XCOR and the Lynx rocket

[Rocket Science]

If Rocketplane can attempt a comeback then who knows...

[CameronD]

XCOR had a bunch of IP relating to extremely reusable engines. I'd leverage that.

Very true.  They emphasize the long-EZ but a lot of that work was done for the Rocket Racing League, which sadly never happened.

On that note:  Where does this leave the RRL stuff?   I seem to recall they flew both the Long-EZ and their two-seater a fair bit but it then seemed to fizzle out (pardon the pun), perhaps for lack of interest.  Presumably these vehicles are sitting in the back of a hangar someplace.. anyone know if they're ever likely to fly again?


Side note:  I find it amusing that the licensing restrictions section of our version of the FAR's includes 'rocket-powered' aircraft alongside 'turbine-powered'.  Maybe it'll happen one day, but unfortunately not soon enough for me.
 

[QuantumG]

They were all disassembled long ago.

[CameronD]

They were all disassembled long ago.

Unreliable?  Too dangerous??

[QuantumG]

Unreliable?  Too dangerous??

9 out of 10 businesses fail in the first year.

[CameronD]

Well, interestingly enough, the Rocket Racing Association has a functioning web site dated 2016 stating that the "Rocket Racing Association extends the early Rocket Racing League success to next-generation Rocket Racers for air show demonstrations leading toward the first phase of “drag race to space” competitions followed by the second phase of closed-circuit virtual raceway competitions.  Rocket Racing Association will also conduct a series of “back seat rides” for adventure seekers, students, private astronaut training, zero gravity payloads and experiments, and media outreach."

http://www.rocketracingassociation.com/

With the demise of their engine manufacturers, maybe not?  Who knows.. If it ever did happen, I'm sure it'd be cool to see - even if a modern turbine-powered version would be far more practical and perhaps even faster/more manouverable than a rocket racer.   

[QuantumG]

Websites are talk, and talk is cheap.

[Patchouli]

Can you quantify "extremely reusable"? I've googled, but all test result claims of high re-usability that I have found stem from 2011(!), but lacking details.

Keeping things to publicly available information, they basically eliminated thermal-cyclic fatigue from the chamber. Most regeneratively cooled engines yield and plastically deform on startup and shutdown, which limits them to 100 or so firings before the chamber breaks from the low-cycle fatigue. Eliminating this increases the number of starts an engine can do, well up into the thousands. "Reusable Rocket Propulsion for Space Tourism Vehicles" has a decent (if old) overview. There were a few other tricks, but thermal-cyclic fatigue was one of the big ones.

Yah too bad Xcor went under as not only did they solve that problem their piston pump solved a lot of issues with the life span of turbo pumps.
Their engines could have been useful in upper stages,space tugs, and landers.

[Robotbeat]

How much would XCOR cost right now? How about to buy their assets in liquidation? My bet it's relatively cheap, not counting things like machine tools.

[Patchouli]

I'm surprised another company hasn't bought all their assets yet.

Potential buyers I can see ARJ as their IP could allow lower cost of their upper stage engines , Orbital ATK to get liquid upper stages for their vehicles or even Vulcan Aerospace.

[Lars-J]

Can you quantify "extremely reusable"? I've googled, but all test result claims of high re-usability that I have found stem from 2011(!), but lacking details.

Keeping things to publicly available information, they basically eliminated thermal-cyclic fatigue from the chamber. Most regeneratively cooled engines yield and plastically deform on startup and shutdown, which limits them to 100 or so firings before the chamber breaks from the low-cycle fatigue. Eliminating this increases the number of starts an engine can do, well up into the thousands. "Reusable Rocket Propulsion for Space Tourism Vehicles" has a decent (if old) overview. There were a few other tricks, but thermal-cyclic fatigue was one of the big ones.

Yah too bad Xcor went under as not only did they solve that problem their piston pump solved a lot of issues with the life span of turbo pumps.
Their engines could have been useful in upper stages,space tugs, and landers.

What public data do we have that they actually solved a lot of issues? The haze of rose tinted glasses and wishful thinking has always been peculiarly strong with XCOR. If their engines were so incredibly groundbreaking they would have found customers or buyers of the technology.

When it comes to XCOR I feel like I'm the only sane person in the room (or one of the few), pointing out that the emperor has no clothes.

[meekGee]

Can you quantify "extremely reusable"? I've googled, but all test result claims of high re-usability that I have found stem from 2011(!), but lacking details.

