The Delta IV Heavy is expendable rocket, the largest type of the Delta IV family.

It is similar to the Medium+ (5,2), except that it uses two additional CBCs instead of using GEMs. These are strap-on boosters which are separated earlier in the flight than the center CBC. The Delta IV Heavy also features a stretched 5-meter composite payload fairing. An aluminum trisector (3 part) fairing derived from the Titan IV

Titan IV

The Titan IV family of space boosters were used by the U.S. Air Force. They were launched from Cape Canaveral Air Force Station, Florida, and Vandenberg Air Force Base, California. At the time of its introduction, the Titan IV was the "largest unmanned space booster used by the Air Force."The...

 fairing is also available. This was first used on the DSP-23 flight.

Capacity (separated spacecraft mass) of the Delta IV Heavy:

• Low Earth orbit
  Low Earth orbit
  A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
  
   (LEO) 22,950 kg
• geosynchronous transfer orbit (GTO) 13,130 kg (28,950 lb), more than any other currently available launch vehicle.
• geosynchronous orbit
  Geosynchronous orbit
  A geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...
  
   (GEO) 6,275 kg
• escape orbit 9,306 kg
• C₃
  Characteristic energy
  In astrodynamics a characteristic energy , a form of specific energy, is a measure of the energy required for an interplanetary mission that requires attaining an excess orbital velocity over an escape velocity required for additional orbital maneuvers...
  
   performance of 30 km²s⁻²: 5,228 kg
• C₃ performance of 60 km²s⁻²: 2,521 kg

The Heavy's total mass at launch is approximately 733,000 kg, much less than that of the Space Shuttle

Space Shuttle

The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

 (2,040,000 kg), but is not reused.

The Orion Multi-Purpose Crew Vehicle is planned for an unmanned test flight launch, known as OFT-1, aboard a Delta IV Heavy rocket in July 2013. If launched, it would be its first launch into orbit.