Сұйық және қатты отынды қолданатын қозғалтқыш

Rocket engine that uses both liquid / gaseous and solid fuel

A hybrid propellant rocket is a rocket with a rocket motor that uses rocket propellants in two different phases: one solid and the other either gas or liquid. The hybrid rocket concept can be traced back to the early 1930s. Hybrid rockets avoid some of the disadvantages of solid rockets like the dangers of propellant handling, while also avoiding some disadvantages of liquid rockets like their mechanical complexity. Because it is difficult for the fuel and oxidizer to be mixed intimately (being different states of matter), hybrid rockets tend to fail more benignly than liquids or solids. Like liquid rocket engines, hybrid rocket motors can be shut down easily and the thrust is throttleable. The theoretical specific impulse performance of hybrids is generally higher than solid motors and lower than liquid engines. as high as 400 s has been measured in a hybrid rocket using metalized fuels. Hybrid systems are more complex than solid ones, but they avoid significant hazards of manufacturing, shipping and handling solid rocket motors by storing the oxidizer and the fuel separately.

The first work on hybrid rockets was performed in the early 1930s at the Soviet Group for the Study of Reactive Motion. Mikhail Klavdievich Tikhonravov, who would later supervise the design of Sputnik I and the Luna programme, was responsible for the first hybrid propelled rocket launch, the GIRD 9, on 17 August 1933, which reached an altitude of In the late 1930s at IG Farben in Germany and concurrently at the California Rocket Society in the United States. Leonid Andrussow, working in Germany, theorized hybrid propellant rockets. O. Lutz, W. Noeggerath, and Andrussow tested a hybrid rocket motor using coal and gaseous N2O as the propellants. Oberth also worked on a hybrid rocket motor using LOX as the oxidizer and graphite as the fuel. The high heat of sublimation of carbon prevented these rocket motors from operating efficiently, as it resulted in a negligible burning rate. In the 1940s, the California Pacific Rocket Society used LOX in combination with several different fuel types, including wood, wax, and rubber. The most successful of these tests was with the rubber fuel, which is still the dominant fuel in use today. In June 1951, a LOX / rubber rocket was flown to an altitude of
In the 1960s, European organizations also began work on hybrid rockets. ONERA, based in France, and Volvo Flygmotor, based in Sweden, developed sounding rockets using hybrid rocket motor technology. The ONERA group focused on a hypergolic rocket motor, using nitric acid and an amine fuel, developing the LEX sounding rocket. The company flew eight rockets: Once in April 1964, three times in June 1965, and four times in 1967. The maximum altitude the flights achieved was over The first SpaceShipOne hybrid tests were successfully conducted by Kline and eAc at Mojave, CA. In 1994, the U. S. Air Force Academy flew a hybrid sounding rocket to an altitude of The rocket used HTPB and LOX for its propellant, and reached a peak thrust of and had a thrust duration of 16 seconds. Compared with liquid based propulsion, re fueling a partially or totally depleted hybrid rocket would present significant challenges, as the solid propellant cannot simply be pumped into a fuel tank. This may or may not be an issue, depending upon how the rocket is planned to be used. In general, much less development work has been completed with hybrids than liquids or solids and it is likely that some of these disadvantages could be rectified through further investment in research and development. One problem in designing large hybrid orbital rockets is that turbopumps become necessary to achieve high flow rates and pressurization of the oxidizer. This turbopump must be powered by something. In a traditional liquid propellant rocket, the turbopump uses the same fuel and oxidizer as the rocket, since they are both liquid and can be fed to the pre burner. But in a hybrid, the fuel is solid and cannot be fed to a turbopump's engine. Some hybrids use an oxidizer that can also be used as a monopropellant, such as hydrogen peroxide, and so a turbopump can run on it alone. However, hydrogen peroxide is significantly less efficient than liquid oxygen, which cannot be used alone to run a turbopump. Another fuel would be needed, requiring its own tank and decreasing rocket performance.

