totm nov 2023 SpaceX Discussion Thread

[Pthigrivi]

23 minutes ago, darthgently said:

There is so much glaring evidence to the contrary to this statement I’m astounded.  Unfathomable

I suppose you mean Tesla? He bought a very promising electric car company and slowly but surely turned into another laughable monument to his own dumpster shaped ego. He does not actually care about climate change or anything besides his own fickle savior fantasies. This should be glaringly obvious to everyone. 

Its been my concern all along that Elon’s increasingly unhinged and careless attitude would start to affect spacex. Was it wise to test the new suits with a fully depressurized vessel with no safe-haven if something went wrong? Probably not. Was there any real scientific reason to send four people into the Van Allen belt for a few days? No. There were safer ways to test both these things. So we push the bar a little further toward expediency and lower cost over safety. That works fine for a while. You can keep making things cheaper and less safe and you look like a genius right up until someone gets injured or killed. This is how Boeing got into the situation its in. 

Edited September 24 by Pthigrivi

[Minmus Taster]

43 minutes ago, Pthigrivi said:

I suppose you mean Tesla? He bought a very promising electric car company and slowly but surely turned into another laughable monument to his own dumpster shaped ego. He does not actually care about climate change or anything besides his own fickle savior fantasies. This should be glaringly obvious to everyone. 

Its been my concern all along that Elon’s increasingly unhinged and careless attitude would start to affect spacex. Was it wise to test the new suits with a fully depressurized vessel with no safe-haven if something went wrong? Probably not. Was there any real scientific reason to send four people into the Van Allen belt for a few days? No. There were safer ways to test both these things. So we push the bar a little further toward expediency and lower cost over safety. That works fine for a while. You can keep making things cheaper and less safe and you look like a genius right up until someone gets injured or killed. This is how Boeing got into the situation its in. 

In all fairness nothing I've seen from SpaceX indicates it's trying to go cheap. More efficient perhaps? But so far it's track record with crewed flight has been flawless. That being said it would be wise to remove Elon from any administrative role in SpaceX so he doesn't screw up our best launch provider when NASA and Co. are on life support.

[darthgently]

42 minutes ago, Pthigrivi said:

I suppose you mean Tesla? He bought a very promising electric car company and slowly but surely turned into another laughable monument to his own dumpster shaped ego. He does not actually care about climate change or anything besides his own fickle savior fantasies. This should be glaringly obvious to everyone. 

Its been my concern all along that Elon’s increasingly unhinged and careless attitude would start to affect spacex. Was it wise to test the new suits with a fully depressurized vessel with no safe-haven if something went wrong? Probably not. Was there any real scientific reason to send four people into the Van Allen belt for a few days? No. There were safer ways to test both these things. So we push the bar a little further toward expediency and lower cost over safety. That works fine for a while. You can keep making things cheaper and less safe and you look like a genius right up until someone gets injured or killed. This is how Boeing got into the situation its in. 

I’m sure that Tesla investors are doing very well and that they are only laughing on the way to the bank.  I’m seeing unhinged right now

[Pthigrivi]

1 hour ago, Minmus Taster said:

In all fairness nothing I've seen from SpaceX indicates it's trying to go cheap. More efficient perhaps? But so far it's track record with crewed flight has been flawless. That being said it would be wise to remove Elon from any administrative role in SpaceX so he doesn't screw up our best launch provider when NASA and Co. are on life support.

Yeah and I don’t want to overstate the case here because thankfully Elon does almost always defer to the team of incredibly talented engineers at spaceX. Dragon is a very sensible and reliable workhorse. But dragon began development in 2004 and underwent a decade of uncrewed testing before crew-dragon was ready for actual passengers. Im fine with blowing up rockets but that kind of rigor really is needed when lives are at stake. I mean i love watching these starship launches and I too grumble when it takes so long to get FAA approval. At the same time we can’t have spacex endangering the population of brownsville and south texas just because Elon wants to move up a premature starship reentry tower catch before reliability demonstrating it can land precisely a dozen times or so without error. Certainly implying those kinds of delays are a threat to humanity is at best unserious hyperbole. 

Edited September 24 by Pthigrivi

[tater]

2 hours ago, PakledHostage said:

This is interesting and it makes sense, but where did you read this? Is that also how they currently recover boosters? From the footage,  it always looks like more of a pure suicide burn?

It's still a suicide burn. The only alternative I see is the boostback shaping a trajectory that drops nearly vertically, which they could also do, since a failure of the boostback burn then drops it offshore. The CRS-16 hydraulic failure (gridfins) had the booster land just off the coast after a nominal boostback and entry burn, however, which suggests that the boostback left it with an offshore trajectory (maybe the gridfins are doing more of the horizontal work than the landing burn?).

