A poll of the SpaceX launch team has given the go for filling of the two-stage launcher with kerosene and liquid oxygen propellants.

SpaceX says rough seas in the downrange booster recovery zone will prevent the Falcon 9 first stage from making a landing on the autonomous spaceport drone ship, a football field-sized barge positioned nearly 400 miles east-northeast of Cape Canaveral.

"The drone ship was designed to operate in all but the most extreme weather," the company said in a statement. "We are experiencing just such weather in the Atlantic with waves reaching up to three stories in height crashing over the decks. Also, only three of the drone ship’s four engines are functioning, making station-keeping in the face of such wave action extremely difficult.

"The rocket will still attempt a soft landing in the water through the storm (producing valuable landing data), but survival is highly unlikely."

Launch remains scheduled for 6:03 p.m. EST (2303 GMT).

There is a 90 percent chance of favorable launch weather today.

"Cloud cover and surface winds have decreased nicely along the Space Coast and are expected to remain favorable through the countdown tonight," the U.S. Air Force's 45th Weather Squadron wrote in a forecast issued this morning. "Upper level winds have also diminished and there is much less shear present over the spaceport compared to yesterday’s vertical profile."

Conditions at launch time are expected to be mostly clear with a few clouds at 2,500 feet, north winds at 12 to 17 mph and a temperature of 58 degrees Fahrenheit.

Upper level winds have "dramatically improved" since yesterday, and high-altitude conditions are currently observed "green" for launch of SpaceX's Falcon 9 rocket.

Liftoff is set for 6:03:32 p.m. EST (2303:32 GMT) in an instantaneous window to send NOAA's Deep Space Climate Observatory to the L1 Lagrange point, an observing post nearly a million miles from Earth. DSCOVR will detect incoming solar storms and monitor Earth's energy budget, while taking multiple full disk images of the day side of the world every 24 hours.

Fueling of the two-stage rocket with rocket-grade kerosene and liquid oxygen should begin just after 3 p.m. EST (2000 GMT).

Tomorrow's launch time is set for 6:03:32 p.m. EST (2303:32 GMT).

SpaceX will drain propellant from the Falcon 9 rocket this evening and put the launcher in a safe configuration ahead of Wednesday's countdown.

The forecast for Wednesday calls for a 90 percent chance of favorable surface weather and improving upper level winds.

SCRUB. The last data on upper level winds continue to show "red" conditions aloft, and SpaceX has halted the countdown and retargeted launch for Wednesday.

T-minus 15 minutes and counting. Here are some statistics on today's launch:

• 15th launch of a Falcon 9 rocket since 2010
• 20th launch of Falcon rocket family since 2006
• 14th Falcon 9 launch from Cape Canaveral
• 10th launch of a Falcon 9 v1.1 rocket
• 9th Falcon 9 v1.1 launch from Cape Canaveral
• 1st launch of an Air Force payload on Falcon 9
• 8th Falcon 9 day launch
• 2nd Falcon 9 launch of 2015
• 2nd launch from Cape Canaveral in 2015

T-minus 17 minutes and counting. The Falcon 9 rocket stands 224 feet tall and measures 12 feet in diameter. At liftoff, its nine Merlin 1D first stage engines will generate about 1.3 million pounds of thrust.

Fully fueled for launch, the Falcon 9 contains about 1.05 million pounds of kerosene and liquid oxygen propellants.

Upper level winds are still no go from the penultimate weather balloon sent aloft during the Falcon 9 countdown. The winds exceed structural loads limits on the booster during ascent.

Ground winds are now gusting above the 30-knot limit for the Falcon 9 rocket.

T-minus 20 minutes and counting. The final poll of SpaceX's 14-person launch team will begin at T-minus 13 minutes before the countdown enters the final phase.

SpaceX expects a final update on upper level winds at T-minus 15 minutes.

The DSCOVR spacecraft is being configured for launch.

