Raptor Engine - General Development Discussion and News

[HVM]

WOW, SpaceX raptor program is advanced more, that I think before:

C. G. Niederstrasser ‏@RocketScient1st

"Shotwell - just shipped first Raptor engine to Texas last night. #SpaceX #smallsat"

And Texas means here, the SpaceX Rocket Development and Test Facility in McGregor,

Blah, Grendal ninjaposted me.

 

[Grendal]

Sorry about that....

 

[HVM]

Raptor Specs:

Cycle: Full-flow staged combustion
Oxidizer: Subcooled liquid oxygen
Fuel: Subcooled liquid methane
Chamber Pressure: 300 bar
Throttle Capability: 20% to 100% thrust

Sea-Level Nozzle
Expansion Ratio: 40
Thrust (SL): 3,050 kN
Isp (SL): 334 s

Vacuum Nozzle
Expansion Ratio: 200
Thrust: 3,500 kN
Isp: 382 s


There should be two turbopumps and two pre-burners +turbines, can you find them?

 

[siai47]

I don't know anything about rocket engines---however a nice picture. Could the pumps be compound pumps? There appears to be one on the side and one of the top of the engine. The nozzle section looks more like the high bay lights in my shop---sure would be bright if lit up but would most likely clean out the shop before departing through the roof !

 

[HVM]

Nasaspaceflightcom's AP3 have same idea; guess for a flow diagram:

Where a LOX Pump, Turbine and the Preburners are integrated same blog as Combustion Chamber.

 

[HVM]

Interesting claim in NSF, about IPD and SpaceX.

"The integrated powerhead demonstrator (IPD) was an U.S. Air Force project in the 1990s and early 2000s run by NASA and the Air Force Research Laboratory (AFRL) to develop a new rocket engine front-end (powerhead) that would utilize a full flow staged combustion cycle (FFSCC). The prime contractors were Rocketdyne and Aerojet.

Future engine development work beyond the powerhead demo was never funded by the US government, and neither Rocketdyne—nor later Aerojet Rocketdyne after a 2013 merger—chose to pursue such development with their own or other private funding." -WIKI

Apollo100 (NSF):
"...Given that SX acquired the IPD Final report, all of the drawings, and all of the hardware, I would imagine that there is quite a bit of IPD heritage in the Raptor engine."

 

[Grendal]

Chris B - NSF on Twitter

Chris B. wrote: Baby Raptor sure packs a punch! Photo by Gary Blair from an airplane over McGregor (well outside of any restricted area of course!).
Here is the picture of the Raptor burn markings:

 

[e-FTW]

So, that had not planned appropriately? Sounds like a very efficient way to start a brush fire. Haha!

 

[Bobfitz1]

Chris B - NSF on Twitter

Chris B. wrote: Baby Raptor sure packs a punch! Photo by Gary Blair from an airplane over McGregor (well outside of any restricted area of course!).
Here is the picture of the Raptor burn markings: View attachment 242056

That is an amazing photo of the Raptor burn markings. Gary Blair just missed one nearby detail!

 

[HVM]

Raptor testing: (IAC 17)
"Over 1200 seconds of firing across 42 main engine tests
Longest test 100 seconds (Due test tanks size); 40 seconds typical tor Mars landing
Test engine operates at up to 200 atmospheres (250 bar for the flight engine, 300 bar < end design target)"

 

[Grendal]

I expect we will see significant improvements in the Raptor engine as we've seen happen with the Merlin engine over the years. From what I'm hearing, it looks like they are moving forward with the Raptor they're testing with only slight modifications. That seems to coincide with the numbers we're seeing. It doesn't look like they're making it as large as was envisioned last year. What we do know is that the Raptor will become the main engine that SpaceX creates.

 

[Grendal]

The Defense Department has awarded $40.75 million to further develop the Raptor engine this last Thursday.

"Space Exploration Technologies Corp., Hawthorne, California, has been awarded a $40,766,512 modification (P00007) for the development of the Raptor rocket propulsion system prototype for the Evolved Expendable Launch Vehicle program. Work will be performed at NASA Stennis Space Center, Mississippi; Hawthorne, California; McGregor, Texas; and Los Angeles Air Force Base, California; and is expected to be complete by April 30, 2018. Fiscal 2017 research, development, test and evaluation funds in the amount of $40,766,512 are being obligated at the time of award. The Launch Systems Enterprise Directorate, Space and Missile Systems Center, Los Angeles AFB, California, is the contracting activity (FA8811-16-9-0001)."

This follows the previous $33.66 million that SpaceX was previously awarded as part of this program back in early 2016:

http://www.spaceflightinsider.com/m...l-atk-spacex-awarded-contracts-u-s-air-force/

 

[ecarfan]

(bold emphasis placed by me)

Space Exploration Technologies Corp., Hawthorne, California, has been awarded a $40,766,512 modification (P00007) for the development of the Raptor rocket propulsion system prototype for the Evolved Expendable Launch Vehicle program.

Oh, the irony...

 

[adiggs]

(bold emphasis placed by me)Oh, the irony...

Apparently the expendability of the launch vehicle is optional

 

[RDoc]

Apparently the expendability of the launch vehicle is optional

What are you talking about? DOD says they're going to expend it, so that's it! What possible advantage would there be for DOD to do something like, say, reuse?

 

[jgalak]

Anyone know if those "1200 seconds of firing across 42 main engine tests" are on a full-scale Raptor or is this still the baby-Raptor?

 

[Grendal]

Anyone know if those "1200 seconds of firing across 42 main engine tests" are on a full-scale Raptor or is this still the baby-Raptor?

All testing has been done on the mini Raptor. I believe Elon just posted on his recent AMA that they just completed building a full scale Raptor. So we might be hearing news on testing for that in the next few months.

I am not a rocket scientist but I've read from more knowledgeable people that upscaling in size is not that big a deal in rocket engines. Dangers come from getting the process correct over different sized parts. Personally, I was surprised by that. SpaceX has successfully tested the process so now they just scale it up to production size.

 

[rabar10]

I am not a rocket scientist but I've read from more knowledgeable people that upscaling in size is not that big a deal in rocket engines. Dangers come from getting the process correct over different sized parts. Personally, I was surprised by that. SpaceX has successfully tested the process so now they just scale it up to production size.

I think this has changed quite a bit in recent years, with computer modeling and finite element analysis that is able to accurately simulate rocketry combustion and flow dynamics. There is a video somewhere that describes SpaceX's detailed work in this area with the Merlin engine.

 

[Grendal]

I think this has changed quite a bit in recent years, with computer modeling and finite element analysis that is able to accurately simulate rocketry combustion and flow dynamics. There is a video somewhere that describes SpaceX's detailed work in this area with the Merlin engine.

Very cool stuff.

 

[ecarfan]

I won’t pretend I understand everything those two rocket scientists were trying to explain, but the overall concepts are pretty awesome! What year was that talk given, and where?

Very cool stuff.