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GBI Orbital Boost Vehicle

Orbital is a subcontractor to The Boeing Company for the design, development and testing of a boost vehicle for the U.S. Missile Defense Agency's (MDA) Ground-based Midcourse Defense (GMD) program, formerly known as the National Missile Defense (NMD) program. The Orbital Boost Vehicle (OBV) is a silo-launched, three-stage rocket derived from our proven Pegasus, Taurus and Minotaur space launch boosters. OBV is designed to carry advanced kinetic-energy interceptors that will locate and destroy long-range hostile missiles in midcourse flight, defending against potential nuclear, chemical or biological weapons of mass destruction.

Under the contract, Orbital has modified Pegasus, Taurus and Minotaur system designs and has verified the resulting GMD booster's performance and operational features in a series of test flights. The Company is now manufacturing boosters for deployment in Alaska and California as well as for continued test flights. The "Orbital" in "OBV" refers to the company, not to the performance of the booster. The OBV was once upon a time the "alternative" or "backup" to Boeings "BV" (Boost vehicle), hence the "Orbital" BV to differentiate it from the "Official" BV.

Development of the initial GBI boost vehicle was more challenging than originally anticipated. Congressional direction in the Defense Authorization Act for fiscal year 2001 included the development of a backup booster option involving proven technologies. A decision was made to develop and test a second boost vehicle, the uncanisterized Alternate Boost Vehicle (ABV). In order to increase the current Boost Vehicle (BV) burnout velocity margin for the most stressing engagement scenarios, a redirected BV program has initiated a competition for a higher performance Alternate BV (ABV). Under pressure from MDA, Boeing set up a competition for an "alternate boost vehicle" in case the problems with the BV could not be solved. Orbital and Lockheed-Martin sumbitted proposals to Boeing. Orbital won in part due to the fact that their candidate design was a "de-rated" Space Launch Vehicle whereas Lockheed's was a "souped-up" suborbital rocket.

The ABV would consist of commercially available, three-stage, solid propellant boosters and an exoatmospheric KV emulator. The KV emulator does not contain the seeker components and normally does not contain the Divert and Attitude Control System (DACS). The emulator is a mass that simulates the configuration of a real KV in terms of weight, center of gravity, and dynamic response characteristics without any functional parts. It is instrumented with accelerometers and microphones to record shock, vibration, and acoustic environments. While the baseline configuration does not contain a divert capability, this document examines the possibility that the KV will contain the DACS components, including the liquid propellants. However, no intercepts of target missiles are planned as part of the ABV tests. The three-stage ABV missile, a variation of the Minuteman, has not been previously flight-tested in this proposed configuration.

The three-stage missile would contain no more than 30,400 kilograms (67,000 pounds) of a hydroxyl-terminated polybutadiene solid rocket fuel propellant, less than that contained in the Minuteman III missiles previously flown in this area. The ABV would have a flight termination system (FTS) that, when activated, detonates an explosive charge that ruptures the solid rocket motor casing, resulting in loss of pressure and termination of thrust.

The uncanisterized ABV test flights would require modifications to a different launch silo and would test the new design of the boost vehicles. Both LF-21 and the site chosen for the ABV testing could be used for future launches of interceptors from Vandenberg AFB, if the verification testing is successful and may require additional tests. ABV tests are needed to gain a higher degree of confidence through tests of an ABV under more operationally realistic conditions. Locations for ABV tests are limited because of the requirement for long-range and high-velocity testing capabilities, providing the capability to conduct testing in a reasonable and cost effective manner while maintaining the existing schedule.

This booster is also referred to as "OSC Lite". This booster, which is essentially the Taurus Lite missile that carries satellites into low-earth orbit, will be reconfigured for the GMD element. Despite the fact that the booster was tested under restricted flight conditions, GMD's prime contractor believed that the legacy development of the Taurus Lite missile is sufficient to prove that the OSC Lite has reached TRL 7. However, because the test was conducted with hardware configured as it was in the Taurus missile, not as it will be configured for GMD's Block 2004, the booster's maturity level is comparable to that of the BV+. The first flight test of a full configuration OSC Lite booster was scheduled for IFT-13B in the first quarter of fiscal year 2004.

MDA implemented a dual-booster development strategy as a risk reduction measure. As a result, a proven boost vehicle built by Boeing subcontractor Orbital Sciences will provide the booster rockets necessary for GMD deployment of up to 10 ground-based interceptors at Ft. Greely, Alaska, and Vandenberg Air Force Base, Calif., on the existing schedule, and for at least four boost vehicles for planned flight tests.

The Orbital Sciences booster had a successful first launch test, BV-6, in August 2003. Orbital is under contract to The Boeing Company to deliver over 50 boosters since the beginning of the contract in early 2002.

Orbital Sciences Corporation announced October 01, 2007 that its Orbital Boost Vehicle (OBV), which is the booster rocket for the Ground-Based Interceptor (GBI), was successfully launched as part of a test of the Ground-Based Midcourse Defense (GMD) program. Orbital provides the OBV as part of an industry team led by The Boeing Company (NYSE:BA) for the U.S. Missile Defense Agency (MDA). The OBV was launched from Vandenberg Air Force Base, CA on Friday, September 28 as part of the test designated as Flight Test Ground-based Midcourse Defense-03a (FTG-03a). Following its launch from a silo, the OBV flew downrange over the Pacific Ocean and successfully supported the intercept of a target vehicle that was launched earlier from Alaska.

Two-Stage Booster

The booster used for the GBIs in Europe is a two-stage configuration of the three-stage booster currently employed at Ft. Greely and VAFB. A two-stage booster has less burn time than the three-stage version, and therefore accommodates the shorter engagement timelines expected from a ballistic missile threat originating from the Middle Est. The modifications required to design, develop and produce a two-stage variant are not extensive, nor are they unprecedented. In fact, the first ten GMD Integrated Flight Tests, conducted between January 1997 and December 2002, successfully utilized a two-stage variant of the standard three-stage Minuteman booster. Additionally, the current three-stage GBI booster was derived from Orbital Sciences four-stage Minotaur launch vehicle. The risks involved with modifying the Orbital Booster are of a similar scale.

The components used in the two-stage booster are nearly identical to those already tested and fielded in the three-stage booster. In fact, the two-stage interceptor has fewer components than its three-stage predecessor. MDA has placed the two-stage booster on contract, and the preliminary analysis and design work is complete. A rigorous component qualification, integration, ground and flight testing program for the two-stage interceptor has been planned, and will include two flight tests prior to completion of the first two-stage interceptor for deployment, one of which will be a booster verification test and the other an EKV intercept of a threat-representative target.

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Page last modified: 21-07-2011 13:04:30 ZULU