Any idea when ME-0525 will break its 5 year silence since its last firing in 2009?
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%.
So.. what they're saying is.. ours go to 11?
Quote from: QuantumG on 08/27/2014 08:07 am So.. what they're saying is.. ours go to 11?Although RS-25D has been tested at 111%, that does not mean that it is certified for 111% which I believe requires additional testing or modifications to the engine.
I understood that the RS-25E would be a simplified design using modern manufacturing techniques, and a considerably reduced part count. So where does the extra ~300 lbs for the new engine come from?Is the new channel-wall nozzle that much heavier than the legacy tube-wall version?
Things should be getting ready to fire shortly, Anyone heard anything?
regarding the new SSME controller - 'if it ain't broke, don't fix it'
IIRC the new RS-25 controller and the new J2X controller are one in the same. So Block II SLS will use a common controller on bothe the core and the upper stage.
Quote from: Hog on 12/21/2014 04:23 pmIIRC the new RS-25 controller and the new J2X controller are one in the same. So Block II SLS will use a common controller on bothe the core and the upper stage.Unlikely. SLS, as currently envisioned up to the 130 mT version, will never fly J-2X on any upper stage.
Quote from: woods170 on 12/21/2014 10:54 pmQuote from: Hog on 12/21/2014 04:23 pmIIRC the new RS-25 controller and the new J2X controller are one in the same. So Block II SLS will use a common controller on bothe the core and the upper stage.Unlikely. SLS, as currently envisioned up to the 130 mT version, will never fly J-2X on any upper stage.My simulations show you need a J-2X or four MB-60 second stage engines to get to 130 t, regardless of the boosters used.
Here's a copy of the Block III SSME Upgrade Project Overview presentation with the pages rotated to the correct orientation.
Test Videohttp://forum.nasaspaceflight.com/index.php?topic=36465.msg1312812#msg1312812
In the article posted on Jan 2 it is mentioned that the head pressures for the fuel and oxidisers will be greater for SLS as opposed to the shuttle. I am just wondering how that would affect the performance of the engines? Increase/decrease thrust or ISP? And will it be a greater or less stress on the turbine pumps?I guess the reason for the tests are two determine the outcomes but if anyone wanted to make an informed guess I would very much appreciate it!ThanksMark
http://www.nasa.gov/exploration/systems/sls/some-assembly-required-the-newest-rs-25-joins-the-space-launch-system-family.html16th RS-25 completed.I believe there also was an engine test today.
The RS-25 is unique among many engines in that it automatically runs through its cycles and programs.
There is a marked throttle up at 1:50 of the video timer and stays upthrottled until 7:20 which is a runtime of 5 mins 30 secs (330 seconds) at this elevated power level.
Quote from: Hog on 05/31/2015 05:29 amThere is a marked throttle up at 1:50 of the video timer and stays upthrottled until 7:20 which is a runtime of 5 mins 30 secs (330 seconds) at this elevated power level.The basics looked similar to Shuttle; the engine is throttled down from "full power" shortly after "liftoff" and then again to something like minimum power level at the end of the test to set up for shutdown.Maybe we'll get to see some detailed test objectives on L2 at some point in the development series.
Quote from: psloss on 05/31/2015 03:15 pmQuote from: Hog on 05/31/2015 05:29 amThere is a marked throttle up at 1:50 of the video timer and stays upthrottled until 7:20 which is a runtime of 5 mins 30 secs (330 seconds) at this elevated power level.The basics looked similar to Shuttle; the engine is throttled down from "full power" shortly after "liftoff" and then again to something like minimum power level at the end of the test to set up for shutdown.Maybe we'll get to see some detailed test objectives on L2 at some point in the development series.Actually, the engines was not at Rated Power Level (RPL) at lift-off (104.5%) but rather at 100%.
Do you mean the test will use the new controller?
http://www.nasaspaceflight.com/2015/08/sls-test-stennis-team-overview-rs25-ignition/Thanks for the great article Philip of which I like to refer to as "The music of the Shuttles"...
