totm nov 2023 SpaceX Discussion Thread

[Entropian]

Talk about breaking a leg...

[mikegarrison]

I hate be a wet blanket and all that, but what's so exciting about this? I watched that video and those guys were giddy with excitement. It's basically the same thing we've already seen, isn't it?

I'm sure for the engineers involved it is very exciting because they just doubled their store of flight data. And probably they tested some new stuff. But as an observer, it's just not terribly entertaining.

[RealKerbal3x]

16 minutes ago, mikegarrison said:

I hate be a wet blanket and all that, but what's so exciting about this? I watched that video and those guys were giddy with excitement. It's basically the same thing we've already seen, isn't it?

I'm sure for the engineers involved it is very exciting because they just doubled their store of flight data. And probably they tested some new stuff. But as an observer, it's just not terribly entertaining.

It's really being able to see two of these flights in such a short time - progress is accelerating, and that's exciting. Pretty soon we'll have the full system, which will be awesome.

[Spaceception]

19 minutes ago, mikegarrison said:

I hate be a wet blanket and all that, but what's so exciting about this? I watched that video and those guys were giddy with excitement. It's basically the same thing we've already seen, isn't it?

To me, at least, it's that they're in the process of crossing over just from tank testing, to more flight testing, and doing hops to prove out their early launch process. There was almost a year in-between Starhopper and SN5, but there was less than a month between SN5 and SN6. So I guess it's the promise for an increasing amount of fight testing that's exciting. And either way, it's better than watching tanks just frost up

Edited September 3, 2020 by Spaceception

[tater]

21 minutes ago, mikegarrison said:

I hate be a wet blanket and all that, but what's so exciting about this? I watched that video and those guys were giddy with excitement. It's basically the same thing we've already seen, isn't it?

I'm sure for the engineers involved it is very exciting because they just doubled their store of flight data. And probably they tested some new stuff. But as an observer, it's just not terribly entertaining.

I never listen to the people talking, I mute that. (I cover the window leaving the bit on the side that shows when the siren went off, and only watch the few seconds of the actual interesting bit)

I don't think the hops are very entertaining by themselves, but the progress is nice to see. About a year ago the "update" on SS/SH said that in 2020 there would be hop tests, and in 2-3 years orbital tests (2022-2023). This is absolutely hitting those timelines so far. It's not "maybe we'll see some progress in a few years." 2 hops going well for 2 vehicles says something about build quality. Every SN# seems to look cleaner than the last. They're slapping them together pretty fast. All told, more interesting that other crap we could be watching on YT.

As such, that is pretty interesting.

I suppose in the short term, getting a few hops in means that we are more likely to see SN8 with a nose cone and fins actually do a free-fall transition to landing sooner rather than later. That promises to be pretty interesting regardless of how it turns out.

I'd be watching BO livestreams if they did any. As soon as Rocket Lab starts recovery ops I'll watch those, too (interesting, though certainly less spectacular than propulsive landing).

Edited September 3, 2020 by tater

[tater]

I have to say, those legs need some serious work.

[mikegarrison]

13 minutes ago, Spaceception said:

And either way, it's better than watching tanks just frost up

I think maybe that's the root of the disconnect. I suppose if you spend months sitting there watching camera feeds and driving by the place taking pictures of the assembly, it might be very exciting to see it fly for a few seconds. Since I haven't been watching any of that stuff and refuse to sit for hours watching a livestream of people talking about whether this vent or that vent is venting more or less than it was 10 minutes ago, I'm not so emotionally invested in it.

[tater]

16 minutes ago, mikegarrison said:

I think maybe that's the root of the disconnect. I suppose if you spend months sitting there watching camera feeds and driving by the place taking pictures of the assembly, it might be very exciting to see it fly for a few seconds. Since I haven't been watching any of that stuff and refuse to sit for hours watching a livestream of people talking about whether this vent or that vent is venting more or less than it was 10 minutes ago, I'm not so emotionally invested in it.

Yeah, having watched some static fires and tests, YouTube puts LabPadre as suggested all the time. Every one in a while I look at the number of people watching, and there will be hundred (or more) watching it at midnight, lol. They must have just left it in a tab or something, it's like watching the grass grow.

I suppose to be fair some of the more mundane testing has ended up being overly interesting (explosions), so maybe there's a "I only watch it to see a crash" aspect for some

 

[Spaceception]

14 minutes ago, mikegarrison said:

I think maybe that's the root of the disconnect. I suppose if you spend months sitting there watching camera feeds and driving by the place taking pictures of the assembly, it might be very exciting to see it fly for a few seconds. Since I haven't been watching any of that stuff and refuse to sit for hours watching a livestream of people talking about whether this vent or that vent is venting more or less than it was 10 minutes ago, I'm not so emotionally invested in it.

Fair enough, I can't watch it for hours either though. I just turn on the livestream once in a while to see if anything is happening. But I think it's also the front row seat aspect to it. When we see launch vehicles in progress, it's usually just some pictures of mostly completed tanks intended for flight, maybe an engine, maybe a mostly completed vehicle, sometimes an engine test. Here, we're seeing a lot more of their process as they go along, so there's that too.