A reverse hybrid rocket, which is not very common, is one where the engine uses a solid oxidizer and a liquid fuel. Some liquid fuel options are kerosene, hydrazine, and LH2. Common fuels for a typical hybrid rocket engine include polymers such as acrylics, polyethylene (PE), cross linked rubber, such as HTPB, or liquefying fuels such as paraffin wax. Plexiglass was a common fuel, since the combustion could be visible through the transparent combustion chamber. Hydroxyl terminated polybutadiene (HTPB) synthetic rubber is currently the most popular fuel for hybrid rocket engines, due to its energy, and due to how safe it is to handle. Tests have been performed in which HTPB was soaked in liquid oxygen, and it still did not become explosive. These fuels are generally not as dense as solid rocket motors, so they are often doped with aluminum to increase the density and therefore the rocket performance.

Additive manufacturing is currently being used to create grain structures that were otherwise not possible to manufacture. Helical ports have been shown to increase fuel regression rates while also increasing volumetric efficiency. An example of material used for a hybrid rocket fuel is acrylonitrile butadiene styrene (ABS). The printed material is also typically enhanced with additives to improve rocket performance.

Common oxidizers include gaseous or liquid oxygen, nitrous oxide, and hydrogen peroxide. For a reverse hybrid, oxidizers such as frozen oxygen and ammonium perchlorate are used. The Virgin Galactic SpaceShipTwo follow on commercial suborbital spaceplane uses a scaled up hybrid motor. SpaceDev was developing the SpaceDev Streaker, an expendable small launch vehicle, and SpaceDev Dream Chaser, capable of both suborbital and orbital human space flight. Both Streaker and Dream Chaser use hybrid rocket motors that burn nitrous oxide and the synthetic HTPB rubber. SpaceDev was acquired by Sierra Nevada Corporation in 2009, becoming its Space Systems division, which continues to develop Dream Chaser for NASA's Commercial Crew Development contract. Sierra Nevada also developed RocketMotorTwo, the hybrid engine for SpaceShipTwo. On October 31, 2014, when SpaceShipTwo was lost, initial speculation had suggested that its hybrid engine had in fact exploded and killed one test pilot and seriously injured the other. However, investigation data now indicates an early deployment of the SpaceShip Two feather system was the cause for aerodynamic breakup of the vehicle. U. S. Rockets manufactured and deployed hybrids using self pressurizing nitrous oxide (N2O) and hydroxyl terminated polybutadiene (HTPB) as well as mixed High test peroxide (HTP) and HTPB. The High test peroxide (H2O2) 86% and (HTPB) and aluminum hybrids developed by U. S. Rockets produced a sea level delivered specific impulse (Isp) of 240, well above the typical 180 of N2O HTPB hybrids. In addition to that, they were self starting, restartable, had considerably lower combustion instability making them suitable for fragile or crewed missions such as Bloodhound SSC, SpaceShipTwo or SpaceShipThree. The company had successfully tested and deployed both pressure fed and pump fed versions of the latter HTP HTPB style. Deliverables to date have ranged from 6 inch to 18 inch diameter, and developed units up to 54 inch diameter. The vendor claimed scalability to over 5 meters diameter with regression rates approaching solids, according to literature distributed at the November 2013 Defense Advanced Research Projects Agency (DARPA) meeting for XS 1. U. S. Rockets is no longer manufacturing large scale rockets. Gilmour Space Technologies began testing Hybrid rocket engines in 2015 with both N2O and HP with HDPE and HDPE+wax blends. For 2016 testing includes a HP/PE engine. The company is planning to use hybrids for both sounding and orbital rockets. Orbital Technologies Corporation (Orbitec) has been involved in some U. S. government funded research on hybrid rockets including the "Vortex Hybrid" concept. Environmental Aeroscience Corporation (eAc) was incorporated in 1994 to develop hybrid rocket propulsion systems. It was included in the design competition for the SpaceShipOne motor but lost the contract to SpaceDev. Environmental Aeroscience Corporation still supplied parts to SpaceDev for the oxidizer fill, vent, and dump system. Rocket Lab formerly sold hybrid sounding rockets and related technology. The Reaction Research Society (RRS), although known primarily for their work with liquid rocket propulsion, has a long history of research and development with hybrid rocket propulsion. Copenhagen Suborbitals, a Danish rocket group, has designed and test fired several hybrids using N2O at first and currently LOX. Their fuel is epoxy, paraffin wax, or polyurethane. The group eventually moved away from hybrids because of thrust instabilities, and now uses a motor similar to that of the V 2 rocket. TiSPACE is a Taiwanese company which is developing a family of hybrid propellant rockets. bluShift Aerospace in Brunswick, Maine, won a NASA SBIR grant to develop a modular hybrid rocket engine for its proprietary bio derived fuel in June 2019. Having completed the grant bluShift has launched its first sounding rocket using the technology. Vaya Space based out of Cocoa, Florida, is expected to launch its hybrid fuel rocket Dauntless in 2023. Reaction Dynamics based out Saint Jean sur Richelieu, Quebec, began developing a hybrid rocket engine in 2017 capable of producing 21.6 kN of thrust. Their Aurora rocket will use nine engines on the first stage and one engine on the second stage and will be capable of delivering a payload of 50–150 kg to LEO. In May 2022, Reaction Dynamics announced they were partnering with Maritime Launch Services to launch the Aurora rocket from their launch site currently under construction in Canso, Nova Scotia, beginning with suborbital test flights in Summer, 2023 with a target of 2024 for the first orbital launch. In 2017 DeltaV Uzay Teknolojileri A.Ş. was founded by Savunma Sanayi Teknolojileri A.Ş (SSTEK), a state company of Turkiye, for hybrid propellant rocket research. The company CEO Arif Karabeyoglu is former Consulting Professor of Stanford University in the area of rocket propulsion and combustion. According to company web site DeltaV achived many firsts in hybrid propellant rocket technology including first paraffin/LOX dual fuel rocket launch, highest specific impulses for a hybrid propellant rocket, first sounding rocket to reach 100 km altittude, first orbital hybrid propellant rocket design, first orbital firing of hybrid propellant rocket.

