Reaction Engines SABRE engine (Skylon Spaceplane)

steelpillow

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It's the kerosene-powered Falcons that are killing the spaceplane. Can't help wondering what they'd be charging if they were doing it with CO2-derived methane. Two noughts on the end?
 

steelpillow

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[BBC link]

"we really don't need to send many people into space. It may seem primitive, it may seem undignified, but rockets are actually all we need at the moment."

Has nobody told Virgin Galactic?

Still, it's nice to see an expert confirm what I was once so lampooned for saying here, that paying passengers require far lower gee forces than the regular payloads, and that is where HOTOL spaceplanes win over the vertical stuff.
 

sferrin

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"SpaceX has a reputation for pushing a lot of boundaries, but it is killing the spaceplane,"

Should make 'em use environment-friendly hydrogen like everyone else, huh.

They're using methane because it's easier to generate on Mars. (Among other things.) As for "every one else", aside from the Delta IV what launcher, anywhere in the world, uses LH2 only? Considering SpaceX's contribution to global pollution is far into the noise, forcing them to fail in order to prop up some other launcher is not cool.
 

steelpillow

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"SpaceX has a reputation for pushing a lot of boundaries, but it is killing the spaceplane,"

Should make 'em use environment-friendly hydrogen like everyone else, huh.

They're using methane because it's easier to generate on Mars. (Among other things.) As for "every one else", aside from the Delta IV what launcher, anywhere in the world, uses LH2 only? Considering SpaceX's contribution to global pollution is far into the noise, forcing them to fail in order to prop up some other launcher is not cool.

This is about the need for a new environmentally-friendly generation of aerospace vehicles, not the dirty old ones. Sure, if SpaceX can make their synthetics as environmentally-friendly as hydrogen, fine, but that hasn't yet happened "anywhere in the world" either.
 

Archibald

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Folks,
At present launch rates (a couple or trio of dozen per year) F9R will never be an issue. Starship BFR by contrast might become an issue if Musk launch them at airliner level of traffic rates. Can't remember what he said in a tweet circa 2019, think 1000 per year or more. At this point methane production and combustion may get out of the "noise". Even more with all the tankers flights since it will take 6 to 8 tankers to send 1 Starship to Mars.
 

sferrin

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"SpaceX has a reputation for pushing a lot of boundaries, but it is killing the spaceplane,"

Should make 'em use environment-friendly hydrogen like everyone else, huh.

They're using methane because it's easier to generate on Mars. (Among other things.) As for "every one else", aside from the Delta IV what launcher, anywhere in the world, uses LH2 only? Considering SpaceX's contribution to global pollution is far into the noise, forcing them to fail in order to prop up some other launcher is not cool.

This is about the need for a new environmentally-friendly generation of aerospace vehicles, not the dirty old ones. Sure, if SpaceX can make their synthetics as environmentally-friendly as hydrogen, fine, but that hasn't yet happened "anywhere in the world" either.
Who is using all LH2/O2? Anywhere. Delta IV, that's it, and it's going away. And again, in the grand scheme of things, space launch's contribution to pollution is not even measurable. Saying, "wait, what is unique to Skylon? Yeah, THAT'S what everybody should be forced to do" does not suggest great confidence in the design. If it were a winner it would succeed on it's own.
 
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steelpillow

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<snip repetition and irrelevance>
So "Sure, if SpaceX can make their synthetics as environmentally-friendly as hydrogen, fine" is Skylon necrophilia? News to me, buddy.

I made a tongue-in-cheek remark about SpaceX. For some reason it struck home and made you sore. Time to move on.
 
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Rhinocrates

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I don't understand this debate. Methane is not harmful if harvested intelligently and burned efficiently (what rockets provide).
I am more concerned with the billion of ppl starting their dusty diesel each morning.
Methane is a very potent greenhouse gas. Turning it into carbon dioxide and water vapour may actually be an improvement.
 

steelpillow

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I am more concerned with the billion of ppl starting their dusty diesel each morning.
The alternative is to start a higher-level CO2 petrol/gasoline polluter. Dust hurts us and our children, then it is gone. CO2 hurts our children's children's children for the next five thousand years. I know who deserves the hit more.

Of course, making a little more rain or just slowing the wind down a bit would be better ideas.
 

steelpillow

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Interesting feature article on the state of play for hydrogen as a fuel, in New Scientist for 6 Feb 2021. A surprisingly large amount is already manufactured for other industries. Making it from fossil fuels is currently way the most dominant, but is even less green than using the fossil fuel direct. Carbon recapture doubles the price, hydrolysis of water using green electricity doubles it again. Volume production using either of the latter two is a decade and more away.

But who knows, maybe enough green capacity to feed a few SABREs will be available by the time the engine reaches the market.

By way of an alternative, a biofuelled rocket called Stardust has just made its first commercial flight. I wonder how its bang-per-buck will work out: https://www.bbc.co.uk/news/world-us-canada-55845762
 

TomcatViP

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Every body here knows that a British company has offered a far more practical hydrogen alternative years ago in the form of pellets that just had to be poored inside a non-pressurized tank?

 
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Nigelhg

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Every body here knows that a British company has offered a far more practical hydrogen alternative years ago in the form of pellets that just had to be poored inside a non-pressured tank?

