4xRS-25 about equal to 1xFalcon 9 block 5 in thrust, but they're supposed to fire for ~9 mins compared to F9's 2.5 minutes.

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nar12605

NASA is not really reporting a great deal of detail so far on their web page about what might have caused the early shutdown (and I did not watch the press conference afterwards).

Here is part of what was reported:

“The test plan called for the rocket’s four RS-25 engines to fire for a little more than eight minutes – the same amount of time it will take to send the rocket to space following launch. The team successfully completed the countdown and ignited the engines, but the engines shut down a little more than one minute into the hot fire. Teams are assessing the data to determine what caused the early shutdown, and will determine a path forward.“

If someone heard any other significant detail, let us know.

Earl

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From an article on the CBS News page:


“But about 50 seconds after engine ignition, a test controller called out "MCF on engine 4," using an acronym that stands for "major component failure." The test director replied, "copy that, but we're still running, still got four good engines, right?"

It appeared so, but a few seconds later the exhaust plume of an engine, presumably No. 4, began changing, dropping in intensity even as a controller reported several "violations" in the telemetry stream. Moments later, the test conductor called "we've got a shutdown."

Honeycutt said there was an unusual "flash" near flexible insulation blankets at the interface between engine No. 4's nozzle and the rocket's aft bulkhead around the time the nozzle steering tests had been planned. But he had no insights into what caused the flash or what it might have indicated.
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Link to full article: https://www.cbsnews.com/news/nasa-t...oon-rocket/#app

Earl

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So, now they have 15 shuttle era RS-25's.


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SO I read they've spent over $17 BILLION dollars and a decade to build an HLV out of old shuttle components, based on the reasoning that building it on *existing* components like the SSME's (RS-25's) and modified shuttle SRB's, and using knowledge gained on building the shuttle External Tank and using its tooling would SAVE TIME AND MONEY... all to build a block 1 booster that basically lifts the same mass to orbit as a Falcon Heavy but it TOTALLY NON-REUSABLE versus Falcon Heavy being about 4/5 reusable (if they land both boosters, the core stage, and the payload fairings successfully for reuse, losing only the upper stage in any event) and which will by most estimates cost well over a billion dollars PER LAUNCH, launching AT MOST every other year, or 1 launch every 3 years... making it hands down *THE* most expensive launch system every conceived in history. AND, it still requires YEARS more development and another few billion dollars for an advanced disposable filament-wound SRB *AND* a large ascent upper stage (powered by J-2X's by all accounts) *AND* a dedicated in-space propulsion stage in order to get to the Congressionally mandated 130 tonne payload mass requirement, and to be able to really do anything beyond this "Apollo 8" loop around the Moon (in a highly elliptical orbit not even capable of doing low lunar orbit like Apollo 8-- barely better than the Soviet Zond missions looping around the Moon or Apollo 13 on free-return trajectory). All this while Elon Musk is building the next generation of reusable space launch vehicles in a beachside village in South Texas on his own dime... while NASA is spending billions and over a decade to recreate what is essentially the B-29 of spaceflight...

Sorry I'm not that impressed. If this thing ever flies it'll be a miracle, or better yet, a testament to gubmint waste, lack of foresight, and stupidity. There's a tiny thing called "sustainability" and NASA simply has never had it... The shuttle was a stab at it but never could achieve it in reality and that was WELL understood even after the Challenger disaster in 1986, a scant five years into what would prove to be a 30 year program before it was FINALLY put down. And now what's replaced it is an abomination-- take the most expensive bits of the shuttle and use them in DISPOSABLE mode... Like shuttle the ONLY thing it's got going for it is it's a huge gubmint jobs program pumping federal tax dollars into the right congressvermin's districts, and the right gubmint contractor's and lobbyists pocketbooks... Other than that it's a disgrace and a farce.

Later! OL J R

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At least the shuttle had the ability to retrieve satellites and return large items to earth. Even though it was expensive and never was what they advertised, it did some really cool stuff. I hated it at first, then I hated to see it go because I knew NASA wouldn't be able to replace it for a long time, and the replacement would be a hot mess. Thankfully Space-X has come along to erase the bulk of the embarrassment.

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NASA held a briefing today (which I did not see) on the hot fire test of this past Saturday.

Esstentially, the hot fire was shut down by the automated test system due to exceeded parameters (just what parameter I do not know) of the APUs that provide hydraulic power to the gimbal actuators for the engines. In this test however, this parameter (and maybe others) was intentionally conservative and specific to the hot fire test and would not have caused a shutdown in actual flight conditions.

Other ‘collateral’ findings are contained in the article below. I don’t believe it has yet been determined whether they will attempt another hot fire test or not.


Full article link: https://blogs.nasa.gov/artemis/2021...good-condition/


Earl

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They better. The cost may be significant to you or me, but it's a drop in the bucket compared to what they've spent on SLS and what it would cost the US if it fails in flight.

