The Dragon 2 ''DragonFly'' (Dragon C201) was a prototype

suborbital A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the surface of the gravitating body from which it was launched. Hence, it will not complete one orbital revolution, will no ...

rocket-powered test vehicle for a propulsively-landed version of the

SpaceX Dragon 2 Dragon 2 is a class of partially reusable spacecraft developed, manufactured, and operated by the American space company SpaceX for flights to the International Space Station (ISS) and private spaceflight missions. The spacecraft, which consi ...

. ''DragonFly'' underwent testing in Texas at the McGregor Rocket Test Facility in October 2015. However, the development eventually ceased, with SpaceX citing a verification burden imposed by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

Design

The ''DragonFly'' test vehicle is powered by eight SuperDraco

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 ...

rocket engines, arranged in a redundant pattern to support

fault-tolerance Fault tolerance is the ability of a system to maintain proper operation despite failures or faults in one or more of its components. This capability is essential for high-availability, mission critical, mission-critical, or even life-critical sys ...

in the propulsion system design. SuperDracos use 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 another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, th ...

combination of

monomethylhydrazine Monomethylhydrazine (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 as nitrogen tetroxide () ...

(MMH)

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 (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...

and

nitrogen tetroxide Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russian 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 ''electron donor''). In ot ...

(NTO), the same propellants used in the much smaller Draco thrusters designed for

attitude control Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle or satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, ...

and maneuvering on the first-generation

Dragon spacecraft Dragon is a family of spacecraft developed and produced by American private space transportation company SpaceX. The first variant, later named Dragon 1, flew 23 cargo missions to the International Space Station (ISS) between 2010 and 2020 be ...

. While SuperDraco engines are capable of of thrust, during use on DragonFly flight test vehicle, each will be throttled to less than to maintain vehicle stability.

History

In May 2014, SpaceX publicly announced an extensive test program for a propulsively-landed

space capsule A space capsule is a spacecraft designed to transport cargo, scientific experiments, and/or astronauts to and from space. Capsules are distinguished from other spacecraft by the ability to survive reentry and return a payload to the Earth's surfa ...

called ''DragonFly''. The tests were to be run in Texas at the McGregor Rocket Test Facility in 2014–2015. A flight test program of up to 60 flights was proposed. An outline for thirty of those flights included two ''propulsive assist'' (parachutes plus thrusters) and two ''propulsive landing'' (no parachutes) landing-only test flights, where DragonFly would be dropped from a helicopter at an altitude of approximately . The other 26 test flights were projected to be vertical takeoff, vertical landing (VTVL) test flights that would take off from a purpose-built pad: eight were to be ''propulsive assist hops'' (landing with parachutes plus thrusters) and 18 were to be ''full propulsive hops'', where the landing is made with only rocket propulsion, similar to the

Grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...

and F9R Dev booster stage test flights that SpaceX also flew out of their McGregor facility. Test flights were planned to include a subset of tests that would test both the DragonFly space capsule and the attached trunk, an unpressurized structure that typically carries mission-specific cargo and houses the power supply system for Dragon orbital flights. The others were planned to be test landings of only the capsule itself, without the trunk. A Final Environmental Assessment was issued by the FAA in August 2014. The FAA determined that the ''DragonFly'' test program "would not significantly impact the quality of the human environment." The assessment estimated that the program would take two years for SpaceX to complete and considered a total of 30 annual operations of the ''DragonFly'' test vehicle in each year of operation. SpaceX received a renewal permit from the FAA on July 29, 2016, to continue another year of flight testing. The DragonFly test vehicle—formerly the Dragon2 test article that was used in the May 2015 pad abort test—was at McGregor for the start of the two-year test program by October 2015. However, the development eventually ceased as the verification burden imposed by

was too great to justify it.

References

External links

* {{Reusable launch systems SpaceX Dragon 2 Experimental rockets of the United States Individual space vehicles SpaceX prototype vehicles Suborbital spaceflight VTVL rockets

Design

History

See also

References

External links