totm nov 2023 SpaceX Discussion Thread

[darthgently]

8 hours ago, Pthigrivi said:

What I mean is if you cared most of all about reducing launch costs and secondarily about securing long-term government contracts and tertiarily about about cornering the orbital delivery market and then, maybe, somewhere down the checklist you worried about human occupants reliably  surviving reentry starship is exactly what you would design. There’s no launch abort system. There’s no plan for failed belly flop or engines exploding on ascent. I mean folks asked early on when all those goofy animations rolled with starships landing on mars “where’s the radiation shielding” and dude was like “we’ll point the engines at the the sun.” Its just so frustrating to see so much intelligence directed at making money and such an obviously stupid and cavalier attitude taken towards safety and actual people’s lives.

This has been addressed.  The plan is to get the reliability on par with commercial aircraft long before humans fly on Starship.  Hundreds of test flights and Starlink/other launches will provide the iteration to achieve this reliability.  Musk has stated up front many times it may not be doable, but they are going to try. 

Do you ask for a parachute and seat near the door when boarding a commercial flight?

Finally, there is a lot of flexibility given outcomes.  For the lunar missions, SpaceX could launchb Starship with no humans, refuel, then have Crew Dragon rendezvous the crew later.

With 100t to play with, a LES could surely be worked out down the road if the crew were to launch on SS.  With that much payload elbow room, on return, one could have a tile encrusted, parachute slathered separable crew compartment inside the Starship cargo area that could provide all the protection one could desire on decent of a lunar crew.

But honestly, I don't think any humans will be present for LEO refueling so why launch a small crew with SS  given a separate crew launch would be required anyway?

Edited April 19, 2023 by darthgently

[tater]

1 hour ago, mikegarrison said:

Well, SpaceX is releasing videos that at least imply humans are going to be launching on trips to Mars in Starships. If this were just a bunch of people on the internet jumping to make assumptions, I would agree with you. But SpaceX themselves seem to be putting this scenario on the table, so I don't think it is at all unreasonable or premature to point out potential problems with it.

Absolutely.

Many of us here and elsewhere have suggested LAS systems as well. The overall tone of the post was that somehow SpaceX was not doing this out of some bizarre concern for money at the cost of lives—when there's no money to be made sending people to Mars, and no government contracts to be made (small potatoes though even those might be) sending humans to/from space without NASA signing off on it.

In short, if NASA puts people on Starship it will be because they have decided it addresses their safety concerns.

I'll believe people launching on top of SS when I see it happening, lol.

Also:

live in under an hour.

 

Edited April 19, 2023 by tater

[Hannu2]

9 hours ago, Pthigrivi said:

What I mean is if you cared most of all about reducing launch costs and secondarily about securing long-term government contracts and tertiarily about about cornering the orbital delivery market and then, maybe, somewhere down the checklist you worried about human occupants reliably  surviving reentry starship is exactly what you would design. There’s no launch abort system. There’s no plan for failed belly flop or engines exploding on ascent. I mean folks asked early on when all those goofy animations rolled with starships landing on mars “where’s the radiation shielding” and dude was like “we’ll point the engines at the the sun.” Its just so frustrating to see so much intelligence directed at making money and such an obviously stupid and cavalier attitude taken towards safety and actual people’s lives.

I believe that humankind can never achieve surviving colonies or even permanent research bases if we can not accept high risk of death. Exploring and colonizing new areas have always been very dangerous. Kings have sent tens of ships and thousands of men over seas before one of them have returned. We may have better technology now but we have also orders of magnitude more difficult challenges.

I think work safety is culturally new thing and somewhat exaggerated in western countries. It is very good for average workers but there should be more freedoms for very special works where highly educated professionals know risks and accept them, like for astronauts. There should also be different attitude about failures. It should be heroic thing instead of losing face for funders or managers.

Musk may have his fantasies about Mars colonization but in real life it is very far away. If he can not get unmanned business running profitably at totally new level there will never be need or possibility to even think manned versions and safety issues. It is very reasonable to develop reliable unmanned freight rocket first. Maybe safety nitpicking decreases in next decades and gives better options for manned operations too.

[JoeSchmuckatelli]

51 minutes ago, mikegarrison said:

I don't think it is at all unreasonable or premature to point out potential problems with it.