[tater]

2 hours ago, Pthigrivi said:

The idea that our salvation lies in colonization of another planet is not just an escapist fantasy, it actively ignores the glaring reality that we actually have no choice but to save the planet we already have. Elon and his ilk have no actual interest in solving the real problem. He is interested entirely in propping up his own ego and increasingly deranged outlook no matter who gets hurt in the process.

Certain POVs always assume they can actually know the contents of another person's mind (and some of the subject matter these folks tend to agree on even require the notion that someone can actually understand the consciousness of someone who is "not me"). Odd.

It's not "escapist," it's simply reality, and has nothing at all to do with not caring about the only good planet in the solar system. I have stated a zillion times that I am not a "Mars Bro," yet nonetheless it is simple fact that a backup is a good plan in the long haul. Such a backup requires a completely self-sufficient offworld colony (the people thrive even if the ships from home stop coming). Do I think this happens soon? LOL, no. Does trying for it soon help humanity? Unambiguously "yes."

How? Any serious attempt at such a path on Mars requires the sort of capability that gives us the ability to mitigate existential threats to Earth. Having to deflect an asteroid with our current capabilities would be nearly impossible. Having 100s (1000s, lol?) of huge fully tanked up ships in LEO gives us many more options in this scenario. Having some of those ships out at Mars adds more options—regardless of the success of said colony.

It's funny that the most off topic, ad hominem attacks (that include some sort of mind-body duality that allows them to know within their bizarre epistemology what another thinks/feels) only ever come from one direction, and the people doing so consider this normal discourse. When I encounter people like this at cocktail parties, their opinion of people broadly is painted by whether those people agree with them on every other issue. A single point of failure in opinion alignment is heresy to that type of person, and the well is poisoned. The unbeliever must be burned at the stake. I'm not religious, myself, and I don't treat nomnally non-religious ideas as religion, either.

BTW, he has said things that mirror Bezos, actually—that Earth is the best planet, and Mars colonization is not someplace better, just someplace different. His arguments for solar, EVs, etc? meant to get rid of burning hydrocarbons as much as possible—the opposite of not caring about Earth. Both want people off the planet doing stuff, and both men's ideas not only complement each other, but have the same endpoint. A better Earth, and an expanded humanity.

Edited September 24 by tater

[zolotiyeruki]

I'm pretty sure the Falcon 9 booster landing burns still start with a trajectory that misses the ASDS, with the landing burn adjusting the trajectory toward the ship.  Compared to RTLS, the difference between the two trajectories can be pretty small.

43 minutes ago, Pthigrivi said:

 just because Elon wants to move up a premature starship reentry tower catch before reliability demonstrating it can land precisely a dozen times or so without error.

I don't recall--how many successful water landings did SpaceX perform before they started attempting to land on the droneships?  It seems like it wasn't very many, certainly not a dozen.

13 hours ago, tater said:

The downward component of the velocity on a normal return trajectory will be offshore, but with a substantial horizontal component towards the pad (land). Lighting the engines (pointed mostly down) will slow the descent rate, so the trajectory will then move ashore as the vertical component is reduced more than the horizontal. The balance of this is adjusted on the fly, obviously. By the time it's headed ashore, it's already very much slower than at the start of the burn, and if there is no relight, it goes in the water. Failure after enough burn time to have the trajectory shaped ashore—it's not going very fast any more.

Just to add to this:  if the relight succeeds, not only will the rocket be moving slower, but it will also have a lot less fuel in it when it gets to the chopsticks, in case something *does* go wrong after relight.

 

[tater]

2 hours ago, Pthigrivi said:

I suppose you mean Tesla? He bought a very promising electric car company and slowly but surely turned into another laughable monument to his own dumpster shaped ego. He does not actually care about climate change or anything besides his own fickle savior fantasies. This should be glaringly obvious to everyone. 

Its been my concern all along that Elon’s increasingly unhinged and careless attitude would start to affect spacex. Was it wise to test the new suits with a fully depressurized vessel with no safe-haven if something went wrong? Probably not. Was there any real scientific reason to send four people into the Van Allen belt for a few days? No. There were safer ways to test both these things. So we push the bar a little further toward expediency and lower cost over safety. That works fine for a while. You can keep making things cheaper and less safe and you look like a genius right up until someone gets injured or killed. This is how Boeing got into the situation its in. 

This is a level of absurdity that I haven't seen since the last (and only) person I have ever blocked on this site.

