'Spaceplane' that flies 25 times faster than the speed of sound passes crucial test

[mystery-ak]

'Spaceplane' that flies 25 times faster than the speed of sound passes crucial test
By Charlotte Edwards, Digital Technology and Science Reporter | The Sun



A 'spaceplane' that flies 25 times faster than the speed of sound has successfully passed a crucial testing milestone.

The hypersonic plane is so fast it could jet from London to New York in less than 60 minutes and transport you from the UK to Australia in four hours.

Oxford-based Reaction Engines has been working with the European Space Agency and the UK Space Agency, along with BAE Systems, to make the powerful aircraft.

Reaction Engines has recently been testing a 'pre-cooler' for the plane, which is technology that would allow it to travel faster than ever before.

The pre-cooler is critical in the plane's development because it is required to stop the engine from melting by lowering the temperature of compressed air in the engine from more than 1,000°C to room temperature in one-twentieth of a second.

more
https://www.foxnews.com/tech/spaceplane-that-flies-25-times-faster-than-the-speed-of-sound-passes-crucial-test

[Elderberry]

Reaction Engines Test Proves Precooler Capability at Supersonic Heat Conditions

http://www.parabolicarc.com/2019/04/08/reaction-engines-test-proves-precooler-capability-supersonic-heat-conditions/


                       Reaction Engines test stand (Credit: Reaction Engines)

WATKINS, Colo. (Reaction Engines PR) — A key element of the revolutionary SABRE™ air-breathing rocket engine successfully passes the first phase of high-temperature testing. Precooler technology will enable a wide variety of high-speed flight and advanced propulsion systems.

Reaction Engines’ precooler heat exchanger successfully achieved all test objectives in the first phase of high-temperature testing designed to directly replicate supersonic flight conditions and future tests are planned at even higher temperatures. The precooler is a key element of Reaction Engines’ revolutionary SABRE engine and is a potential enabling technology for advanced propulsion systems and other commercial applications.

The ground-based tests saw Reaction Engines’ unique precooler successfully quench the 420°C (~788°F) intake airflow in less than 1/20th of a second. The intake temperature replicates thermal conditions corresponding to Mach 3.3 flight, or over three times the speed of sound. Mach 3.3 matches the speed record of the SR-71 Blackbird aircraft, the world’s fastest jet-engine powered aircraft produced to date and is over 50% faster than the cruising speed of Concorde.

More at link above

[Joe Wooten]

Interesting! A British company doing their testing in the US.

[Elderberry]

Interesting! A British company doing their testing in the US.

@Joe Wooten

https://en.wikipedia.org/wiki/Reaction_Engines_Limited

In January 2014, REL entered into a Cooperative research and development agreement (CRADA) with the United States Air Force Research Laboratory (AFRL) to assess and develop SABRE technology.[13]

In 2015 AFRL announced their analysis "confirmed the feasibility and potential performance of the SABRE engine cycle.” however they felt SSTO as a first application was a very high risk development path and proposed that a Two Stage to Orbit (TSTO) vehicle was a more realistic first step.

In 2015 BAE Systems agreed to buy a 20% stake in the company for £20.6m as part of an agreement to help develop Reaction's Synergetic Air-Breathing Rocket Engine (SABRE) hypersonic engine designed to propel the Skylon orbiter.[5][6]

In 2016 AFRL released two TSTO concepts using SABRE in the first stage: The first 150 feet (46 m) long carrying an expendable upper stage in an underside opening cargo bay capable of delivering around 5,000 pounds (2.3 t) to a 100 nautical miles (190 km) orbit, the second 190 feet (58 m) long carrying a reusable spaceplane on its back, capable of delivering around 20,000 pounds (9.1 t) to a 100 nautical miles (190 km) orbit.[14]

In March 2017, REL announced the formation of an American subsidiary, Reaction Engines Inc (REI), led by Adam Dissel in Castle Rock, Colorado.

In September 2017, REI announced a contract from DARPA to test a REL precooler test article "THX" at temperatures exceeding 1,000 °C (1,830 °F),[15] previous precooler tests focusing on frost control having been conducted from ambient temperature.

In April 2018, Boeing announced its investment in Reaction Engines, through Boeing HorizonX Ventures with a $37.3 million Series B funding alongside Rolls-Royce PLC and BAE Systems.[7]

[Elderberry]

Skylon (spacecraft)

https://en.wikipedia.org/wiki/Skylon_(spacecraft)

