totm nov 2023 SpaceX Discussion Thread

[AckSed]

Nominal orbit

[Minmus Taster]

Looking for a signal

[AckSed]

Signal acquired!

[Minmus Taster]

Signal! Clipper is clearing port!

We're in thermal roll, issue with a vent?

When are the panels unfurling?

SEVERAL HOURS? How much power do we have?

[tater]

 

[RKunze]

3 hours ago, cubinator said:

The computer you sent this message on can most likely pull off such a maneuver in a realistic simulation, in terms of raw calculation.

The computer you read this on can probably do it in a grossly inefficient, interpreted language running within a space simulation game. For examples, see all those working kOS scripts out there that manage accurate boost back and landing...

[magnemoe]

2 hours ago, tater said:

Wonder of IFT-6

I've seen claims that the F9 booster uses a voting trio of dual core x86s. So not terribly compute intensive. SH is certainly not concerned about the mass of different possible computer systems, whatever it is is probably lighter than a single reinforcement stringer

Yes been some time since dual core x86 was a thing outside bottom barrel budget so this is probably some hardened chips. And no its not very computer power intensive. 
Think Mechjeb but having multiple input sources and also be able to handle more changes and having abort modes so 100 times harder but still. 

One very nice thing in KSP 2 was that the trajectory took in the TWR changes and similar to projections. it made Tylo landings so much much easier.  I could set up an braking trajectory Add some up vector to it so I was say an km up at the end still some forward momentum so I could do some adjustments for my landing burn. then I staged as I used an crasher stage and an lander with an rover. 
Still the professionals has way better tools. 

[tater]

 

[CatastrophicFailure]

OFT-5 launch captured from ISS:

 

And this:

 

[JoeSchmuckatelli]

16 minutes ago, CatastrophicFailure said:

OFT-5 launch captured from ISS:

 

And this:

 

They started closing before the rocket was close - which is both cool and insane. 

 

In the animated renders we saw (RyanSpace?) just before ITF-5, one concern was 'bounce' from moving the heavy arms quickly.  From what I can see in this, the rapid early partial closure took care of the bounce and allowed for a smaller ROM to catch without damage to the booster. 

[tater]

5 hours ago, zolotiyeruki said:

I just noticed that one of the ten engines in the second ring isn't glowing and flaming like the other nine.  The graphics on SpaceX's feed show all 10+3 engines running nominally for the landing burn, but something is different about this one:

Looking at that latest landing video (only 3 running), it's certainly different than the others, but watching the 13 drop to 3 on the stream rebroadcast, it seemed to be running when they said it was running, then when they shut down the outer, gimbal engines, that one went black sooner. Maybe it ran rich or something, and was cooler?

[AckSed]

Side note: going back to Starship's reentry, did anyone catch sight of some sort of bracket on the leeward side? Had a hole in it.

It wasn't even in the path of the plasma, yet it was still glowing red-hot down to the start of the belly-flop. Goes to show reentry's harsh.

[tater]

 

[darthgently]

17 hours ago, Brotoro said:

Loading propellants? Wow. Even if it’s just liquid nitrogen…I’m surprised the quick disconnect plumbing is still in working order, considering the way it was belching flame like crazy as the booster was landing (and for several minutes afterward). I guess maybe it’s supposed to flame like an angry dragon despite that looking like an undesirable anomaly.

Was it possibly normal venting of methane that ignited from aero heating?  I think I got that from Scott Manley, can’t remember for sure

40 minutes ago, tater said:

 

The precision on catch is amazing. Those detonation waves on launch are awesome

[PakledHostage]

8 hours ago, Hotel26 said:

It's an interesting comparison to try to make.

Firstly, IFT-5 was a coaster ride for an hour or so.  Spectacular and gripping.  Highly climactic.  The achievement technologically was powerful, particularly because there was a load of incredulity to overcome, which is normal when something brand new and so thoroughly audacious  is being attempted.  It has implications for progress and advancement in the future, for those who understand those implications, but the sensational appeal of IFT-5 is directly, visually accessible to a whole world audience.  As a contender for second to Apollo 11, I cannot think of another worthy.  Maybe Juno comes to mind as a further-off third (but that's only me).

