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....