Big Dumb Booster (BDB) is a general class of launch vehicle 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. [1] As referred to by the Office of Technology Assessment:
The term Big Dumb Booster has been applied to a wide variety of concepts for low-cost launch vehicles, especially those that would use "low technology" approaches to engines and propellant tanks in the booster stage. As used here, it refers to the criterion of designing launch systems for minimum cost by using simplified subsystems where appropriate. [2]
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. [1]
Concept work was led by proponents at Aerospace Corporation, TRW, and Aerojet General, beginning in the late 1950s. The typical approach included maraging steel (HY-140) for structure, pressure-fed engines using N2O4 / UDMH, later LOX /RP-1, with pintle injectors scaled up from TRW's Lunar Module Descent Engine (LMDE). [1] [3]
The Sea Dragon was an extremely large BDB/MCD 2-stage launch vehicle defined by Robert Truax 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. [4]
TRW (now Northrop Grumman) developed and fired several engines, including their TR-106, a robust, low-cost engine of 2890 kN (650 klb) thrust to demonstrate the engine technology readiness. [5] [6] 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. [3] [7]
Beal Aerospace furthered the quintessential BDB/MCD with their BA-1 and BA-2 launch vehicles. [8]
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. [1]
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. [9]
A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; The inception of gunpowder rockets in warfare can be credited to the ancient Chinese, and in the 13th century, the Mongols played a pivotal role in facilitating their westward adoption.
The Centaur is a family of rocket propelled upper stages that has been in use since 1962. It is currently produced by U.S. launch service provider United Launch Alliance, with one main active version and one version under development. The 3.05 m (10.0 ft) diameter Common Centaur/Centaur III flies as the upper stage of the Atlas V launch vehicle, and the 5.4 m (18 ft) diameter Centaur V has been developed as the upper stage of ULA's new Vulcan rocket. Centaur was the first rocket stage to use liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, a high-energy combination that is ideal for upper stages but has significant handling difficulties.
The Delta rocket family was a versatile range of American rocket-powered expendable launch systems that provided space launch capability in the United States from 1960 to 2024. Japan also launched license-built derivatives from 1975 to 1992. More than 300 Delta rockets were launched with a 95% success rate. The series was phased out in favor of the Vulcan Centaur, with the Delta IV Heavy rocket's last launch occurring on April 9, 2024.
Merlin is a family of rocket engines developed by SpaceX. They are currently a part of the Falcon 9 and Falcon Heavy launch vehicles, and were formerly used on the Falcon 1. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin engine was originally designed for sea recovery and reuse, but since 2016 the entire Falcon 9 booster is recovered for reuse by landing vertically on a landing pad using one of its nine Merlin engines.
The RS-68 (Rocket System-68) was a liquid-fuel rocket engine that used liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants in a gas-generator cycle. It was the largest hydrogen-fueled rocket engine ever flown.
The staged combustion cycle is a power cycle of a bipropellant rocket engine. In the staged combustion cycle, propellant flows through multiple combustion chambers, and is thus combusted in stages. The main advantage relative to other rocket engine power cycles is high fuel efficiency, measured through specific impulse, while its main disadvantage is engineering complexity.
The pressure-fed engine is a class of rocket engine designs. A separate gas supply, usually helium, pressurizes the propellant tanks to force fuel and oxidizer to the combustion chamber. To maintain adequate flow, the tank pressures must exceed the combustion chamber pressure.
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. In 2013, Aerojet was merged by GenCorp with the former Pratt & Whitney Rocketdyne to form Aerojet Rocketdyne.
The Sea Dragon was a 1962 conceptualized design study for a two-stage sea-launched orbital super heavy-lift launch vehicle. The project was led by Robert Truax while working at Aerojet, one of a number of designs he created that were to be launched by floating the rocket in the ocean. Although there was some interest at both NASA and Todd Shipyards, the project was not implemented.
Aquarius is a launch vehicle concept designed for low-cost by Space Systems/Loral to carry small, inexpensive payloads into LEO.
