Author Topic: RS-25 testing/development at Stennis for SLS - DISCUSSION  (Read 35456 times)

Offline AnalogMan

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #60 on: 11/24/2015 01:35 PM »
The press release does not indicate how many RS-25 engines will be manufactured under the $1.16 Billion dollar contract.  Anyone know?

In NASA's press release it says:

"The contract also allows for a potential future modification that would enable NASA to order six flight engines."

See: http://forum.nasaspaceflight.com/index.php?topic=31740.msg1448620#msg1448620

Online Khadgars

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #61 on: 11/24/2015 05:13 PM »
And in other news, Aerojet-Rocketdyne was just awarded their contract to reopen the RS-25 production line.

http://www.satprnews.com/2015/11/24/nasa-and-aerojet-rocketdyne-to-restart-production-of-the-rs-25-engine-for-the-space-launch-system/

Exciting news!  Good to see them restarting production at an early stage.

Online Lars-J

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #62 on: 11/24/2015 05:15 PM »
The press release does not indicate how many RS-25 engines will be manufactured under the $1.16 Billion dollar contract.  Anyone know?
This contract is for re-developing the RS-25 to suit the SLS requirements beyond the 16 re-purposed STS SSME's. The contract can be modified to include the construction of 6 new engines.

Ah lovely, a billion dollars for no flying hardware. This is the kind of contract that Aerojet Rocketdyne dreams of. Right up their alley, now they can kick the can down the road for a few more years until they close up shop.

Offline RocketGoBoom

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #63 on: 11/25/2015 01:25 AM »

Ah lovely, a billion dollars for no flying hardware. This is the kind of contract that Aerojet Rocketdyne dreams of. Right up their alley, now they can kick the can down the road for a few more years until they close up shop.

I can't help but think that most of these new engines will end up parked in front of various museums around the USA after the SLS program is cancelled due to unsustainable costs.

« Last Edit: 11/25/2015 01:27 AM by RocketGoBoom »

Online Lars-J

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #64 on: 11/25/2015 01:37 AM »

Ah lovely, a billion dollars for no flying hardware. This is the kind of contract that Aerojet Rocketdyne dreams of. Right up their alley, now they can kick the can down the road for a few more years until they close up shop.

I can't help but think that most of these new engines will end up parked in front of various museums around the USA after the SLS program is cancelled due to unsustainable costs.



But this contract doesn't even produce any engines at all, that's my issue. SLS would have to go really well for them to issue a follow-up contract to actually build the engines that might one day end up as museum pieces.

Online Khadgars

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #65 on: 11/25/2015 01:54 AM »

Ah lovely, a billion dollars for no flying hardware. This is the kind of contract that Aerojet Rocketdyne dreams of. Right up their alley, now they can kick the can down the road for a few more years until they close up shop.

I can't help but think that most of these new engines will end up parked in front of various museums around the USA after the SLS program is cancelled due to unsustainable costs.



But this contract doesn't even produce any engines at all, that's my issue. SLS would have to go really well for them to issue a follow-up contract to actually build the engines that might one day end up as museum pieces.

Do we really need this kind blabber in every SLS thread?  SLS has progressed farther than opponents were saying even just couple years ago.

Offline woods170

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #66 on: 11/25/2015 12:02 PM »

Ah lovely, a billion dollars for no flying hardware. This is the kind of contract that Aerojet Rocketdyne dreams of. Right up their alley, now they can kick the can down the road for a few more years until they close up shop.

I can't help but think that most of these new engines will end up parked in front of various museums around the USA after the SLS program is cancelled due to unsustainable costs.



But this contract doesn't even produce any engines at all, that's my issue. SLS would have to go really well for them to issue a follow-up contract to actually build the engines that might one day end up as museum pieces.

Do we really need this kind blabber in every SLS thread?  SLS has progressed farther than opponents were saying even just couple years ago.
Exactly. The next president will not take office until early 2017. By which time SLS has progressed to the point where flight-hardware is being tested prior to first flight. If that next president decides to kill SLS that late in the game it will be the biggest waste of money, on an unflown program for NASA, ever. Much worse in fact than the killing of Constellation.
CxP was killed-off long before any of the proposed vehicles even got close to CDR. Both SLS and Orion have passed that point.
CxP was killed-off long before any flight-hardware was being manufactured. Both SLS and Orion have passed that point.
Etc, etc.
The way I see it SLS will not be killed off until after (at least) EM-1. By that time it will be similar to prematurely ending Apollo or STS.