SpaceX tested the EVA suits on Earth in a vaccum chamber. Safe haven? Gemini had no "safe haven." The Apollo CM and LM had no "safe haven." Even Shuttle or ISS—with airlocks—have no safe haven should a suit fail on EVA, the cycle time of the system is not the Discovery airlock in 2001. The fastest EVA abort I think was the Italian guy who got water in his helmet, and I think the repress was about 30 minutes. Given the hours of prebreathing, etc, I'm honestly not sure what the actual min safe time is—EVAs are incredibly complex. Since all 4 astronauts were on the same EVA in terms of breathing, they could simply close the hatch and repress to the suit air levels (exactly what they did for prebreathing beforehand), then slowly bring the capsule to the usual mix.

[tater]

A

A render of ship 31 vs 33 showing the smaller, leeward fins, etc, done by https://x.com/ScottLikesSLS

 

[darthgently]

25 minutes ago, tater said:

A

A render of ship 31 vs 33 showing the smaller, leeward fins, etc, done by https://x.com/ScottLikesSLS

 

I’d wondered about the seemingly large surface area of the fore flaps given most of the mass is aft on re-entry.  The new design clicks better with what seems a better balance of control authority.  KSP has taught me remorselessly that craft really want to shuttlecock with the more massive engine end leading on re-entry.

[Ultimate Steve]

1 hour ago, Pthigrivi said:

At the same time we can’t have spacex endangering the population of brownsville and south texas just because Elon wants to move up a premature starship reentry tower catch before reliability demonstrating it can land precisely a dozen times or so without error.

Any deviation in expected landing location from the land immediately surrounding the launch site is unacceptable. However, this deviation would have to be humongous to endanger the public.

Hitting the closest bit of Brownsville would mean a miss by over 8 miles. Hitting an actual inhabited part of Brownsville would mean a miss of over 15 miles (almost all of which is overshoot). Although South Padre Island is 5 miles away (almost all of which is lateral).

It is my understanding that Super Heavy boosts back to a velocity that would ballistically take it to a point decently offshore, and then it glides the rest of the way, same as Falcon. If something passively fails, Super Heavy isn't getting to shore. It would take a few overlapping active failures to pose a risk to any populated areas. You'd need some combination of the Raptors overburning and/or the vehicle overperforming in glide slope, the vehicle not noticing and correcting, and then for the AFTS/AFSS (or any non automated checks) to not catch the fact that this booster is hurtling 15 miles beyond its target towards Brownsville.

I'm not saying that's impossible, Ariane 5 did have one launch where it went 20 degrees in the wrong direction, and Starship has had a problem with an insufficient AFTS in the past (which has since been remedied, but that failure is IMO the biggest red flag of the Starship program thus far), but I don't think there has ever been a Falcon 9 overshoot. Closest thing would be that one mission that had a control failure and was unable to glide, and undershot. SpaceX has a track record of being able to hit targets, although one more ocean landing for Starship would probably be an alright idea.

I also think the idea of a dozen successful ocean landings before coming back to land is a little bit much. The nearest inhabited area from LZ-1, I think, is 8 miles downrange, or 6 miles crossrange looking at Google maps. So about comparable to the Texas launch site. At the time of its first land landing attempt, Falcon had:

• 2 failed ocean landings
• 3 controlled ocean landings
• 2 failed drone ship landings
• I don't count these, but for completion's sake, there were also 2 parachute landing attempts

And then was allowed to attempt land landings (which it nailed on the first try) without ever having attempted a boostback burn before (to my knowledge) on the very first flight of the "Full Thrust" version of the rocket. 7 attempts is a lot more than 2 attempts, of course (3 boostback burn attempts). Starship right  now has:

• 1 successful-ish ocean landing on target
• 1 failed ocean landing either on target or undershot (unclear if the boostback engine outs were compensated for)
• 1 failed boostback burn attempt

One more test would be prudent, even considering SpaceX's track record with Falcon 9, but 12 consecutive successes?

Whether or not it's a good idea to risk the tower is another question entirely (second tower is nearly done and it is possible that they learned a lot while building the first tower, and it may not be that important to them any more), but I don't think there is significant risk to the public.

[darthgently]

1 hour ago, Pthigrivi said:

Yeah and I don’t want to overstate the case here because thankfully Elon does almost always defer to the team of incredibly talented engineers at spaceX. Dragon is a very sensible and reliable workhorse. But dragon began development in 2004 and underwent a decade of uncrewed testing before crew-dragon was ready for actual passengers. Im fine with blowing up rockets but that kind of rigor really is needed when lives are at stake. I mean i love watching these starship launches and I too grumble when it takes so long to get FAA approval. At the same time we can’t have spacex endangering the population of brownsville and south texas just because Elon wants to move up a premature starship reentry tower catch before reliability demonstrating it can land precisely a dozen times or so without error. Certainly implying those kinds of delays are a threat to humanity is at best unserious hyperbole. 

