Reaction Engines Receives $37.6 Million Investment

Skylon with the SABRE engine. (Credit: Reaction Engines)

Reaction Engines has received a large investment by Boeing HorizonX and two other companies, CNBC reports.

The U.S. industrial giant joined Rolls-Royce and defense company BAE Systems in a $37.6 million fundraising round for U.K.-based propulsion company Reaction Engines. This is both the second foreign investment and the second space investment for Boeing HorizonX Ventures, which contributed to the $15 million funding round for Australian satellite company Myriota last month.

Reaction Engines’ advanced propulsion “could change the future of air and space travel,” according to Boeing HorizonX vice president Steve Nordlund.

“We expect to leverage their revolutionary technology to support Boeing’s pursuit of hypersonic flight,” Nordlund said in a statement.

Reaction Engines, which has now raised more than $140 million over the last three years, is developing a hybrid jet and rocket engine. In theory, the company’s SABRE engine will be capable of operating as a jet at take-off and transitioning to a rocket at higher altitudes.

  • Andrew Tubbiolo

    Skylon is still largely a dream and if built will be just below Falcon 9’s upmass to LEO. BFR will be flying long before this thing flies, at that point it’s the end of of launch vehicle development for a LONG time.

  • Mr Snarky Answer

    Money down the drain

  • Michael Halpern

    Not necessarily there’s room for smaller lift and a peer competitor with bfr

  • Andrew Tubbiolo

    Consider that launches of BFR will be going up mostly empty for years after being operational. BFR could very well launch on a schedule so long as there’s minimal work. If so, you send your satellite up in a FedEx standard container for a very predictable fee that will probably be quite low. You might be right, in the face of standardized containerized fixed price launch at a predictable schedule, comparing that to flying the way we fly today …. ? Well, we shall see.

  • Michael Vaicaitis

    The work available for a given service is a function of the demand for that service. However, we do know that demand is affected by price. SpaceX must surely expect that a low price service will increase demand. Additionally, such a large mass and volume lift capacity will surely stimulate new demand, specifically in human spaceflight. I think your first post was closer to the mark.

  • momerathe

    Everything since the BAE acquisition points to Skylon being effectively dropped – or at least indefinitely postponed. It’s all about the airbreathing Mach-5 engine, at this point.

  • delphinus100

    If Skylon performs as advertised, there is a greater flexibility in takeoff (not simply ‘launch’) / landing locations, as well as self-ferry.

    There’s room for more than one kind of orbital vehicle…

  • Michael Vaicaitis

    The BAE investment amounts to a 20% ownership, so not an acquisition. Regardless, of how one feels about Skylon, SABRE is 80+% of the development in any case, and as you imply, SABRE has other non-space uses. In fact the crucial technology component of SABRE is the heat exchanger, which could lead to non aerospace markets. Basically, in any case, there’s no path to Skylon that doesn’t first start with a fully working and validated SABRE.

  • Michael Vaicaitis

    “There’s room for more than one kind of orbital vehicle…”
    Only if the development costs (REL estimated $10 billion over 10 years) and operating price make sense. REL calculated the eventual manufacture cost at around $650+ million for a one-off, dropping closer to $450 million each, for a fleet of 20+ Skylons with 200 mission lifetimes. Operating costs based on a fleet scenario are hoped to be circa $5 million per flight. That’s lifting 15 tonnes equatorial or 12.5 tonnes at Cape latitudes, or a 30 person passenger module. But if the price isn’t competitive, they won’t get the market penetration, and if they don’t get the market volume, then the price per mission/kg/person will be higher. Certainly, at the time of Skylon conception, there was no partially reusable F9/FH on the horizon, let alone BFR. I fear the Skylon concept (and SSTO generally) may taken too long to advance and has been superseded by a more flexible and robust approach to space launch, i.e. BFR.

    SABRE is an LH2 fuelled rocket engine – so operating flexibility (whether for space launch or terrestrial alternative) will still be limited by infrastructure.

