Delta IV
Parker Solar Probe

Launch Highlights

Live Status

Saturday, Aug. 11, 2018 @ 2150 UTC (5:50 p.m. EDT)

This is Delta Launch Control from the Delta Operations Center at Cape Canaveral Air Force Station in Florida as we begin a second launch attempt for the Delta IV Heavy rocket carrying NASA’s Parker Solar Probe.

The Air Force weather officer on duty at the 45th Weather Squadron just provided a briefing to senior management on conditions expected during retraction of the launch pad’s mobile service gantry and the forecast for the rest of the evening.

Overall, weather looks favorable for rolling the tower to its launch position. Typical summertime thunderstorms around Central Florida are being monitored, but skies at the Cape are clear right now. One final weather check will be made before the actual move begins.

The tower was returned to its position shielding the rocket following this morning’s scrub and de-fueling operations. Now, we’re getting ready to retract the tower for tonight’s countdown.

2220 UTC (6:20 p.m. EDT)

The ULA launch director has given approval for MST roll.

2231 UTC (6:31 p.m. EDT) -- Countdown begins

This is Delta Launch Control at T-minus 8 hours and counting.

The launch team has initiated a second countdown to fly the United Launch Alliance’s Delta IV Heavy rocket and send NASA’s Parker Solar Probe on its voyage to become the first spacecraft to “touch” the sun.

The application of power to the avionics aboard the Delta IV Heavy rocket is beginning at the start of today's countdown. The equipment is being powered up to start launch day testing and final preparations for fueling operations.

Activities are on schedule for liftoff at 3:31 a.m. EDT (0731 UTC). The day’s launch window will remain open through 4:36 a.m. (0836 UTC), a duration of 65 minutes.

The countdown features two pre-planned, built-in holds, each lasting 30 minutes, scheduled in the count. One pause is reserved prior to fueling at T-minus 4 hours, 15 minutes, the other occurs prior to the Terminal Count at T-minus 4 minutes.

2252 UTC (6:52 p.m. EDT)

As a precaution, tower roll will wait until a storm cell passes the area.

2320 UTC (7:20 p.m. EDT)

Vehicle power up has been completed.

2331 UTC (7:31 p.m. EDT)

We are exactly 8 hours away from liftoff time.

United Launch Alliance is using its Delta IV Heavy rocket, augmented with an extra third stage, to propel NASA’s Parker Solar Probe on a daring adventure to fly closer to the Sun than ever before, becoming the fastest spacecraft in history at 430,000 miles per hour.

The Parker Solar Probe will make repeated journeys into the Sun’s corona during 24 elliptical orbits over the 7-year mission. The mission seeks to answer fundamental questions about the Sun such as why the solar atmosphere is dramatically hotter than the Sun’s surface, what accelerates the solar wind that blows outward through the solar system and what is the source of high-energy solar particles.

Parker Solar Probe will endure intense radiation and temperatures of 2,500 degrees Fahrenheit, yet the science instruments will remain at room temperature behind a 4.5-inch-thick carbon composite shield.

The spacecraft was named in honor of Eugene Parker, an astrophysicist who discovered the solar wind in 1958.

2341 UTC (7:41 p.m. EDT)

Weather conditions have improved, allowing tower rollback final preparations to get underway.

2352 UTC (7:52 p.m. EDT)

The mobile service tower is being raised, using 40 hydraulic cylinders at pressures nearing 3,500 psi, several inches in preparation for the upcoming roll to the launch position.

Shortly, an undercarriage transport system will slowly move the 33-story building at a top speed of 0.25 miles per hour.

0001 UTC (8:01 p.m. EDT)

At Space Launch Complex 37, the mobile service tower retraction to the launch position has begun. It was returned to the service position surrounding the Delta IV Heavy following this morning’s scrub.

First motion today occurred at 8:01 p.m. EDT (0001 UTC).

0015 UTC (8:15 p.m. EDT)

The flight control operational test is underway for the Delta IV Heavy rocket. This test is known as flight slews, which will perform gimbal checks of the rocket engine nozzles on the vehicle.

0057 UTC (8:57 p.m. EDT) – MST rolled back

The mobile service tower at Space Launch Complex 37 has been retracted to the launch position, revealing the United Launch Alliance Delta IV Heavy rocket for its overnight flight to send NASA’s Parker Solar Probe to the sun.

The gantry-like structure, standing 330 feet tall and weighing nearly 10 million pounds, was wheeled on rail tracks about the length of a football field away from the rocket. It was secured in the launch location at 8:57 p.m. EDT (0057 UTC).