Test complete!Here's Philip's article to mark the series and preview the next - plus more on the turnaround of the engine between test six and seven. Top work by Philip with the access and quotes.http://www.nasaspaceflight.com/2015/08/rs-25-completes-test-series-next-engine/
Quote from: Chris Bergin on 08/27/2015 08:23 pmTest complete!Here's Philip's article to mark the series and preview the next - plus more on the turnaround of the engine between test six and seven. Top work by Philip with the access and quotes.http://www.nasaspaceflight.com/2015/08/rs-25-completes-test-series-next-engine/Very nice article!So we have DE-0525 which currently just finished its duty on the test stand for this current round of tests. DE-0525 will now be swapped out for the 2nd Development Engine-DE-0528 for another battery of tests for SLS usage. 16 Main Engines and 2 Development Engines for a total of 18 RS-25s in NASA's current inventory.Block II/RS25D Engines with flight experience (listed with last mission flown)1) 2044 STS-1332) 2045 STS-1353) 2047 STS-135 4) 2048 STS-1335) 2050 STS-1206) 2051 STS-1327) 2052 STS-132 2054 STS-1319) 2056 STS-12110) 2057 STS-13411) 2058 STS-13312) 2059 STS-13413) 2060 STS-13514) 2061 STS-134Unflown Block II/RS25D engines15) 2062 (circa 2010 build)16) 2063 (2015 build)Development Engines Block II/RS25D17) 052518) 0528According to the supplied excerpt from the 2000 Block III SSME Upgrades Project Overview which states that there are three-Block III Development Engines and two-Block III Certification Engines with a total of 154 starts and 60,000 seconds (16.6 hours)of hotfire runtime that were in existence at some time.001-Development Engine002-Development Engine003-Development Engine004-Certification Engine005-Certification EngineI wonder what became of these Block III RS-25 engines?Heres a link to the 2000 Block III SSME proposal for those who haven't seen it.http://archive.org/stream/nasa_techdoc_20000112952/20000112952#page/n0/mode/2upHopefully the next round of testing using DE-0528 goes as well as testing with DE-0525 did.
The press release does not indicate how many RS-25 engines will be manufactured under the $1.16 Billion dollar contract. Anyone know?
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/
Quote from: Todd Martin on 11/24/2015 01:25 pmThe 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.
Quote from: Lars-J on 11/24/2015 05:15 pmAh 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.
Quote from: RocketGoBoom on 11/25/2015 01:25 amQuote from: Lars-J on 11/24/2015 05:15 pmAh 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.
Quote from: Lars-J on 11/25/2015 01:37 amQuote from: RocketGoBoom on 11/25/2015 01:25 amQuote from: Lars-J on 11/24/2015 05:15 pmAh 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.
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.
A few years ago, Ross said the following:Quote from: kraisee on 12/30/2009 06:00 amMost 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?
Epic, certainly, but why on Earth are they firing this thing for so long? It will never approach this in flight.
Published on 19 Oct 2017Engineers at NASA’s Stennis Space Center in Mississippi on Oct. 19 completed a hot-fire test of RS-25 rocket engine E2063, a flight engine for NASA’s new Space Launch System (SLS) rocket. Engine E2063 is scheduled to help power SLS on its Exploration Mission-2 (EM-2), the first flight of the new rocket to carry humans.This video is available for download from NASA's Image and Video Library: https://images.nasa.gov/#/details-NAS...
If the engine goes up to 109% thrust, why dont they make that 100% thrust? And why dont they just make 10 louder instead of adding 11? And why wont these kids get off my lawn?
There's something I've wondered about for the past 10- or 15-odd years, and maybe someone here knows the answer.The SSME underwent many years of development, some of it at the hands of Pratt engineers who were asked to come in and quietly fix Rocketdyne's design issues, and some of it by engineers who came well after. The AR-22 seems to provide evidence that the RS-25 is a much better engine than the one that first flew in 1981. IIRC, the downcomer was next on the redesign list when SSME production was discontinued. Does someone know whether PWR just picked up where they'd left off? I know it's far more reliable now, but how much? How close is the RS-25 to its original reuseability design goals?
