The SpaceX Draco is a
hypergolic
A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other.
The two propellant components usually consist of a fuel and an oxidizer. The ...
liquid
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, an ...
rocket engine
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive Jet (fluid), jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, i ...
designed and built by
SpaceX
Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...
for use in their
space capsule
A space capsule is an often-crewed spacecraft that uses a blunt-body reentry capsule to reenter the Earth's atmosphere without wings. Capsules are distinguished from other satellites primarily by the ability to survive reentry and return a paylo ...
s. Two engine types have been built to date: Draco and SuperDraco.
The original Draco
thruster
Thruster may refer to:
Propulsion devices
A thruster is a propulsive device used by spacecraft and watercraft for station keeping, attitude control, in the reaction control system, or long-duration, low-thrust acceleration.
* Reaction eng ...
is a small rocket engine for use on the
Dragon spacecraft.
SuperDraco
SuperDraco is a hypergolic propellant rocket engine designed and built by SpaceX. It is part of the SpaceX Draco family of rocket engines. A redundant array of eight SuperDraco engines provides fault-tolerant propulsion for use as a launch escap ...
uses the same
storable (non-cryogenic) hypergolic
propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the ...
as the small Draco thrusters, but is much larger and delivers over 100 times the
thrust
Thrust is a reaction force
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can al ...
. SuperDraco engines are being used on the
Crew Dragon
Dragon 2 is a class of partially reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX, primarily for flights to the International Space Station (ISS). SpaceX has also launched private missions such as In ...
spacecraft to provide
launch-escape capability in case of a failure in the launch vehicle.
Draco and SuperDraco combine the functions of a
reaction control system
A reaction control system (RCS) is a spacecraft system that uses thrusters to provide attitude control and translation. Alternatively, reaction wheels are used for attitude control. Use of diverted engine thrust to provide stable attitude con ...
and
main propulsive engine.
Draco
Draco thrusters generate 400
newtons
The newton (symbol: N) is the unit of force in the International System of Units (SI). It is defined as 1 kg⋅m/s, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after Isaac Newton in ...
(90
pounds-force
The pound of force or pound-force (symbol: lbf, sometimes lbf,) is a unit of force used in some systems of measurement, including English Engineering units and the foot–pound–second system.
Pound-force should not be confused with pound- ...
) of thrust using a
storable propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...
mixture of
monomethyl hydrazine
Monomethylhydrazine (mono-methyl hydrazine, MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula . It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such a ...
fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy bu ...
and
nitrogen tetroxide
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium ...
oxidizer
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...
. The Draco thrust is comparable to the
Marquardt R-4D engine developed for the Apollo Service and Lunar Modules in the 1960s and used for apogee/perigee maneuvers, orbit adjustment, and attitude control.
Sixteen Draco thrusters are used on the
Dragon spacecraft
American private space transportation company SpaceX has developed and produced several spacecraft named Dragon. The first family member, now referred to as Dragon 1, flew 23 cargo missions to the ISS between 2010 and 2020 before being retired. ...
for
attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
and maneuvering.
SuperDraco
On February 1, 2012 SpaceX announced that it had completed the development of a new, more powerful
storable-propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, th ...
rocket engine, this one called SuperDraco. This high-thrust hypergolic engine—about 200 times larger than the Draco RCS thruster hypergolic engine—offers deep throttling ability and just like the Draco thruster, has multiple restart capability and uses the same shared hypergolic propellants. Its primary purpose is for SpaceX's
LAS (launch abort system) on the Dragon spacecraft. According to the NASA press release, the engine has a transient from ignition to full thrust of 100 ms.
The development of the engine was partially funded by NASA's
CCDev 2 program.
SuperDracos are used on both the
Crew Dragon
Dragon 2 is a class of partially reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX, primarily for flights to the International Space Station (ISS). SpaceX has also launched private missions such as In ...
and were used on the
SpaceX DragonFly, a prototype low-altitude
test article that was used for
flight test
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. D ...
ing various aspects of the propulsive-landing technology. While the engine is capable of of thrust, during use for DragonFly testing, the engines were planned to be
throttled to to maintain vehicle stability.
First firing of all 8 Super Draco engines took place on 6 May 2015 at 9am EST at the SpaceX Crew Dragon Pad Abort Test.
SuperDraco engines are capable of being restarted many times, and have the capability to
deeply reduce their thrust providing precise control during
propulsive landing
Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing", "touchdown" or ...
of the Dragon capsule.
SpaceX have since announced they will not be using propulsive landing on the Dragon 2.
, SuperDraco is the third most powerful engine developed by SpaceX, approximately 200 times
[
] more powerful than the Draco RCS thruster engines, and only outmatched by the
Raptor and
Merlin
Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and le ...
.
In addition to the use of the SuperDraco thrusters for powered-landings on Earth,
NASA's Ames Research Center studied the feasibility of a
Dragon-derived Mars lander for scientific investigation until 2017.
[ Preliminary analysis indicated that the final deceleration needed would be within the retro-propulsion SuperDraco thruster capabilities.][
][
]
See also
* SpaceX Kestrel
*SpaceX Merlin
Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9 and Falcon Heavy launch vehicles. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin eng ...
*SpaceX Raptor
Raptor is a family of full-flow staged-combustion-cycle rocket engines developed and manufactured by SpaceX for use on the in-development SpaceX Starship. The engine is powered by cryogenic liquid methane and liquid oxygen ("methalox") rather ...
References
External links
Official SpaceX announcement and test video
Multiple Draco Test Firings
Test firing video of a set of five Draco thrusters for various intervals, SpaceX, 2010-01-27.
{{DEFAULTSORT:Draco (Rocket Engine)
SpaceX rocket engines
Rocket engines using hypergolic propellant
Rocket engines using the pressure-fed cycle
Rocket engines of the United States