The MST is a critical part of the launch complex, proving the primary access and weather protection to the rocket during its stay on the launch pad, and its overhead crane system serves a vital role in vertical integration of payloads onto the Delta IV rockets.

Rollback of the MST signals a major milestone early in launch day operations. Configuring launch pad systems and securing equipment will be completed over the next couple of hours before all personnel clear the site for fueling.

Activities remain on schedule for a liftoff at 3:31 a.m. EDT (0731 UTC).

0110 UTC (9:10 p.m. EDT)

This is Delta Launch Control at T-minus 5 hours, 21 minutes and counting.

The initiation of gaseous nitrogen flow to the launch vehicle has started. This changes the environmental control systems to supply conditioned nitrogen gas rather than air to the internal compartments of the Delta IV Heavy rocket and the payload fairing in preparation for the transfer of cryogenic propellants and in-flight environments.

We are tracking no issues this evening. An update from the Air Force launch weather officer is coming up in about an hour.

0131 UTC (9:31 p.m. EDT)

Learn more about the United Launch Alliance Delta IV Heavy rocket’s launch of NASA's Parker Solar Probe mission in our Mission Profile video.

0151 UTC (9:51 p.m. EDT)

ULA Trajectory Engineer Nick Driver discusses launching NASA's Parker Solar Probe mission atop ULA's Delta IV Heavy rocket in this video. Usually used for large satellites, in this case the heavy lifter is being used to give a small spacecraft a high-energy delivery to the sun.

0205 UTC (10:05 p.m. EDT) – Weather 70% GO

This is Delta Launch Control at T-minus 4 hours, 26 minutes and counting. Launch Weather Officer Kathy Rice from the Air Force's 45th Weather Squadron reports that conditions at Cape Canaveral are favorable for the flight of Delta IV rocket and Parker Solar Probe, forecasting a 70 percent chance of acceptable weather at liftoff time.

The outlook calls for a few low-level clouds, a broken deck of high clouds, a chance of thunderstorms offshore from the Cape, good visibility, southwesterly winds of 10 knots and a temperature of 78 degrees F.

The only concern is anvil clouds drifting close to the launch site from the storms off the coast.

At this time, all weather conditions are "go."

0216 UTC (10:16 p.m. EDT) -- Countdown holding

This is Delta Launch Control at T-minus 4 hours, 15 minutes and holding. The countdown has entered the first of two planned, built-in holds that are scheduled in today’s timeline. Each is 30-minute blocks of time that gives the countdown some margin to resolve issues or catch up on work could be running behind.

This particular hold serves as a margin before fueling operations begin. At the present time, however, all activities are on schedule and no problems are being addressed by the launch team.

The final hold occurs at T-minus 4 minutes.

0218 UTC (10:18 p.m. EDT)

The launch pad crew has completed its hands-on work to ready Space Launch Complex 37 for today’s mission, and the launch conductor has given the instruction for personnel to depart the site in advance of fueling operations.

0226 UTC (10:26 p.m. EDT)

NASA's Parker Solar Probe and its United Launch Alliance Delta IV Heavy launch vehicle prepare for an unprecedented mission to "kiss the Sun." The spacecraft aims to unravel 60 years' worth of mysteries surrounding the sun’s corona. Watch a NASA Launch Services Program video about the mission.

0236 UTC (10:36 p.m. EDT)

The Parker Solar Probe will swoop to within 4 million miles of the sun's surface, facing heat and radiation like no spacecraft before it. Learn more about the mission’s science goals to gather new data on solar activity and make critical contributions to our ability to forecast major space-weather events that impact life on Earth.

0244 UTC (10:44 p.m. EDT) – GO for fueling

A readiness poll of the launch team by Launch Conductor Scott Barney, with concurrence of ULA Launch Director Lou Mangieri has authorized cryogenic tanking operations to begin as the countdown continues this morning. The Delta IV Heavy rocket will be loaded with approximately 465,000 gallons of liquid oxygen and liquid hydrogen over the next couple of hours.

0246 UTC (10:46 p.m. EDT) -- Countdown resumes

This is Delta Launch Control at T-minus 4 hours, 15 minutes and counting. The next phase of today’s launch countdown has been initiated on schedule as we continue to target 3:31 a.m. EDT (0731 UTC) for liftoff of the United Launch Alliance Delta IV Heavy rocket and the Parker Solar Probe for NASA.

Preparatory steps for fueling are being kicked off, including liquid hydrogen storage tank pressurization and charging the helium bottles on the three common booster cores and second stage.

0311 UTC (11:11 p.m. EDT) – Chilldown begins

A "go" has been given to start the cold gas chilldown conditioning of the liquid hydrogen systems on the three common booster cores. This is the precursor step before filling the stages with propellant.

