[Quagmire]

Originally Posted by kscherer Monday, August 29, 8:33 AM EDT. All the way to the moon and back! With as many problems as this thing has had, I think an unscheduled disassembly is as likely as anything else. But, I do hope it is successful. Edit: If you're bored, here's the live feed.

I doubt a RUD would happen.

It's all heritage hardware. Only way it RUD's is because they went beyond the 1 year limit of the SRB's once stacked. But that is mostly due to the joints and the changes made post-Challenger and a human rating limit then hardware limit.

And of course it's not the SpaceX approach to development. Everything was tested to the wazoo, but in simulations and piecemeal. STS-1 had more risks than Artemis-1.

[kscherer]

Originally Posted by Quagmire I doubt a RUD would happen.

I'm not hoping for it, but it would be fun to watch.

There's no one onboard other than the Astromites, so no harm done-ish.

[Brad]

Man, Ars's take on the SLS really hits all the notes I've been feeling lately…

The SLS rocket is the worst thing to happen to NASA—but maybe also the best?

President Eisenhower signed the law establishing the National Aeronautics and Space Administration on July 29, 1958. At the time, the United States had put about 30 kg of small satellites into orbit. Less than 11 years later, Neil Armstrong and Buzz Aldrin landed on the Moon. President Obama signed a NASA Authorization Act on October 11, 2010. Among its provisions, the law called on NASA to create the Space Launch System rocket and have it ready for launch in 2016. It seemed reasonable. At the time, NASA had been launching rockets, including very large ones, for half a century. And in some sense, this new SLS rocket was already built. … So here we are, nearly a dozen years after that authorization act was signed, and NASA is finally ready to launch the SLS rocket. It took the agency 11 years to go from nothing to the Moon. It has taken 12 years to go from having all the building blocks for a rocket to having it on the launch pad, ready for an uncrewed test flight. I have decidedly mixed emotions.

[kscherer]

Yep. And in that same time frame SpaceX went from nothing to launching and landing reusable rockets at a prodigious rate, and building the largest rocket ever made while simultaneously learning to recover it with vertical landing.

Oh, and they shoved hundreds of small communications satellites into orbit on their own dime.

And they launched a car into space for giggles.

And it's quite possible that their launch permits for Starship have been held up so that NASA could be "first" with SLS.

[Frank777]

Originally Posted by Brad Man, Ars's take on the SLS really hits all the notes I've been feeling lately… The SLS rocket is the worst thing to happen to NASA—but maybe also the best?

Terrific piece of journalism.

[kscherer]

My favorite bits come right at the beginning:

The most challenging aspect of almost any launch vehicle is its engines. No problem—the SLS rocket would use engines left over from the space shuttle program. Its side-mounted boosters would be slightly larger versions of those that powered the shuttle for three decades. The newest part of the vehicle would be its large core stage, housing liquid hydrogen and oxygen fuel tanks to feed the rocket's four main engines. But even this component was derivative. The core stage's 8.4-meter diameter was identical to the space shuttle's external tank, which carried the same propellants for the shuttle's main engines. Alas, construction wasn't that easy. NASA's SLS rocket program has been a hot mess almost from the beginning. It has been efficient at precisely one thing, spreading jobs around to large aerospace contractors in the states of key congressional committee leaders. Because of this, lawmakers have overlooked years of delays, a more than doubling in development costs to above $20 billion, and the availability of far cheaper and reusable rockets built by the private sector.

But this bit is just eye-rolling.

Who doesn't want to watch a huge, Brobdingnagian rocket consume millions of kilograms of fuel and break the surly bonds of Earth's gravity?

What a dumb word. Just eliminate it, make the sentence flow, and save the chest-thumping for the journalism super bowl.

