Delta IV Heavy launch recap: Historic final rocket flight from Cape Canaveral, Florida

Launch recap: Scroll down to review live coverage of the Tuesday, April 9, liftoff of the last Delta IV Heavy rocket from Cape Canaveral.

It's launch day — and the end of an era for the mighty Delta IV Heavy rocket!

Welcome to FLORIDA TODAY's Space Team live coverage of United Launch Alliance's 12:53 p.m. EDT attempt to send the triple-core rocket into orbit from Launch Complex 37 at Cape Canaveral Space Force Station. This mission was previously scrubbed on March 28.

The 16th and final Delta IV Heavy will deploy a National Reconnaissance Office satellite on the NROL-70 national security mission.

Cape Canaveral: Is there a launch today? Upcoming rocket launch schedule for SpaceX, ULA, NASA in Florida

The Space Force’s 45^th Weather Squadron predicted 90% “go for launch” conditions, with cumulus clouds posing the primary meteorological threat.

No Central Florida sonic booms are expected, since the rocket’s side boosters do not return for landings.

Countdown Timer

Watch today's Delta IV Heavy launch

Update 1:15 p.m.: ULA officials just tweeted this video footage of today's liftoff.

ULA issues today's launch recap

Update 1:08 p.m.: ULA has just released the following brief recap of today's 12:53 p.m. liftoff:

"The eight-and-a-half-hour countdown started at 4:23 a.m. EDT under the guidance of ULA Launch Conductor Scott Barney. Retraction of the Mobile Service Tower, final configuring of the pad then followed and was cleared of all personnel.

"The 'go' for fueling was given by ULA Launch Director Tom Heter III and tanking operations were successfully performed as 470,000 gallons of liquid hydrogen and liquid oxygen were placed into the rocket’s eight tanks.

"The clear to launch was given at 12:47 p.m. EDT by NRO Mission Director Col. Eric Zarybnisky, who serves as the director of the NRO's Office of Space Launch."

Delta IV Heavy rocket stages, fairing separate

Update 1 p.m.: A mere four minutes after liftoff, the Delta IV Heavy was already traveling 15 times the speed of sound, ULA officials reported.

The early phase of the mission has been deemed a success by company officials, per the launch broadcast.

Liftoff!

Update 12:53 p.m.: Liftoff!

ULA final poll: 'Go for launch'

Update 12:49 p.m.: ULA Launch Conductor Scott Barney just conducted the mission's verbal terminal count readiness poll of more than two dozen engineers and managers.

The consensus: All systems are verified "go for launch."

Launch approaching with no reported issues

Update 12:44 p.m.: ULA has reached a prescheduled hold time in the countdown, and "the team is not working any issues and the weather is green."

"This is Delta Launch Control at T-minus 4 minutes and holding, with 8 minutes remaining in this built-in hold. We continue to target 12:53 p.m. EDT (1653 UTC) for launch of NROL-70. The team is not working any issues and the weather is green," ULA reported at 12:41 p.m.

Launch weather clear today across Florida

Update 12:39 p.m.: This National Weather Service radar loop shows no significant clouds across the Florida peninsula.

Here at NASA's KSC press site, low, thin puffy white clouds are dotting the otherwise sunny sky.

ULA: Weather remains 'go for launch'

Update 12:32 p.m.: The latest meteorological report from ULA, issued less than 10 minutes ago:

"The launch weather officer reports the current and forecast conditions are acceptable for the Delta IV Heavy liftoff of NROL-70. Weather is GO."

ULA launch webcast begins

Update 12:27 p.m.: ULA's launch broadcast is now posted above, right below the countdown clock.

Liftoff is scheduled in 26 minutes from Cape Canaveral Space Force Station.

Delta IV Heavy launch prep underway in Brevard

Update 12:18 p.m.: Brevard County Emergency Management officials have activated the agency's launch operations support team ahead of ULA's upcoming Delta IV Heavy launch.

ULA: No technical issues in the countdown

Update 12:10 p.m.: "The rocket is fueled and its 8 cryogenic tanks are being conditioned for launch. We are tracking no technical issues in the countdown," ULA officials reported one hour ahead of upcoming liftoff.

This diagram depicts the physical components of today's NROL-70 mission.