The three common booster cores will be loaded with 330,000 gallons of super-cold liquid hydrogen that is chilled to minus-423 degrees Fahrenheit. The liquid hydrogen, along with the liquid oxygen to be loaded shortly as well, will be consumed by the three RS-68A main engines during the first minutes of the launch to exit Earth’s atmosphere.

The port and starboard boosters will fire at full throttle for nearly four minutes and then separate. The center booster burns at partial thrust for most of that time in a fuel-conservation mode until the outer cores jettison, then its RS-68A engine revs up to full throttle for another minute-and-a-half of propulsion before staging.

0331 UTC (11:31 p.m. EDT)

This is Delta Launch Control at T-minus 3 hours, 30 minutes and counting.

The Delta IV Heavy rocket stands 233 feet tall, is 53 feet wide and will weigh 1.6 million pounds once fully fueled. It will launch on 2.1 million pounds of thrust from the three RS-68A main engines.

The Parker Solar Probe atop the launch vehicle is 9.8 feet tall, about 3.3 feet in diameter and has a mass of over 1,400 pounds.

The relatively small spacecraft needs the full power of the Delta IV Heavy rocket to achieve the necessary speed to surf through the corona and not get pulled into the sun during the close encounters.

0340 UTC (11:40 p.m. EDT) – CBC LH2 loading begins

This is Delta Launch Control at T-minus 3 hours, 5 minutes and counting. The cold gas chilldown conditioning of the common booster cores’ liquid hydrogen system has been accomplished, clearing the way to begin propellant loading in "slow-fill" mode. That will transition to "fast-fill" after a small portion of the tanks are loaded

0342 UTC (11:42 p.m. EDT)

The fueling specialist in the launch control room confirms that liquid hydrogen is flowing into the Delta IV Heavy rocket at the Space Launch Complex 37 pad.

0347 UTC (11:47 p.m. EDT) – CBC LOX chilldown

This is Delta Launch Control at T-minus 3 hours, 14 minutes and counting. The thermal condition process, known as chilldown, has started for the liquid oxygen systems on Delta IV Heavy rocket's three common booster cores. This preps the tanks and plumbing to guard against shock when the super-cold oxidizer begins flowing into the rocket stages.

0351 UTC (11:51 p.m. EDT)

The common booster cores liquid hydrogen loading operation is switching from "slow-fill" to "fast-fill" mode as planned.

The cryogenics are fed to the three CBCs via umbilicals from the tail service masts on the launch table.

0354 UTC (11:54 p.m. EDT) – CBC LOX loading begins

This is Delta Launch Control at T-minus 3 hours, 6 minutes and counting. The liquid oxygen chilldown is complete for the three booster cores, allowing 120,000 gallons of super-cold LOX to begin transferring into the rocket for today’s launch.

0357 UTC (11:57 p.m. EDT) – DCSS LH2 chilldown

The “go” has been given to start the chilldown conditioning of the Delta Cryogenic Second Stage liquid hydrogen system in preparation for filling that tank.

0409 UTC (12:09 a.m. EDT)

The common booster core liquid oxygen tanking operation is switching from "slow-fill" to "fast-fill" mode. The LOX is chilled to minus-298 degrees F.

Meanwhile, the common booster core liquid hydrogen level has reached 40 percent.

0414 UTC (12:14 a.m. EDT) – DCSS LOX chilldown

This is Delta Launch Control. Approval has been given to the operators at the fueling console here in the Delta operations Center to begin the second stage liquid oxygen chilldown procedures.

0421 UTC (12:21 a.m. EDT) – DCSS LOX loading begins

Chilldown of the second stage liquid oxygen system is complete, and the vehicle is ready to begin receiving 4,500 gallons of LOX for launch.

0424 UTC (12:24 a.m. EDT) – DCSS LH2 loading begins

The next step in fuel operations is getting underway by loading 10,000 gallons of liquid hydrogen into the Delta Cryogenic Second Stage following completion of that system’s chilldown.

The stage receives its fuel from the launch pad’s middle swing arm that extends from the Fixed Umbilical Tower to the Delta IV Heavy rocket.

This is the last of the rocket's cryogenic tanks to be filled in today's countdown.

0443 UTC (12:43 a.m. EDT)

This is Delta Launch Control at T-minus 2 hour, 18 minutes and counting. We have finished the “fast-fill” loading mode for the three common booster core liquid hydrogen tanks, and the post-fueling checks and valve tests are underway before topping commences.

