Delta IV Second Stage Final Firing

The Delta IV Heavy second stage is firing its small thrusters to position itself and the Parker Solar Probe into the proper position to fire its main engine for the final time during the mission. Everything remains on schedule for the flight.

Liftoff! The ULA Delta IV Heavy Rocket Clears the Launch Pad With NASA’s Parker Solar Probe

The United Launch Alliance Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station at 3:31 a.m. EDT, carrying NASA's Parker Solar Probe.
The United Launch Alliance Delta IV Heavy rocket lifts off from Space Launch Complex 37 at Cape Canaveral Air Force Station at 3:31 a.m. EDT, carrying NASA’s Parker Solar Probe. Photo credit: NASA

Booster ignition and liftoff of the United Launch Alliance Delta IV Heavy rocket at 3:31 a.m. EDT, from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida, carrying NASA’s Parker Solar Probe.

About four minutes into flight, a series of key events occurs in rapid succession: Delta IV port and starboard booster engines shut down and separate, main booster engine cutoff, separation of the booster from the second stage, ignition of the second stage main engine, then jettison of the payload fairing.

T-4 Minutes and Counting

ULA Delta IV Heavy on Space Launch Complex 37.The Parker Solar Probe countdown is underway toward a liftoff at 3:31 a.m. EDT. During the last four minutes of the countdown, the Delta IV Heavy propellant tanks will be brought up to flight pressure, the rocket and spacecraft will be confirmed on internal power, and the Eastern Range and launch managers will perform final status checks. A computerized autosequencer will take over the countdown in order to conduct a host of activities in precise order.

T-4 Minutes and Holding

The launch countdown is in a T-4 minute hold. The launch team is proceeding toward launch of a United Launch Alliance Delta IV Heady rocket carrying Parker Solar Probe on a mission to the Sun.

Liftoff is scheduled for 3:31 a.m. EDT, at the beginning of a 65-minute launch window. The forecast is now at 95 percent chance for favorable weather conditions for launch.

Parker Solar Probe Named for Physicist

Photo of Eugene Parker at a prelaunch mission briefing at NASA's Kennedy Space Center in Florida.
In Kennedy Space Center’s Operations and Support Building II, Thursday, Aug. 9, 2018, members of the media participate in a prelaunch mission briefing on NASA’s Parker Solar Probe. Listening to the presentation is Eugene Parker, front row, far left, the S. Chandrasekhar Distinguished Service Professor Emeritus, Department of Astronomy and Astrophysics at the University of Chicago. Photo credit: NASA/Kim Shiflett

In 2017, the mission was renamed for Eugene Parker, the S Chandrasekhar Distinguished Service Professor Emeritus, Department of Astronomy and Astrophysics at the University of Chicago. In the 1950s, Parker proposed a number of concepts about how stars–including our Sun–give off energy. He called this cascade of energy the solar wind, and he described an entire complex system of plasmas, magnetic fields, and energetic particles that make up this phenomenon. Parker also theorized an explanation for the superheated solar atmosphere, the corona, which is –contrary to what was expected by physics laws–hotter than the surface of the Sun itself. This is the first NASA mission that has been named for a living individual.