX engineers will again attempt to recover the Falcon 9 rocket’s first stage after Friday’s liftoff from Cape Canaveral.

An ocean-going platform departed a mooring at Port Canaveral earlier this week, heading for the planned landing point about 185 miles (300 kilometers) northeast of the launch pad.

Officials hope to master rocket landings on the barge — called a drone ship by SpaceX — as the company intends to ramp up its launch rate and start flying used boosters in a bid to cut the cost of its missions.

Congrats to the @SpaceX team & @ElonMusk! Way to stick the landing & send #Dragon to @Space_Station. https://t.co/TCJCQljJBZ

— NASA (@NASA) 8 de abril de 2016

Hans Koenigsmann, SpaceX’s vice president of flight reliability, said the company hopes to prove it can recover rockets on the drone ship following a successful return-to-launch-site landing demonstration after a blastoff in December.

“On this particular flight, we decided we wanted to go for the drone ship and see if we could get a successful landing on the drone ship, partly also because the next two or three flights are going to be drone ship landings — there’s no choice there,” Koenigsmann told reporters Thursday. “It’s a good opportunity for us to refine our drone ship landing capabilities and get this done because in the long run, that’s certainly something we need to demonstrate over and over again to get the first stages back.”

File photo of SpaceX’s rocket landing platform. Credit: SpaceX

Koenigsmann said SpaceX can retrieve the first stage at a landing site onshore after about one-third to one-half of Falcon 9 flights. The rocket is not technically capable of returning to the coast after heaving hefty satellites into high-altitude orbits, such as large telecommunications satellites.

The rocket is traveling too fast on such missions to turn around and come back to land. That is when the drone ship is required, allowing the first stage booster to continue arcing downrange.

SpaceX’s landings at sea have not been successful to date.

The landing platforms are about the size of a football field and require underwater control thrusters to stay in position. Trailing support boats are staffed with engineers and rocket experts to assist with the recovery after landing.

“If you have a drone ship out there, it’s going to be more expensive,” Koenigsmann said. “We know how much that it is. On the flip side, if you land on land, you don’t have to wash it and get the salt off. So there’s less refurbishment on the land side.

“Our goal is to get to very minimal refurbishment at all, and to fly the rockets after an inspection as soon as possible,” he said.

When SpaceX’s behemoth Falcon Heavy launcher begins flying, it will further ease the need for landings at sea. Its two liquid-fueled strap-on boosters, each roughly equivalent to a Falcon 9 first stage, will always be able to return to landing onshore, Koenigsmann said.

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Video: Soyuz crew blasts off en route to space station

Live coverage of the Expedition 47 mission on the International Space Station. Text updates will appear automatically below; there is no need to reload the page.

A Russian Soyuz rocket has reached its last stop before liftoff Friday with two Russian cosmonauts and veteran NASA flight engineer Jeff Williams, who is slated to break the record for the most cumulative time spent in space by a U.S. astronaut.

http://spaceflightnow.com

LIVE: Soyuz rocket to launch Resurs P3 Earth observation satellite

Launch of Resurs-P #3 on Russian Soyuz 2-1B
A Soyuz 2-1B rocket will launch the third Resurs P3 Earth observation satellite from Baikonur Cosmodrome in Kazakhstan on March 13.

The Resurs series of Earth observation satellites are being used for collecting remote data for Russian civilian Earth observation agencies and foreign customers. The Resurs-P satellites are based on their military counterparts and deliver a similar image resolution.

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SPACEX , LAUNCH SES-9

livestream.com

 

   SpaceX

Date

 SpaceX

Unfortunately upper-level winds continue to exceed acceptable limits and are expected to get worse as we approach tonight’s launch window, so we are forgoing today’s launch attempt. Winds are forecast to exceed acceptable limits through Thursday. Our team will continue working with the Air Force’s Launch Weather Officer to evaluate the best available opportunity for flight in the coming days.

SES-9 

Science & Technology / Space · Less event details

Date

Tue, Mar 1 2016 8:35 PM ART — Tue, Mar 1 2016 10:05 PM ART

About

SpaceX’s Falcon 9 rocket will deliver SES-9, a commercial communications satellite for SES, to a Geostationary Transfer Orbit (GTO). SES is a world-leading satellite operator that provides satellite-enabled communications services to broadcasters, Internet service providers, mobile and fixed network operators, and business and governmental organizations worldwide using its fleet of more than 50 geostationary satellites. SpaceX is targeting an evening launch of SES-9 from Space Launch Complex 40 at Cape Canaveral Air Force Station, Fla. The approximately 90-minute launch window opens on February 25 at 6:46 pm ET. The satellite will be deployed approximately 31 minutes after liftoff.