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True, BUT the whole "return satellites to Earth" bit was basically useless... as they found out. By the time an operational satellite actually fails, it is usually so obsolete that the expense of returning to Earth and repairing it and having to RE-LAUNCH it, it would have been cheaper to simply build a new satellite with the latest technology, with a lot more capability and capacity, than the original had to begin with, and launching it on a cheaper launcher. It was the US determination to FORCE *everything* to be launched on shuttles, which basically imposed greater costs due to the additional requirements for launching aboard a MANNED vehicle versus cheaper expendable unmanned vehicles, that drove the commercial launch business overseas-- first to Ariane and then later China and Russia, and now Japan and India. Thank goodness for SpaceX which is actually bringing the launch business back to the US via lower costs and reusability.

While the shuttle's capability to return things like Spacelab to Earth was useful, we'd have actually done better to have "free flyer" modules in orbit, which could have been done with expendable rockets (or reusables like Falcon 9). Dragon can return cargo to Earth, even some hardware, whatever can fit through the hatches anyway. This I think will prove quite sufficient for the foreseeable future.

If and when Starship cargo gets up and running, it'll be able to return larger cargoes than shuttle dreamed of.

Shuttle's biggest limitation was that it was basically BARELY capable of staggering to a medium Low Earth Orbit... Basically the Hubble mission was the highest a shuttle ever flew, and it took basically EVERY BIT OF AVAILABLE PERFORMANCE to even get to that altitude. While it made servicing Hubble possible, it also required "stranding" Hubble in a terrible orbit for astronomical observations... in LEO there's a huge honkin' planet in the way of whatever you're trying to look at for nearly 45 minutes out of every 90 minute orbit! Plus, the telescope constantly going into and out of Earth's shadow, causing temperatures to plummet to -200 degrees in darkness and soar to +250 degrees in sunlight, causes the entire structure of the Hubble to "pop" and jiggle for several minutes twice every orbit, further limiting observations until the structure "settles down". So basically even the 'crown jewel' of the shuttle program, HST, was as much a victim of it as enabled by it. It's been proven that for the costs of launching and servicing HST it would have been cheaper to launch and entire FLEET of HST clones using expendable rockets, which COULD have placed the telescopes in FAR more advantageous observational orbits (high earth orbit, geosynchronous, highly elliptical orbit, or better yet at a Lagrange point halo orbit of either the Moon or Sun, far enough away from Earth it would only appear as a "dot" in the sky from the telescope's position, never blocking its observations... Plus the science return from a bunch of Hubbles, even if some of them played out earlier due to failures that couldn't be reached by shuttle for repair, and thus failed completely, would have been FAR more than what we actually have gotten from the single shuttle-hobbled HST (the mirror flaw and subsequent repair mission was effectively caused by shuttle funding shortfalls, diverting money from other projects like HST development to cover the additional costs, which under Dan Goldin's "Faster, Better, Cheaper" program did away with "unnecessary" tests (like a simple ground test of the mirror which would have revealed the flaw before it ever launched).

HST was far from shuttle's only victim over the years, either. We almost lost the "grand tour" of the planets via Voyager 1 and 2 missions, which were nearly canceled due to shuttle development cost overruns. The Galileo mission to Jupiter was similarly crippled due to shuttle problems-- including years of delays and changes to the mission trajectory requiring playing ping-pong among the inner planets to get enough speed via gravity-assist "slingshot maneuvers" to even get to Jupiter, which was basically the cause of the failure of the foldable high-gain antenna failure which would have doomed the mission if not for heroic efforts of the mission scientists to make a 'work around' using the low gain antenna to return the science data to Earth; however, due to the lower transmission rates, over half the scientific data gathered by the probe and recorded on the on-board tapes during each pass through the Jovian system on its long orbits, was simply recorded over on the next pass, as there simply wasn't enough time to transmit it all back to Earth on the low-gain antenna system. We'll never know what amazing discoveries were on that data-- what photographs that could have revolutionized our understanding of Jupiter and the solar system that were simply recorded over on the next pass due to insufficient time to send them back to Earth on the low-gain system. All because of the stupid "requirement" that Galileo be launched on the shuttle. FORTUNATELY they didn't make the same mistake on the next deep-space probe mission-- Cassini was launched by the expendable Titan IV.

For all these reasons and many more I've learned about over the years, the shuttle will never be more than a "successful failure" of a program to me. It set us back DECADES in our exploration of the solar system and even our exploitation and development of the Low Earth Orbit environment... ie space stations and space industry, as well as improvements in the state of the art of launch vehicles here on Earth.

Later! OL J R

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Oh, yes, I very much agree. If I were the program manager (and as you comment, it would be pennies compared to what has already been spent), I’d say hang the cost, we are going to do a full duration test fire before we put that thing on the pad.

Considering that they probably really didn’t get much of their gimballing profile performed, one would think they’d want to get that full set of data at the very least.

Earl

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Earl L. Cagle, Jr.
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