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T-minus 30 minutes and counting. Today's launch is timed for exactly 6:05:33.5 p.m. EST (2305:33.5 GMT).

Checks of the rocket's hydraulic systems have been completed, and topping of liquid oxygen is continuing at this point in the countdown.

The Air Force's launch weather officer reports upper level winds remain red and are not expected to change much over the next hour.

Weather at the surface remains favorable, with scattered clouds at 2,000 feet, northwest winds at 20 to 27 mph and a temperature of 59 degrees Fahrenheit.

Weather balloons are sent aloft throughout the countdown to monitor the upper level winds. The final balloon data is expected around 5:50 p.m. EST (2250 GMT).

All four propellant tanks on the Falcon 9 rocket have been filled in this afternoon's countdown. The cryogenic liquid oxygen tanks on the first and second stages will continue to be slowly replenished until the final minutes before launch to replace propellant that gradually boils off due to the warm ambient temperatures in Florida.

NASA TV coverage of today's launch can be seen here at 5 p.m. EST (2200 GMT).

Upper level winds continue to be "red" for this evening's launch, but there is still a chance for conditions to improve later in the countdown.

Testing of the Falcon 9 rocket's flight termination system is complete at this point in the countdown, as fueling of the two-stage launcher is wrapping up.

A final weather briefing is planned at the T-minus 1 hour point in the countdown, but no problems with weather are expected this evening.

It will take about 35 minutes for the Falcon 9 rocket deliver the Deep Space Climate Observatory to its targeted escape trajectory away from Earth. DSCOVR will take 110 days to reach its operating post around the L1 Lagrange point a million miles from Earth.

Fueling of the Falcon 9 rocket is underway with kerosene and liquid oxygen propellants, but officials are watching unfavorable upper level winds over Cape Canaveral.

Maximum upper level winds today are predicted to be from the northwest at 90 knots near 30,000 feet. The upper level wind conditions are currently "red" but weather balloons will continue to be released throughout the countdown to monitor for changes.

Radio checks between the rocket and the Air Force's Eastern Range have been completed, and first motion checks are coming up next in the countdown.

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With rain showers passing over Cape Canaveral today, forecasters expect much improved conditions Tuesday, calling for a 70 percent chance of good weather for launch of SpaceX's Falcon 9 rocket at 6:05 p.m. EST (2305 GMT).

"On Tuesday, the rain and cloud cover should diminish by mid-day as the cold front pushes south," the U.S. Air Force's 45th Weather Squadron wrote in the official launch forecast. "Very strong northerly winds of 25-30 miles per hour behind the front will persist through the day. These strong winds create a concern for a liftoff wind violation. Maximum upper-level winds will be from the northwest at 90 knots near 30,000 feet."

Scattered clouds at 2,500 feet and 25,000 feet are expected at launch time, with good visibility and a temperature of 57 degrees Fahrenheit. The only concern is with strong surface winds.

On Wednesday, conditions improve more with less than a 10 percent chance of exceeding one of the launch weather rules, again due to liftoff winds.

Officials have confirmed the next Falcon 9 launch attempt with NOAA's Deep Space Climate Observatory is Tuesday at 6:05 p.m. EST (2305 GMT).

A backup launch opportunity is available on Wednesday, officials said.

"Weather for an attempt on Monday, Feb 9 is unfavorable," officials said in a joint statement. "If that attempt were to scrub for weather, we would lose either the Tuesday or Wednesday launch opportunity due to crew rest requirements for the Air Force.

"Teams will target launch on Tuesday with a backup of Wednesday as weather is more favorable on both of those days. While it is not required for flight, SpaceX will leverage the extra time to replace a video transmitter on the first stage in advance of the next attempt."

An official forecast issued late Sunday indicated a 70 percent chance of good weather for Tuesday's launch opportunity.

NOAA has deleted the tweet announcing Tuesday as the new target launch date for DSCOVR. We are standing by for officials to clarify when the next launch attempt could occur.