   SpaceX,

  SpaceX,

Falcon 9 with SES-9 satellite are vertical on Pad 40 at Cape Canaveral Air Force Station, Fla.

   SpaceX

Official SpaceX mission patch for the SES-9 mission.

http://livestream.com

Video ,United Launch Alliance Delta 4 rocket carrying the NROL-45

(Launch webcast begins at 3:19 a.m. local (6:19 a.m. EST; 1119 GMT)

Mission Status Center

Live coverage of the United Launch Alliance Delta 4 rocket carrying the NROL-45 payload for the National Reconnaissance Office. Text updates will appear automatically below; there is no need to reload the page. Follow us on Twitter.

0409 GMT (8:09 p.m. local)The 32-story-tall mobile service tower is being retracted from the Delta 4 rocket at Vandenberg's Space Launch Complex 6 pad for today's flight that will place a surveillance satellite into orbit for the U.S. National Reconnaissance Office.

The wheeled structure, a modified piece of hardware from the pad's history as a manned launch site, is moving along rail tracks to its retracted position east of the rocket.

The 13-million-pound gantry shielded the Delta from the elements during the stay on the pad since July, provided workers 360-degree access to the various areas on the vehicle and was instrumental in attaching the strap-on solid motors and the payload during the launch campaign.

Crews will spend the next couple of hours securing the complex for launch before leaving the danger area around the pad. All workers must be clear of the area for the start of hazardous operations in the countdown, which include fueling the vehicle later tonight.

Liftoff remains scheduled for 3:39 a.m. local. The actual length of the day's available launch window to get the rocket airborne today is not disclosed to the public.

TUESDAY, FEBRUARY 9, 2016 Ready to support the national security needs of the country, a Delta 4 rocket is poised for liftoff early Wednesday from California to deliver a classified payload into space.

Liftoff from Vandenberg Air Force Base of the United Launch Alliance rocket is planned for 3:39 a.m. local (6:39 a.m. EST; 1139 GMT).

"Things are looking really great. I was down at the pad this morning, giving the rocket one last look. The weather looks great, we had a beautiful weekend, the weather is great today and the forecast for (Wednesday) is looking really well," Lt. Col. Eric Zarybnisky, 4th Space Launch Squadron commander, said in a telephone interview from Vandenberg on Monday.

"Our final closeout activities are going on today and tomorrow, kind of the normal flow as we pull some of those remove-before-flight pins and items. We've already moved the mobile assembly shelter out of the way. That was done late last week," he added.

This will be the 31st Delta 4 rocket launch since debuting in 2002 and the sixth to fly from Vandenberg.

It's hard to say it is just another Delta. Every rocket is unique. There's a lot of intricacies built in. Each of the missions have their own unique flavor. And there's a lot of folks who come together to make the mission happen. It is hard to say it is just another rocket, because it is rocket science at the end of the day," Zarybnisky said.

The two-stage rocket was rolled from the Horizontal Integration Facility to the pad in July to be hydraulically raised into the vertical position atop the launch table.

A full countdown dress rehearsal and fueling exercise occurred in early November.

The payload, already encapsulated in the rocket's 5-meter nose cone, was lifted from the payload processing facility at Space Launch Complex 6 and transported the short distance to the rocket for mating in mid-January.

Countdown activities will get underway Tuesday evening with retraction of the mobile service gantry and the start of fueling operations that will continue into the early morning of Wednesday.

"This launch will deliver a vital capability to our warfighters and our nation," said Zarybnisky, who will serve as the Air Force launch director.

"There really is no day without space. Launch is the gateway to that high ground. We stress that to our folks every day that hey, this isn’t just another launch. Each one of them is drastically important."

MONDAY, FEBRUARY 8, 2016 PREVIEW: Beginning the National Reconnaissance Office's campaign of four launches in 2016 using boosters big and small to deploy a varied collection of new intelligence satellites, a Delta 4 rocket stands ready for liftoff before sun-up Wednesday from California.

SUNDAY, FEBRUARY 7, 2016 PREVIEW: It was 1986 and the U.S. Air Force was on the cusp of something unprecedented in human spaceflight -- launching a space shuttle crew from California and paving the way for people to fly true polar missions.

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ARIANE FLIGHT VA228, Intelsat 29e

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