StrandedonEarth

SpaceX is unusually public with their testing. Does anyone know how many RS-25s failed acceptance testing? RS-68s? RL-10s, F-1s, J-2s? BE-4s certainly had a troubled development; how many of those make it through acceptance testing these days? How many Merlins get scrapped without flying? The reason high-tech precision machinery is so expensive is that not all units produced pass testing, just like with silicon chips. "Perfect" is the enemy of good enough, something I fight with myself about as I can be a bit of a perfectionist. Mucking around to make something (more) perfect can end up ruining the piece. Granted, with something like a rocket engine, often only perfect is good enough, but to maintain high production rates you can't try to make everything perfect every time. Mistakes happen, things are missed. That's why there is Quality Control/Assurance, audits and inspections, and finally acceptance testing. If it's not perfect enough, it gets fixed or scrapped. Some get scrapped before testing, some are scrapped after testing, and some are passed for use. That's the nature of manufacturing, vs the hand-made, may-as-well-be-custom-made ways of early rocketry, when still not everything made it to the test stand. I will add that I work in manufacturing, although the tolerances involved are not anywhere near the precision required of aerospace. For that matter, I doubt anything is ever truly perfect. There are tolerances, and if a product is within tolerance, it's all good. But if you take a close look, there will still be minute, tolerable imperfections. NASA is (was?) known for taking tolerances to seven decimal places, but if you take a perfectly (within tolerance) round shaft and go down another decimal place or two, there will still be peaks and valleys: no longer perfectly round. From the Moon, the Earth looks perfectly round, but I can look out my window at mountains that say otherwise. How many Raptor tests are for acceptance testing, versus testing new materials/configurations/ideas, to see if it'll work for future versions? Nobody outside SpaceX knows. This is why they test, so they can find flaws and then test the fixes for the flaws. Every failure is a lesson. The only real cause for concern is when the same mistakes keep happening. Do the Raptors keep failing for the same reasons on identical hardware? That's a human problem, and it is one definition of insanity: doing the same things over and over while expecting different results. If there is one thing not happening at Boca Chica, it's doing the same things over and over (unless it already works, like making rings and barrel sections, and even those methods may still be getting iterated); every build has changes that are thought to improve the vehicle. Once everything is functioning the way it should, and only then, the design gets frozen, like F9B5. But hey, if you want to build a test stand for full-up, full-mission-duration, full power, full 33-engine Superheavy testing out of your own pocket, I don't think SpaceX will object. Good luck getting permission to build it anywhere in this hemisphere, though.

11:18pm Sunday night, Pacific time. Deep in the slumber zone for me…

LH2 has a higher specific heat than methane, so it’s more effective at cooling the heat shield. I’d cite my source, but it’s tricky on mobile; I just asked Siri and by the graphs it appears H2 is better

Enquiring minds wanna know!

Forum acting up on me or maintenance? testing....

Forum maintenance going on for awhile?

Testing… testing

I solved my problem with a coworker who was sometimes snarly by getting a job with a different, closer company in the same industry, doing the same job. Much better work environment

I do know that Saturn V Moon missions launched into a parking orbit where system checkouts were performed, before relighting the third stage for TLI. As for the rest, no idea

If you count each core launched, five FH launches makes 15 cores launched, for a total of 106 Falcon cores launched…

I was wondering when all the talk about precision fermentation would go mainstream…

Yeah, I like this, takes me straight back to the ship I was creating when I quit.

I don't know if there's a setting I'm missing or what, but probably my biggest peeve is that the dV/TWR/burn time readouts on the staging stack are too tiny. Even with my reading glasses on my old eyes, it's not readable to me beyond being barely able to tell if TWR is more or less than 1. I haven't bothered trying to use a magnifier to get a better look, figuring pixelation would still make it difficult.

It's not currently easy to use, that's for sure. I keep wanting to use the SAS vector ball to adjust nodes, which IMO would be a slick way to integrate a separate node editor. I am surprised they didn't try to port/imitate over the KSP1 stock editor in the first place, but I suppose it was a lower priority than other game systems so they used a quick placeholder.

Yes, SLS got a full-duration static fire of the core stage. They also had full duration (as if there's any other kind with solids) static firings of a single SRB at a time. They never did or could do any kind of static fire of the entire stack. That is what you are expecting SpaceX to do. Imagine the size and expense of the facility could could handle a full-duration Superheavy static fire. The engineering challenge would almost be greater than the entire Starship program itself! Yes, new F9 cores get a full-mission-duration static at McGregor before entering service, but that's nearly an order of magnitude smaller. (4900 tons vs 550 tons GLOW).

@Vanamonde Well, speak of the devil, S&SF is back to working for me on mobile. But I dare say the issue isn’t fixed, because KSP1 Discussion still gives me a white screen. I don’t know what oddity keeps coming and going that makes these two subforums throw fits. Must be a gremlin on the loose…

Looks more dirt color to me, but not huge clouds. Was BC experiencing a dry spell at the time? The exhaust blasting over the dirt of the surrounding areas could raise some dust…

That would almost certainly work, but would require replacing a few ancient stereos with sufficiently loud bluetooth speakers. It's amazing how something that normally seems plenty loud enough becomes nearly inaudible in the work environment...

I'm not sure how well multiple devices streaming the same station will sync up. With modern internet-based cable converters, I can rarely get the two TV's in my house to sync up, and echoes are almost as annoying as stereo wars.

Well, I mucked around with Steam Remote Play and it did work, but maintaining the connection when I'm not always focused on my laptop seemed problematic. So I installed it on my laptop (i5-9300H, 24GB RAM, GTX 1650) and ran the graphics settings to low, and the performance has been quite acceptable. I may have seen some stuttering during one liftoff, but my Mun landing mission didn't seem to have any stutter. Given that I'd launch 700-part behemoths back in the KSP 0.20's on a GT630M, I'm used to slideshow launches. So far, I'm happy. It's tempting to still try to stream from my son's PC for the extra performance/eye candy, but from what I can tell, KSP2 doesn't seem to have a "save to the Steam Cloud" option, which complicates things if I want to play when my kid wants his PC. But it seems I can make do with my laptop, at least for now. I might change my tune when I try to launch Jool tours...

Yo.

I’ll add that the problem also affects KSP1 Discussion for me, but not really an issue because I rarely go there.

With KSP you should expect some input lag really; after all, this is deep-space communications we're talking about here, lol!

Yes, there are a few of us having issues, esp. with mobile. Weirdly limited and frustrating with clumsy workarounds. Details: Yes, I remember the event. Just seeing "Booster 7" was enough to know it wasn't recent. I think heads rolled for that one (shakeup for sure), but fortunately it wasn't as catastrophic as it could have been.

A quick Google look for FM transmitters (for either streaming radio or a playlist) seems to only turn up the type meant to transmit to car radios, which I doubt have the range we'd need. I did find this: (From: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf02087.html#q4) In Canada, low power FM transmitters that produce a field strength of under 100μV/m @ 30 meters can be operated legally without license, as long as they comply to Broadcasting Equipment Technical Standards 1. I don't know how that translates to what the effective range of a legal transmitter is i.e. is a strength of 100μV/m sufficient for consumer stereos to tune in to? 30m would be plenty of range for the shop. Apparently I need to start digging deeper than a surface Google search to find specs on power/range for the offerings out there. I suppose they are cheap enough to experiment with.