Yesterday's test was spectacular, but Apollo 8 needs a mention. The Voyagers too. And Cassini/Huygens... Plus all the Mars rovers... let's not lose perspective.  This was a progression of the landing a booster on legs idea. All of what they learned doing that fed into this achievement.  To achieve the goal of rapid reusabilty, they next need to successfully catch the Starship. And both craft need to be able to come back in a state where they can be reused. There is still a lot of work to do.

What impresses me as an engineer who's worked in aviation most of my career is that SpaceX is trying this, and sticking with it long enough to be within sight of pulling it off. Aerospace is a conservative industry. Tory Bruno's tweet cited up thread touches on exactly this. Doing what SpaceX is doing is hard to justify when you're answerable to the banks and fund managers who are your big shareholders. But SpaceX has a bigger vision,  and they're willing to put a lot of their eggs in that basket.

I am happy to see their progress.  It's a massive engineering achievement, and it gives us all hope for amazing things to come. But there's still a lot of work to do . As I said, let's not lose perspective. 

[darthgently]

10 minutes ago, PakledHostage said:

Yesterday's test was spectacular, but Apollo 8 needs a mention. The Voyagers too. And Cassini/Huygens... Plus all the Mars rovers... let's not lose perspective.  This was a progression of the landing a booster on legs idea. All of what they learned doing that fed into this achievement.  To achieve the goal of rapid reusabilty, they next need to successfully catch the Starship. And both craft need to be able to come back in a state where they can be reused. There is still a lot of work to do.

What impresses me as an engineer who's worked in aviation most of my career is that SpaceX is trying this, and sticking with it long enough to be within sight of pulling it off. Aerospace is a conservative industry. Tory Bruno's tweet cited up thread touches on exactly this. Doing what SpaceX is doing is hard to justify when you're answerable to the banks and fund managers who are your big shareholders. But SpaceX has a bigger vision,  and they're willing to put a lot of their eggs in that basket.

I am happy to see their progress.  It's a massive engineering achievement, and it gives us all hope for amazing things to come. But there's still a lot of work to do . As I said, let's not lose perspective. 

I am immune to your wet (though soft) blanket.  This is the major piece of a feasible freight train to orbit.  And done in the face of so much negativity.  I give SpaceX a big W with zero “buts” or “not enoughs”

[tater]

1 hour ago, PakledHostage said:

Yesterday's test was spectacular, but Apollo 8 needs a mention. The Voyagers too. And Cassini/Huygens... Plus all the Mars rovers... let's not lose perspective.  This was a progression of the landing a booster on legs idea. All of what they learned doing that fed into this achievement.  To achieve the goal of rapid reusabilty, they next need to successfully catch the Starship. And both craft need to be able to come back in a state where they can be reused. There is still a lot of work to do.

What impresses me as an engineer who's worked in aviation most of my career is that SpaceX is trying this, and sticking with it long enough to be within sight of pulling it off. Aerospace is a conservative industry. Tory Bruno's tweet cited up thread touches on exactly this. Doing what SpaceX is doing is hard to justify when you're answerable to the banks and fund managers who are your big shareholders. But SpaceX has a bigger vision,  and they're willing to put a lot of their eggs in that basket.

I am happy to see their progress.  It's a massive engineering achievement, and it gives us all hope for amazing things to come. But there's still a lot of work to do . As I said, let's not lose perspective. 

I agree completely. But like I said, the "vibe" is that can-do attitude, the grit to keep at it—as we did with Apollo. That's what's so cool. It's not solved, but yesterday was proof of concept. It's now safe to say it's certainly doable. Both stages returned intact enough to make controlled landings, one with apparently something like 0.5 cm precision (I thought Gerst misspoke, but that catch fitting has little room for error)—or at least a few (single-digit) cms. Amazing.

[PakledHostage]

1 hour ago, darthgently said:

I am immune to your wet (though soft) blanket.  