0448 UTC (12:48 a.m. EDT)

Liquid oxygen loading to the three common booster cores has finished. Topping will be completed shortly.

0459 UTC (12:59 a.m. EDT)

The weather forecast has improved to 80 percent favorable for launch today.

0505 UTC (1:05 a.m. EDT)

The Delta Cryogenic Second Stage has been loaded with its liquid hydrogen fuel supply. The propellant, along with liquid oxygen that continues to be filled, will be consumed by the stage’s RL10B-2 engine during two burns that will accelerate Parker Solar Probe into its initial parking orbit, then boost the craft on the intermediate escape trajectory today.

0521 UTC (1:21 a.m. EDT)

ULA Systems Engineer Patrick Moore has been working on the Parker Solar Probe mission for the past three years, working with Northrop Grumman to integrate a third stage to the Delta IV Heavy that will offer additional performance. Watch this video describing the integration of the third stage.

0541 UTC (1:41 a.m. EDT)

Coming off the pad on 2.1 million pounds of thrust from the combined power of the three common booster cores, the rocket will perform pitch and yaw maneuvers to align with an easterly heading along a flight azimuth of 94.6 degrees. The vehicle will hit Mach 1, the speed of sound, in 78 seconds.

The port and starboard boosters will complete their burns and separate four minutes after liftoff, leaving the central core to continue firing for another minute-and-a-half before staging.

The Delta Cryogenic Second Stage then ignites for a four-and-a-half-minute burn to reach a preliminary parking orbit around Earth. Just after the burn begins, the composite payload fairing that protected Parker Solar Probe during atmospheric ascent will be jettisoned above the edge of space. After the first main engine cutoff, the vehicle will coast in that orbit for about 12 minutes before an engine restart occurs for a 14-minute firing to escape Earth’s gravity.

MECO 2 occurs just over 37 minutes into flight, followed quickly by deployment and ignition of the solid-fuel third stage for a dramatic increase in overall velocity for Parker Solar Probe’s daring trek.

Release of the spacecraft from the launch vehicle is expected about 44 minutes after liftoff, or 4:15 a.m. EDT (0815 UTC) given an on-time launch.

0545 UTC (1:45 a.m. EDT)

Loading of the upper stage liquid oxygen tank was just reported complete, giving us a 1.6-million-pound Delta IV Heavy rocket that is fueled for launch at 3:31 a.m. EDT (0731 UTC) today. At T-minus 1 hour, 15 minutes, 23 seconds and counting, this is Delta Launch Control.

0601 UTC (2:01 a.m. EDT)

This is Delta Launch Control at T-minus 60 minutes and counting. We will be taking the countdown clock to T-minus 4 minutes before holding there for a pre-planned, 30-minute built-in hold. That is when the status polls by management will be performed to verify all is in readiness for liftoff.

0609 UTC (2:09 a.m. EDT)

The launch team is setting up for flight slews, the next major milestone in the countdown. This is the steering test patterns run on the Delta IV Heavy rocket nozzles to ensure proper gimbaling during the ascent.

0616 UTC (2:16 a.m. EDT)

This launch uses a special three-stage configuration of the United Launch Alliance Delta IV Heavy rocket to launch Parker Solar Probe from the Earth.

This configuration of the Delta IV is created by taking three hydrogen-fueled common booster cores, each with an Aerojet Rocketdyne RS-68A main engine, and strapping them together to provide over two million pounds of Earth-shaking thrust at liftoff. The Delta Cryogenic Second Stage, powered by an Aerojet Rocketdyne RL10B-2 engine, puts the vehicle into a preliminary orbit, then fires a second time to achieve an Earth-escape trajectory. A Star 48BV third stage, built by Northrop Grumman, provides a significant kick of additional velocity for the Parker Solar Probe on its journey into the inner solar system.

The Delta IV Heavy launches on the combined power of three RS-68A engines, burning liquid hydrogen and liquid oxygen to produce 702,000 pounds of thrust each. The port and starboard boosters are more than 150 feet tall, and the center core with the interstage attached is over 175 feet in length. They measure 16.7 feet in diameter.

The Delta Cryogenic Second Stage also burns liquid hydrogen and liquid oxygen to produce 24,750 pounds of thrust from the RL10B-2 engine. The powerplant features a deployable carbon-carbon nozzle that is 7 feet in diameter.

The Star 48BV motor serves as the Delta IV Heavy’s third stage. It is the latest evolution in the long line of Star 48 stages and incorporates a vectorable nozzle for added maneuverability.

The Delta IV Heavy has successfully flown into space 9 times before, deploying vital national security payloads for the U.S. Air Force and National Reconnaissance Office and sending NASA’s Orion capsule on its first flight test.