Hyperbole and overstating, indeed.  You may not want, nor intend, to overstate, as you claim, and yet, it somehow just happens.  I’m not going to venture why as there is nothing of value in pretending to read minds.  But I can wish you a better day and believe you capable of having one

[Ultimate Steve]

20 minutes ago, darthgently said:

I’d wondered about the seemingly large surface area of the fore flaps given most of the mass is aft on re-entry.  The new design clicks better with what seems a better balance of control authority.  KSP has taught me remorselessly that craft really want to shuttlecock with the more massive engine end leading on re-entry.

That's a bit because engines in KSP are very heavy. Raptor 3 is ~1.7 tons (including vehicle side stuff), so about 10-11 tons of engine hardware depending on how much heavier the vacuum version is. This is 16.5 meganewtons of thrust, give or take depending on how much Raptor 3 ends up being capable of.

To obtain the same thrust with Vector engines in KSP, you would need 66 tons of them.

[darthgently]

1 minute ago, Ultimate Steve said:

That's a bit because engines in KSP are very heavy. Raptor 3 is ~1.7 tons (including vehicle side stuff), so about 10-11 tons of engine hardware depending on how much heavier the vacuum version is. This is 16.5 meganewtons of thrust, give or take depending on how much Raptor 3 ends up being capable of.

To obtain the same thrust with Vector engines in KSP, you would need 66 tons of them.

Still, on re-entry, with only a small amount of wet mass and the raptors on the extreme end, the aft end will tend to lead and need more aero control authority and the bow needs as little drag as practical.  

Related:  Is the landing header tank still in the nose?  If so, how does the downcomer route through the payload area?

[Nuke]

5 hours ago, Pthigrivi said:

Look, we may send people there in the next 10-15 years, maybe do some good science. But a self-sustaining colony is still 100 years out. You’ll have a few foolhardy goofs who don’t mind dying of cancer in their 50s, but living on Mars, most likely underground, is about 100 times less pleasant than living on Antarctica. The year round population of Antarctica is 1000 people. 1000 people can’t form a colony thats fully self sufficient and independent of earth. You probably need 100 million which wont happen for a very long time. There’s also no money in it, so the business model is senseless. Dont get me wrong spaceX is cool but colonizing mars is at best a goofy marketing pitch for the musk bros. 

The idea that our salvation lies in colonization of another planet is not just an escapist fantasy, it actively ignores the glaring reality that we actually have no choice but to save the planet we already have. Elon and his ilk have no actual interest in solving the real problem. He is interested entirely in propping up his own ego and increasingly deranged outlook no matter who gets hurt in the process.

Elon is very, very good at getting the Saudi’s to dump billions of dollars on him, and like many people will billions of dollars and no grounded sense of reality he believes that makes him good at everything else. The truth is, however, he’s just another wealthy, megalomaniacal moron when it comes to most other things. I think one need look no further than cybertruck or hyperloop for evidence of that. 

i was debating the prospect of replacing plastics with glass. it can be recycled, and it can be reused many times with a simple sterilization process. metals are also highly recyclable with a minimal injection of virgin material. best you can do with plastics is downcycle and the demand for downcycled plastic is nowhere near the demand for virgin plastic. environmental types kept poking holes in the idea while not providing a better alternative. so much for the beaches they said. if you use something else that will run out too. in fact there is no recycling process that is 100% efficient (thats before you account for the energy requirements). earth materials are finite and so if we are going to continue being wasteful selfish humans, and that shows no sign of changing, then we need to start exploiting external resources before we live on a mined out plastic strewn wasteland. would rather we start this century instead of when its too late.

frankly i wish musk would turn to lunar colonization first. it stands a higher chance of success. access is easier, and you can haul more mass. which you will need to bootstrap industry, and an economy. the regolith alone is loaded with useful stuff, and we have no idea whats below the surface. its easier to launch a flotilla to mars from the moon than it is from earth. and you can use nuclear engines the likes of which nobody wants to launch from earth. anyway here is how you do that:

Edited September 24 by Nuke

[Pthigrivi]

3 hours ago, tater said:

It's not "escapist," it's simply reality, and has nothing at all to do with not caring about the only good planet in the solar system. I have stated a zillion times that I am not a "Mars Bro," yet nonetheless it is simple fact that a backup is a good plan in the long haul. Such a backup requires a completely self-sufficient offworld colony (the people thrive even if the ships from home stop coming). Do I think this happens soon? LOL, no. Does trying for it soon help humanity? Unambiguously "yes."