There are a number of hybrid rocket motor systems available for amateur/hobbyist use in high powered model rocketry. These include the popular HyperTek systems and a number of 'Urbanski Colburn Valved' (U/C) systems such as RATTWorks, Contrail Rockets, and Propulsion Polymers. All of these systems use nitrous oxide as the oxidizer and a plastic fuel (such as Polyvinyl chloride (PVC), Polypropylene), or a polymer based fuel such as HTPB. This reduces the cost per flight compared to solid rocket motors, although there is generally more ground support equipment required with hybrids.

An October 26, 2005 episode of the television show MythBusters entitled "Confederate Rocket" featured a hybrid rocket motor using liquid nitrous oxide and paraffin wax. The myth purported that during the American Civil War, the Confederate Army was able to construct a rocket of this type. The myth was revisited in a later episode entitled Salami Rocket, using hollowed out dry salami as the solid fuel. In the February 18, 2007, episode of Top Gear, a Reliant Robin was used by Richard Hammond and James May in an attempt to modify a normal K reg Robin into a reusable Space Shuttle. Steve Holland, a professional radio controlled aircraft pilot, helped Hammond to work out how to land a Robin safely. The craft was built by senior members of the United Kingdom Rocketry Association (UKRA) and achieved a successful launch, flew for several seconds into the air and managed to successfully jettison the solid fuel rocket boosters on time. This was the largest rocket launched by a non government organisation in Europe. It used 6 × 40960 NS O motors by Contrail Rockets giving a maximum thrust of 8 tonnes. However, the car failed to separate from the large external fuel tank due to faulty explosive bolts between the Robin and the external tank, and the Robin subsequently crashed into the ground and seemed to have exploded soon after. This explosion was added for dramatic effect as neither Reliant Robins nor hybrid rocket motors explode in the way depicted.