Offline Space Invaders

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #67 on: 12/23/2015 06:48 PM »
A few years ago, Ross said the following:

Most prominent of all the possible upgrades is the Brazed Tube Nozzle.   That is currently the most time-consuming and expensive element in the SSME.   It consists of 1080 separate tubes, each carefully formed with continually changing diameter and circular/elliptical shape along its entire length.   These tubes are then brazed together into the shape we all know, and a jacket is then mounted around them for support, plus forward and aft ducts and other tubing.   The whole operation involves intensive human touch-labour throughout, so this is an extremely expensive and inefficient way of making things.   The Brazed Tube Nozzle approach is the reason for the current production "bottleneck" which restricts production to a maximum of 12 units per year.

If the Nozzle were replaced with a Channel Wall Nozzle, the part count and the touch labor would be *massively* reduced and the production bottleneck effectively removed -- with just one change.

This change alone, while certainly not a trivial change, should reduce the cost of the SSME by about ~20%.   It is therefore one of the most significant single upgrades under consideration.

Has there been any progress on this front?

Online Chris Bergin

Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #68 on: 12/23/2015 07:52 PM »
I'm shocked to the core to see negative posts about SLS! Shocked I tell you ;)

But seriously, let's not get dragged into this "It's L- one day but I still say SLS will never fly. OK, they've launched, but like I said, SLS will NEVER FLY!!!" ;D

Online russianhalo117

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #69 on: 12/23/2015 10:55 PM »
A few years ago, Ross said the following:

Most prominent of all the possible upgrades is the Brazed Tube Nozzle.   That is currently the most time-consuming and expensive element in the SSME.   It consists of 1080 separate tubes, each carefully formed with continually changing diameter and circular/elliptical shape along its entire length.   These tubes are then brazed together into the shape we all know, and a jacket is then mounted around them for support, plus forward and aft ducts and other tubing.   The whole operation involves intensive human touch-labour throughout, so this is an extremely expensive and inefficient way of making things.   The Brazed Tube Nozzle approach is the reason for the current production "bottleneck" which restricts production to a maximum of 12 units per year.

If the Nozzle were replaced with a Channel Wall Nozzle, the part count and the touch labor would be *massively* reduced and the production bottleneck effectively removed -- with just one change.

This change alone, while certainly not a trivial change, should reduce the cost of the SSME by about ~20%.   It is therefore one of the most significant single upgrades under consideration.

Has there been any progress on this front?
Im aware of talk a while back of develop the capability to 3D print most or all of the nozzle for either tube or channel design. AR is currently working on it as part of project within production restart contract. we should get more info as this contract kicks off next year

Online Hog

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #70 on: 08/07/2016 08:47 PM »
Looks like DE-0528 lit off nicely.  Anyone have interesting developments they wish to share?  Please, discuss.
Paul

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Re: RS-25 testing at Stennis for SLS - DISCUSSION
« Reply #71 on: 03/13/2017 06:58 PM »
Upcoming hotfire test green running flight hardware(engine controller) IIRC it should be FM2(March), then FM3(April), then FM4 to be tested on good old Qualification Engine E-0528 (which continues on in active qualification service with her sister E-0525).

Then come Summer time we get into some flight engine acceptance testing with E-2063, then early Autumn E-2062.
The Summer/Fall testing of 2017 at Stennis will see E-2063, which was built in 2014, and E-2062, which was the last RS-25D engine that was built a year before the SSP was stood down. These 2 flight engines, that are awaiting certification, will get their "green runs" during these 2017 sessions.  If all goes well, NASA will then have 16 fully functioning and hotfired pieces of flight hardware and will further increase the over 1 million seconds, or over 280 hours of hotfire experience that RS-25 has gathered.

 We have these 2 engines which along with E-2047 and E-2059 are scheduled to be primary flight engines on EM2, and are scheduled as contingency engines for EM-1, in case the Primary EM-1 flight set consisting of engines: 2045, 2056, 2058, 2060 must be removed and replaced prior to the launch of EM-1.

The 16 flight engines, who are they? where they been? where they from? burning more than hydrogen on your tongue. (a small tribute to Metallica-Holier than Thou)

Exploration Mission–1 (ready for launch in 2018)
• Engine 2045, STS–95 – John Glenn’s return to space
• Engine 2056, STS–109 – Hubble Space Telescope
   servicing mission
• Engine 2058, STS–133 – Last flight of orbiter Discovery
• Engine 2060, STS–135 – Final flight of the Space Shuttle Program

Exploration Mission–2 (slated for 2021)
• Engine 2047, STS–98 – Delivered Destiny lab module
   to the International Space Station (ISS)
• Engine 2059, STS–117 – Longest mission for the
   orbiter Atlantis
• Engine 2062, New engine never flown
• Engine 2063, New engine never flown

Exploration Mission–3
• Engine 2048, STS–92 – 100th mission of the Space Shuttle
• Engine 2054, STS–126 – Most supplies and equipment ever on
   a single mission
• Engine 2057, STS–125 – Final servicing mission of Hubble
   Space Telescope
• Engine 2061, STS–130 – Delivered the Tranquility node and
its 7-window cupola to ISS

Exploration Mission–4
• Engine 2044, STS–88 – First mission to ISS
• Engine 2050, STS–108 – Delivered U.S. Harmony module to ISS
• Engine 2051, STS–128 – Delivered Quest airlock module to ISS
• Engine 2052, STS–99 – Longest mission for Atlantis, lasting
  more than 13 days and 20 hours


Just in case you missed it, here is the assembly of E2063 in late 2014 condensed down into a 2 minute clip. This is NASA's newest RS-25, and completes the "sweet sixteen" number of flight engines for 4 SLS missions.