I agree in general about highlighting problems with early human exploration of Mars.  And yes, SX has been beyond open, to actually aspirational, about Mars as a destination.  So general concern about how that will work?  Sure. 

 

But at the stage we are at? 

[AtomicTech]

1 hour ago, mikegarrison said:

Well, SpaceX is releasing videos that at least imply humans are going to be launching on trips to Mars in Starships. If this were just a bunch of people on the internet jumping to make assumptions, I would agree with you. But SpaceX themselves seem to be putting this scenario on the table, so I don't think it is at all unreasonable or premature to point out potential problems with it.

Perhaps a solution could be launching crew with Dragon and rendezvousing with Starship?

[mikegarrison]

1 hour ago, darthgently said:

Do you ask for a parachute and seat near the door when boarding a commercial flight?

You know that if an airplane's engines fail, it can still glide, right? Not that this is ideal, but it's better than just plummeting to the ground helplessly.

7 minutes ago, AtomicTech said:

Perhaps a solution could be launching crew with Dragon and rendezvousing with Starship?

Possibly. Or other similar things. Let's see what happens with the uncrewed Starship first. And then with the lunar lander version.

[darthgently]

4 minutes ago, mikegarrison said:

You know that if an airplane's engines fail, it can still glide, right? Not that this is ideal, but it's better than just plummeting to the ground helplessly.

I think engine failure is becoming a smaller and smaller percentage of commercial aircraft failures.  I could be wrong but I remember airframe failures and control systems failures are an increasing fraction while engine failures are a decreasing fraction.  

Sadly, intentional crashing of perfectly good aircraft is on the list for suicidal or ideological reasons

[tater]

10 minutes ago, mikegarrison said:

You know that if an airplane's engines fail, it can still glide, right? Not that this is ideal, but it's better than just plummeting to the ground helplessly.

On top of that, "airline level reliability" would be an almost impossibly high bar for a spacecraft—because airliners are so incredibly, shockingly safe.

They pick over ocean routes based on 1-engine ranges to emergency runways, right? But if they lost both engines over blue water, while they could glide, then ditch, the chance of a happy outcome would be nearly zero I imagine—but the chance of all engines out is incredibly low because of extremely high reliability. I suppose that's the way SpaceX will do the math to show SS as a crew vehicle?

15 minutes ago, mikegarrison said:

Possibly. Or other similar things. Let's see what happens with the uncrewed Starship first. And then with the lunar lander version.

Indeed. Crew seems a looong way off right now.

Starlink launch moved farther into the window again:

 

[Pthigrivi]

Just like a stupid question: Why is starship's architecture the way it is? Why not have a superheavy first stage, a reusable second stage, and then a big capsule with a LES and an ablative heatsheild? Like in hindsight the shuttle was an incredibly janky and risky system top to bottom and those heat tiles injected zillions of failure points that risked total loss of vehicle. And now we're doing that again? But now with heat tiles on moving joints and this really risky belly-flop maneuver? And no landing legs that spread out the landing base? We're literally going to drop this thing over a populated area and have it sit down exactly on stage zero and just assume well we tested it 15 or 20 times nothing bad could happen on the 21st. And from top to bottom the plan seems to be that this architecture is gonna work for the moon and even mars, and we're just hauling the airframe around everywhere? It seems like the decision was made to organize it this way basically because Elon liked how Buck Rogers it looked. It had that wow-cool-innovation kinda attitude that gets investors excited. 

And dont get me wrong. It is cool. Its maybe the coolest thing Ive ever seen. And they're not putting people in it right away, but all indications are eventually thats the plan. Im just wondering if this really high risk tollerance and move-fast break-stuff culture is actually a good idea when it comes to people's lives. 

Edited April 19, 2023 by Pthigrivi

[magnemoe]

4 minutes ago, tater said:

On top of that, "airline level reliability" would be an almost impossibly high bar for a spacecraft—because airliners are so incredibly, shockingly safe.

They pick over ocean routes based on 1-engine ranges to emergency runways, right? But if they lost both engines over blue water, while they could glide, then ditch, the chance of a happy outcome would be nearly zero I imagine—but the chance of all engines out is incredibly low because of extremely high reliability. I suppose that's the way SpaceX will do the math to show SS as a crew vehicle?