Edit: And to my point:

To the extent that the series is remembered today, it's because of a quote given to me by then-NASA Administrator Charles Bolden. I asked him why NASA needed a heavy-lift rocket when SpaceX had started to build the Falcon Heavy, which had about 70 percent of the lift capacity of the SLS booster, at less than 10 percent the cost. (An expendable Falcon Heavy costs about $150 million. A single launch of the SLS rocket costs at least $2 billion per year.) "Let’s be very honest,” Bolden said in response. "We don’t have a commercially available heavy-lift vehicle. The Falcon 9 Heavy may some day come about. It’s on the drawing board right now. SLS is real." The Falcon Heavy flew for the first time in 2018 and is now commercially available. Bolden's comment has become a meme.

[Quagmire]

Originally Posted by kscherer And it's quite possible that their launch permits for Starship have been held up so that NASA could be "first" with SLS.

Doubt it. SpaceX wasn’t even close to being ready for an orbital launch attempt. Just look at how long it has been between the environmental review to them even getting ready to static fire booster 7( first attempt before the boom).

The propellant farm was a complete crap show.

[709]

NASA has called a scrub on its first attempt to launch the Space Launch System rocket. The problem was due to an "engine bleed" issue, which effectively means that one of the four main engines could not be properly chilled ahead of its ignition. It is not clear when the next launch attempt will occur. NASA has an availability to launch at 12:48 pm ET (16:48 UTC) on September 2. However, if work is needed on one of the engines, the rocket likely would need to be rolled back to the Vehicle Assembly Building, pushing back a launch attempt until at least October.

Hope they can fix these issues while it's still on the pad.🤞

[Brad]

https://blogs.nasa.gov/artemis/2022/...empt-scrubbed/

The launch director halted today’s Artemis I launch attempt at approximately 8:34 a.m. EDT. The Space Launch System rocket and Orion spacecraft remain in a safe and stable configuration. Launch controllers were continuing to evaluate why a bleed test to get the RS-25 engines on the bottom of the core stage to the proper temperature range for liftoff was not successful, and ran out of time in the two-hour launch window. Engineers are continuing to gather additional data.

Assuming this issue is resolved and no more are found, the next launch opportunity is this Friday, September 2 at 12:48 EDT. Otherwise, we're probably looking at October.

https://twitter.com/sciguyspace/stat...81402715127808

Due to the need to service the flight termination system inside the VAB, it sounds like if NASA rolls out to the pad, but does not make the Aug. 29-Sept. 5 launch window, they not be able to attempt another launch until Oct. 17-31.

There are a few tropical storms possibly brewing in the Atlantic, though. Here's hoping they veer away. (This picture is already a few days old)

[kscherer]

Considering its the exact same Hydrogen leak in the exact same place …

What does a million gallons of hydrogen look like when it goes off in one pop?

[Quagmire]

Originally Posted by kscherer Considering its the exact same Hydrogen leak in the exact same place … What does a million gallons of hydrogen look like when it goes off in one pop?

They managed to stop the leak.

The other issues including the one that led to the scrub were unrelated.

[kscherer]

Originally Posted by Quagmire They managed to stop the leak.

Yeah, but the leak was the same leak from an earlier test, so it seems to be a recurring problem, and that's no good with rockets.

[Quagmire]

Originally Posted by kscherer Yeah, but the leak was the same leak from an earlier test, so it seems to be a recurring problem, and that's no good with rockets.

Yep and Shuttle experienced similar issues early in the program. Hydrogen is a tough gas to work with.

[PB PM]

Why did they feel the need to reinvent the wheel. Just build another Saturn V type rocket, at least the things worked.

[Brad]

More excellent journalism from Ars:

Warning sign? NASA never finished a fueling test before today’s SLS launch attempt

Also, yikes.