NOAA has tweeted the launch of DSCOVR is now set for Tuesday at 6:05 p.m. EST (2305 GMT) due to unfavorable weather predicted for Monday.

SpaceX's Elon Musk says a problem with an Air Force tracking radar triggered the abort of tonight's countdown. The telemetry transmitter issue discussed by SpaceX was with the first stage on-board video system, he tweeted.

Musk said scrub gives SpaceX time to replace the faulty component. The video transmitter was "not needed for launch, but nice to have."

NASA spokesperson Mike Curie says the launch team tentatively plans for another launch attempt Monday at 6:07 p.m. EST (2307 GMT). More attempts are available Tuesday and Wednesday, before the mission would have to stand down until Feb. 20.

The Falcon 9 rocket is being put into a safe configuration as the SpaceX launch team backs out of countdown procedures following tonight's scrub.

The next launch opportunity is Monday at 6:07:49 p.m. EST (2307:49 GMT), assuming the problems that caused tonight's aborted countdown can be resolved in time.

The weather outlook calls for a 60 percent chance of conditions exceeding one of the Falcon 9's launch constraints. The primary concern is with thick clouds.

SCRUB. Liftoff of the Falcon 9 rocket will not occur today.

The Air Force Eastern Range called a hold due to a loss of tracking with the rocket. The SpaceX launch team was also working a telemetry problem in the final minutes of the countdown, and it's not clear if both conditions were "no go" for launch.

T-minus 3 minutes and counting. The rocket's destruct system is on internal power and being armed, and liquid oxygen topping is being terminated.

The strongback has retracted into the launch position about 20 degrees from the rocket.

The second stage thrust vector steering system has checked out and is ready for flight.

T-minus 5 minutes and counting. The cradles connecting the strongback to the Falcon 9 rocket have opened.

An issue with a range tracking radar is also being discussed at this time.

T-minus 6 minutes and counting. The Falcon 9 rocket is now operating on internal power.

The strongback umbilical tower will soon be lowered a few degrees to clear the rocket for launch. The procedure begins with opening of cradles gripping the rocket at attach points, then hydraulics lower the tower into launch position.

T-minus 6 minutes, 30 seconds. The Falcon 9's heaters are being deactivated, and the rocket will be transitioned to internal power in a few seconds.

T-minus 7 minutes and counting. Within the next minute, the Falcon 9's flight computer will be commanded to its alignment state. The Merlin engine pumps are continuing to chill down.

T-minus 8 minutes and counting. Good chilldown continues on the first stage engines, and closeouts of the upper stage's gaseous nitrogen attitude control system are underway.

T-minus 9 minutes, 30 seconds. Prevalves leading to the Falcon 9's Merlin 1D first stage engines are opening, permitting super-cold liquid oxygen to flow into the engines to condition the turbopumps for ignition.

T-minus 10 minutes and counting. The terminal countdown autosequence has started. Any hold after this point will result in an automatic abort and recycle to T-minus 13 minutes.

T-minus 12 minutes. The launch team has verified all consoles are go for liftoff at 6:10:12 p.m. EST (2310:12 GMT).

The countdown is expected to progress down to T-minus 2 minutes in hopes an issue with a first stage telemetry link can be resolved.

The terminal countdown autosequence is about to begin at the T-minus 10 minute mark.

T-minus 15 minutes and counting. Here are some statistics on today's launch:

• 15th launch of a Falcon 9 rocket since 2010
• 20th launch of Falcon rocket family since 2006
• 14th Falcon 9 launch from Cape Canaveral
• 10th launch of a Falcon 9 v1.1 rocket
• 9th Falcon 9 v1.1 launch from Cape Canaveral
• 1st launch of an Air Force payload on Falcon 9
• 8th Falcon 9 day launch
• 2nd Falcon 9 launch of 2015
• 2nd launch from Cape Canaveral in 2015

T-minus 17 minutes and counting. The Falcon 9 rocket stands 224 feet tall and measures 12 feet in diameter. At liftoff, its nine Merlin 1D first stage engines will generate about 1.3 million pounds of thrust.