Excellent article by Phillip Sloss, from Feb 22/17.
https://www.nasaspaceflight.com/2017/02/rs-25-test-sls-team-waits-new-controllers/

Lots of excitement in store from Stennis this year.  RS25's are my favourite Hydrogen combustion devices.


Online Hog

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Re: RS-25 testing/development at Stennis for SLS - DISCUSSION
« Reply #72 on: 10/01/2017 03:22 PM »
Over on the Update thread, PSLOSS fills us in that the new terminology for the RS25 is Heritage, Adaptation, Restart.
http://forum.nasaspaceflight.com/index.php?topic=34671.140

Heritage-the old school SSME with the original SSME controllers-14 flight veterans and 2 engines which still require "green runs" at Stennis- ME-2062 (circa2010) and ME-2063(circa 2014)
Adaptation- the same 16 engines after hotfiring in an SLS environment with SLS equipment incl. SLS controllers
Restart-new build specifically designed for SLS, not yet in existence (what us oldschoolers would rather call RS25-"E") ideally to be used post EM-4, provided all 16 "ADAPTATION" engines test and operate nominally in preflight.

IMO, RS25-D(SSME), RS-25D+(SLSME), RS-25E(SLSME) would work, but no matter.

The new "RESTART" engines only will run at 111%RPL no doubt to overcome the extra mass of the new engines. She only has a service life of 4 starts and 1700 seconds, much different than the reusable "HERITAGE" units.  Just like what occurred when the Block-II-A RS25 came into usage for STS (STS-89)
which required a bump from 104% to 104.5% to compensate for the new Block-II-A and eventual Block-II RS-25-D masses.

Engine durability can be traded for increased thrust, no need for such extreme costs for low weight in a SLS spec engine. The new nozzle is a perfect example of this.

Hopefully we get a 4 engine core stage "greenrun" before the end of the decade.


I've included the graphic supplied by PSLOSS just for quick reference.  Thanks Phillip!
Paul

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Re: RS-25 testing/development at Stennis for SLS - DISCUSSION
« Reply #73 on: 10/03/2017 06:22 PM »
Very cool thank you Hog.  I never quite understood peoples obsession with RS-25 being a bottleneck for SLS. 

Online Hog

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Re: RS-25 testing/development at Stennis for SLS - DISCUSSION
« Reply #74 on: 10/08/2017 02:47 PM »
NASA has ME-2063 mounted up in the test stand at Stennis.  It should be noted that ME-2063 is the 16th Main Engine of 16 currently available for SLS usage and is currently scheduled for flight duty in the next decade during EM-2.
ME-2063 was built in 2014 is only 1 of 2 ME's that have never been hot fired, so new that she doesn't appear in the oft seen SSME History Diagram(4th picture bellow- 15 of the 16 current 16 RS-25s have asterisks below them on the diagram-on the lower right of the diagram).
 Her sister ME-2062 was built back in 2010 when the STS program was still operational.

Here is ME-2063 being assembled is a couple posts up.

ME-2063 is to be tested during a public display on October 19, so long as you are a USA citizen.  I guess I'll watch from home.  2063 is the 2nd flight engine to be tested after ME-2059 was fired.

(First picture, you can see why modifications to the test stand we required as the engines are roughly the same size as the test stand. joke)
Paul

Online Chris Bergin

New test, this time with Engine 2063 - which has never been tested before.

Awesome feature article from Philip Sloss:
https://www.nasaspaceflight.com/2017/10/stennis-fire-up-untested-rs-25-engine/


Online Chris Bergin

T-5 minutes. Sirens sounding. Those cars are going to get a free wash.

Online Chris Bergin

Epic view.

Offline Joffan

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Re: RS-25 testing/development at Stennis for SLS - DISCUSSION
« Reply #79 on: 10/19/2017 08:04 PM »
Epic, certainly, but why on Earth are they firing this thing for so long? It will never approach this in flight - will it?

[It certainly feels like an incredibly long test time.... maybe that is an illusion]

Ah finally they are done :)
« Last Edit: 10/19/2017 08:11 PM by Joffan »
When I say "Jump!", you say "To which orbital inclination?"

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