Keeping things to publicly available information, they basically eliminated thermal-cyclic fatigue from the chamber. Most regeneratively cooled engines yield and plastically deform on startup and shutdown, which limits them to 100 or so firings before the chamber breaks from the low-cycle fatigue. Eliminating this increases the number of starts an engine can do, well up into the thousands. "Reusable Rocket Propulsion for Space Tourism Vehicles" has a decent (if old) overview. There were a few other tricks, but thermal-cyclic fatigue was one of the big ones.

Yah too bad Xcor went under as not only did they solve that problem their piston pump solved a lot of issues with the life span of turbo pumps.
Their engines could have been useful in upper stages,space tugs, and landers.

What public data do we have that they actually solved a lot of issues? The haze of rose tinted glasses and wishful thinking has always been peculiarly strong with XCOR. If their engines were so incredibly groundbreaking they would have found customers or buyers of the technology.

When it comes to XCOR I feel like I'm the only sane person in the room (or one of the few), pointing out that the emperor has no clothes.

Their engine had clothes.  But it takes more than a clothed engine to turn a profit.

No suborbital company really has a financial leg to stand on yet, and for that matter, small sat companies are also all shooting at a barely-existent and insufficient market.  The future of small sats is in large constellations, so you still need large launchers.  The number of tons in orbit is going to increase, not decrease.

Maybe their technology can bridge the gap between pressure-fed and turbo-fed thrusters for things like large vehicle reaction control motors.

[john smith 19]

How much would XCOR cost right now? How about to buy their assets in liquidation? My bet it's relatively cheap, not counting things like machine tools.

Good question. By company standards, not a lot. The question is what do you get for it? How much of it is actual IP and how much is "know how." that's in the heads of the staff but was never written down?

What public data do we have that they actually solved a lot of issues? The haze of rose tinted glasses and wishful thinking has always been peculiarly strong with XCOR. If their engines were so incredibly groundbreaking they would have found customers or buyers of the technology.

Their repeated ability to win development contracts and deliver working hardware (when competitors delivered Poweroints) going back over 2 decades.

XCOR's had a cautious plan to gradually move to orbital transport.
There tragedy was they could get enough money to tick over but not advance the core design fast enough, or find ways to get the intermediate steps to generate revenue.
The did not have a single very wealthy backer (and since they came from Rotary Rocket I suspect actively avoided one  )

When it comes to XCOR I feel like I'm the only sane person in the room (or one of the few), pointing out that the emperor has no clothes.

Yes I know exactly how you feel.

[john smith 19]

Their engine had clothes.  But it takes more than a clothed engine to turn a profit.

A big enough profit to remain both financially viable and to move your development plan forward.

No suborbital company really has a financial leg to stand on yet, and for that matter, small sat companies are also all shooting at a barely-existent and insufficient market.  The future of small sats is in large constellations, so you still need large launchers.  The number of tons in orbit is going to increase, not decrease.

"All that is past is prologue." as Shakespeare put it.   
Let's hope it ends better than it did for Globalstar, Iridium and Orbcomm.
As a side note Orbcomm, coming out of Orbital and using Pegasus for the initial deployment, was the closest in structure to Starlink.
It was also one of the most modest in terms of capabilities, and seems to have been the most long term sustainable.

Maybe their technology can bridge the gap between pressure-fed and turbo-fed thrusters for things like large vehicle reaction control motors.

[Nomic]

"Reusable Rocket Propulsion for Space Tourism Vehicles" has a decent (if old) overview. There were a few other tricks, but thermal-cyclic fatigue was one of the big ones.

Good read, copy here, think a couple of other companies (Mastern?) have used similar saddle type cooling jackets.

For piston pumps, suspect electrically driven centrifugal pumps are a better option now for small/low chamber pressure kerlox engines, 10/15 years ago battery tech and brushless motors might not have been up to it, but are now ridiculously cheap.

Xcor never released any weights or ISP figures, also never said they got there engine running in a closed cycle, described in these two patents, presumably they were running an expander bleed cycle?

[Katana]

How much would XCOR cost right now? How about to buy their assets in liquidation? My bet it's relatively cheap, not counting things like machine tools.

Good question. By company standards, not a lot. The question is what do you get for it? How much of it is actual IP and how much is "know how." that's in the heads of the staff but was never written down?