How? Any serious attempt at such a path on Mars requires the sort of capability that gives us the ability to mitigate existential threats to Earth. Having to deflect an asteroid with our current capabilities would be nearly impossible. Having 100s (1000s, lol?) of huge fully tanked up ships in LEO gives us many more options in this scenario. Having some of those ships out at Mars adds more options—regardless of the success of said colony.

No in the long term I agree it's a good idea. The last impact that could have plausibly threatened human existence was 65 million years ago so I think the statistical immediacy of this threat is way down on the list but of course having a more developed space infrastructure is great. I just think it will be at least 100 years before a mars colony could plausibly sustain itself as a back up plan so histrionics about week to week FAA approvals are kind of silly.
 

3 hours ago, tater said:

It's funny that the most off topic, ad hominem attacks (that include some sort of mind-body duality that allows them to know within their bizarre epistemology what another thinks/feels) only ever come from one direction, and the people doing so consider this normal discourse. When I encounter people like this at cocktail parties, their opinion of people broadly is painted by whether those people agree with them on every other issue. A single point of failure in opinion alignment is heresy to that type of person, and the well is poisoned. The unbeliever must be burned at the stake. I'm not religious, myself, and I don't treat nomnally non-religious ideas as religion, either.

BTW, he has said things that mirror Bezos, actually—that Earth is the best planet, and Mars colonization is not someplace better, just someplace different. His arguments for solar, EVs, etc? meant to get rid of burning hydrocarbons as much as possible—the opposite of not caring about Earth. Both want people off the planet doing stuff, and both men's ideas not only complement each other, but have the same endpoint. A better Earth, and an expanded humanity.

First of all I don't think one need any kind of telepathy to know what Elon thinks about almost anything given he posts every thought that pops into his mind on twitter.  I also don't think it's very difficult to question Musk's or Bezos' actual sincerity on much of anything besides making more money. His treatment of his employees, family, and random people he encounters online is also happening in the public eye often because he deliberately put it there. Rather than telepathy I think not acknowledging some of his clear personality flaws requires a bit of willful ignorance. Now, none of this is particularly on-topic unless his lack of concern for others' safety or generally erratic behavior begins to leak into SpaceX's decision making. I hadn't seen much evidence of that until the last year or so. 
 

3 hours ago, Ultimate Steve said:

Hitting the closest bit of Brownsville would mean a miss by over 8 miles. Hitting an actual inhabited part of Brownsville would mean a miss of over 15 miles (almost all of which is overshoot). Although South Padre Island is 5 miles away (almost all of which is lateral).

It is my understanding that Super Heavy boosts back to a velocity that would ballistically take it to a point decently offshore, and then it glides the rest of the way, same as Falcon. If something passively fails, Super Heavy isn't getting to shore. It would take a few overlapping active failures to pose a risk to any populated areas. You'd need some combination of the Raptors overburning and/or the vehicle overperforming in glide slope, the vehicle not noticing and correcting, and then for the AFTS/AFSS (or any non automated checks) to not catch the fact that this booster is hurtling 15 miles beyond its target towards Brownsville.

...

Whether or not it's a good idea to risk the tower is another question entirely (second tower is nearly done and it is possible that they learned a lot while building the first tower, and it may not be that important to them any more), but I don't think there is significant risk to the public.

Yeah Im not that worried about superheavy except that it might continue to suffer from ice-clogging and hit the tower. That would be very bad and dumb but not really a threat to people's lives. Like I said a single nominal hover would seem like a good idea. Starship is a different animal. It'll be coming in from the west so any loss of control or breakup during reentry could pose a risk to people on the ground. Even that wouldn't worry me too much except for the way they're approaching the TPS system, where a single tile loss in a critical place could threaten the stability of the vehicle. In 3 or 5 reentry tests you might get lucky. If however they're able to demonstrate a good number of nominal hover-landings without losing tiles that might give more confidence that they have the problem solved. They'd still be perfectly able to deliver starlink V2 and iron out any kinks with booster catching in that time. 
 

4 hours ago, tater said:

This is a level of absurdity that I haven't seen since the last (and only) person I have ever blocked on this site.

SpaceX tested the EVA suits on Earth in a vaccum chamber. Safe haven? Gemini had no "safe haven." The Apollo CM and LM had no "safe haven." Even Shuttle or ISS—with airlocks—have no safe haven should a suit fail on EVA, the cycle time of the system is not the Discovery airlock in 2001. The fastest EVA abort I think was the Italian guy who got water in his helmet, and I think the repress was about 30 minutes. Given the hours of prebreathing, etc, I'm honestly not sure what the actual min safe time is—EVAs are incredibly complex. Since all 4 astronauts were on the same EVA in terms of breathing, they could simply close the hatch and repress to the suit air levels (exactly what they did for prebreathing beforehand), then slowly bring the capsule to the usual mix.