The rocket experienced several issues during the countdown early on Monday before running into a technical problem the launch team could not solve: an RS-25 rocket engine that did not properly chill down prior to ignition. Even if the engine problem had been resolved, weather along the Florida coast on Monday morning proved dicier than anticipated. … For example, fueling operations started nearly two hours late due to lightning in proximity to the launch pad. This forced the team to push hard through a compressed timeline ahead of a launch window that opened at 8:33 am ET (12:33 UTC). Once the launch team got into propellant loading, work to fill the large liquid hydrogen tank was stymied by a leak at an 8-inch inlet leading into the tank. This problem was ultimately resolved by stopping the process and then restarting propellant loading—yes, NASA resolved the problem by essentially turning off the SLS and turning it back on again. After this, the countdown proceeded reasonably smoothly for about an hour until a problem with one of the rocket's four main engines. As part of the pre-launch process, cryogenic propellant is "bled" from the fuel tanks into the engines to chill them to about 5° Celsius prior to flight. … In troubleshooting this engine issue, launch controllers could not find a way to address what appears to have been a problem on the core stage side of the vehicle. So the launch attempt was scrubbed. … Beginning in April of this year, NASA conducted four separate "wet dress rehearsal" tests during which the agency aimed to fully fuel the SLS rocket and countdown to T-10 seconds, ending the test before ignition of the main engines. Each of these four tests ultimately ended prematurely, although the fourth attempt in June saw engineers bring the rocket down to T-29 seconds. However, to reach that late stage in the countdown, NASA had to "fool" the flight computer. During the test, a 4-inch hydrogen line—smaller than the problematic 8-inch line on Monday—had a leaky seal. To complete the wet dress test, NASA chose to mask the leak from the ground launch sequencer, the ground-side computer that controls the majority of the countdown. Because of this masking, NASA could not complete the engine chill portion of the test. Had it done so, the agency may well have uncovered the problem that caused a scrub on Monday.

[Quagmire]

Originally Posted by PB PM Why did they feel the need to reinvent the wheel. Just build another Saturn V type rocket, at least the things worked.

No reinventing the wheel. That was the whole point of SLS. Everything is heritage hardware. The SRB's are Shuttle SRB's with an extra segment and new fuel mixing. Core stage is the external tank stretched. The ICPS is a modified Delta IV upper stage. The engine on the service module is the Shuttle OMS engine. The main RS-25 engines are literally engines that flew on Shuttle.

I would say this is due mostly of the time between Shuttle and SLS that a lot of old knowledge wasn't passed along due to the turn over. It's why a rocket that barely flies( aka Delta IV Heavy) runs into issues a lot.

Originally Posted by Brad More excellent journalism from Ars: Warning sign? NASA never finished a fueling test before today’s SLS launch attempt Also, yikes.

Bashing on SLS/NASA is popular....

If these guys were around during Apollo, I wonder how they would be reacting to Apollo 4. " What you mean they are testing the Saturn V in an all up test!?!?!?"

[kscherer]

Originally Posted by Quagmire Bashing on SLS/NASA is popular....

If SLS works, then it's an engineering achievement worth celebrating. But, the bashing is due to the fact that SLS is less a means to get men back on the moon as much as it's a means to get politicians reelected.

[Quagmire]

Originally Posted by kscherer If SLS works, then it's an engineering achievement worth celebrating. But, the bashing is due to the fact that SLS is less a means to get men back on the moon as much as it's a means to get politicians reelected.

I’m no fan of SLS. It’s 5 years late, it’s bloated, and ridiculously expensive. It’s not even as capable as Saturn V. I fully know why SLS exists and it’s due to clowns like Senator Shelby.

BUT….. I’m able to separate the politics of it and realizing SLS is the crap platter that was handed to NASA. Bash SLS and the politics that is keeping it alive. But don’t bash for bashing sake because it’s the popular thing to do. I personally don’t have an huge issue with them going for a launch attempt without testing this bleed system fully. If it worked it worked. If it didn’t, it didn’t. This was not an issue that would cause the rocket to blow up mid-flight. If it failed, it failed in the exact manner we saw yesterday. For me it was an acceptable risk to take. Now them considering skipping the green run or making Artemis-1 crewed, that is an unacceptable risk. Heck I’m unsure about only do doing only one uncrewed flight. It took two unmanned launches of Saturn V to find big issues with the current design. Apollo 4 went smooth, but issues presented themselves with Apollo 6. So I’m glad they decided against skipping green run and keeping it uncrewed. I still question how Ars if they were around during the Apollo days would react to Apollo 4. An all up test was not the norm back then. But due to Saturn V development falling behind, they took that risk to help catch back up. That was by far a greater risk taken then NASA going for a launch attempt with SLS yesterday. Heck STS-1 was by far the riskiest thing NASA has ever decided to do. So don’t expect me to latch onto Ars trying to stir outrage over them not doing another WDR just to test the bleed system.