Indeed. Crew seems a looong way off right now.

Rockets are much more high strung than commercial aviation, probably even more than fighter jets. 
And I think Starship landing is probably the most dangerous part. 
I'm a bit surprised they have not done more jumps with landings, it might be that the rocket will change a lot getting reentry to work so these data will be pretty irrelevant. 

[magnemoe]

1 minute ago, Pthigrivi said:

Just like a stupid question: Why is starship's architecture the way it is? Why not have a superheavy first stage, a reusable second stage, and then a big capsule with a LES and an ablative heatsheild? Like in hindsight the shuttle was an incredibly janky and risky system top to bottom and those heat tiles injected zillions of failure points that risked total loss of vehicle. And now we're doing that again? But now with heat tiles on moving joints and this really risky belly-flop maneuver? And no landing legs that spread out the landing base? We're literally going to drop this thing over a populated area and have it sit down exactly on stage zero and just assume well we tested it 15 or 20 times nothing bad could happen on the 21st. And from top to bottom the plan seems to be that this architecture is gonna work for the moon and even mars, and we're just hauling the airframe around everywhere? It seems like the decision was made to organize it this way basically because Elon liked how Buck Rogers it looked. It had that wow-cool-innovation kinda attitude that gets investors excited. 

Think main problem is that this would make the second stage harder to recover and unique for the manned version. But I don't think the grab it with the sticks will be relevant for an manned version. To risky and lack of abort options. 
Option to land in Europe or Africa after an fail is very valuable or land other place then back at launch site if you get an problem and weather is bad at launch site. 
Now I believe it would be pretty easy to add an abort system to SS. have the top deck the escape capsule who can separate from rest of the ship using the header tank fuel. Crew is on upper deck during launch and landing. they would need separate rockets for this escape module. 

[Pthigrivi]

6 minutes ago, magnemoe said:

Think main problem is that this would make the second stage harder to recover and unique for the manned version. But I don't think the grab it with the sticks will be relevant for an manned version. To risky and lack of abort options. 
Option to land in Europe or Africa after an fail is very valuable or land other place then back at launch site if you get an problem and weather is bad at launch site. 
Now I believe it would be pretty easy to add an abort system to SS. have the top deck the escape capsule who can separate from rest of the ship using the header tank fuel. Crew is on upper deck during launch and landing. they would need separate rockets for this escape module. 

Yeah I mean maybe thats it, that there are going to be a lot of really significant architectural changes made before a crew goes near this thing. If all you're doing is pez-dispensing starlinks the current system seems fine and clever. Maybe its that these marketing animations showing basically that but with people just aren't all that well thought out. 

Edited April 19, 2023 by Pthigrivi

[tater]

MECO, stage sep, SES-1, fairing

[darthgently]

22 minutes ago, Pthigrivi said:

Yeah I mean maybe thats it, that there are going to be a lot of really significant architectural changes made before a crew goes near this thing. If all you're doing is pez-dispensing starlinks the current system seems fine and clever. Maybe its that these marketing animations showing basically that but with people just aren't all that well thought out. 

They don't need to be completely thought out yet.  That is all still in the brainstorming visionary phase.

I feel like our culture is becoming less and less appreciative of how success typically emerges iteratively in a fairly decentralized manner as new discoveries across far-ranging fields and individuals emerge rather than being centrally preplanned based on current information.

I partially blame gaming where multiple generations of players are "god" and control every aspect.  Sim City and Civilization will be seen as a seminal bad things overall some day, lol.  That is not how cities and civilizations work at a very fundamental level.  Broken messaging for several generations now

[tater]

 

[tater]

51 minutes ago, Pthigrivi said:

Just like a stupid question: Why is starship's architecture the way it is? Why not have a superheavy first stage, a reusable second stage, and then a big capsule with a LES and an ablative heatsheild?

LES has been discussed here and elsewhere. LES systems have their own failure modes, as would the parachute system, etc. All the chances of failure are then addressed, and a composite picture of estimated safety emerges. Adding things might make it more dangerous. Now we have hypergolic props in the nose for the LES. Or are they solids that need to be replaced every XX days?