[Nightside]

3 hours ago, Entropian said:

Yes, but the CoT should have no effect on the position of the vehicle when landed.  I think it's at a slight angle, but I could be wrong.

It’s the difference between balancing a broom on its handle and balancing a hockey stick.
Because the center of mass is slightly offet, the starship Will land at a slight angle and impact the feet on one side first.

for all we know the legs are designed to crush on impact...

[Entropian]

4 hours ago, mikegarrison said:

what's so exciting about this?

Rockets.

[CatastrophicFailure]

5 hours ago, Nightside said:

It’s the difference between balancing a broom on its handle and balancing a hockey stick.
Because the center of mass is slightly offet, the starship Will land at a slight angle and impact the feet on one side first.

for all we know the legs are designed to crush on impact...

They are, it's very visible in some of the post-landing pix of SN5. It's a very, very simple, one-way design: they can absorb impact by (more or less) crushing but there's no rebound like F9 legs, so once a leg is collapsed it stays that way, causing a post-landing lean. I reckon we'll stop seeing that if they move to Leg 2.0 while they're still doing single-engine hops. It just occurred to me too, if these are the 1.1 legs that Elon said are 60% longer, they possibly have a longer crumple zone too, which could make a more pronounced lean even with a softer (to the SN) landing.

[CatastrophicFailure]

 

[RealKerbal3x]

Lots of great views from NASASpaceflight:

 

[Lukaszenko]

18 hours ago, mikegarrison said:

I hate be a wet blanket and all that, but what's so exciting about this? I watched that video and those guys were giddy with excitement. It's basically the same thing we've already seen, isn't it?

I'm sure for the engineers involved it is very exciting because they just doubled their store of flight data. And probably they tested some new stuff. But as an observer, it's just not terribly entertaining.

It's like watching the Falcon 9 rocket launches. They're getting less and less exciting by the launch, but it's not the launch itself that's interesting, it's the fact that each one represents a step on the ladder to making space cheap and accessible. 

I don't watch any other rocket launches, whether bigger or faster or whatever, because they don't represent progress to making us a properly space-faring civilization; they just represent the same 'ol excrements.

[Shpaget]

26 minutes ago, Lukaszenko said:

I don't watch any other rocket launches, whether bigger or faster or whatever, because they don't represent progress to making us a properly space-faring civilization; they just represent the same 'ol excrements.

And when Blue Origin starts to show us some new stuff, they'll get our attention as well.

Of course, once when orbital launches start happening multiple times per day, the novelty will wear off for most of us, but don't forget, there are still train/plane/ship spotters.

[sevenperforce]

I did some math on thrust balancing for a 1+7 configuration (because, again, it is super compact). I assumed a minimum throttle of 40% and a max thrust of 2200 kN.

Assuming a 300-tonne-empty booster, there's actually no way to successfully hover with the 1+7 configuration. The closest you can come is lighting three engines as shown in the center. You'd think it would work (three engines at 40% gives about 0.9 gees), but the topmost engine cannot throttle below 73% or the thrust will be unbalanced.

So either you hoverslam every time, or you use a different configuration.

9 hours ago, CatastrophicFailure said:

 

This view...

That's art.

 

 

11 hours ago, CatastrophicFailure said:

It just occurred to me too, if these are the 1.1 legs that Elon said are 60% longer, they possibly have a longer crumple zone too, which could make a more pronounced lean even with a softer (to the SN) landing.

It is hard to be sure but they look like they are the same size:

SN5 at left; SN6 at right.

[RealKerbal3x]

20 minutes ago, sevenperforce said:

[snip]

It is hard to be sure but they look like they are the same size:

SN5 at left; SN6 at right.

Huh, at first I had thought that SN6 would have got the larger legs, but since it was built at a similar time to SN5 it makes sense that they would be the same.

Presumably SN5 has the larger legs now, as its original legs were removed and discarded after it was lifted from the landing pad.

[Spaceception]

26 minutes ago, sevenperforce said:

This view...

That's art.

That'll be awesome to see for the 20 km hop.

[sevenperforce]

23 minutes ago, Spaceception said:

That'll be awesome to see for the 20 km hop.

I know.

It reminded me of animation renders like these:

Except now it's actually real.

[Flying dutchman]

quick someone make a screenshot before they fix the title.

 

edit:  they changed it already. i think some intern is going to have a very bad day..

Edited September 4, 2020 by Flying dutchman

[RealKerbal3x]

36 minutes ago, Flying dutchman said:

 

edit:  they changed it already. i think some intern is going to have a very bad day..

Got it:

I was on my phone at the time so the whole title isn't visible, but the important part is.

[kerbiloid]

Looking at those two foam jets, it's the biggest can of cola with mentos ever seen on youtube.

[RealKerbal3x]

Comparison of SN5 and SN6's flights. I feel like SN6 had an overall smoother flight than SN5 (and didn't blowtorch the launch stand) but it might have overcompensated on the landing, leading to the pronounced lean.

 

[RCgothic]

The fairings didn't stick the Starlink landing unfortunately: