SuperDraco firing at full thrust
|Country of origin||United States|
|Application||LAS (Launch Abort System), powered landing|
|Propellant||nitrogen tetroxide / monomethyl hydrazine|
|Thrust (vac.)||73,000 newtons (16,400 lbf)|
|Chamber pressure||6,900 kilopascals (1,000 psi) |
|Isp (SL)||235s |
|Burn time||25 seconds |
|Propellant capacity||1,388 kg (3,060 lbs)|
|Dragon V2, DragonFly test vehicle|
SuperDraco is hypergolic liquid rocket engine designed and built by SpaceX. A redundant array of eight SuperDraco engines provides fault-tolerant propulsion for use as a launch escape system and also propulsive-landing thrust for the Dragon V2 passenger-carrying space capsule.
SuperDracos will be used on both the Dragon V2 crew- and cargo-transporting space capsule as well as on the DragonFly (rocket), a prototype low-altitude reusable rocket that will be used for flight testing various aspects of the propulsive-landing technology. While the engine is capable of 73,000 newtons (16,400 lbf) of thrust, during use for DragonFly testing, the engines will be throttled to 68,170 newtons (15,325 lbf) to maintain vehicle stability.
On February 1, 2012 SpaceX announced that it had completed the development of a new, more powerful version of a storable-propellant 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, was designed to provide multiple restart capability and use the same shared hypergolic propellants as Draco. Its primary purpose was to be for SpaceX's LAS (launch abort system) on the Dragon spacecraft. According to a NASA press release, the engine has a transient from ignition to full thrust of 100 ms. During launch abort, eight SuperDracos were expected to fire for 5 seconds at full thrust. The development of the engine was partially funded by NASA's CCDev 2 program.
SuperDraco is the second most powerful engine developed by SpaceX, approximately 200 times more powerful than the Draco thruster engines. By comparison, it is more than twice as powerful as the Kestrel engine that was used in SpaceX's Falcon 1 launch vehicle second stage, and about 1/9 the thrust of a Merlin 1D engine.
In addition to the use of the SuperDraco thrusters for powered-landings on Earth, NASA's Ames Research Center is studying the feasibility of a Dragon-derived Mars lander for scientific investigation. Preliminary analysis in 2011 indicated that the final deceleration would be within the retro-propulsion SuperDraco thruster capabilities.[dated info]
The SuperDraco engine development program had an extensive test program that spanned several years. By December 2012, the SuperDraco ground-test engines had been fired a total of 58 times for a total firing-time duration of 117 seconds and SpaceX reported that the test results exceeded the original requirements for the engine. The SuperDraco completed qualification testing in May 2014 – including testing "across a variety of conditions including multiple starts, extended firing durations and extreme off-nominal propellant flow and temperatures."
On September 5, 2013 Elon Musk tweeted an image of a regeneratively cooled SuperDraco rocket chamber emerging from an EOS 3D metal printer, and indicated that it was composed of the Inconel superalloy. This was later shown to be the production technique for the flight-level engines.
It was announced in May 2014 that the flight-qualified version of the SuperDraco engine is fully printed, and is the first fully printed rocket engine. In particular, the engine combustion chamber is printed of Inconel, an alloy of nickel and iron, using a process of direct metal laser sintering, and operates at a chamber pressure 6,900 kilopascals (1,000 psi) at a very high temperature. The engines are contained in a printed protective nacelle to prevent fault propagation in the event of an engine failure. The engine completed a full qualification test in May 2014, and is slated to make its first orbital spaceflight in 2015 or 2016.
The ability to 3D print the complex parts was key to achieving the low-mass objective of the engine. According to Elon Musk, "It’s a very complex engine, and it was very difficult to form all the cooling channels, the injector head, and the throttling mechanism. Being able to print very high strength advanced alloys ... was crucial to being able to create the SuperDraco engine as it is."
- Bergin, Chris (2014-05-30). "SpaceX lifts the lid on the Dragon V2 crew spacecraft". NASAspaceflight.com. Retrieved 2014-05-30.
- James, Michael; Salton, Alexandria; Downing, Micah (November 12, 2013), Draft Environmental Assessment for Issuing an Experimental Permit to SpaceX for Operation of the Dragon Fly Vehicle at the McGregor Test Site, Texas, May 2014 – Appendices, Blue Ridge Research and Consulting, LCC, p. 12
- "SuperDraco Thruster Powers Revolutionary Launch Escape System (Rocket Thruster Test)". Satnews Daily. 2014-05-27. Retrieved 2014-05-28.
- "SpaceX Test Fires Engine Prototype for Astronaut Escape System". NASA. 2012-02-01. Retrieved 2012-02-01.
- "Red Dragon" (PDF), Feasibility of a Dragon-derived Mars lander for scientific and human-precursor investigations, 8m.net, October 31, 2011, retrieved 2012-05-14
- "NASA ADVISORY COUNCIL (NAC) - Science Committee Report" (PDF). Ames Research Center, NASA. 1 November 2011. Retrieved 2012-05-01.
- Lindsey, Clark (2012-12-14). "NASA commercial crew & cargo update - Dec. 2012". NewSpace Watch. Retrieved 2012-12-18. (subscription required (. ))
- Norris, Guy (2014-05-30). "SpaceX Unveils ‘Step Change’ Dragon ‘V2’". Aviation Week. Retrieved 2014-05-30.
- Kramer, Miriam (2014-05-30). "SpaceX Unveils Dragon V2 Spaceship, a Manned Space Taxi for Astronauts — Meet Dragon V2: SpaceX's Manned Space Taxi for Astronaut Trips". space.com. Retrieved 2014-05-30.
- Foust, Jeff (2014-05-30). "SpaceX unveils its "21st century spaceship"". NewSpace Journal. Retrieved 2014-05-31.