No thanks, this is interesting. It was my assumption that the safest situation was to have an airlock with people not in EVA suits on the other side in case anything went wrong. You're right though given time to repressurize you might even be better off with people already at suit pressure. I wonder how long it takes to bring the capsule back to 5psi?



 

[Ultimate Steve]

10 minutes ago, Pthigrivi said:

I wonder how long it takes to bring the capsule back to 5psi?

It was 8 minutes for this mission, presumably it can be done faster in an emergency. Though they do not nominally repress with pure oxygen.

[CatastrophicFailure]

5 hours ago, tater said:

 

There’s zero chance of a high-speed impact on the tower area. Falcon 9 has a glide ratio of around 1:1, that is dang good for a metal tube with a bunch of cups poking out one end. You can really see this on some RTLS videos, it’s coming back at a very visible angle of attack. Superheavy has been designed to do even better, with long strakes like New Glenn, better grid fin position and a better mass to size ratio. If the engines don’t light, or don’t all light, or the computer detects anything at all out of spec, the booster goes in the drink. 

If something is going to go all Kerbal, and I do think it’s ballsy as heck for them to try this so soon, but they DO have more experience in landing boosters than anyone else, if something does go wrong, it’ll be the booster contacting the tower at slow speed and ripping itself open, or smacking into the ground like that Chinese rocket the other day. So lots of FIRE!, and flying bits of metal, but not the blast wave of a detonation. It will look spectacular but seems like something they could design the tower to withstand, with light damage if not unscathed. The arms are probably most vulnerable, but fairly easy to replace as well. 

[RCgothic]

And even so there's no way impact explosion damage outweighs launch explosion damage. The quantities of propellant involved are just so vastly different.

[Pthigrivi]

1 hour ago, CatastrophicFailure said:

 

There’s zero chance of a high-speed impact on the tower area. Falcon 9 has a glide ratio of around 1:1, that is dang good for a metal tube with a bunch of cups poking out one end. You can really see this on some RTLS videos, it’s coming back at a very visible angle of attack. Superheavy has been designed to do even better, with long strakes like New Glenn, better grid fin position and a better mass to size ratio. If the engines don’t light, or don’t all light, or the computer detects anything at all out of spec, the booster goes in the drink. 

If something is going to go all Kerbal, and I do think it’s ballsy as heck for them to try this so soon, but they DO have more experience in landing boosters than anyone else, if something does go wrong, it’ll be the booster contacting the tower at slow speed and ripping itself open, or smacking into the ground like that Chinese rocket the other day. So lots of FIRE!, and flying bits of metal, but not the blast wave of a detonation. It will look spectacular but seems like something they could design the tower to withstand, with light damage if not unscathed. The arms are probably most vulnerable, but fairly easy to replace as well. 

The question is whether they lose thrust due to engine failure during the landing burn. One of the engines in IFT4 failed to light during this maneuver just a km from the target and in the surface camera view you can see flames billowing out of the side of rocket the even as its going 150kph right over the LZ. I know they've done a lot to mitigate the ice contamination issue and maybe they have it nailed. Why not just do one more test to make sure? The risk/reward of the catch vs waiting till IFT6 seems out of wack to me as an outside observer. Same with doing IFT1 before getting the deluge system fully ready. I get "move fast and break things" but there is a point where you are breaking things you don't have to and it becomes counterproductive. 

Edited September 24 by Pthigrivi

[RCgothic]

They have a second launch tower nearly ready. Not a big setback if they break the first.

Much useful data to learn.

Edited September 24 by RCgothic

[tater]

4 hours ago, Nuke said:

frankly i wish musk would turn to lunar colonization first. it stands a higher chance of success. access is easier, and you can haul more mass. which you will need to bootstrap industry, and an economy. the regolith alone is loaded with useful stuff, and we have no idea whats below the surface. its easier to launch a flotilla to mars from the moon than it is from earth. and you can use nuclear engines the likes of which nobody wants to launch from earth. anyway here is how you do that:

I don't think the Moon will ever be "colonized" as I am pretty uncertain that 1/6g is enough to make healthy humans. I'm unsure that 0.38g is healthy, actually, and if it isn't, a Mars colony is also off the table completely.

[tater]

3 hours ago, Pthigrivi said:

No in the long term I agree it's a good idea. The last impact that could have plausibly threatened human existence was 65 million years ago so I think the statistical immediacy of this threat is way down on the list but of course having a more developed space infrastructure is great. I just think it will be at least 100 years before a mars colony could plausibly sustain itself as a back up plan so histrionics about week to week FAA approvals are kind of silly.