51 minutes ago, Pthigrivi said:

Like in hindsight the shuttle was an incredibly janky and risky system top to bottom and those heat tiles injected zillions of failure points that risked total loss of vehicle. And now we're doing that again? But now with heat tiles on moving joints and this really risky belly-flop maneuver? And no landing legs that spread out the landing base? We're literally going to drop this thing over a populated area and have it sit down exactly on stage zero and just assume well we tested it 15 or 20 times nothing bad could happen on the 21st. And from top to bottom the plan seems to be that this architecture is gonna work for the moon and even mars, and we're just hauling the airframe around everywhere?

The underlying goal was a vehicle that worked on Mars. Making money at any meaningful level is not a thing, the launch market is pretty finite (and small) unless there is a sea change—and such a change would be a function of lower cost, which is counter to making maximal money per launch.

 

51 minutes ago, Pthigrivi said:

It seems like the decision was made to organize it this way basically because Elon liked how Buck Rogers it looked.

Do you have a quote of him saying this, are you skilled at mind-reading, or did you just make this up?

 

51 minutes ago, Pthigrivi said:

It had that wow-cool-innovation kinda attitude that gets investors excited. 

?

This concern about investors is funny. I'm not seeing much economic case at all, presumably high-value investors are better at this than I am, and if they wanted to invest in a Musk project for return... tesla is a better option, it already generates more revenue in a quarter than SpaceX could hope to capture in a year.

 

51 minutes ago, Pthigrivi said:

And dont get me wrong. It is cool. Its maybe the coolest thing Ive ever seen. And they're not putting people in it right away, but all indications are eventually thats the plan. Im just wondering if this really high risk tollerance and move-fast break-stuff culture is actually a good idea when it comes to people's lives. 

Sigh.

How is NASA sending astronauts to ISS right now, I forget?

[sevenperforce]

1 hour ago, Pthigrivi said:

Why is starship's architecture the way it is? Why not have a superheavy first stage, a reusable second stage, and then a big capsule with a LES and an ablative heatsheild?

How do you propose to make a reusable second stage?

You have three options for reusing your orbital stage. First, you can have it enter butt-first with its own heat shield, like the Stoke Space design and the Chrysler SERV design, and perform a propulsive landing or a parachute landing. Second, you can have it enter head-first with its own heat shield, like the old Delta Clipper concept or the original reusable Falcon Heavy Upper Stage concept, then execute a 180° aerodynamic flip maneuver, then perform a propulsive landing. Third, you can spread your TPS across the side of the vehicle and have it enter sideways. With the third concept, you can either land it horizontally with wings or you can execute a 90° aerodynamic flip with a propulsive landing.

Those are your options. There really isn't anything else on the table.

1 hour ago, Pthigrivi said:

And now we're doing that again? But now with heat tiles on moving joints and this really risky belly-flop maneuver?

The Shuttle also had heat tiles on moving joints -- in fact, it had heat tiles on the landing gear door seams.

Why do you think the belly-flop maneuver is risky? The Shuttle had an incredibly thin range of allowable flight angles during re-entry, far less than what Starship can handle. Columbia didn't come apart directly due to heat shield failure; it came apart because the change in drag over the failure area became greater than what the control surfaces and RCS could handle and so it yawed out of the acceptable flight angle range.

1 hour ago, Pthigrivi said:

 We're literally going to drop this thing over a populated area and have it sit down exactly on stage zero and just assume well we tested it 15 or 20 times nothing bad could happen on the 21st.

That's not how modern testing works. This is not KSP. SpaceX isn't just using 15 or 20 flights as single "well that looks safe" datapoints. Rather, every one of the tens of thousands of sensors all over Starship is firing at every single moment in every single flight. It's the sensor data that is most valuable.

Besides, this thing is going to get a lot more than 20 flights before we put humans on board. At least for launch and Earth EDL.

1 hour ago, Pthigrivi said:

And from top to bottom the plan seems to be that this architecture is gonna work for the moon and even mars, and we're just hauling the airframe around everywhere?

What airframe? The HLS lunar Starship is just a tube with engines. All rockets are tubes with engines. Do you have a better idea for a lunar airframe?