Great engine... huge effort to make it truly resuable. So, could someone explain to me again why we are throwing four of them away each flight?
I do hate seeing that beautiful engine being thrown away though.
Quote from: ulm_atms on 07/11/2018 01:22 amI do hate seeing that beautiful engine being thrown away though.I wonder how much it would cost to develop a SMART system (like Vulcan) to recover them.
They shouldn't even wait for SLS to start trying. Just make some dummies and put the dummies on a Vega as the payload then try to parachute the dummies. Vega's only cost 37 million so it should be a lot cheaper then throwing away 4 of those beauties.
But more seriously, it's pretty damn infuriating that they are yanking bits out of the old space shuttles for the SLS. It's like looting the Parthenon for marble. If they are going to throw away RS-25s, they should throw away the ones that are made for a single use. They've had plenty of time to get them ready.
Quote from: daveklingler on 07/10/2018 02:39 pmThere's something I've wondered about for the past 10- or 15-odd years, and maybe someone here knows the answer.The SSME underwent many years of development, some of it at the hands of Pratt engineers who were asked to come in and quietly fix Rocketdyne's design issues, and some of it by engineers who came well after. The AR-22 seems to provide evidence that the RS-25 is a much better engine than the one that first flew in 1981. IIRC, the downcomer was next on the redesign list when SSME production was discontinued. Does someone know whether PWR just picked up where they'd left off? I know it's far more reliable now, but how much? How close is the RS-25 to its original reuseability design goals?The SSME went through several iterations. FMOF [First Manned Orbital Flight] (1981), Phase I (1983), Phase II (1988), Block I (July 1995), Block IA (Oct. 1995), Block IIA (1998), and Block II (2001). I'm of the understanding, but someone else will probably correct me, that all SSMEs Block I and later could be full-duration fired multiple times with little more than borescope inspections.
Quote from: AncientU on 07/11/2018 12:39 amGreat engine... huge effort to make it truly resuable. So, could someone explain to me again why we are throwing four of them away each flight?To funnel more money to AR? I kid but it is because this engine was/is the most powerful engine they had at the time when designing SLS and they were trying to do it on the "cheap"....so no engine development money was available. I do hate seeing that beautiful engine being thrown away though.I know you knew the answer when you asked however... Edit: Forgot words...Twice...I'm tired...
I confess that I have the attitude toward SMART that many people have after watching a whole bunch of F9 landings: "Huh?"
They shouldn't even wait for SLS to start trying.
Also for Falcon 9 vertical landing makes more sense because of how early the separation is. Falcon 9 has a heavy second stage with RP-1 instead of the LH2. SLS has LH2 in the first stage as well as the second stage plus it has those massive boosters. All that adds up to the SLS first stage needs to be going pretty darn fast to do it's job so a vertical landing would be tough.
More than it costs to buy the engines.
You do understand how products are designed, right?
what another couple of $Billion?
The SLS has to stage higher and faster because of the EDS. Which also means if you were to detach the engine compartment it would be traveling through space for a while before entering Earth's atmosphere at a heck of a velocity. Did you anticipate that?
Quote from: johnfwhitesell on 07/11/2018 03:18 amQuote from: ulm_atms on 07/11/2018 01:22 amI do hate seeing that beautiful engine being thrown away though.I wonder how much it would cost to develop a SMART system (like Vulcan) to recover them.More than it costs to buy the engines. But more importantly, it was not a requirement from Congress.You do understand how products are designed, right? They start with a list of requirements, and if reusability is not part of the requirements, then they don't design for it. The SLS was not designed, in any way, for reusability or recovery of it's components....
Is there a plan/schedule already in place for subsequent testing (Retrofit 1C / Retrofit 2 / something else), I guess starting to certify newly-built RS-25s for the fifth SLS?
