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RS-25 testing/development at Stennis for SLS - DISCUSSION

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Hog:
The unflown ME-0525 test engine has been installed in the A-1 test stand July 10, 2014 at Stennis. 

Any idea when ME-0525 will break its 5 year silence since its last firing in 2009?

Anticipation for the RS-25 testing/operations is growing.


RS-25 testing for SLS - UPDATE - thread is located here:

http://forum.nasaspaceflight.com/index.php?topic=35220.0

Articles on this path:

http://www.nasaspaceflight.com/tag/ssme/ <---pretty much a few years of recent history on the path to testing on that one page.

E0525 is now installed on the A-1 Test Stand. So we're getting close.
http://www.nasaspaceflight.com/2014/07/rs-25-stennis-testing-sls-schedule/

AnalogMan:

--- Quote from: Hog on 07/25/2014 01:47 PM ---Any idea when ME-0525 will break its 5 year silence since its last firing in 2009?

--- End quote ---

Last public info I saw was this:

Pegasus Barge to begin renovations for SLS core shipping
July 7, 2014 by Chris Bergin

"According to L2 information, Test stand A-1 modifications were completed June 30, with engine E0525 mounted on the stand July 1. E0525 testing is still scheduled to start NET (No Earlier Than) August 20"

http://www.nasaspaceflight.com/2014/07/pegasus-barge-renovations-sls-core-shipping/

L2 link:
http://forum.nasaspaceflight.com/index.php?topic=32883.msg1222678#msg1222678

Hog:
Remembering a post that Wayne Hale made over in the Q&A section.
http://forum.nasaspaceflight.com/index.php?topic=17437.3210


Quoted in its entirety to avoid snipe quoting, emphasis mine.

"Unfortunately there is a lot of oversimplification going on in this thread which could lead to an inaccurate understanding of several complex subjects regarding the SSME and its upgrade.  The block upgrade (from Phase II+ to Block I to Block II) took almost a decade and cost over $2B.  The intention was to provide a more robust engine, not just because of some pad abort that occurred.  The newer block engine had lower ISP (by about 1.5 sec) which required an increase in thrust from 104% RPL to 104.5%RPL to make up for the performance loss.  Neither engine was certified for 109% operation but that was certainly the intent for the Block II engine.  Both nominal flight and all intact aborts used the 104.5% RPL thrust level.  During testing to certify the 109% for aborts, it was found that there were components in the main propulsion piping in the orbiter which likely could not withstand the higher vibration environment associated with that flow rate.  Cracking of the metallic components could have lead to liberation of metal pieces into the engine inlet which would not have been good at the pumps.  So efforts to certify 109% or 111% were terminated.  109% throttles were authorized only in 'do or die' contingency abort scenarious which were multiple failures deep."


In light of the issues which were proven at the 109% RPL using the existing Shuttle MPS piping. 
1)Does this mean that the MPS piping/valves/hardware removed from the OV's would not be used on the test stand?
2) Was the Shuttle MPS piping/valves etc. removed from the Orbiters just in case the SLS core stage used 3 RS25 engine, and now that 4 engines will be used, that MPS hardware is not able to be used on thetest stand or as flight hardware?

3) Will any 111%RPL be tested, or do abort modes such as an ATO(Abort to Orbit), such as an engine out later in the 2nd stage after the solid boosters have jettisoned, increase the remaining 3 RS25's to 111%RPL to help reach a more desireable velocity, or do these Shuttle'esque off-nominal engine thrust settings/ATO scenarios not apply to SLS?

Steven Pietrobon:
My understanding is that the existing RS-25D engines will be flown at 109%. The new RS-25E engines will be flown at 111%. From page 25 of the attached document. The RS-25D has been certified at 109% and also ground tested at 111%.

QuantumG:

--- Quote from: Steven Pietrobon on 08/27/2014 08:05 AM ---My understanding is that the existing RS-25D engines will be flown at 109%. The new RS-25E engines will be flown at 111%. From page 25 of the attached document. The RS-25D has been certified at 109% and also ground tested at 111%.

--- End quote ---

So.. what they're saying is.. ours go to 11?

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