Big Dumb Booster (BDB) is a general class of

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...

based on the premise that it is cheaper to operate large rockets of simple design than it is to operate smaller, more complex ones regardless of the lower payload efficiency.Schnitt, Arthur (1998
''Minimum Cost Design for Space Operations''.
/ref> As referred to by the

Office of Technology Assessment The Office of Technology Assessment (OTA) was an office of the United States Congress that operated from 1974 to 1995. OTA's purpose was to provide congressional members and committees with objective and authoritative analysis of the complex scien ...

: Even though the large minimum-cost design (MCD) booster is less efficient for all around operation, its total cost of operation is cheaper because it is easier to build, operate and maintain, with the benefit of high reliability because of reduced parts counts.

History

Concept work was led by proponents at

Aerospace Corporation The Aerospace Corporation is an American nonprofit corporation that operates a federally funded research and development center (FFRDC) in El Segundo, California. The corporation provides technical guidance and advice on all aspects of space mi ...

, TRW, and

Aerojet General Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp. I ...

, beginning in the late 1950s. The typical approach included

maraging steel Maraging steels (a portmanteau of "martensitic" and "aging") are steels that are known for possessing superior strength and toughness without losing ductility. ''Aging'' refers to the extended heat-treatment process. These steels are a special clas ...

( HY-140) for structure, pressure-fed engines using /

UDMH Unsymmetrical dimethylhydrazine (UDMH; 1,1-dimethylhydrazine, НДМГ or codenamed Geptil) is a chemical compound with the formula H2NN(CH3)2 that is used as a rocket propellant. It is a colorless liquid, with a sharp, fishy, ammonia-like smell ...

, later

LOX Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an appli ...

RP-1 RP-1 (alternatively, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. RP-1 provides a lower specific impulse than liquid hydrogen (LH2), but is cheaper, is st ...

, with pintle injectors scaled up from TRW's Lunar Module Descent Engine (LMDE). The Sea Dragon was an extremely large BDB/MCD 2-stage launch vehicle defined by

Robert Truax Captain Robert C. Truax (United States Navy, USN) (September 3, 1917 – September 17, 2010) was an American Aerospace engineering, rocket engineer in the United States Navy, and companies such as Aerojet and Truax Engineering, which he founded. T ...

and others at Aerojet. Space Technology Laboratories, Inc. (TRW) contributed to the design effort. It was to be able to carry a payload of over 500 metric tons into low Earth orbit. TRW (now

Northrop Grumman Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military techn ...

) developed and fired several engines, including their

TR-106 The TR-106 or low-cost pintle engine (LCPE) was a developmental rocket engine designed by TRW Inc., TRW under the Space Launch Initiative to reduce the cost of Launch service provider, launch services and space flight. Operating on LOX/LH2 the en ...

, a robust, low-cost engine of 2890 kN (650 klb) thrust to demonstrate the engine technology readiness.Dressler, Gordon A. and J. Martin Bauer (2000
''TRW Pintle Engine Heritage and Performance Characteristics''
AIAA 2000-3871. TRW also defined a low-cost shuttle-surrogate booster to launch 29 metric tons into a 28-degree orbit at a cost of about $59 million.TRW, Inc., “Low Cost Shuttle Surrogate Booster (LCSSB),” final report (Redondo Beach, Calif., 15 May 1981). Beal Aerospace furthered the quintessential BDB/MCD with their BA-1 and BA-2 launch vehicles.Beal Aerospace Technologies, Inc

Minimum cost design

The MCD methodology was developed by Arthur Schnitt. It is a process of making trade analyses to understand the cost versus mass implications. It is not a specific design choice like pressure-fed engines or single engine per stage. The process shows how to reduce costs by allowing mass to increase where there is a favorable impact on life-cycle cost. Some of the early design concepts were referred to as big dumb boosters, not necessarily in a favorable manner. The cost of a launch vehicle relative to the payload mass (e.g. dollars per kilogram to orbit) can be determined from the rocket equation, along with mass ratios and cost ratios. As low-tech rocket hardware gets heavier (such as the mass of tanks relative to propellants and the mass of engines relative to thrust), the cost of that hardware (dollars per kg of material) must become vastly cheaper, which explains why a big dumb booster would likely be impractical.“Launch Vehicle Cost: A Low Tech Analysis,” J. Whitehead, AIAA 2000-3140, 36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 16–19 July 2000. Figure 4 in this reference compares options for reducing cost.

References and notes

{{reflist Spacecraft propulsion

History

Minimum cost design

See also

References and notes