  • Michael Vaicaitis

    Doug – SABRE is not a hybrid jet and rocket engine – it is an LH2/LOX rocket engine. At all regimes of flight, from standstill on the runway, all the way to orbit, it is a hydrogen burning rocket engine. The difference between this and conventional rockets being that SABRE can use atmospheric oxygen up to about Mach 5.5 and 25 km, thus reducing its need to carry so much LOX all the way from the ground.

    Skylon’s original space launch case seems to have been eclipsed by the rise of SpaceX, which might be part of the reason for the apparent change of emphasis to hypersonic atmospheric cruiser. Interestingly then, in a speech yesterday, Shotwell doubled down on BFR airlines, estimating a ticket price between economy and business, but for a 1 hour flight (instead of 10+ hours). Curious that where doubters (which may be all of us to varying degrees) see noise pollution, sonic booms, vomit filled cabins, and long boat journeys at either end, SpaceX remain confident of the viability of the idea and that it will happen within 10 years.
    May be Elon has a secret vendetta against REL, or perhaps it’s his evil genius plan to get rich(er) by selling earmuffs.

  • Geoff T

    Even as an enthusiastic SpaceX fanboy I think the BFR for point to point transport idea is ridiculous. Even assuming you can waive all complaints about noise, overflights of populated areas, not causing ICBM false alarms and the like there’s a slight problem.

    Their rendering at last years presentation showed launching from a seabourne platform miles out to sea. Good luck finding a place that’s a safe distance from a major city, major shipping lanes and quickly reached by passenger ferry. Negates the 45 minute flight time if it takes several hours to go from city to ferry and back on the other end.

    A Sabre powered hypersonic passenger aircraft may equally be a pipedream, but at least major cities have airports you can reach fairly easily.

  • Larry J

    If only there was a vehicle that could fly out to offshore platforms instead of being limited to a slow transfer by boat. It would have to be VTOL which is difficult but technically possible… /s

  • Larry J

    For a launch system, perhaps. As a propulsion system for a hypersonic weapon, maybe not.

  • Geoff T


  • Michael Vaicaitis

    Been thinking about the hypersonic weapon idea. SABRE would still need to be strapped a large expensive hydrogen carrying vehicle. That would be a very large and very expensive missile system.

  • Larry J

    Instead of directly powering a missile, one or two SABRE engines might be used to power a hypersonic vehicle capable of carrying multiple missiles or other payloads.

  • Michael Halpern

    Yes and if they can adapt the technology to run on denser fuels like CH4 it can be a very efficient and powerful engine

  • Michael Vaicaitis

    Not even gonna try arguing against the many, and let’s be honest, obvious, objections. But SpaceX is not populated with idiots, yet they are pitching it as not only plausible, but likely.

    SABRE is still a rocket engine, that will make the noise of a rocket engine. And, it requires a good long runway, in a location that is happy to hold and handle hundreds of tonnes of liquid hydrogen. Does that describe major cities and airports?.

  • Michael Vaicaitis

    To cool the incoming airflow from 1300 Kelvin to 120 Kelvin in 1/100 of a second requires a very cold sink, hence the liquid hydrogen. The only alternative might be liquid helium, but you’d be replacing 150 tonnes of hydrogen with 400? tonnes of helium and 300? tonnes of methane.
    The liquid hydrogen is not just the propellant, it is central to the thermodynamics of the engine, as well as the overall vehicle mass.

  • Michael Halpern

    If a SABRE derivative is to be useful it might not be in space, and they may have to try to change fuel though it may lower precooler efficiency, if they can get a methane powered derivative, the high chamber pressure of a rocket system can enable a powerful, efficient and clean engine, noise in transportation is often treated as a secondary problem so long as it doesn’t cause property damage

  • Michael Halpern

    Then don’t bother with cooling it all the way,

  • Michael Vaicaitis

    Separating the missiles from the vehicle at Mach 5 in atmosphere would be a challenge, and you’d also need a vehicle capable of a round trip – I’m feeling some scope creep here.

  • Michael Vaicaitis

    Well that oxygen is being cooled and then compressed for use in a rocket engine. Don’t know what the upper limits are for temperature, density and viscosity of oxygen/air for a useful rocket engine.