SpaceX has had far more blunders in starship/super heavy development and they get a pass from the public/media( besides the at the time great articles after a boom). Heck a lot of it isn’t even covered( again the orbital tank farm was a complete cluster of a mess up).

[kscherer]

Hey, like I said, if it works, then Kudos. If it doesn't, then we all get to see what a million gallons of hydrogen looks like when it scorches the pad. I don't want it to blow up, but I won't be surprised if it does. And, yeah, NASA got handed crap by politicians trying to get reelected. And, unfortunately, NASA will get blamed if things go awry. Which is too bad. There should be a string attached back to Congress. But there isn't.

[Quagmire]

Listening to the update conference call, they sort of think it could be a sensor problem than actual problem.

The pressure of hydrogen flowing into engine #3 was nominal and similar to the other engines. But for some reason was reading 30 degrees warmer.

[kscherer]

Originally Posted by Quagmire But for some reason was reading 30 degrees warmer.

Bad sensors are bad!

I seem to recall the Apollo program was riddled with faulty sensors. Interestingly enough, many moon landings happened even when some Very Important Sensor™ went bananas at the worst possible moment. I guess it just depends on what the sensor is monitoring, and whether or not it makes things go BOOM!

[Quagmire]

Engine 3 is becoming a meme.....

SpaceX went to static fire Booster 7, the first two engines fired up. But engine 3, aborted its start sequence...

[Brad]

They just officially scrubbed today's potential Artemis launch (which would have been in the next few hours) due to a leak in the tail service mast.

They've been doing some troubleshooting this morning with the liquid hydrogen fast fill, and hydrogen was detected outside the rocket, there's apparently there is a leak in a quick-disconnect seal, and there are some visible cracks in the TPS (Thermal Protection System) foam.

[Quagmire]

Hydrogen is a real B*OTCH. Saturn V and Shuttle went through these issues when starting out.

Just can't wait to hear Eric Berger's next idiotic take.

[kscherer]

Funny. I completely forgot about it until I read this thread's most recent updates. Fortunately, I didn't miss the explosion.

If they fixed all that with the Shuttle, why not just reuse those designs? They seem to have worked.

[turtle]

So did DART actually deflect the astroid in a meaningful fashion? I've not really dug into it. Saw some images posted about the cloud it produced when it hit it. I'm just wondering if the momentum actually made a difference.

[709]

I was questioning that earlier today as well, but apparently it'll take a couple of weeks to see if and how much the collision affected it. Pretty neat that we were even able to try such a thing. *bonus: google search "dart mission" for a fun little easter egg.

Juno does a close fly-by of Europa today. Can't wait to see what kind of images come from that.

[Frank777]

The whole project baffled me. With Earth's luck, it's likely we'd deflect the asteroid into hitting us.

I support a space program, but do we not have enough real problems to solve down here?

Are we really spending money to reenact Deep Impact/Armaggedon scenarios?

[kscherer]

SpaceX has gotten so good at this that, even when 4 humans are shot off into space, no one even notices anymore. It's becoming routine.

[Matsu]

It’s good for humanity to reach into new frontiers. Curiosirty and the wonder of new discovery fuel the spirit. And, I say it’s hardly trivial to think about saving the planet from potential extinction. Sure, it’s long odds on something happening in our lifetime, but it’s happened before, and it’s been a bitch. For a species, for the first time in our planet’s known history, to have the capacity to contemplate both the scale of the catastrophe and to imagine and (attempt to) devise the means of its own salvation… it would seem foolish not to test the theory at least.