Fully fueled for launch, the Falcon 9 contains about 1.05 million pounds of kerosene and liquid oxygen propellants.

T-minus 20 minutes and counting. The final poll of SpaceX's 14-person launch team will begin at T-minus 13 minutes before the countdown enters the final phase.

The DSCOVR spacecraft will be switched to internal battery power in a few minutes.

See our Facebook page for images of today's countdown and launch!

T-minus 30 minutes and counting. Today's launch is timed for exactly 6:10:12 p.m. EST (2310:12 GMT).

Liquid oxygen topping continues on the Falcon 9 rocket's first and second stages.

The Falcon 9 countdown is in a quiet phase now, with the two-stage rocket filled with kerosene and super-cold liquid oxygen.

The weather outlook has improved, now with a 100 percent chance of favorable conditions at launch time.

Former Vice President Al Gore is here at the Kennedy Space Center to view the launch of the Falcon 9 rocket with DSCOVR. Gore conceived the idea to send a satellite to the L1 Lagrange point to capture around-the-clock views of the sunlit face of Earth, yielding data on the planet's climate and offering inspirational views accessible to everyone.

"The constant ability to see the Earth -- whole -- fully sunlit every single day, the opportunity for every man, woman and child who lives on the Earth to see -- if they wish -- their own home in the context of the whole, can add to our way of thinking about our relationship to the Earth and, of course, the Earth's ecosystem," Gore said in remarks to reporters moments ago.

Testing of the Falcon 9 rocket's flight termination system are getting underway at this point in the countdown, as fueling of the two-stage launcher is wrapping up.

A final weather briefing is planned at the T-minus 1 hour point in the countdown, but no problems with weather are expected this evening.

It will take about 35 minutes for the Falcon 9 rocket deliver the Deep Space Climate Observatory to its targeted escape trajectory away from Earth. DSCOVR will take 110 days to reach its operating post around the L1 Lagrange point a million miles from Earth.

Radio telemetry checks are reported complete between the Falcon 9 rocket and the Air Force's Eastern Range.

Fueling of the Falcon 9's first stage with RP-1 kerosene has been completed.

Fueling of the 208-foot-tall Falcon 9 rocket is about to get underway at Cape Canaveral's Complex 40 launch pad after the SpaceX launch team issued a "go" to begin propellant loading.

The two-stage rocket burns RP-1 fuel -- a high-refined kerosene -- and liquid oxygen during today's nine-minute launch sequence.

Radio checks between the rocket and the Air Force's Eastern Range are scheduled for 3:25 p.m. EST (2025 GMT), followed by first motion checks at 3:40 p.m. EST (2040 GMT).

Testing of the Falcon 9 rocket's destruct mechanisms are scheduled for 4:25 p.m. EST (2125 GMT), and the launcher's on-board power systems will be activated at 4:40 p.m. EST (2140 GMT).

A poll of the SpaceX launch team has given the go for filling of the two-stage launcher with kerosene and liquid oxygen propellants.

Reload this page to ensure you see live streaming video of the launch.

At launch time, forecasters predict near-ideal conditions with a few clouds at 3,000 feet and scattered clouds at 9,000 feet, and southeast winds at 8 to 12 mph.

There is a 90 percent chance of acceptable weather at the launch time of 6:10:12 p.m. EST (2310:12 GMT).

At this point in the countdown, SpaceX workers should be clearing Cape Canaveral's Complex 40 launch pad in preparation for fueling of the Falcon 9 rocket with kerosene and liquid oxygen propellants.

A poll of the SpaceX launch team is planned for 2:51 p.m. EST (1951 GMT) to give the go for fueling, and propellant will be pumped aboard beginning at 3:11 p.m. EST (2011 GMT).