  • Michael Halpern

    Mainly want it as sort of a scram jet that works effectively at any altitude, or as a clean burning alternative to conventional turbojets that is also an upgrade functionally there are a lot of commonalities between jet engines (as a whole including all varieties) and liquid bipropellant rocket engines, so there shouldn’t be a upper limit so long as there is some cooling and compression so LCH4 and possibly even near freezing LCH4 should be fine as a heat sink. My goal isn’t theoretical best configuration for the system, but most practical from a business perspective

  • Larry J

    Yes, it would be difficult to separate missiles from a vehicle traveling at Mach 5. Remember, though, that Lockheed managed to separate missiles from the YF-12A flying at Mach 3.2 back in the 1960s. It is difficult but not unprecedented. As for the vehicle itself, both Boeing and Lockheed are researching hypersonic aircraft designs. Whether they go with scramjets or SABRE remains to be seen.

  • Michael Halpern

    Remember in ffsc both propellants are gas phase when they reach the combustion chamber

  • duheagle

    You can’t liquify oxygen using LCH4 as a heat sink. Methane boils 19 degrees K. warmer than LOX. The thermodynamics are upside down.

    And SABRE is based on what one might call thermodynamic arbitrage. Liquifying the oxygen is just the means to the end of purifying it by stripping off all that atmospheric nitrogen that brings nothing to the combustion party. One does this by leveraging the fact that nitrogen boils – and liquifies – 10 degrees K. colder than oxygen. So the oxy gets liquified and tanked. But LH2 is absolutely crucial as the heat sink.

    There may be a thermodynamic sweet spot where air, densified as much as possible by dumping its compression heat into LCH4, can be burned with gaseous CH4 efficiently to achieve endoatmospheric Mach 6+ vehicle velocities. I just don’t know and lack the tools to analyze matters suitably.

    If you have appropriate clearances, you might want to see if the Lockheed Skunk Works would show you their archives. My understanding is that Kelly Johnson and His Merry Men initially considered an LH2-fueled design early in the process that gave birth to the SR-71. A look at their notes would, I’m sure, be quite instructive.

    But an engine based on this sort of cycle would in no significant way resemble SABRE nor would it be capable of achieving orbital velocity.

  • duheagle

    Poop the ordnance out the rear like the old A3J Vigilante did.

  • Michael Halpern

    Then don’t liquify it.

  • Lee

    Also known as the RA-5C in the recon version. My first flight instructor was an old RA-5C driver, who had flown A3Ds (all three deads) before that. I learned more from Wilster talking about flying in the (civilian) ready room than I ever did in the air…

  • H. Keith Henson

    There is really just one market where Skylon makes sense and that’s power satellites built at a high rate. The estimated cost to LEO goes down to less than $100/kg at close to a million flights per year. That’s about what it takes if we are going to get off fossil fuels. The cost graph is about 17 slides into this pdf.

    At that flight rate you have to be careful about messing up the ozone. NOAA ran a study of this which came out over a year ago.

    “Global atmospheric response to emissions from a proposed reusable space launch system”

    The video here

    proposes a way to get the cost from LEO up to GEO down to around $100/kg

    BTW, the Skylon engines are not related to scramjets at all.

  • Paul451

    You can’t liquify oxygen using […]
    And SABRE is based on what one might call thermodynamic arbitrage. Liquifying the oxygen […] So the oxy gets liquified and tanked.

    SABRE doesn’t liquify oxygen, and Skylon doesn’t store oxygen during its flight. The LOx is loaded before flight. Rather, SABRE cools and densifies the incoming air, exposing the engine parts to less extreme heat and increasing the thrust and efficiency of the jet combustors, but it doesn’t liquify the incoming air. They aren’t trying to create LOx, they aren’t trying to exclude nitrogen. Alan Bond specifically avoided going that route when conceiving Skylon.

    I think you are getting Skylon/SABRE confused with Marquardt’s LACE concept from the ’60s.