Getting anything interesting done in space, particularly with humans will never happen at all left to government. Since there is no economic case for the Moon or Mars, it can solely happen as a project paid for a person or group willing to light the required money on fire to do it, not hobbled by partisan politics (changing goals every X years, or even what districts get the $$$ to work on it). So the time constraint is currently his lifespan... maybe Bezos' lifespan assuming BO gets their act together.

3 hours ago, Pthigrivi said:

much of anything besides making more money

Space is a money loser. If it was about money he'd just sell cars/robots and buy a yacht to chill on. SpaceX/BO/etc is chump change.

All of your ad hominem claims are based on mind-reading—except that apparently you consider disagreeing with any of your personal politics evidence of mental illness . Or something.

3 hours ago, Pthigrivi said:

Yeah Im not that worried about superheavy except that it might continue to suffer from ice-clogging and hit the tower. That would be very bad and dumb but not really a threat to people's lives. Like I said a single nominal hover would seem like a good idea. Starship is a different animal. It'll be coming in from the west so any loss of control or breakup during reentry could pose a risk to people on the ground. Even that wouldn't worry me too much except for the way they're approaching the TPS system, where a single tile loss in a critical place could threaten the stability of the vehicle. In 3 or 5 reentry tests you might get lucky. If however they're able to demonstrate a good number of nominal hover-landings without losing tiles that might give more confidence that they have the problem solved. They'd still be perfectly able to deliver starlink V2 and iron out any kinks with booster catching in that time. 

I think that it's reasonable to wonder about more ocean landing tests, but then again, I don't have the data that SpaceX has. They know a little something about rocket landing trajectories after all, and they have all the data. It's not like they have nothing to lose, either, they're literally aiming it at their launch facility. Note that FTS is still active, and they literally see the trajectory forming during the boostback burn in real time. Should it be off nominal at all... BOOM. The vehicle can't possibly make its way back to the point it is closest to SPI/Brownsville and possibly do something to impact either location, Newton would have shown that problem starting to happen at the beginning of boostback.

3 hours ago, Pthigrivi said:

No thanks, this is interesting. It was my assumption that the safest situation was to have an airlock with people not in EVA suits on the other side in case anything went wrong. You're right though given time to repressurize you might even be better off with people already at suit pressure. I wonder how long it takes to bring the capsule back to 5psi?

I mean I think an airlock is a good idea, and in a larger vehicle, having 2 on EVA and 2 inside at least means that only 2 can die from an EVA failure. It would be reasonable to ask why they did 4 crew instead of 2 in the case of Polaris, they'd have gotten all the EVA/suit data, risking half as many lives. That said, they did test everything on the ground (as they talked about well before the flight).

The fact that EVA is currently so incredibly complicated is not something I ever paid much attention to, but it makes sense, particularly with PLSS requiring the densest possible amount of consumables carried (hence pure O2), so all the problems of deep sea diving become a thing.

Edited September 24 by tater

[darthgently]

49 minutes ago, tater said:

I don't think the Moon will ever be "colonized" as I am pretty uncertain that 1/6g is enough to make healthy humans. I'm unsure that 0.38g is healthy, actually, and if it isn't, a Mars colony is also off the table completely.

It is interesting that the 2nd easiest way to have 1G off-earth is in a spun-up orbital.  The first easiest is linear acceleration.  People think “base on surface” = gravity, but, no, not really.  Not 1G.

Interesting response from SpaceX wrt FAA public statements 

Full text:
SPACEX

September 24, 2024

The Honorable Kevin Kiley U.S. House of Representatives 1032 Longworth House Office Building Washington, D.C. 20515

Dear Congressman Kiley,

SpaceX writes to thank you for taking the opportunity to seek answers from Federal Aviation Administration (FAA) Administrator Mike Whitaker on FAA's licensing challenges relating to commercial space launch and reentry during his appearance before Congress today on unrelated matters. In responding to your questions, Administrator Whitaker made several incorrect statements today regarding SpaceX. In fact, every statement he made was incorrect.

First, SpaceX was fully licensed to conduct these Falcon launches and FAA has not alleged otherwise. With respect to Starship, neither of the two items he referenced, including the sonic boom, are related to public safety, but to environmental considerations that had been previously evaluated as posing no risk to the environment. Additionally, his assertion that SpaceX violated state law is simply wrong. SpaceX did not violate state law-SpaceX had a permit for deluge operations from Texas Commission on Environmental Quality (TCEQ). It is deeply concerning that the Administrator does not appear to have accurate information immediately available to him with respect to SpaceX licensing matters. SpaceX has issued a letter on each of these matters previously - here and here.

SpaceX rejects any allegations from FAA that SpaceX violated any laws. SpaceX is the safest, most reliable launch provider in the world, and is absolutely committed to safety in all operations.

