This model of thrust chamber was developed for the Apollo Lunar Module decent stage and made 10 flights during the Apollo program. The engine type became famous again in the 1995 with the release of the movie "Apollo 13" as the engine that powered the crippled Apollo 13 spacecraft from the moon back to earth because the Service Propulsion System was never used subsequent to the cryotank stir/explosion. Because the extent of damage to the SPS was unknown, there was great concern at the time that collateral damage could have caused a catastrophic malfunction (if the engine was fired). Instead the LMDE was used for the return burn and subsequent course correction. Quite a famous engine.
Of course, this is not that exact engine as it burned up in the earth's atmosphere after being jettisoned when the Apollo 13 crew returned to earth in the Command Module.Flown engines, of course, are either left on the surface of the moon (Apollo 11, 12, 14, 15, 16, 17), crashed into the moon (Apollo 10), or burned up in earth’s atmosphere (Apollo 5, 9, 13).
The combustion chamber consists of an ablative-lined titanium alloy case to the 16:1 area ratio. Fabrication of the 6A1-4V alloy titanium case was accomplished by machining the chamber portion and the exit cone portion from forgings and welding them into one unit at the throat centerline. The ablative liner is fabricated in two segments and installed from either end. The shape of the nozzle extension (not installed on the example in this collection) is such that the ablative liner is retained in the exit cone during transportation, launch and boost. During engine firing, thrust loads force the exit cone liner against the case. The titanium head end assembly which contains the Pintle Injector and propellant valve subcomponents is attached with thirty-six A-286 steel ¼ inch bolts.
In order to keep the maximum operating temperatures of the titanium case in the vicinity of 800 degrees (F), the ablative liner was designed as a composite material providing the maximum heat sink and minimum weight. The selected configuration consisted of a high density, erosion-resistant silica cloth/phenolic material surrounded by a lightweight needle-felted silica mat/phenolic insulation.
The Pintle Injector, unique to TRW designed liquid propulsion systems, provides improved reliability and less costly method of fuel oxidizer impingement in the thrust chamber then conventional coaxial distributed-element injectors typically used on liquid biproellant rocket engines.
Dry mass: 300 pounds (with Columbian Nozzle Extension Installed)
Length: 51 inches - Gimbal attachment to nozzle tip (minus nozzle extension)
Maximum diameter: 34 inches (minus nozzle extension)
Mounting: gimbal attachment above injector
Engine cycle: pressure fed (15.5 atm reservoir)
Oxidizer: 50/50 N_2O_4/UDMH at 8.92 kg/s
Fuel: monomethyl hydrazine at 5.62 kg/s
O/F ratio: 1.60
Thrust: 42.923 kN vac
Specific impulse: 303 s vacuum
Expansion ratio: 16:1, 43:1 (with Expansion Nozzle)
Cooling method: quartz phenolic chamber ablation and columbium (niobium) nozzle radiation
Chamber pressure: 7.1 atm
Ignition: hypergolic, started by 28 V electrical signal to on/off solenoid valves
Burn time: 500 s for total of 5 starts; 10 350 s single burn
Thanks to Scott Schneeweis for the technical description of this artifact.
David -
That's a sweet thrust chamber.
It's been great following your diverse blogs
Posted by: Parker | September 17, 2007 at 09:58 AM
So the descent engine was designed by TRW?? Who actually manufactured it?
Posted by: Gordon R. Vaughan | September 30, 2007 at 02:55 AM
I am sort of a NASA missions enthusiast and I dont get it. When the Aquarius LM (Apollo 13) was abandonded in "earth orbit" this engine would have been left on the LM to be burned up on reentry. Did it survive reentry and was later recovered or is this a replica.
I am not try to start a war I just am confused.
Posted by: Simon Mall | April 14, 2009 at 07:04 PM
Something seems amiss....
Here is a link to an image of the complete TRW TR-201 Bipropellant Rocket Engine, which was used as the descent engine on ALL Lunar Modules: "http://www.rocketrelics.com/tr201.jpg".
Valid documentation can be found HERE: "http://www.rocketrelics.com/spacecraft_componets.htm".
As you can see, the TRW TR-201 thrust chamber is completely different from the lower thrust chamber that you exhibit.
I do not wish to generate confusion, only confirm fact.
Posted by: RonRay | May 09, 2009 at 05:44 PM
Simon - Of course you are correct. I was not trying to say that this was the exact engine that flew on Apollo 13, just that this model engine saved the crew. I have re-written the first paragraph of the post to eliminate confusion.
RonRay - I don't understand. The thrust chamber is exactly the same as the photos in the images you include above. Of course, the item in my collection is just the thrust chamber - it does not have the valve package on top or the lower skirt on the bottom.
Posted by: David Meerman Scott | May 10, 2009 at 06:23 AM
RonRay...the TRW manufactured TR-201 is derived from the heritage Lunar Module Descent Engine (LMDE) thrust chamber. Difference in appearance is due to 1) a different throttle valve actuator and propellant feed arrangement both in design and placement (on the LMDE they were mounted Parallel with to the engine centerline on the side of the TCA); the TR-201 has a simple dual Throttle Actuator mounted to the top of the engine manifold and 2) the LMDE had a Gimbal cradle mounted just below the throttle package around the throat of the TCA; the TR-201 instead uses Gimbal interfaces directly connected to bosses on the top of the engine (they are attached to the manifold head itself).
The engines do share identical thrust chambers and pintle injectors. I hold a complete TR-201 within my collection.
Scott
http://www.SPACEAHOLIC.com/
Posted by: Scott Schneeweis | May 10, 2009 at 09:00 AM
David,
Sorry, I guess it is the perspective of the different images that cause them to appear different. My apologies and congratulations on owning such a RARE item!
Posted by: RonRay | May 10, 2009 at 01:42 PM
My father was a technical writer for the LMDE project. If anyone has any pictures of the assembly of the engine in San juan Capistrano, Ca., I would appreciate an email.. Someone took all of our pictures.
I have a few very rare First Day Covers I would be willing to trade.
Thanks David for the quick reply.
Roger Mattson
[email protected]
Posted by: Roger Mattson | July 20, 2009 at 03:49 PM
hello
i want to know which kind of material(metal)
usually is used in injctor plate of an liquid-propellent engine.and an sampel technical drawing of injector plate.
please help me
thancks alot
Posted by: sami | July 22, 2010 at 01:59 AM