The NK-33 and NK-43 are rocket engines designed and built in the late 1960s and early 1970s by the Kuznetsov Design Bureau. The NK designation is derived from the initials of chief designer Nikolay Kuznetsov. The NK-33 was among the most powerful LOX/RP-1 rocket engines when it was built, with a high specific impulse and low structural mass. They were intended for the ill-fated Soviet N1F Moon rocket, which was an upgraded version of the N1. The NK-33A rocket engine is now used on the first stage of the Soyuz-2-1v launch vehicle. When the supply of the NK-33 engines are exhausted, Russia will supply the new RD-193 rocket engine. It used to be the first stage engines of the Antares 100 rocket series, although those engines are rebranded the AJ-26 and the newer Antares 200 and Antares 200+ rocket series uses the RD-181 for the first stage engines, which is a modified RD-191, but shares some properties like a single combustion chamber unlike the two combustion chambers used in the RD-180 of the Atlas V and the four combustion chambers used in the RD-170 of the Energia and Zenit rocket families, and the RD-107, RD-108, RD-117, and RD-118 rocket engines used on all of the variants of the Soyuz rocket.
The Space Launch Initiative (SLI) was a NASA and U.S. Department of Defense joint research and technology project to determine the requirements to meet all the nation's hypersonics, space launch and space technology needs. It was also known as the second generation Reusable Launch Vehicle program, after the failure of the first. The program began with the award of RLV study contracts in 2000.
The pintle injector is a type of propellant injector for a bipropellant rocket engine. Like any other injector, its purpose is to ensure appropriate flow rate and intermixing of the propellants as they are forcibly injected under high pressure into the combustion chamber, so that an efficient and controlled combustion process can happen.
The TR-106 or low-cost pintle engine (LCPE) was a developmental rocket engine designed by TRW under the Space Launch Initiative to reduce the cost of launch services and space flight. Operating on LOX/LH2 the engine had a thrust of 2892 kN, or 650,000 pounds, making it one of the most powerful engines ever constructed.
Rocket propellant is the reaction mass of a rocket. This reaction mass is ejected at the highest achievable velocity from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.
The descent propulsion system or lunar module descent engine (LMDE), internal designation VTR-10, is a variable-throttle hypergolic rocket engine invented by Gerard W. Elverum Jr. and developed by Space Technology Laboratories (TRW) for use in the Apollo Lunar Module descent stage. It used Aerozine 50 fuel and dinitrogen tetroxide oxidizer. This engine used a pintle injector, which paved the way for other engines to use similar designs.
The TR-201 or TR201 is a hypergolic pressure-fed rocket engine used to propel the upper stage of the Delta rocket, referred to as Delta-P, from 1972 to 1988. The rocket engine uses Aerozine 50 as fuel, and N
2O
4 as oxidizer. It was developed in the early 1970s by TRW as a derivative of the lunar module descent engine (LMDE). This engine used a pintle injector first invented by Gerard W. Elverum Jr. and developed by TRW in the late 1950s and received US Patent in 1972. This injector technology and design is also used on SpaceX Merlin engines.
The DARPA XS-1 was an experimental spaceplane/booster with the planned capability to deliver small satellites into orbit for the U.S. Military. It was reported to be designed to be reusable as frequently as once a day, with a stated goal of doing so for 10 days straight. The XS-1 was intended to directly replace the first stage of a multistage rocket by taking off vertically and flying to hypersonic speed and high suborbital altitude, enabling one or more expendable upper stages to separate and deploy a payload into low Earth orbit. The XS-1 would then return to Earth, where it could ostensibly be serviced fast enough to repeat the process at least once every 24 hours.
KVD-1 was an upper stage LOX/LH2 cryogenic engine developed by the Isayev Design Bureau (now KB KhIMMASH) of Russia in the early 1960s. It is a modified version of the RD-56, developed for a never-completed cryogenic upper stage of the N-1 super-heavy lift rocket, with the goal of enabling crewed lunar missions by the USSR. The KVD-1 produces a thrust of 7.5 tonnes.
During the lifetime of the Space Shuttle, Rockwell International and many other organizations studied various Space Shuttle designs. These involved different ways of increasing cargo and crew capacity, as well as investigating further reusability. A large focus of these designs were related to developing new shuttle boosters and improvements to the central tank, but also looked to expand NASA's ability to launch deep space missions and build modular space stations. Many of these concepts and studies would shape the concepts and programs of the 2000s such as the Constellation, Orbital Space Plane Program, and Artemis program.