Vulcan VC4L

Vulcan VC4L

The Vulcan VC4L is a configuration of the Vulcan Centaur launch vehicle family, developed and operated by United Launch Alliance (ULA), the American launch services joint venture between Boeing and Lockheed Martin. It represents one of the higher-performance variants within the Vulcan Centaur lineup, distinguished by its use of four solid rocket boosters alongside the core first stage.

Vehicle Overview

Vulcan Centaur was designed as the successor to ULA's workhorse Atlas V and Delta IV families, incorporating modern propulsion and structural advances while maintaining the reliability standards for which ULA is widely known. The VC4L designation reflects the vehicle's configuration: "VC" for Vulcan Centaur, "4" for the number of GEM-63XL solid rocket boosters attached to the core, and "L" for the five-meter long payload fairing. Standing 67.4 meters tall with a core diameter of 5.4 meters, the Vulcan VC4L is a large-class vehicle capable of delivering 24,600 kg to low Earth orbit and 11,700 kg to geostationary transfer orbit, placing it firmly in the heavy-lift category.

The first stage is powered by two BE-4 engines developed by Blue Origin, burning liquefied natural gas and liquid oxygen. The upper stage is the Centaur V, a high-energy cryogenic stage burning liquid hydrogen and liquid oxygen, directly descended from the long-heritage Centaur upper stage that has served American launch vehicles for decades.

Operational History

Within the flight record maintained here, the Vulcan VC4L has been tracked across two missions, both conducted during the 2026–2027 period. Both missions were flown in support of Dream Chaser CRS 2, Sierra Space's uncrewed spaceplane contracted to carry cargo to and from the International Space Station under NASA's Commercial Resupply Services 2 program. The two flights — Dream Chaser CRS 2 Flight 1 and Dream Chaser CRS 2 Flight 2 — represent a significant commercial and programmatic milestone, as Dream Chaser required the larger payload fairing and performance headroom that the VC4L configuration provides.

Vulcan Centaur launches from Space Launch Complex 41 (SLC-41) at Cape Canaveral Space Force Station in Florida, the same pad used by Atlas V for many years.

Role and Significance

The VC4L configuration targets missions demanding high payload mass or volume, making it well suited for large spacecraft, crewed vehicle support, and complex government payloads. Its four-booster configuration meaningfully expands the performance envelope compared to the baseline Vulcan Centaur, while the long fairing accommodates physically large spacecraft such as Dream Chaser, which cannot be easily adapted to a smaller enclosure.

As ULA transitions its manifest from Atlas V and Delta IV to the Vulcan Centaur family, variants like the VC4L serve as critical tools for retaining high-value government and commercial customers that require heavy-lift capability with the mission assurance standards that have long defined ULA's market position.