Earlier quoted context omitted.
Pretty sure KSP RAPIER is a fictional copy of the described SABRE engine.
The names seem to indicate that, both being similar kind of weapons.
Skylon’s SABRE Engine Passes a Big Test
31–40 of 47 posts
Re: Skylon’s SABRE Engine Passes a Big Test
#32Earlier quoted context omitted.
>After shutting the inlet cone off at Mach 5.14, and at an altitude of 28.5 km, the system continues as a closed-cycle high-performance rocket engine burning liquid oxygen and liquid hydrogen from on-board fuel tanks the benchmark of today - SpaceX - separates the first stage at Mach6-8 at 65-80km height. Thus, the SpaceX second stage has less delta-v to add and don't have to carry all that weight - the SABRE would n…
I think the benefit of launching horizontaly is overstated. Any airport would still need to handle LOX and hydrogen which could be pretty dangerous. And the airport is not necessarily going to be in the right place for launch. Also traditional rockets have most of the forces acting vertically. A horizontal launch space plane must also deal with a completely different set of forces.
One might argue that a 3km runway is harder to obtain than a single launch pad.
Also, I wonder if the traditional safety requirement of an East coast is still necessary: that's an additional constraint on location. Plus the need to be closeish to the equator won't change.
Re: Skylon’s SABRE Engine Passes a Big Test
#33Earlier quoted context omitted.
These things take time, but it's not the complete story, Virgin Galactic has been around since 2004, so the same year GMail launched, without producing a single passenger flight. Blue Origin has been around for almost 20 years, and they have a few suborbital flights to their credit, and an engine that has yet to fly. SpaceX, on the other hand, has been around since 2002 and achieved orbit in 2008, and have completed…
"Virgin Galactic has been around since 2004" I'm 54 - Sabre/Skylon were in the news when I was in high school!
I think the name Skylon was first used for this project in 1993 [1], so unless you repeated quite a few years, i doubt that's true.
RB454/HOTOL could have been in the news back then, though. I remember having some sort of brochure for HOTOL back in the mid-80s.
[1] https://ui.adsabs.harvard.edu/abs/1993SpFl...35..162V/abstra...
Re: Skylon’s SABRE Engine Passes a Big Test
#34Earlier quoted context omitted.
I think the benefit of launching horizontaly is overstated. Any airport would still need to handle LOX and hydrogen which could be pretty dangerous. And the airport is not necessarily going to be in the right place for launch. Also traditional rockets have most of the forces acting vertically. A horizontal launch space plane must also deal with a completely different set of forces.
One might argue that a 3km runway is harder to obtain than a single launch pad. Also, I wonder if the traditional safety requirement of an East coast is still necessary: that's an additional constraint on location. Plus the need to be closeish to the equator won't change.
The UK is looking at West Coast locations for a new Spaceport.
Re: Skylon’s SABRE Engine Passes a Big Test
#35Isn't it inevitable the SpaceX will (and already does) dominate the entire space industry? Won't it be cheaper to launch on starship than anythign else even for very small payloads? Yes, I know about RocketLab but I wonder if they will be able to survive once starship is up and running.
Citations, please.
Re: Skylon’s SABRE Engine Passes a Big Test
#36Everyone over here on HN seems to be quite negative about the SABRE engine. While there's very little evidence for this engine being useful for orbital applications, it is instead a very compelling idea for a Concorde and/or SR-71 replacement. Scramjet engines don't seem to be happening anytime soon (I just listened to a Queensland University researcher saying that their research may yield an actual engine in 4-5 decades). This idea of pre-cooling the incoming air seems closer to reality.
Re: Skylon’s SABRE Engine Passes a Big Test
#37Earlier quoted context omitted.
These things take time, but it's not the complete story, Virgin Galactic has been around since 2004, so the same year GMail launched, without producing a single passenger flight. Blue Origin has been around for almost 20 years, and they have a few suborbital flights to their credit, and an engine that has yet to fly. SpaceX, on the other hand, has been around since 2002 and achieved orbit in 2008, and have completed…
Sense of urgency lets one leverage the best current technologies and take the best compromises within the time and monetary budget. But this is incremental innovation. It fails at tackling novel concepts where the paths forward are not so clear. You can't incrementally tunnel through a wall. At one point maybe SABRE is ready and the next SpaceX comes along and will build a spaceship with it. The spoils of innovation…
> The spoils of innovation seldom accrue with the inventors.
We are British, why change the habit of a lifetime ;)
That said, critical aspects of the design are protected and the private investors (big scary defense contractors etc) would no doubt sic the lawyers on anyone that attempted to rip it off.
Re: Skylon’s SABRE Engine Passes a Big Test
#38These guys don't disappear - they have been around forever with their Skylon plane. Just a heads up, it's a long way from testing one component of an engine on the ground to getting a full engine demo going to then testing it in the air to then build the plane then integrating engine - then getting orbital trips working with reentry! I am curious how much private capital they have been able to attract (outside of gov…
You speak as if the design has not changed over time. To be precise, the history dates back to American studies in the 50s and 60s which were not taken forward but that were picked up by Alan Bond in the UK and evolved, then later developed into the HOTOL design, and still later into Skylon/SABRE - with significant work undertaken throughout this history.
I think that there are some factors to give one faith that this won't just become another sad episode of unrealised promise to add to the history: the engine design has had significant verification along the way by authorities of the very highest credentials, is furthermore thought to be of sufficient promise to have attracted significant external funding, and finally has resulted in working hardware on the test stand that has not yet indicated that the expectations of success are ill-founded; it's getting to the point where the glaring flaw that some seem to want to be uncovered is increasingly unlikely to be found (I'd add personally I find it a little sad that amongst tech/space enthusiasts many seem so sceptical about SABRE when the facts suggests otherwise, and I wonder whether it would be a different story if it were an American project - I'm enthusiastic for anything that gets the human race off this rock, no matter where it comes from).
That said, I think it is important to separate SABRE and Skylon. The former as I've said is thought by many well credentialled people to have genuine promise, whereas the latter seems far more of a PR exercise to illustrate potential application of the technology. Nobody's actually building parts of Skylon yet as far as I'm aware, wheres they are building bits of SABRE and getting them signed off as workable.
Re: Skylon’s SABRE Engine Passes a Big Test
#39These guys don't disappear - they have been around forever with their Skylon plane. Just a heads up, it's a long way from testing one component of an engine on the ground to getting a full engine demo going to then testing it in the air to then build the plane then integrating engine - then getting orbital trips working with reentry! I am curious how much private capital they have been able to attract (outside of gov…
. . . it's a long way from testing one component of an engine on the ground to getting a full engine demo going to then testing it in the air to then build the plane then integrating engine . . . True, but my understanding is that the heat exchanger is the critical piece of difficult technology/engineering. With that, they have the potential to revolutionise industries even if none of the rest comes to pass.
Exactly, there is talk of it having significant impact even if it never flies a mile.
Re: Skylon’s SABRE Engine Passes a Big Test
#40Earlier quoted context omitted.
"Virgin Galactic has been around since 2004" I'm 54 - Sabre/Skylon were in the news when I was in high school!
I think the name Skylon was first used for this project in 1993 [1], so unless you repeated quite a few years, i doubt that's true. RB454/HOTOL could have been in the news back then, though. I remember having some sort of brochure for HOTOL back in the mid-80s. [1] https://ui.adsabs.harvard.edu/abs/1993SpFl...35..162V/abstra...
Yeah - you are probably correct - basically the same thing though albeit done by a different company.