What public data do we have that they actually solved a lot of issues? The haze of rose tinted glasses and wishful thinking has always been peculiarly strong with XCOR. If their engines were so incredibly groundbreaking they would have found customers or buyers of the technology.

Their repeated ability to win development contracts and deliver working hardware (when competitors delivered Poweroints) going back over 2 decades.

XCOR's had a cautious plan to gradually move to orbital transport.
There tragedy was they could get enough money to tick over but not advance the core design fast enough, or find ways to get the intermediate steps to generate revenue.
The did not have a single very wealthy backer (and since they came from Rotary Rocket I suspect actively avoided one  )

When it comes to XCOR I feel like I'm the only sane person in the room (or one of the few), pointing out that the emperor has no clothes.

Yes I know exactly how you feel.

How much money did they spent before failing during the long run?

[Katana]

"Reusable Rocket Propulsion for Space Tourism Vehicles" has a decent (if old) overview. There were a few other tricks, but thermal-cyclic fatigue was one of the big ones.

Good read, copy here, think a couple of other companies (Mastern?) have used similar saddle type cooling jackets.

For piston pumps, suspect electrically driven centrifugal pumps are a better option now for small/low chamber pressure kerlox engines, 10/15 years ago battery tech and brushless motors might not have been up to it, but are now ridiculously cheap.

Xcor never released any weights or ISP figures, also never said they got there engine running in a closed cycle, described in these two patents, presumably they were running an expander bleed cycle?

No welding between walls, this requires thick and heavy inner wall to withstand inward pressure. Maybe 5 times heavier than standard design.

The engines are almost as big as tanks on the EZ, also note two large helium bottles, "for fire extinguishers"?

[Gliderflyer]

No welding between walls, this requires thick and heavy inner wall to withstand inward pressure. Maybe 5 times heavier than standard design.

The engines are almost as big as tanks on the EZ, also note two large helium bottles, "for fire extinguishers"?

I don't know where you got "5 times heavier", but it was nowhere near that (Doug's use of "slightly" is much more appropriate).
The EZ-Rocket engines were pretty small; about the size of soda cans. The vehicle was pressure fed, and the helium was used for pressurizing the tanks.

Xcor never released any weights or ISP figures, also never said they got there engine running in a closed cycle, described in these two patents, presumably they were running an expander bleed cycle?

Somewhat surprisingly, the updated XCOR website has some performance numbers for the 5H25 and 8H21 hydrogen engines. As far as the cycle, it was closed in both coldflows (using the heat from a train) and in hotfire tests, although at "reduced power". There was a small update on one of the Space Access 2016 slides, which was tweeted by parabolicarc.

[Nomic]

Somewhat surprisingly, the updated XCOR website has some performance numbers for the 5H25 and 8H21 hydrogen engines. As far as the cycle, it was closed in both coldflows (using the heat from a train) and in hotfire tests, although at "reduced power". There was a small update on one of the Space Access 2016 slides, which was tweeted by parabolicarc.

Thanks missed that, the numbers for the 8H21 are specifications of a design rather than a finished engine though, also even with an aluminium nozzle 47:1 TWR, roughly the same as an RL-10.

[meekGee]

Their engine had clothes.  But it takes more than a clothed engine to turn a profit.

A big enough profit to remain both financially viable and to move your development plan forward.

No suborbital company really has a financial leg to stand on yet, and for that matter, small sat companies are also all shooting at a barely-existent and insufficient market.  The future of small sats is in large constellations, so you still need large launchers.  The number of tons in orbit is going to increase, not decrease.

"All that is past is prologue." as Shakespeare put it.   
Let's hope it ends better than it did for Globalstar, Iridium and Orbcomm.
As a side note Orbcomm, coming out of Orbital and using Pegasus for the initial deployment, was the closest in structure to Starlink.
It was also one of the most modest in terms of capabilities, and seems to have been the most long term sustainable.

Maybe their technology can bridge the gap between pressure-fed and turbo-fed thrusters for things like large vehicle reaction control motors.

Concern trolling...

Conditions are different, and level of execution is different.

Previous constellations were built in anticipation of a demand that never materialized.  Demand today exists.

Previous constellations didn't have a wholly owned reusable launcher.  SL does.

Finally SL grabs the bull by the horns, solves the whole problem  and at large scale.  If there is a critical mass, SL is above it.

--

.. and if the above is wrong, life for smallsats launchers will be even more difficult.