0631 UTC (2:31 a.m. EDT) -- Third stage power up

We are entering the final 60 minutes of our countdown to launch of the Delta IV Heavy rocket and NASA’s Parker Solar Probe, a mission decades in the making to fly through the sun’s outer atmosphere to obtain in-situ measurements of how the corona is heated and how the solar wind is accelerated.

The launch team has begun to power up the Northrop Grumman Star 48BV third stage. The stage provides a significant kick of additional velocity for the Parker Solar Probe on its journey into the inner solar system.

No significant issues are being addressed by the launch team, the current weather conditions are favorable and all activities are progressing smoothly for a liftoff at 3:31 a.m. EDT (0731 UTC).

0640 UTC (2:40 a.m. EDT)

This is Delta Launch Control at T-minus 21 minutes and counting. We remain on schedule, headed to the final hold at T-minus 4 minutes, for a launch this morning at 3:31 a.m. EDT (0731 UTC).

Propellant conditioning has been achieved on all 8 liquid hydrogen and liquid oxygen tanks of the Delta IV Heavy vehicle.

0646 UTC (2:46 a.m. EDT)

We are 45 minutes away for liftoff time for the Delta IV Heavy rocket and NASA’s Parker Solar Probe bound for close encounters with the sun.

It's surprisingly hard to go to the sun Learn more on the challenges for Parker Solar Probe.

0651 UTC (2:51 a.m. EDT)

The Thermal Protection System, or TPS, that is an essential technology that enables Parker Solar Probe to get so close to the sun. Learn more in this video .

0657 UTC (2:57 a.m. EDT) -- Countdown holding

This is Delta Launch Control at T-minus 4 minutes and holding. The countdown has entered the planned 30-minute built-in hold designed to give a bit of margin to deal with any problems. Also during this time, the final readiness polls of the launch team and management members will be performed.

We remain on schedule for a liftoff at 3:31 a.m. EDT (0731 UTC) from Space Launch Complex 37 at Cape Canaveral. Today’s launch opportunity is available for 65 minutes, extending to 4:36 a.m. EDT (0836 UTC).

0658 UTC (2:58 a.m. EDT)

NASA’s live coverage and commentary of today’s launch is about to begin in the embedded stream on this page.

0702 UTC (3:02 a.m. EDT)

Weather is observed and forecast “go” for liftoff of the Delta IV Heavy rocket from Cape Canaveral at the opening of today’s launch window, the Air Force launch weather officer just reported in the countdown’s final scheduled briefing.

0711 UTC (3:11 a.m. EDT)

This will be 129th mission for United Launch Alliance and our 32nd mission for NASA. It is the 380th Delta rocket launch since 1960, the 37th for a Delta IV rocket since 2002 and the 10th Delta IV Heavy.

“ULA is honored to launch the one-of-a-kind Parker Solar Probe,” said Tory Bruno, ULA president and CEO. “Only the Delta IV Heavy possesses the capability to deliver this unique mission to orbit, and we are proud to provide unmatched launch services to our NASA mission partners.”

0716 UTC (3:16 a.m. EDT)

The launch team is controlling the countdown from the Delta Operations Center, or DOC, located about one-and-a-half miles from the launch pad, in conjunction with a team of engineers in ULA’s Denver Operations Support Center.

Engineers from NASA’s Launch Services Program are monitoring systems from consoles at Launch Vehicle Data Center rooms in Cape Canaveral’s Hangar AE. NASA leadership representatives are seated in the Mission Director’s Center at Hangar AE.

The Johns Hopkins University Applied Physics Lab in Laurel, Maryland, will perform ground commanding and flight operations for the Parker Solar Probe during its seven-year mission, as well as data processing and archiving.

0719 UTC (3:19 a.m. EDT)

This is Delta Launch Control at T-minus 4 minutes and holding. All of the communications loops are quiet at the present time during this hold. The countdown remains on target for liftoff at 3:31 a.m. EDT (0731 UTC) when today's 65-minute launch opportunity opens.

It will take nearly 45 minutes to perform this Delta IV Heavy mission, from liftoff until deployment of Parker from the third stage of the launch vehicle.

Our rocket variant being flown today is a special three-stage configuration that will give Parker the required velocity to escape the Earth’s gravity and begin its journey to the inner solar system. The three hydrogen-fueled cores will provide the initial thrust out of the atmosphere, then the cryogenic second stage will achieve a parking orbit and an intermediate escape orbit with two burns. The solid-fuel third stage – called the Star 48BV and produced by Northrop Grumman -- will deliver the final push on a trajectory to fly by Venus for the first time in about two months and make the first encounter with the sun in November.

