Payload Blog

A Look Back at Delta IV Heavy Launches

This month marks the end of an era. The final launch of the United Launch Alliance (ULA) Delta IV Heavy rocket lifts off from Cape Canaveral Space Force Station for the NROL-70 mission.

Kennedy Space Center Visitor Complex is honored to have watched so many of these powerful rockets launch from our backyard. Look back at some of the notable missions launched from Florida's Space Coast and how you can get up close to them today inside Gateway: The Deep Space Launch Complex®.

ULA Successfully Launches the First Delta IV Heavy

After United Launch Alliance successfully completed the Delta IV Heavy demonstration flight in December of 2004, they launched the first operational flight test of the new rocket on November 10, 2007. This launch successfully sent the Delta IV Heavy from Space Launch Complex-37 carrying a satellite for the U.S. Air Force. This satellite joined others of its kind in orbit to help provide an early warning of intercontinental missile launches.

EXPLORE MORE: See a Delta IV Heavy scale model and learn more about this powerful rocket inside Gateway: The Deep Space Launch Complex®.

The first Delta IV Heavy mission, DSP-23.

The Flight of EFT-1

Before the Orion spacecraft launched atop the Space Launch System (SLS) rocket in 2022, it flew with the help of a Delta IV Heavy rocket in 2014. The Exploration Flight Test, or EFT-1, launched in December of that year, helped test Orion's systems ahead of a future crewed launch to the Moon. This mission also used an Aerojet Rocketdyne RL-10 engine to help propel Orion to its destination after separation from the rocket.

EXPLORE MORE: Inside Gateway, you can see the flight-flown Orion spacecraft from EFT-1 and try your hand at some mission-centered interactive games. Plus, visit the Aerojet Rocketdyne RL-10 engine and see if you can fire it up (virtually, of course)!

The Delta IV Heavy with the Orion spacecraft on top.

Parker Solar Probe Sails Toward the Sun

In 2018, the Delta IV Heavy rocket helped the Parker Solar Probe begin its journey to the sun. Launching in the early hours of August 12, the Delta IV Heavy and its 2.1 million pounds of thrust propelled the probe on its long journey to orbit the sun. The mission was named in honor of Dr. Eugene Parker, who discovered solar wind in 1958. At 91 years of age, Dr. Parker viewed the launch from Kennedy Space Center, making him the first living person to witness the launch of a mission named after themselves.

EXPLORE MORE: Visit Robotic Space Explorers on the second floor of Gateway to learn more about the Parker Solar Probe.

The Parker Solar Probe launches atop a Delta IV Heavy rocket.

Dr. Eugene Parker watches as the mission named after him launches.

The Final Mission of the Delta IV Heavy

The last launch of the Delta IV Heavy will carry the NROL-70 mission for the National Reconnaissance Office, or the NRO. The majority of the Delta IV Heavy launches were for the NRO office; this will mark the 12th mission for the NRO and the 16th Delta IV Heavy launch overall. NRO missions are primarily classified as they center on collecting intelligence. NROL-70 will provide information to the United States intelligence analysts, warfighters, and decision-makers.

The NROL-68 mission, June 2023.

What is next? ULA is working on its new rocket, the Vulcan. Per ULA, “the Vulcan rocket will provide higher performance and greater affordability for ULA customers across national security, civil and commercial markets.” With the option of zero, two, four and six solid rocket booster configurations and three payload fairing options, the Vulcan has a wide-ranging capability to meet the needs of this new era of spaceflight. Learn more about the Vulcan rocket on ULA’s website.

The Vulcan rocket on Space Launch Complex 41.

Learn more about United Launch Alliance and many more commercial space partners inside Gateway: The Deep Space Complex, included with admission.