As for Mars, yes: the concept was to have a vehicle which can go to Mars, land on Mars, take off from Mars, and land on Earth. If we want people to go back and forth between Mars reliably, that will become necessary.

1 hour ago, Pthigrivi said:

Im just wondering if this really high risk tollerance and move-fast break-stuff culture is actually a good idea when it comes to people's lives. 

"Move fast break stuff" is the development strategy which is designed for fast iteration and finding faults faster. If you have a potentially fatal defect in your vehicle, then the more testing and more iteration you do, the more likely you are to expose that defect.

Operational flights with people on board are not part of the development strategy.

[Terwin]

2 hours ago, Pthigrivi said:

Just like a stupid question: Why is starship's architecture the way it is? Why not have a superheavy first stage, a reusable second stage, and then a big capsule with a LES and an ablative heatsheild? Like in hindsight the shuttle was an incredibly janky and risky system top to bottom and those heat tiles injected zillions of failure points that risked total loss of vehicle. And now we're doing that again? But now with heat tiles on moving joints and this really risky belly-flop maneuver? And no landing legs that spread out the landing base? We're literally going to drop this thing over a populated area and have it sit down exactly on stage zero and just assume well we tested it 15 or 20 times nothing bad could happen on the 21st. And from top to bottom the plan seems to be that this architecture is gonna work for the moon and even mars, and we're just hauling the airframe around everywhere? It seems like the decision was made to organize it this way basically because Elon liked how Buck Rogers it looked. It had that wow-cool-innovation kinda attitude that gets investors excited. 

And dont get me wrong. It is cool. Its maybe the coolest thing Ive ever seen. And they're not putting people in it right away, but all indications are eventually thats the plan. Im just wondering if this really high risk tollerance and move-fast break-stuff culture is actually a good idea when it comes to people's lives. 

As far as I am aware, no one has taken a Launch abort pod version of starship off of the table.

My understanding is that Elon would prefer to have a starship so reliable that transferring passengers to and from a Dragon capsule for ferrying people to and from the earth would actually increase the total risk of the end-to-end voyage.  Like so much else, this is aspirational until it has been demonstrated as possible.

My expectation is that the first several 'manned' starships will launch without crew and get a transfer from a Dragon(or possibly SLS) capsule.  (probably for a trip to the moon)

I also expect Starship to have 100+ flights and probably 50+ consecutive 'norminal' flights before it ever launches with crew on-board, even a version with a LES pod.

I consider both launching and landing a Starship design similar to the current one with crew(on earth) to be aspirational as opposed to expected.

And just like other Musk aspirations, they will be great if they can be managed, but that is by no means certain.

I will be pleasantly surprised if there is never a need for a starship 'shuttle' configuration with a smaller second stage and built-in LES(similar to Dragon) that is only used for transporting several dozen(or perhaps 1-2 hundred) people to and from orbit where it docks with longer-range starships that will actually transport them to the moon/mars/stations outside of LEO.  (replacing the more expensive ticket of using a Dragon capsule for this purpose)

[tater]

22 minutes ago, Terwin said:

I also expect Starship to have 100+ flights and probably 50+ consecutive 'norminal' flights before it ever launches with crew on-board, even a version with a LES pod.

A useful testing failure would be an engine out landing of Starship. Wonder if they will do that intentionally at some point.

[JoeSchmuckatelli]

44 minutes ago, Terwin said:

Starship to have 100+ flights and probably 50+ consecutive 'norminal' flights before it ever launches with crew on-board, even a version with a LES pod.

That seems excessive.  Dragon flew - what? 20 flights before Crew Dragon was a thing?

I suspect they'll have a few 'dry' landings of it before they start playing around with docking and lunar landings - and they might fund their own 'mission to Mars' just to prove/learn about how SS does in the Martian landing config.

OfC they might just skip terrestrial landings and go straight to work on docking/lunar - because that's leading them in the direction they already want to go.  (Guessing that depends on whether SS reusability really is a gamechanger in price/ton to orbit)

[magnemoe]

3 minutes ago, JoeSchmuckatelli said:

That seems excessive.  Dragon flew - what? 20 flights before Crew Dragon was a thing?