NASA selected ULA’s Delta IV Heavy for its unique ability to deliver the necessary energy to begin the Parker Solar Probe’s journey to the sun. After launch, the spacecraft will orbit directly through the solar atmosphere – the corona – closer to the surface than any human-made object has ever gone.

0725 UTC (3:25 a.m. EDT) -- GO for launch!

The ULA Launch Director Lou Mangieri has given the final approval to resume the countdown for flight of Delta IV Heavy rocket to send NASA’s Parker Solar Probe to the sun. His concurrence was made following a status check by NASA Launch Manager Omar Baez of the agency’s advisory team and a readiness poll of the launch team by Launch Conductor Scott Barney that verified all systems are "go."

0727 UTC (3:27 a.m. EDT) -- Countdown resumes

T-minus 4 minutes and counting. The final phase of today’s countdown is underway at Cape Canaveral to launch the Delta IV Heavy rocket and Parker Solar Probe for NASA. The countdown clocks have resumed, leading us to a 3:31 a.m. EDT (0731 UTC) liftoff.

Over the next minute, the Delta Cryogenic Second Stage liquid oxygen tank will be secured at flight level, replenishment of liquid hydrogen and liquid oxygen to the three boosters will be secured in preparation to pressurize the tanks for launch, the Delta IV Heavy rocket will switch from ground-fed power to internal batteries and ordnance devices aboard the vehicle will be armed.

0728 UTC (3:28 a.m. EDT)

T-minus 2 minutes, 30 seconds. We remain GO for liftoff of the Delta IV Heavy and Parker Solar Probe.

The liquid oxygen tanks in the three common booster cores are been confirmed at the proper level and pressure for flight. The liquid hydrogen tanks will achieve this status about one minute from now.

The liquid hydrogen system on the Delta Cryogenic Second Stage will be secured starting at T-minus 80 seconds.

0729 UTC (3:29 a.m. EDT)

T-minus 1 minutes, 45 seconds. NASA Launch Manager Omar Baez has confirmed that the Parker Solar Probe is on internal power and GO for launch.

0730 UTC (3:30 a.m. EDT)

T-minus 55 seconds and counting. Computers have verified that the three RS-68A main engines are ready for ignition and the Air Force’s Eastern Range at Cape Canaveral has confirmed its “green” condition for launch.

Coming up at T-minus 30 seconds, a final status check will be announced on Delta and Parker Solar Probe readiness, followed by the vehicle going inertial, the residual hydrogen burnoff ignitors firing beneath the main engines, the Terminal Countdown Sequencer Rack taking control and the staggered ignitions of the main engines starting at T-minus 7 seconds with the starboard booster and T-minus 5 seconds for the center and port boosters. The 12 holddown bolts will fire to release the vehicle for liftoff at T-0 and the three swing arms on the launch pad will pull back.

0731 UTC (3:31 a.m. EDT) -- LIFTOFF!

Liftoff of the United Launch Alliance Delta IV Heavy rocket with NASA’s Parker Solar Probe on a mission to touch the sun!

0732 UTC (3:32 a.m. EDT)

T+plus 60 seconds into Parker Solar Probe’s trek to the sun.

The Delta IV Heavy performed its pitch and yaw maneuvers off the launch pad to achieve the proper heading with a due east azimuth of 94.6 degrees. The port and starboard cores are firing at full throttle with their RS-68A main engines operating at the maximum power setting of 108.5 percent thrust. The center booster has throttled back its engine to the partial power setting of 54.5 percent thrust for fuel conservation in order to burn longer.

0732 UTC (3:32 a.m. EDT)

T+plus 85 seconds. The Delta IV Heavy rocket has broken through the sound barrier to go supersonic and also passed the period of maximum aerodynamic stresses in the lower atmosphere.

0733 UTC (3:33 a.m. EDT)

T+plus 2 minutes, 40 seconds. The Delta IV Heavy rocket now weighs only half of what it did at liftoff. The port and starboard boosters remain at full power and the center engine continues in its partial thrust mode as planned. The rocket is consuming nearly 5,000 pounds of liquid hydrogen and liquid oxygen per second.

0734 UTC (3:34 a.m. EDT)

T+plus 3 minutes. Now at Mach 5. Coming up in about a minute, the port and starboard boosters will throttle back and then shut down their RS-68A main engines in preparation for jettison.

0735 UTC (3:35 a.m. EDT)

T+plus 4 minutes, 10 seconds. A clean separation of the port and starboard boosters is confirmed, and the center core has throttled up to its full power mode to consume the fuel that has been conserved by burning at lower thrust for the past four minutes. The rocket will nearly double its velocity in this next phase of flight.

