Delta 2313

Delta 2313

The Delta 2313 is an American expendable orbital launch vehicle operated by NASA and manufactured by McDonnell Douglas, representing one of the many incremental variants of the long-running Delta rocket family. Like other members of the Thor-Delta lineage, the 2313 was designed to provide reliable medium-lift launch services for government and commercial satellite customers during the 1970s.

Design and Configuration

Standing 35 metres tall with a core diameter of 2.44 metres, the Delta 2313 follows the modular design philosophy that defined the Delta family throughout this era. The four-digit variant designation encodes the vehicle's configuration: the number of strap-on solid rocket boosters, the type of second stage, the third stage, and the fairing arrangement. The 2313 designation indicates a configuration featuring a cluster of solid strap-on boosters augmenting the main liquid-fueled core stage, a proven approach that allowed engineers to tune performance to mission requirements. The vehicle is capable of delivering approximately 500 kg to low Earth orbit, placing it in the light-to-medium payload class suited to the communications and scientific satellites of its day.

Launches were conducted from facilities on the Eastern Range at Cape Canaveral, Florida, the primary site for Delta operations during this period.

Operational History

The Delta 2313 flew during a relatively compact period of activity, with all tracked flights occurring between 1974 and 1977. Across three recorded flights, the vehicle achieved two successes and one failure or partial failure, yielding a success rate consistent with the broader challenges of launch vehicle development during this generation of spaceflight.

The United States Air Force stands as the vehicle's most prominent customer in the flight record, reflecting the Delta family's important role in placing military communications satellites into orbit during the Cold War era. Among the missions associated with the Delta 2313 are Skynet IIA and Skynet IIB, British military communications satellites procured under a defense relationship between the United Kingdom and the United States, as well as Sirio 1, an Italian scientific and communications satellite, demonstrating the vehicle's role in supporting allied and international space programs.

Legacy and Context

The Delta 2313 sits within one of the most significant lineages in launch vehicle history. The Delta family, tracing its origins to the Thor intermediate-range ballistic missile of the late 1950s, evolved through dozens of configurations over several decades and became a workhorse of American civil and military space launch operations. Each variant designation reflected incremental upgrades in booster count, stage performance, and fairing size, allowing the rocket to grow alongside the increasing mass and complexity of commercial and government payloads.

Although the 2313 configuration had a brief operational window, its missions contributed meaningfully to the deployment of NATO-allied communications infrastructure and international scientific capability during a formative period in the use of geostationary orbit. The vehicle embodies the pragmatic, iterative engineering culture that made the Delta family one of the most reliable and enduring launch vehicle programs of the twentieth century.