I am not trying to spoil anyone's fun. I find it hard to believe that anyone is more excited and impressed with yesterday's success than I am. I just think comparing the achievement to Apollo 11 is a bit much. There have been several massive achievements in space flight over the past decades, but Apollo 11 was in a class of its own. It was the fulfillment of a dream that spanned millenia. It united mankind. As one of the astronauts in the documentary "In the Shadow of the Moon" (Mike Collins?) said: People all over the world, who they met afterwards said "we did it!" Yesterday's catch was cool, and pretty good for a mere bunch of apes (to paraphrase Elon Musk), but let's keep it in perspective. 

[tater]

30 minutes ago, PakledHostage said:

I am not trying to spoil anyone's fun. I find it hard to believe that anyone is more excited and impressed with yesterday's success than I am. I just think comparing the achievement to Apollo 11 is a bit much. There have been several massive achievements in space flight over the past decades, but Apollo 11 was in a class of its own. It was the fulfillment of a dream that spanned millenia. It united mankind. As one of the astronauts in the documentary "In the Shadow of the Moon" (Mike Collins?) said: People all over the world, who they met afterwards said "we did it!" Yesterday's catch was cool, and pretty good for a mere bunch of apes (to paraphrase Elon Musk), but let's keep it in perspective. 

I think the Apollo comparisons were more in my "vibe" sense. For anyone old enough to know what was going on, Apollo was a shocking historical achievement that they witnessed. For those of use who saw it, but as little, clueless kids, or those who know it afterwards, it's a historical fact, without much emotional feeling about it (thinking it's cool is not the same as knowing how cool it is watching it in real time). This is the latter, watching something cool taking shape in real time, and this is such a critical first step to full, rapid reuse that it has I think a similar feel.

Like I said up thread, for me, growing up with Apollo, landing people on the Moon was just a thing we did. VERY cool and interesting to me, but something, well, normal. Maybe that's why I have such disinterest in which particular dude is the 13th human to make footprints on the Moon, it's something we already know how to do, and our lack of doing it has just been lack of will. Sunday was an exercise of will, and it bodes well for the near future of spaceflight.

Counterfactual: You saw Apollo 11 at the time, and knew we'd do it a few times, then all the people involved would likely be dead before we did anything that interesting in space again. Would that change your view of the whole era/program? I think it would for me (I still feel gypped out of the cool space future we were supposed to get ).

Edited October 15 by tater

[Nuke]

8 hours ago, magnemoe said:

Yes been some time since dual core x86 was a thing outside bottom barrel budget so this is probably some hardened chips. And no its not very computer power intensive. 
Think Mechjeb but having multiple input sources and also be able to handle more changes and having abort modes so 100 times harder but still. 

One very nice thing in KSP 2 was that the trajectory took in the TWR changes and similar to projections. it made Tylo landings so much much easier.  I could set up an braking trajectory Add some up vector to it so I was say an km up at the end still some forward momentum so I could do some adjustments for my landing burn. then I staged as I used an crasher stage and an lander with an rover. 
Still the professionals has way better tools. 

arm's low power capabilities are likely very useful for space applications. assuming rad-hard parts are currently available. its usually a long process to convert a design over and could take close to a decade due to all the long term verification testing they need to do. so you usually end up with a processor that's 10 or so years behind the curve and less performant than the cpu it was based on.

7 minutes ago, PakledHostage said:

I am not trying to spoil anyone's fun. I find it hard to believe that anyone is more excited and impressed with yesterday's success than I am. I just think comparing the achievement to Apollo 11 is a bit much. There have been several massive achievements in space flight over the past decades, but Apollo 11 was in a class of its own. It was the fulfillment of a dream that spanned millenia. It united mankind. As one of the astronauts in the documentary "In the Shadow of the Moon" (Mike Collins?) said: People all over the world, who they met afterwards said "we did it!" Yesterday's catch was cool, and pretty good for a mere bunch of apes (to paraphrase Elon Musk), but let's keep it in perspective. 

my concern here is that this was just luck and that this method of recovery might be failure prone and not be suited for manned operation. this is more relevant to catching starships than boosters though. you can catch boosters all day every day and if you blow up a tower every now and again its still cheaper than throwing away a rocket every time you launch. i have a hard time comparing a test flight to apollo 11 though.