0737 UTC (3:37 a.m. EDT)

T+plus 6 minutes, 15 seconds. A successful staging and ignition of the Delta Cryogenic Second Stage is confirmed.

The Center core completed its burn and then separated, allowing the RL10B-2 engine to deploy its nozzle and begin its first of two burns during the launch.

Also, the composite payload fairing that protected Parker Solar Probe during ascent through the atmosphere has been jettisoned now that the rocket has ascended above the edge of space.

The Delta IV rocket has shed 95 percent of its liftoff weight!

0738 UTC (3:38 a.m. EDT)

T+plus 8 minutes, 15 seconds. A look at first stage performance numbers show a nominal burn by the three common booster cores.

0740 UTC (3:40 a.m. EDT)

T+plus 9 minutes. The RL10B-2 engine is performing well with good operating parameters reported. This first burn by the Delta Cryogenic Second Stage will last less than five minutes to place the vehicle into an initial parking orbit around the Earth.

0741 UTC (3:41 a.m. EDT)

T+plus 10 minutes. The second stage of the Delta IV Heavy rocket continues firing to obtain orbital velocity, burning liquid hydrogen and liquid oxygen propellants.

0741 UTC (3:41 a.m. EDT)

T+plus 10 minutes, 45 seconds. The first main engine cutoff (MECO 1) is confirmed for the Delta Cryogenic Second Stage, completing the first of two burns during today’s launch sequence for Parker Solar Probe. The vehicle has reached a preliminary Earth orbit where it will coast above the Central Atlantic for the next 13 minutes before the Earth escape burn begins.

0745 UTC (3:45 a.m. EDT)

T+plus 14 minutes. That first burn by the second stage inserted the rocket into the precise target orbit as planned.

0748 UTC (3:48 a.m. EDT)

T+plus 17 minutes. Now about half-way through this coast period.

0754 UTC (3:54 a.m. EDT)

T+plus 23 minutes, 30 seconds. Ignition! The Delta Cryogenic Second Stage's single RL10B-2 engine has re-ignited to propel Parker Solar Probe out of Earth orbit on an intermediate escape trajectory.

0756 UTC (3:56 a.m. EDT)

T+plus 25 minutes. This 14-minute firing by the Delta IV Heavy’s second stage is progressing well, according to nominal parameters streaming back from the rocket.

0759 UTC (3:59 a.m. EDT)

T+plus 28 minutes. Good engine performance and nominal telemetry from stage systems continue to be reported as the rocket accelerates Parker Solar Probe toward its flight path to the inner solar system.

0803 UTC (4:03 a.m. EDT)

T+plus 32 minutes. The second burn continues to progress smoothly with proper power bus and battery values, stable body rates and nominal engine operating signatures.

0806 UTC (4:06 a.m. EDT)

T+plus 35 minutes, 40 seconds. About two minutes remain in this burn by the high-performance RL10B-2 cryogenic engine, burning its supplies of liquid hydrogen and liquid oxygen to achieved a hyperbolic orbit.

0808 UTC (4:08 a.m. EDT)

T+plus 37 minutes, 45 seconds. The second main engine cutoff (MECO 2) is confirmed for the Delta Cryogenic Second Stage, boosting Parker Solar Probe on its escape trajectory. A burn coming up by the third stage will dramatically increase the spacecraft’s speed even further.

0810 UTC (4:10 a.m. EDT)

T+plus 39 minutes. Third stage ignition confirmed!

After separating from the Delta Cryogenic Second Stage, the Northrop Grumman solid-fuel Star 48BV third stage, a special addition for this Delta IV Heavy rocket launch, has begun its 89-second firing to increase Parker Solar Probe’s velocity.

0812 UTC (4:12 a.m. EDT)

T+plus 41 minutes. Still awaiting on data to confirm the third stage burn.

0816 UTC (4:16 a.m. EDT) -- SPACECRAFT SEPARATION!

T+plus 45 minutes, 45 seconds. NASA’s Parker Solar Probe has been deployed by the third stage rocket motor to complete this morning’s launch that begins a 7-year mission to explore the sun’s outer atmosphere.

0820 UTC (4:20 a.m. EDT)

Cape Canaveral Air Force Station, Fla. - A United Launch Alliance Delta IV Heavy rocket carrying the NASA Parker Solar Probe spacecraft lifts off from Space Launch Complex-37 at 3:31 a.m. ET.

Photo by United Launch Alliance

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1035 UTC (5:35 a.m. EDT)

Today continued 100 percent success for the United Launch Alliance in 129 missions.