Quote from: eeergo on 09/06/2018 05:45 pmIs there a plan/schedule already in place for subsequent testing (Retrofit 1C / Retrofit 2 / something else), I guess starting to certify newly-built RS-25s for the fifth SLS?A lot of that is covered in our summer two parter.Part 1:https://www.nasaspaceflight.com/2018/07/rs-25-program-production-restart-test-series/Part 2:https://www.nasaspaceflight.com/2018/07/aerojet-rocketdyne-six-engine-rs-25-run/
I may have missed it, but I didn't see stated what's the purpose of the 9th test in the Retrofit 1B series (unless there were 7 tests in 1A), although I guess having a spare ECU is quite probable?
And concerning the old SSMEs to be used in the first SLSs, will they keep their new components (POGO accumulator etc) they hot-fired them with, or are they just certifying those designs, but the actual flight configuration will be with the heritage ones?
https://www.nasa.gov/nasaliveRS-25 test firing to be broadcast live at 16:30 today, 26 September
3:12 PM and all I've got on NASA TV is a replay of the press conference of the Soyuz, is the test today not happening (which doesn't make any sense, totally unrelated program to the ISS, right?) or is it just not shown?
Is this a flight-proven Shuttle engine or a new unit?
I'm actually surprised that it (test) continued on for so long with the fire present. One would think someone is watching cameras focused on the engine...
Quote from: butters on 12/12/2018 08:56 pmIs this a flight-proven Shuttle engine or a new unit?...Prior to today’s hot-fire, E0525 has 87 ground test starts at Stennis in its service for Shuttle and SLS, accumulating 43,133 seconds of run time on its powerhead. Similarly, E0528 has 109 ground test starts, accumulating 58,842 seconds of run time on its powerhead at Stennis."https://www.nasaspaceflight.com/2018/09/development-engine-rs-25-testing-2/
Quote from: robertross on 12/12/2018 10:10 pmI'm actually surprised that it (test) continued on for so long with the fire present. One would think someone is watching cameras focused on the engine...I also share this surprise and concern. If anyone knows; don't they use some form of Pyrometers, or other instrumentation to detect a fire outside the engine? And related to this question, it seems like this would be even more needed in the engine bay of a rocket. Was this something that they had in the shuttle?
Wonder if any Merlin's come close
Quote from: Arb on 12/12/2018 10:45 pmWonder if any Merlin's come close Next year some might get close in number of ignitions at least. Runtime is quite a bit off with those 5s landing burns .More on topic, has anyone figured out how much that great cost saving measure by reusing shuttle parts has cost yet compared to buying a bunch of BE-4 or comparable? Northrop also tried reusing 30 year old engines. After that Cygnus flew on Atlas for a bit...
Quote from: niwax on 12/13/2018 07:30 amNorthrop also tried reusing 30 year old engines. After that Cygnus flew on Atlas for a bit...None of the RS-25D engines that are going to be flown on the SLS are that old.
Northrop also tried reusing 30 year old engines. After that Cygnus flew on Atlas for a bit...
Quote from: Arb on 12/12/2018 10:45 pmWonder if any Merlin's come close >SpaceX likes to blow up their test articles by ramping up the conditions >
Part of the Merlin’s qualification testing involves feeding a stainless steel nut into the fuel and oxidizer lines while the engine is running—a test that would destroy most engines but leaves the Merlin running basically unhindered.
ARTICLE: Government MECO delays RS-25 testing following premature shutdown -https://www.nasaspaceflight.com/2019/01/government-meco-rs-25-premature-shutdown/ https://twitter.com/NASASpaceflight/status/1083064629364953088
Quote from: catdlr on 04/05/2019 02:53 amNASA Achieves Testing Milestone with Engines for Initial SLS MissionsNASA conducted a hot fire test of RS-25 flight engine No. 2062 on the A-1 Test Stand at Stennis Space Center on April 4, with a full-duration of 500 seconds. The hot fire caps more than four years of testing for engines that will help power the first four missions of NASA’s new Space Launch System (SLS) rocket. All 16 former space shuttle main engines that will help launch the first four SLS missions have undergone acceptance testing and have completed developmental and acceptance testing for new controllers to be used by the engines. It also concludes a 51-month test series that demonstrated RS-25 engines can perform at the higher power level needed to launch the super heavy-lift SLS rocket.Does this mean the Retrofit 1b test series is complete, and certification of the new HIP MCC, HPFTP and POGO accumulators is now complete (along with the certification of the ECUs for the first four SLS flights)? If so, the next RS-25 testing we can expect is within the Retrofit 2 series, to certify the flexible ducting? How long is that program expected to last before Retrofit 3 is reached? I understand the deadline for finishing all Retrofit series and deliver a non-flight certification engine is the middle of next year, to have six new "production restart" engines delivered 3 years later.
