Titan 4B rocket
U.S. AIR FORCE FACT SHEET
Posted: July 26, 2001
The Air Force Titan 4B launch vehicle is the
nation's largest, most powerful expendable space launch
vehicle and provides access to space for the United States
government's largest payloads. In 1989, a follow-on
procurement to the existing Titan 4A space lift vehicle
resulted in the Titan 4B model. The upgraded rocket
incorporates significant technology advancements to
decrease operational processing time and increase overall
reliability. The Titan 4B is capable of placing 47,800
pounds into low-Earth orbit or more than 12,700 pounds
into geosynchronous orbit - 22,300 miles above the
Titan 4 rocket blasts off from Complex 40. Photo: Russ Underwood, Lockheed Martin Space Systems
The Titan 4B consists of two solid-propellant
stage "0" motors, a liquid propellant two-stage core and a
16.7-foot-diameter payload fairing. Upgraded three-segment
solid rocket motors increase the vehicle's
payload capability by approximately 25 percent over the
Titan 4A. During a Titan 4 launch the strap-on solid
rocket motors are fired first. When the solid propellant is
almost depleted (approximately 130 seconds into flight),
the first stage is fired and the solid motors are separated
from the vehicle. The second stage and upper stage are
fired as the previous stage is depleted of fuel and
The Titan family of launch vehicles was
established in October 1955 when the Air Force awarded
the Martin Company (today Lockheed Martin Astronautics) a contract to build a heavy-duty space system. It
became known as the Titan 1, the nation's first two-stage, intercontinental ballistic missile (ICBM) and first
underground silo-based ICBM. The Titan 1 rocket provided many structural and propulsion techniques that were
later incorporated into the Titan 2.
Martin Company and the Martin Marietta Corporation built more than 140 Titan ICBMs, once the
vanguard of America's nuclear deterrent force, for the Air Force. Titan 2s were flown as space launch vehicles
in NASA's Gemini manned space program in the mid-1960s. Deactivation of the Titan 2 ICBM system began
in July 1982. The last missile was taken from its silo at Little Rock Air Force Base, Arkansas, on June 23, 1987.
Years later, the Titan 2 evolved into the Titan 3 family and the Titan 34D. The larger Titan expendable space
launch vehicle was originally developed as a backup for the space shuttle in the 1980s, but has become a
mainstay for heavy payloads. The Titan 4B represents significant improvements from the Titan 34D and Titan
4A from which it evolved. The first Titan 4B flew February 23, 1997 from Cape Canaveral's launch complex
40 carrying the Defense Support Program satellite designated Flight 18.
The Titan 4B's core consists of an LR87 liquid-propellant rocket that features structurally independent
tanks for its hypergolic fuel of Aerozine 50 (hydrazine and unsymmetrical dimethyl-hydrazine) and oxidizer
(Nitrogen Tetroxide). This minimizes the hazard of the two mixing if a leak should develop in either tank.
Additionally the engines' propellant can be stored in a launch-ready state for extended periods. The use of
propellants stored at normal temperature and pressure eliminates delays and gives the Titan 4B the capability
to meet critical launch windows. The second stage consists of an LR91 liquid propellant rocket engine attached
to an airframe, like stage 1.
The Titan 4B uses a "clean vehicle" approach for
delivering hardware to the launch sites. This method shifts
production-oriented tasks, such as liquid rocket engine
installation and electronic system installation, to the
factory. When the rocket is shipped to the launch site it
requires only check-out testing and a minimum of final processing.
Assembly and integration of the Solid Rocket
Motor Upgrade occurs in the new Solid Motor Assembly
and Readiness Facility at Cape Canaveral Air Station and
the Solid Motor Processing Facility at Vandenberg Air
Force Base, California.
Standard vehicle configuration
The Titan 4B common core design provides a
standard mechanical and electrical configuration to the
various upper stages and payloads. With this feature, all
Titan 4B vehicles are identical up to the interface just below the payload fairing. The Titan 4B standard
vehicle design allows hardware to be quickly reallocated to different missions as launch dates or national
priorities are changed. It also eliminates the need for unique engineering and specialized processes for each
individual core vehicle.
Solid Rocket Motor Upgrade (SRMU)
The new SRMU provides increased payload capacity and improved safety, reliability, and launch site
operability, while reducing cost per pound of payload. The SRMU features a three-segment design. Light-weight
graphite composite cases coupled with the use of high
performance propellant results in a 25 percent increase in lift
capability. The number of critical field joints has been reduced
from eight on a Titan 4A to two on the Titan 4B, with each
field joint having redundant seals. Five full-scale static test
firings qualified the motor design in 1993.
Obsolete technology and unprocurable hardware
necessitated upgrades to the Titan 4's electrical systems. The
new systems on the Titan 4B were designed to improve overall
reliability and maintainability. Guidance system technology
advancements include ring laser gyros and a new computer that
doubles data processing capability. The system is packaged in a
single guidance control unit which weighs 40 pounds less than its
Titan 4A equivalent. By using modern parts and manufacturing
techniques, the recurring cost of the guidance system has been
decreased by more than 50 percent. A new data distribution and
acquisition system provides higher data rates and more accurate
telemetry for systems evaluation.
Range safety improvements
The Titan 4B procurement also provided an opportunity to bring the Flight Termination System (FTS)
into a configuration that meets the latest range safety requirements. The Titan 4B automatic and command
destruct systems are completely redundant. The system was streamlined by combining multiple functions in a
new flight termination controller.
Programmable Aerospace Ground Equipment
Titan 4B pre-launch vehicle check-out and launch countdown are controlled by a new automated
ground processing system, called Programmable Aerospace Ground Equipment (PAGE). During the
countdown, PAGE controls vehicle processing, continuously monitoring vehicle systems status and trends. In
the event of a vehicle or ground system malfunction, PAGE can hold or abort the launch process up to ignition
of the solid rocket motors. The new PAGE system will eliminate obsolete hardware and resolve maintenance
problems with the existing system.
Flight data file
Vehicle: Titan 4B/IUS (B-31)
Launch date: July 27, 2001
Launch window: 4:08-8:08 a.m. EDT (0808-1208 GMT)
Launch site: SLC-40, Cape Canaveral, Fla.
Launch timeline - Chart with times and descriptions of events to occur during the launch.
DSP-21 - Description of the Defense Support Program satellite system.