Skylon is a series of designs for a single-stage-to-orbit spaceplane by the British company Reaction Engines Limited (REL), using SABRE, a combined-cycle, air-breathing rocket propulsion system. The vehicle design is for a hydrogen-fuelled aircraft that would take off from a purpose-built runway, and accelerate to Mach 5.4 at 26 kilometres (16 mi; 85,000 ft) altitude (compared to typical airliners' 9–13 kilometres (6–8 mi; 30,000–40,000 ft)) using the atmosphere's oxygen before switching the engines to use the internal liquid oxygen (LOX) supply to take it into orbit.[3]:5 It could carry 17 tonnes (17,000 kg; 37,000 lb) of cargo to an equatorial low Earth orbit (LEO); up to 11 tonnes (11,000 kg; 24,000 lb) to the International Space Station, almost 45% more than the capacity of the European Space Agency's Automated Transfer Vehicle;[4] or 7.3 tonnes; 7,300 kilograms (16,000 lb) to Geosynchronous Transfer Orbit (GTO), over 24% more than SpaceX F9 RTLS (As of 2018.[5][6]) The relatively light vehicle would then re-enter the atmosphere and land on a runway, being protected from the conditions of re-entry by a ceramic composite skin. When on the ground, it would undergo inspection and necessary maintenance, with a turnaround time of approximately two days, and be able to complete at least 200 orbital flights per vehicle.

As work on the project has progressed, information has been published on a number of design versions, including A4,[7]:Fig 1 p165 C1,[8] C2,[3] and D1.[9] Testing of the key technologies was successfully completed in November 2012, allowing Skylon's design to advance from its research phase to a development phase.[10][11] As of 2017, an engine test facility was being built at Westcott and if all goes to plan, the first ground-based engine tests could happen in 2020, and SABRE engines could be performing unmanned test flights by 2025.[12]

In paper studies, the cost per kilogram of payload carried to LEO in this way is hoped to be reduced from the current £1,108/kg (as of December 2015),[13] including research and development, to around £650/kg, with costs expected to fall much more over time after initial expenditures have amortised.[2] In 2004, the developer estimated the total lifetime cost of the Skylon C1 programme to be about $12 billion.[2] As of 2017, only a small portion of the funding required to develop and build Skylon had been secured. For the first couple of decades the work was privately funded, with public funding beginning in 2009 through a European Space Agency (ESA) contract. The British government pledged £60 million to the project on 16 July 2013 to allow a prototype of the SABRE engine to be built,[14] contracts for this funding were signed in 2015.

SABRE engines

Main article: SABRE (rocket engine)
A cross section of a model of an early SABRE engine design

One of the most significant features of the Skylon's design is its powerplant, known as Synergetic Air-Breathing Rocket Engine (SABRE).[57] The design of the SABRE engine has drawn heavily upon the STRICT/STERN experimental engines, sharing many features such as the propellant and the adoption of the trialled Expansion Deflection Nozzle, as well as building upon the wider field of liquid air cycle engines (LACE).[20][33][3]:4 The engines are designed to operate much like a conventional jet engine to around Mach 5.5 (1,700 m/s),[55] 26 kilometres (16 mi) altitude, beyond which the air inlet closes and the engine operates as a highly efficient rocket to orbital speed.[55] The proposed SABRE engine is not a scramjet, but a jet engine running combined cycles of a precooled jet engine, rocket engine and ramjet.[2] Originally the key technology for this type of precooled jet engine did not exist, as it required a heat exchanger that was ten times lighter than the state of the art.[42] Research conducted since then has achieved the necessary performance.[3]:4[58]

Operating an air-breathing jet engine at velocities of up to Mach 5.5 poses numerous engineering problems; several previous engines proposed by other designers have worked well as jet engines, but performed poorly as rockets.[55] This engine design aims to be a good jet engine within the atmosphere, as well as being an excellent rocket engine outside; however, the conventional problem posed by operating at Mach 5.5 has been that the air coming into the engine rapidly heats up as it is compressed into the engine; due to certain thermodynamic effects, this greatly reduces the thrust that can be produced by burning fuel.[55][33] Attempts to avoid these issues have typically resulted in the engine being much heavier (scramjets/ramjets) or has greatly reduced the thrust generated (conventional turbojets/ramjets); in either of these scenarios, the end result would be an engine that possesses a poor thrust to weight ratio at high speeds, which in turn would be too heavy to assist much in reaching orbit.[55]

The SABRE engine design aims to avoid the historic weight-performance issue by using some of the liquid hydrogen fuel to cool helium within a closed-cycle precooler, which quickly reduces the temperature of the air at the inlet.[55] The air is then used for combustion in a similar manner to a conventional jet engine; once the helium has left the pre-cooler, it is further heated by the products of the pre-burner, giving it enough energy to drive the turbine and the liquid hydrogen pump.[55] As a consequence of the air being cooled at all speeds, the jet can be built of light alloys and the weight is roughly halved.[55] Additionally, more fuel can be burnt at high speeds. Beyond Mach 5.5, the air would normally become unusably hot despite the cooling; accordingly, the air inlet is closed upon attaining this speed and the engine instead is solely fed via on-board liquid oxygen and hydrogen fuel, as in a traditional rocket.[55][33]