The 224-foot-tall Falcon 9 rocket has been rolled out and rotated vertical atop Cape Canaveral's Complex 40 launch pad, aiming for liftoff at precisely 6:10:12 p.m. EST (2310:12 GMT).

Workers then began plugging into electrical and propellant lines ahead of the start of the countdown today.

No problems are reported at this stage in the launch preparations. Fueling of the two-stage rocket with RP-1 fuel -- a highly-refined kerosene -- and liquid oxygen should begin shortly after 3 p.m. EST (2000 GMT).

The rocket is one of the tallest in the world. The Falcon 9's first and second stages measure 12 feet in diameter, and the SpaceX-built payload fairing housing the Deep Space Climate Observatory spacecraft is 17 feet in diameter (5.2 meters) and 43 feet tall.

Today's flight marks the 15th launch of a Falcon 9 rocket since debuting in June 2010. It's the 10th mission of the improved Falcon 9 v1.1 version, which made its inaugural launch in September 2013 from Vandenberg Air Force Base.

The weather outlook for today's launch calls for a 90 percent chance of favorable conditions.

A rocket recovery team positioned off Florida’s East Coast is standing by for liftoff Sunday of a Falcon 9 launcher with a space weather satellite, but the demanding trajectory of the flight adds more unknowns to the company’s dicey endeavor to land the booster on a ship at sea, a SpaceX official said Saturday.

Read our full story.

The world’s most distant weather outpost is set for liftoff from Cape Canaveral on Sunday aboard a SpaceX Falcon 9 rocket, launching to a point a million miles from Earth to warn forecasters of solar storms that could disrupt global air traffic, satellite navigation and power grids.

Read our full story.

Technicians are putting the finishing touches on a Falcon 9 rocket set for liftoff Sunday with a NOAA satellite built more than a decade ago, put in storage and resurrected to give early warning of solar storms.

The Deep Space Climate Observatory is set for launch at 6:10:12 p.m. EST (2310:12 GMT) Sunday aboard a Falcon 9 rocket from Cape Canaveral's Complex 40 launch pad.

The 224-foot-tall rocket will send the refrigerator-sized satellite on a high-speed path to break free of Earth's gravity, heading for a position one million miles away at the L1 Lagrange point, a gravitationally-stable location lined up between the Earth and the sun.

It will take about 35 minutes for the Falcon 9 rocket to give DSCOVR the boost necessary to reach its target.

The $340 million mission is a partnership between NOAA, which leads management of the program, and NASA and the U.S. Air Force. NASA was responsible for refurbishing the satellite and readying it for launch -- with funding from NOAA -- and the Air Force is paying SpaceX about $97 million for the launch itself.

"The spacecraft is in great shape," said Steven Clarke, director of NASA's Joint Agency Satellite Division. "We're not working any issues at this time, final closeouts will occur later today, and we're looking forward to SpaceX providing DSCOVR a great ride tomorrow evening on its journey to L1."

DSCOVR was originally conceived in the late 1990s as the Triana mission, which was heralded by former Vice President Al Gore as a way to raise awareness of climate issues among the public.

Triana was canceled in the early 2000s, and the finished spacecraft was put into storage at NASA's Goddard Space Flight Center in Maryland until 2008, when it was reactivated and tested for a new goal of measuring the incoming solar wind and give warning of events that could disrupt communications, navigation, satellite operations and power grids.

Sunday's launch will mark SpaceX's first launch beyond Earth orbit, and it is the second Falcon 9 flight of the year.

Engineers worked inside a climate-controlled clean room for two months to ready NOAA’s new space weather observatory for launch aboard a SpaceX Falcon 9 rocket.

See photos of the spacecraft's preparations.

Forecasters predict mostly clear skies, light winds and comfortable temperatures for Sunday’s launch of a Falcon 9 rocket with a NOAA satellite designed to warn of solar storms that could disrupt navigation and communication technology on Earth.

Read our full story.