I suspect they'll have a few 'dry' landings of it before they start playing around with docking and lunar landings - and they might fund their own 'mission to Mars' just to prove/learn about how SS does in the Martian landing config.

OfC they might just skip terrestrial landings and go straight to work on docking/lunar - because that's leading them in the direction they already want to go.  (Guessing that depends on whether SS reusability really is a gamechanger in price/ton to orbit)

SS is way more radical than dragon. 

 

Edited April 19, 2023 by magnemoe

[Ultimate Steve]

1 minute ago, magnemoe said:

That would be an crash. followed by an explosion. Crazy part is that might be survivable of crew is small as in 20. Not something you want to do even if offered serious money but you can add serious crumble  zones and an armored box around the crew compatment. 

If a single engine failure on landing is causing LOCV, then the landing burn needs to be started earlier.

[magnemoe]

1 minute ago, Ultimate Steve said:

If a single engine failure on landing is causing LOCV, then the landing burn needs to be started earlier.

Yes, edited out that part as yes  its an problem. 

[CatastrophicFailure]

3 hours ago, Pthigrivi said:

It seems like the decision was made to organize it this way basically because Elon liked how Buck Rogers it looked.

It’s also worth noting that Elon does not, in fact, run SpaceX in a vacuum (har har). He has an increasingly larger team of incredibly talented people working with him, with access to all the data us plebs will never see, and all of them are on board with the current design philosophies (or they wouldn’t still be working there).  He’s not the only one making decisions and it’s actually far more likely he was not the one who first fielded the change from composite to stainless steel, the bilateral instead of trilateral flaps, Mechazilla, etc. And even if he did, all these concepts, to say nothing of the silly little details in which lay the devils, also went through the reviews of many other people who eventually agreed, “yeah, this is workable… as far as we know now.”

[tater]

I suppose it needs to be said periodically, but SpaceX exists to "make humanity multiplanetary." (doesn't matter who here signs on to that—they do)

Everything else is increasing capability needed to complete that goal, or incidental to that goal. Failure to internalize this means that people will always argue that Starship is too big for the job (launching cubesats is presumably "the job" here), or that some other vehicle would be better for the job... "the job" is always wrong, since the job is colonizing Mars—or gaining the capability to do so.

Money is certainly needed, since Mars has no spice. In short, no economic rationale.

LEO launch is not going to generate vast quantities of money, IMO. There's a chicken and egg issue with what presumably will be lowered cost to orbit in the not too distant future.

BO will presumably try to compete on price with SpaceX, otherwise why bother? It's important to remember that since there is literally no competition, SpaceX only needs to be $1 cheaper than the next lowest price to be the most affordable choice, so minus anyone actually trying to compete, there's zero reason for prices to drop much. OK, so assume that NG flies, heck assume Stoke flies, and Neutron as well. 3 competitors with reuse all competing with Falcon 9. The cost for SpaceX of F9 is debated, but some number between $15M and $30M is pretty likely. So even with F9, SpaceX has margin to burn to compete without Starship. If Starship can actually function in a reusable mode, the only competition is Stoke. Both vehicles will have marginal costs equal to their infrastructure costs, and propellants. BO and Rocket Lab will be throwing upper stages away at the very least. Dunno where the race to the bottom ends, but the bottom line is that it would be slightly cheaper per kg than BO or Rocket Lab can bid (not in Stoke's interest to cut too low, either, best would be to underline dissimilar capability, and grab payloads that their vehicle shines at). No reason to be any lower.

If it was to half launch costs not a lot changes except the launch market maybe grows a small amount, but I doubt it doubles—and unless it at least doubles with a 50% price drop, the providers all lose money.

What if costs dropped by "only" an order of magnitude to a couple hundred bucks a kg? Well, the commercial launch market gets swept up by SpaceX as much as it could be (hasn't it already done that?), but now SpaceX makes 1/10th the revenue. Even if they had an internal cost 2 orders of magnitude cheaper, they make more margin, but the total dollars is a big nothingburger.

The only way to make loads of money while also dropping launch costs by a huge amount would be to create an entirely new market. Possible markets include tourism (assuming crazy safe rockets, which... yeah, pretty difficult), and maybe asteroid mining. Nothing else leaps to mind.

Edited April 19, 2023 by tater