ULA CEO: 'Feeling like a good day to go to space'

Update 11:50 a.m.: Rocket fueling is complete, ULA reported — so the Delta IV Heavy now weighs 1.6 million pounds.

Launch-pad cameras are performing post-fueling inspections of the rocket's outer thermal insulation.

"Feeling like a good day to go to space," ULA President and CEO Tory Bruno said in a morning tweet.

ULA attempt follows March 28 scrub

Update 11:30 a.m.: Today's Delta IV Heavy launch attempt follows a March 28 scrub roughly four minutes before liftoff that ULA attributed to a pump failure along a NASA-operated gaseous nitrogen pipeline.

Afterward, FLORIDA TODAY asked for more information. A NASA communications strategist deferred comment to Air Liquide, which provided this statement last week. The company did not elaborate further:

"Air Liquide is committed to providing a safe and reliable supply of industrial gases to the U.S. space industry, as it has successfully been doing for more than 60 years. Air Liquide confirms that a pump failure occurred on March 28 at its nitrogen plant supplying NASA’s Space Launch System (SLS). Air Liquide worked diligently with NASA to understand the circumstances and resolve the situation and is prepared onsite to support the rescheduled launch of the Delta IV Heavy rocket."

Delta IV Heavy launch less than two hours away

Update 11:10 a.m.: ULA officials are reporting a "green status board," meaning no major pre-launch issues have emerged as the countdown continues ticking down.

ULA celebrates Delta rocket history

Update 10:50 a.m.: Within the hour, ULA officials tweeted a video featuring historic highlights of the retiring Delta rocket program, which debuted in 1960.

The video showcases "some of the groundbreaking firsts & iconic missions launched on Delta rockets."

Back to the present, a 10:35 a.m. ULA update said all weather rules are "go for launch," including criteria for clouds, rain, lightning and winds.

Delta IV Heavy should be visible across Florida

Update 10:30 a.m.: As a reminder, today's launch should be visible across most of the Florida peninsula (depending on local cloud cover, of course).

The rocket will ascend over the Atlantic Ocean along a due east trajectory. Click here for FLORIDA TODAY information on ULA's launch visibility map, which details viewing opportunities from Jacksonville to Miami to Tampa.

ULA: No pre-launch issues to report

Update 10:10 a.m.: Seventeen minutes ago — at the three-hour mark before liftoff — ULA officials provided an optimistic mission update on the upcoming launch.

"Liftoff is planned for 12:53 p.m. EDT (1653 UTC). Fueling is proceeding smoothly and the launch team is not working any issues," the ULA update said.

"Weather remains 90 percent GO for today's window," the update said.

Delta IV Heavy fueling underway

Update 9:50 a.m.: The Delta IV Heavy rocket will receive about 470,000 gallons of liquid oxygen and liquid hydrogen over the next couple hours.

Personnel launched the first weather balloon of the countdown before 9 a.m., and more balloons will go up this morning to measure speeds and directions of upper-level winds, ULA reported.

In a blog post this morning, ULA officials offered a chronological "did you know?" about the storied Delta rocket program.

"When the first Delta launched in 1960, Dwight Eisenhower was president, the No. 1 song in the nation was 'Stuck on You' by Elvis Presley and a loaf of bread cost approximately 20 cents," the post said.

Space Force: 90% favorable launch weather

Update 9:30 a.m.: It's a sunny, mild morning at NASA's Kennedy Space Center press site, a few miles from Launch Complex 37.

"An area of high pressure that has brought mild weather the last few days will continue to move slowly eastward. By Tuesday, winds will begin to pick up as the pressure gradient tightens between that high, off Florida’s east coast, and a developing low over Texas," the 45th Weather Squadron said in its forecast, which was issued Monday.

As of 8:55 a.m., the National Weather Service noted fair skies, a temperature of 74 and southeast wind of 18 mph at Cape Canaveral Space Force Station. The wind is rippling the U.S. flag mounted atop a flagpole next to NASA's outdoor countdown clock, which is frequently seen during media broadcasts.

For the latest news from Cape Canaveral Space Force Station and KSC, visit floridatoday.com/space.

Rick Neale is a Space Reporter at FLORIDA TODAY (for more of his stories, click here.) Contact Neale at [email protected]. Twitter/X: @RickNeale1

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This article originally appeared on Florida Today: Delta IV Heavy launch recap: Historic final rocket flight from the Cape