Quick Facts

1. Administrator Whitaker alleged that SpaceX launched without a permit. a. That is false-SpaceX was fully licensed to launch the Falcon missions for which FAA has, incorrectly, alleged non-compliances. FAA has not alleged SpaceX was not "permitted" or not "licensed" to launch these missions. SpaceX receives FAA licensing for all missions subject to the Commercial Space Launch Act.

2. Administrator Whitaker alleged that SpaceX "moved a fuel farm closer to the population" and that SpaceX did not perform a risk analysis.

a. SpaceX moved the fuel farm to a location that is more than twice the distance from the nearest publicly accessible area and provided the FAA with all required analysis.

b. Prior to the launch, Federal Range Safety authorities approved the new location of the fuel farm, and FAA was on console and did not stop the countdown.

c. FAA took months to review and approve the revised location, and ultimately required no changes to the previously approved Federal Range configuration.

3. Administrator Whitaker stated that SpaceX "failed to provide an updated sonic boom analysis," that it was "safety related incident," and that FAA had to enter into a two-month consultation with Fish and Wildlife Service (FWS). This has nothing to do with safety. FWS already reviewed Starship sonic booms and determined them to have no environmental impact for booms under 1 psf.

a. SpaceX recently provided FAA data showing a slightly larger sonic boom area. Despite the slightly larger area, there is no new environmental impact. Nevertheless, FAA entered a new environmental consultation with FWS, which could result in a two-month delay. This is a paperwork exercise that could be swiftly addressed between agencies as a minor paperwork update.

4. Administrator Whitaker alleged that SpaceX did not have a permit for its deluge system and that this delayed FAA licensing. At no time did SpaceX operate its deluge without a permit.

a. SpaceX was operating under a permit from the TCEQ. TCEQ staff were physically present during operation of the deluge. FAA and FWS have evaluated use of the deluge and determined no environmental risk.

b. At EPA's request, SpaceX is seeking a different type of permit to cover these operations. The FAA, TCEQ, and EPA have confirmed that deluge operations may continue in the interim, and operation of the system will not change under this new permit.

Respectfully,

/s/

Mat Dunn

Senior Director, Global Government Affairs

[Pthigrivi]

30 minutes ago, tater said:

Getting anything interesting done in space, particularly with humans will never happen at all left to government. Since there is no economic case for the Moon or Mars, it can solely happen as a project paid for a person or group willing to light the required money on fire to do it, not hobbled by partisan politics (changing goals every X years, or even what districts get the $$$ to work on it). So the time constraint is currently his lifespan... maybe Bezos' lifespan assuming BO gets their act together.

I mean the current moon missions (mess that they are) are government funded, as are all of the really quite cool probe work going on. Totally agreed that partisan backtracking is utterly annoying and counterproductive but the US isn't really in a good place right now for cooperating on basically anything. China has advanced really quite far in a relatively short period of time but I have even less to like about their government. Also agreed there's no real business plan for colonizing mars which is part of the reason I think it may not even happen, billionaire vanity project or no. There is a huge amount of money in mass to orbit though which is why SX is valued around 210B as of the last private equity round. Its no Apple or Amazon but there's definitely money in it in the short run. I just think if they ever actually started doing things that weren't profitable like colonization that money would evaporate. Either a lofty and unrealistic goal or just vaporware. 

As to Elon's mental state, its kinda like Kanye, his political ideas are dumb but not nearly the most worrying thing about him. It wouldn't matter except he's got thousands of employees, his cars and rockets have the potential to hurt people, and it's dangerous to have an unstable person in that kind of position. 
 

1 hour ago, tater said:

I think that it's reasonable to wonder about more ocean landing tests, but then again, I don't have the data that SpaceX has. They know a little something about rocket landing trajectories after all, and they have all the data. It's not like they have nothing to lose, either, they're literally aiming it at their launch facility. Note that FTS is still active, and they literally see the trajectory forming during the boostback burn in real time. Should it be off nominal at all... BOOM. The vehicle can't possibly make it's way back to the point it is closest to SPI/Brownsville and possibly do something to impact either location, Newton would have shown that problem starting to happen at the beginning of boostback.

No Im not worried about superheavy hitting brownsville. It's the longer term plan to bring Starship down in the same location. The FAA should be incredibly scrutinizing when that time comes. This is in the context of Elon saying the he's being hampered by regulation, and sure, he is, but given that Boeing currently has doors blowing off and planes falling out of the sky I think its easy to argue corporate regulatory capture and an overly deferential posture by regulators is the bigger problem. SpaceX gets away with a lot because they've got a decent track record (so far) and the US sees them as a critical strategic asset.