[darthgently]

6 minutes ago, PakledHostage said:

I am not trying to spoil anyone's fun. I find it hard to believe that anyone is more excited and impressed with yesterday's success than I am. I just think comparing the achievement to Apollo 11 is a bit much. There have been several massive achievements in space flight over the past decades, but Apollo 11 was in a class of its own. It was the fulfillment of a dream that spanned millenia. It united mankind. As one of the astronauts in the documentary "In the Shadow of the Moon" (Mike Collins?) said: People all over the world, who they met afterwards said "we did it!" Yesterday's catch was cool, and pretty good for a mere bunch of apes (to paraphrase Elon Musk), but let's keep it in perspective. 

That is a lot of words just to make the blanket wetter.  You aren’t getting it.

A few humans on the Moon has much less real world implication than lowering cost to orbit 1000x+.  
 

What has more implication; a few astronauts on the Moon or most heavy industry moved off world, multiple orbiting habitats, and most humans vacationing in space or on the Moon at some point in their lives?   It is all about cost to orbit.  Apollo was a grand and amazing thing, but mostly symbolic, and compared to humanity off world en masse was a very expensive dog and pony show.  The low cost to orbit that reusable rocketry ushers in has staggering implications in comparison.  Apollo showed that something greater than Apollo was possible if we spent even more unimaginable amounts of money,  while reusable rocketry will make that something greater actually happen.  Implications.

[tater]

^^^ I think it's a sense of the future from here, vs the here and now. Apollo 11 in the here and now (1969 here and now) was astounding, and way, way beyond IFT-5 historically. That said, at the time, had you asked people what it would look like in 10 years, or 20 years, many would have predicted that the movie 2001 was just showing what they'd in fact see 32 years in the future, or something very similar. The Shuttle was supposed to do that. Pickup truck to space. Constantly flying, building stuff in orbit, like maybe the Moon rockets to build a base there! Or, instead... nothing much at all, for 3 decades.

This feels like the post Apollo 11 vibe at the time, that things were going to look more futuristic—and this time I actually think the cool things will be tried. I sure hope some are before I'm dead.

Edited October 15 by tater

[darthgently]

22 minutes ago, Nuke said:

arm's low power capabilities are likely very useful for space applications. assuming rad-hard parts are currently available. its usually a long process to convert a design over and could take close to a decade due to all the long term verification testing they need to do. so you usually end up with a processor that's 10 or so years behind the curve and less performant than the cpu it was based on.

my concern here is that this was just luck and that this method of recovery might be failure prone and not be suited for manned operation. this is more relevant to catching starships than boosters though. you can catch boosters all day every day and if you blow up a tower every now and again its still cheaper than throwing away a rocket every time you launch. i have a hard time comparing a test flight to apollo 11 though.

I see most payload launched from Earth to become increasingly one-way trips with propulsive landings for empty reusable vehicles and some cargo.
For human return on Starship, if propulsive landing is deemed too dangerous, they could sky dive from the belly flopping craft after terminal velocity is reached, lol.  Though going from microgravity to a sky dive landing is not likely something one’s doctor would recommend, it would be very Kerbal and sure to be a crowd pleaser

 

[tater]

On a less philosophical note, there are 2 starlink launches in the next ~4 hours.

Edited October 15 by tater

[JoeSchmuckatelli]

On yet another note - Starship Launched Starlink.

They're already looking to have a money-maker to pay for launch capabilities.

SpaceX Tips Gigabit Speeds for Starlink After Successful Starship Test | PCMag

Like... if this is real, and relatively soon... does this mean Falcon 9 retirement?  

 

*Relatively = relatively.  It was, IIRC, 2 years from Falcon 9 first launch to commercial worthiness and 9 before they started putting Starlink up.  If it's 2 years to put up commercial Starship... they might just have Big Starlink waiting to go.

Edited October 15 by JoeSchmuckatelli