I didn't.... But thank you.. Very interesting.
 

PMN1

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Every body here knows that a British company has offered a far more practical hydrogen alternative years ago in the form of pellets that just had to be poored inside a non-pressured tank?


From the Cella website

cropped-New-Cella-Logo.jpg




We regret to inform that Cella Energy Limited are currently in administration: https://beta.companieshouse.gov.uk/company/09019506/insolvency

WEBSITE SUSPENDED

( Webmasters: frontdesk@systemcore.co.uk | +44 (0) 1483 428655)
 

Trident

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The alternative is to start a higher-level CO2 petrol/gasoline polluter. Dust hurts us and our children, then it is gone. CO2 hurts our children's children's children for the next five thousand years. I know who deserves the hit more.

Not only that, modern turbocharged, direct-injection petrols are often *dustier* than diesels with particulate filters (which are near ubiquitous by now). With emissions regulations tightening, we are now seeing particulate filters added to petrol exhaust systems as a result, exacerbating their CO2/consumption disadvantage and diminishing the cost benefit. A similar development previously played out with NOx, which killed off a number of petrol lean burn technologies because they would have required expensive, diesel-like aftertreatment.

The diesel is far better than its reputation after diesel-gate, which was basically caused by OEMs evading NOx regs so they could fit efficient diesels into cheap, small cars to meet fleet CO2 limits. Don't get me wrong, the car makers deserve every bit of the flak they received for their fraud, but the point is that the diesel still has its role to play.
 

Nik

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Would the Cella pellets be Ammonia Borane per ... ?

Sorry, thought there was an article on PhysOrg, but I cannot find it...
 

Flyaway

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Latest update from REL.

 

TomcatViP

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Every body here knows that a British company has offered a far more practical hydrogen alternative years ago in the form of pellets that just had to be poored inside a non-pressured tank?


From the Cella website

cropped-New-Cella-Logo.jpg




We regret to inform that Cella Energy Limited are currently in administration: https://beta.companieshouse.gov.uk/company/09019506/insolvency

WEBSITE SUSPENDED

( Webmasters: frontdesk@systemcore.co.uk | +44 (0) 1483 428655)
They were not very good communicating for what I know.
There is also the fact that at the same period a fair number of breaking grounds aerospace SME mysteriously shut down their activities soon after reaching market visibility.
I have somewhere an actual picture of the product (not the green glowing rock you see on the add) and it looked like NaClO3 but with bigger grains. If I can dig it back, I'll post it.
 
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steelpillow

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Archibald

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I've just re-read some stuff about REL clever ammonia / hydrogen blend as aircraft fuel.


And it just dawned on me... hydrogen has high energy but awful density - and ammonia is the exact opposite.

First atempt

Build an aircraft with a small hydrogen tank (in the rear fuselage, can't go into the wings) with ammonia tanks in the wings and elsewhere - and mix the two fuels into the engines - no need for cracking.

Second atempt

How about building an aircraft with ammonia tanks in place of kerosene tanks (wings and fuselage) and some kind of wing mounted hydrogen tanks ? Use reduced amount of hydrogen in "reasonable size" tanks to energize the ammonia when needed.

Is cracking absolutely necessary ? can't hydrogen and ammonia tanks be carefully balanced in an ordinary aircraft ?
 
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Archibald

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I deleted the out of place and offensive post. Doesn't the change the basic fact that cancer is a rotten illness.
 

aonestudio

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publiusr

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Just having ammonia as a coolant X-15 style, maybe burned off at the last?

Could you have jacketed thrust…where one exhaust serves as a combustion chamber for a second, hotter combustion no physical nozzle could take. Annular solids that slide off as a ring.. like Gnom…airbreathing solids?
 

steelpillow

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Just having ammonia as a coolant X-15 style, maybe burned off at the last?

Could you have jacketed thrust…where one exhaust serves as a combustion chamber for a second, hotter combustion no physical nozzle could take. Annular solids that slide off as a ring.. like Gnom…airbreathing solids?
The relevance to SABRE being?
 

publiusr

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To help with cooling perhaps
Cooling in general is not directly SABRE-related and belongs in a different topic. Since you are not reporting on work in the field, The Bar would be the appropriate forum here, thanks.
The reason I mentioned it here was a recent advance from Guntae Kim at UNIST who can break ammonia into hydrogen more easily and with less electricity than with water. If it is that easy…could you do it on the fly…without as much cryogenics than is needed to get the ball rolling. If this can be done IN FLIGHT, Skylon may yet have new life breathed into it with reduced tankage demands, though I am probably fooling myself again. I was thinking “ammonia to engine—ammonia to hydrogen—hydrogen to SABRE engine…exhaust.
 

Flyaway

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View: https://twitter.com/ReactionEngines/status/1442745162715774982


we have tested the engine’s advanced hydrogen preburner at energy delivery levels in excess of two megawatts and proved output temperature uniformity under pressurised conditions. The preburner will now be combined with the HX3 heat exchanger to provide heat to the SABRE cycle at take-off and early flight.
During this campaign, the S & C control systems were combined with the REL Engine Control System for the first time and to great effect. The new N-site facility at Cotswold Airport proved to be a very suitable location for operating this and other future aerospace engine technologies using hydrogen.
 

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