    (Similarly, while the LH is the heat-sink, SABRE uses gaseous helium in the heat exchange. Again, it was LACE which used LH directly in the heat-exchange.)

    IMO, liquid methane would be perfectly reasonable for a sub-hypersonic version of the engine.

  • Paul451

    Well that oxygen is being cooled and then compressed for use in a rocket engine.

    In SABRE, the densified air is only used in the jet combustors. The rocket uses stored LOx.

    (Pedantic aside: Also, technically, the incoming air isn’t “compressed”, the densification by super-cooling replaces the compression stages of a conventional jet engine.)

  • Paul451

    as well as self-ferry.

    Skylon’s pretty rubbish at self-ferry. In jet-mode, the engines have awful efficiency compared to any conventional jet engine. AIUI, the plan was to operate it out of a small number of dedicated sites.

  • Paul451

    SABRE is still a rocket engine, that will make the noise of a rocket engine. And, it requires a good long runway, in a location that is happy to hold and handle hundreds of tonnes of liquid hydrogen. Does that describe major cities and airports?

    The A2 version is also hypersonic. So it is hardly immune to the fly-over problem.

    Indeed, it would be worse than BFR, since once launched, the BFR travels over the atmosphere, no noise reaches the ground except at launch and landing. BFR can therefore overfly regions that would never allow a supersonic or hypersonic jet. (Also, under the outer space treaty, SpaceX doesn’t need permission to fly over nations or regions, only the launch/landing nations. A2 would require permission from each and every country they flew over.

  • Paul451

    While first-class passengers might chopper back to the city, a fast-cat 100-passenger offshore ferry can do over 70km/h sustained. “Several hours” thus implies the site is over 200km from the city it’s serving. Which seems excessive.

    [Plus you can do the customs and immigration screening on the ferry, during the trip. Instead of spending hours in a queue at the airport, spend it on the ferry.]

  • Paul451

    SABRE is not a hybrid jet and rocket engine

    I don’t know if the design has changed, but in the early version (C3) there was a ring of ramjet combustors around the four rocket engines. So it is literally a hybrid rocket/jet engine.

  • MzUnGu

    Pretty cheap investment for Boeing to get some IP.

  • Paul_Scutts

    It seems to me that a lot of interest in SABRE, hence Reaction Engines, would be for potential Skunk Works. The possible super/hypersonic commercial applications would just be a bonus.

  • duheagle

    Did a bit more checking and it turns out you are right. I stand corrected. I knew Alan Bond had been involved in some Liquid Air Cycle Engine work before SABRE and just assumed SABRE was the same. It isn’t. Not liquifying the oxygen must save the heat exchanger a lot of work as one does not have to suck the heat of vaporization out of the oxy to liquify it.

  • Vladislaw

    I agree.. that is why i am betting on a lunar pizza shop ..

  • windbourne

    yeah, I have to say that the idea of BFR doing p2p does not make sense to me,
    However, I then think back to the 60s and remember the many ppl that would swear that we could not possibly get to the moon. Likewise, so many others swore that the 747 would never fly either.
    Will BFR do Chicago to middle of China? NOT A CHANCE.
    But, if it does happen, it will likely do offshore of LA to offshore of China, Japan and Australia. Likewise, we will likely see Atlantic hops. Another would be UK to LA and Japan/Australia over the pole. This way it avoids populated areas (save greenland and alaska).

  • windbourne

    I wonder if that approach can be used for regular scram jets to get their O2 up and lower the pollutants? That would actually enable the coming new generation of supersonics/hypersonics to burn much cleaner. Heck, that might even help repopulate the ozone layer.

  • Paul451

    I wonder if that approach can be used for regular scram jets

    I’m not sure it works, conceptually.

    Non-scramjets slow the incoming supersonic air below the speed of sound, the SABRE/Scimitar heat-exchange helps with that. Scramjets don’t slow the air down (hence the name, and the incredible difficulty people have had getting them to work.)

    The point of SABRE/etc is to avoid having supersonic combustion.

  • IamGrimalkin

    Yes, those are still in the design (as of less than a year ago, anyway).