Delta IV Overview

Delta V family Delta IV launch vehicles can accommodate single or multiple payloads on the same mission. The rockets can launch payloads to polar orbits, sun-synchronous orbits, geosynchronous and geosynchronous transfer orbits (GTO), and low Earth orbit (LEO).

Each Delta IV rocket is assembled horizontally, erected vertically on the launch pad, integrated with its satellite payload, fueled and launched. This process reduces on-pad time to less than 10 days and the amount of time a vehicle is at the launch site to less than 30 days upon arrival from the factory. This reduces costs associated with launch site operations and increases customer schedule flexibility.


All configurations utilize a common booster core first stage with the Pratt & Whitney Rocketdyne RS-68 main engine:

  • Bell-nozzle design with fewer parts
  • Liquid hydrogen, liquid oxygen fuel mix


The Delta IV second stage possesses the following components:

  • Pratt & Whitney RL10B-2 upper stage engine
  • Two sizes of expanded fuel and oxidizer tanks

Payloads, Fairings, and Payload Attach Fittings


Delta IV vehicles can launch payloads weighing from 4,300 kg (9,480 lb) to 12,980 kg (28,620 lb) to GTO, and can lift over 23,000 kg (50,000 lbs.) to LEO.


  • Delta IV Medium and Medium+ vehicles use 4-m (13.1-ft) or 5-m (16.6-ft) diameter composite fairings.
  • The Delta IV Heavy vehicle uses a 5-m (16.6-ft) diameter composite fairing or a 19.8-m (65-ft) long, 5-m (16.6-ft) diameter aluminum fairing.

Payload Attach Fittings:

  • Compatible with industry-standard interfaces for current and future spacecraft
  • Dual-payload attach fitting capability