NASA Achieves Testing Milestone with Engines for Initial SLS MissionsNASA conducted a hot fire test of RS-25 flight engine No. 2062 on the A-1 Test Stand at Stennis Space Center on April 4, with a full-duration of 500 seconds. The hot fire caps more than four years of testing for engines that will help power the first four missions of NASA’s new Space Launch System (SLS) rocket. All 16 former space shuttle main engines that will help launch the first four SLS missions have undergone acceptance testing and have completed developmental and acceptance testing for new controllers to be used by the engines. It also concludes a 51-month test series that demonstrated RS-25 engines can perform at the higher power level needed to launch the super heavy-lift SLS rocket.
Quote from: eeergo on 04/09/2019 01:19 pmQuote from: catdlr on 04/05/2019 02:53 amNASA Achieves Testing Milestone with Engines for Initial SLS MissionsNASA conducted a hot fire test of RS-25 flight engine No. 2062 on the A-1 Test Stand at Stennis Space Center on April 4, with a full-duration of 500 seconds. The hot fire caps more than four years of testing for engines that will help power the first four missions of NASA’s new Space Launch System (SLS) rocket. All 16 former space shuttle main engines that will help launch the first four SLS missions have undergone acceptance testing and have completed developmental and acceptance testing for new controllers to be used by the engines. It also concludes a 51-month test series that demonstrated RS-25 engines can perform at the higher power level needed to launch the super heavy-lift SLS rocket.Does this mean the Retrofit 1b test series is complete, and certification of the new HIP MCC, HPFTP and POGO accumulators is now complete (along with the certification of the ECUs for the first four SLS flights)? If so, the next RS-25 testing we can expect is within the Retrofit 2 series, to certify the flexible ducting? How long is that program expected to last before Retrofit 3 is reached? I understand the deadline for finishing all Retrofit series and deliver a non-flight certification engine is the middle of next year, to have six new "production restart" engines delivered 3 years later.Retrofit 1b testing should now be complete with the 9th test. POGO accumulator was on DE-0528 for Retrofit 1a and the same POGO assembly was retrofitted on DE-0525 for Retrofit 1b.Retrofit-2 will use DE-0528 for testing and will include the flex hoses you mentioned, a change from the complicated flex-joints which were used on Shuttle. Going from reusable to expendable plus the reduction in gimbaling requirements allowed for this change. We will see the 2nd MCC and 2nd POGO assemblies along with some gimbaling action using the new thrust vector control (TVC) assembly added to the A-1 test stand.The test scheduling on the restart of RS-25 production seems to be on schedule, I'm guessing we'll see E-0528 loaded with the new parts for Retrofit2 testing soon(Summerish??EDIT possibly next year-AR-22 gets another round of tests in addition to last Summers testing at A-1)).The original 16 "Heritage" engines have now been accepted as "Adaptation Engines" which will run at 109% RPL. Along with the engines 17 new controllers, 4 for each mission, with a single spare controller.The contract delivery date for those six "new build" engines is July of 2024. The single "Certification Engine" as they are calling it, is really a Development Engine, regardless it will have all the features of a flight engine, but will never see space. We are to see the new build "Certification Engine" by mid 2021.pics1) Testing/Development/Production restart for RS-25 engine program2) Differences between "Heritage(RS-25D/SSME)" "Adaptation" and "Restart" SR25 engines
In the imperial system maybe, but not in the metric system.