”The unique requirements of this mission made the Delta IV Heavy the perfect launch vehicle to deliver Parker Solar Probe into orbit with the highest precision,” said Gary Wentz, ULA vice president of Government and Commercial Programs. “Congratulations to our team and mission partners, we are proud to launch this exceptional spacecraft that will provide invaluable scientific information benefiting all of humankind.”

1045 UTC (5:45 a.m. EDT)

Our next launch is targeted for Sept. 15 from Vandenberg Air Force Base in California when the final planned Delta II rocket carries NASA’s ICESAT-2 environment satellite into polar orbit to precisely measure the height of ice sheets, glaciers and sea ice around the globe.

1000 UTC (6:00 a.m. EDT)

Cape Canaveral Air Force Station, Fla., (Aug. 11, 2018) – A United Launch Alliance (ULA) Delta IV Heavy rocket carrying NASA’s Parker Solar Probe spacecraft lifted off from Space Launch Complex-37 on Aug. 12 at 3:31 a.m. EDT. NASA selected ULA’s Delta IV Heavy for its unique ability to deliver the necessary energy to begin the Parker Solar Probe’s journey to the sun. Read our news release.

Launch photo gallery

See our Flickr page for a collection of beautiful photos of today’s launch of the Delta IV Heavy rocket taken by United Launch Alliance.

Launch highlights video

The United Launch Alliance highlights video reliving this morning’s spectacular Delta IV Heavy rocket launch of the Parker Solar Probe is now posted on our YouTube channel!

“ULA

Delta IV Heavy to Launch Parker Solar Probe

Rocket: Delta IV Heavy
Mission: Parker Solar Probe
Launch Date: Sunday, Aug. 12, 2018
Launch Time: 3:31 a.m. EDT at the beginning of a 65-minute launch window
Launch Broadcast: Tune in beginning at 3 a.m. EDT
Launch Location: Space Launch Complex-37, Cape Canaveral Air Force Station, Florida

Mission Information: Parker Solar Probe is humanity’s first mission to the sun. After launch, it will orbit directly through the solar atmosphere – the corona – closer to the surface than any human-made object has ever gone. While facing brutal heat and radiation, the mission will reveal fundamental science behind what drives the solar wind, the constant outpouring of material from the sun that shapes planetary atmospheres and affects space weather near Earth.

Parker Solar Probe is part of NASA’s Living With a Star Program to explore aspects of the connected sun-Earth system that directly affect life and society.

Launch Notes: Due to the extremely high energy required for this mission, the Delta IV Heavy’s capability will be augmented by a powerful third stage provided by Northrop Grumman Innovation Systems.

Launch Updates: To keep up to speed with updates to the launch countdown, dial the ULA launch hotline at 1-877-852-4321 or join the conversation at www.facebook.com/ulalaunch, twitter.com/ulalaunch and instagram.com/ulalaunch; hashtag #DeltaIV

 

Go Delta! Go Parker Solar Probe!

 

The Delta IV rocket

United Launch Alliance’s Delta IV rocket has served the nation’s high-priority U.S. Air Force and National Reconnaissance Office space programs with distinction since entering service in 2002. Having flown 36 missions in a variety of configurations ranging from medium-lift to heavy-lifter, the Delta IV continues the legacy of the Delta rocket family that dates to 1960.

Specs

  • Height: 233 feet
  • Weight: 1.6 million pounds
  • Thrust: 2.1 million pounds
  • Fuel: 465,000 gallons of liquid hydrogen and liquid oxygen, solid-fuel third stage

Parker Solar Probe will launch aboard a special three-stage configuration of the Delta IV Heavy rocket to embark on a journey to surf through the sun's corona. The rocket features three hydrogen-fueled common booster cores, each with an RS-68A main engine, to provide the initial thrust out of Earth's atmosphere, a Delta Cryogenic Second Stage with an RL10B-2 engine to achieve an intermediate escape orbit and a Northrop Grumman Innovation Systems solid-fuel third stage -- called the Star 48BV -- to deliver the final push to send Parker Solar Probe on its trajectory to the inner solar system. The spacecraft is protected during atmospheric ascent by a 63-foot-long bi-sector composite payload fairing.

 

A United Launch Alliance (ULA) Delta IV Heavy rocket will deliver NASA’s Parker Solar Probe to an interplanetary trajectory to the sun. Liftoff will occur from Space Launch Complex-37 at Cape Canaveral Air Force Station, Florida. NASA selected ULA’s Delta IV Heavy for its unique ability to deliver the necessary energy to begin the Parker Solar Probe’s journey to the sun.