totm nov 2023 SpaceX Discussion Thread

[darthgently]

1 hour ago, JoeSchmuckatelli said:

Problem for whom? 

This is what I find fascinating.  Let's imagine that raptors are completely unreliable and blow up all the time.  Who has the most (all?) skin in the game?  Who would know the most about the problem?  Whose literal business would it be to solve this problem?  SpaceX.  No one else.

I fail to grasp the value of pretending that ppl far from the problem and zero skin in the game have much of value to contribute compared to SpaceX.  These ppl, in fact, have vastly less to contribute and are far less motivated to have accurate views on a problem such as this even if they had access to every byte of test data.

Now let's go back to the real world where raptors are not blowing up all the time...

 

[mikegarrison]

1 hour ago, CatastrophicFailure said:

Once Earth EDL is solved, which they are very near to now, and which is necessary for both Earth and lunar operations, extending that to Mars EDL will be a relatively simple problem.

Earth EDL has been a "solved" issue since the 1960s, but landing on Mars has still never been easy. Starship still loses most of its orbital energy by aerobraking, and that's still a problem on Mars, so "relatively" is doing a lot of work there.

1 hour ago, darthgently said:

I fail to grasp the value of pretending that ppl far from the problem and zero skin in the game have much of value to contribute compared to SpaceX.  These ppl, in fact, have vastly less to contribute and are far less motivated to have accurate views on a problem such as this even if they had access to every byte of test data.

Doesn't stop people from saying what Boeing should do about 737s, for example.

[CatastrophicFailure]

19 minutes ago, mikegarrison said:

Earth EDL has been a "solved" issue since the 1960s, but landing on Mars has still never been easy. Starship still loses most of its orbital energy by aerobraking, and that's still a problem on Mars, so "relatively" is doing a lot of work there.

“Solved” wrt to Starship and its reuse is the context here. SpaceX will be getting plenty of data from a similar atmospheric regime (hypersonic/translunar speeds in the upper atmosphere), enough to extrapolate to Mars, so it’s not reinventing the wheel, either. We’ve already seen from some of their earliest BFR renders that they already have some idea, carbon-Starship is shown flying a Mars entry inverted at times, using aerodynamic lift to actually hold itself down in the atmosphere. So, it’s an extension and further optimization of work they’re already doing. 

1 hour ago, darthgently said:

fail to grasp the value of pretending that ppl far from the problem and zero skin in the game have much of value to contribute compared to SpaceX.  These ppl, in fact, have vastly less to contribute and are far less motivated to have accurate views on a problem such as this even if they had access to every byte of test data.

Dunning-Kruger… 

[NFUN]

41 minutes ago, mikegarrison said:

Earth EDL has been a "solved" issue since the 1960s, but landing on Mars has still never been easy. Starship still loses most of its orbital energy by aerobraking, and that's still a problem on Mars, so "relatively" is doing a lot of work there.

Doesn't stop people from saying what Boeing should do about 737s, for example.

They lack information, sure, but people who will likely fly on 737s definitely have skin in the game dude...

[cubinator]

41 minutes ago, mikegarrison said:

Earth EDL has been a "solved" issue since the 1960s, but landing on Mars has still never been easy. Starship still loses most of its orbital energy by aerobraking, and that's still a problem on Mars, so "relatively" is doing a lot of work there.

At least when flying a bunch to and from the Moon they should be able to get a pretty good preliminary idea of how much heat it can take.

[darthgently]

2 hours ago, mikegarrison said:

Doesn't stop people from saying what Boeing should do about 737s, for example.

Those jets are sold as products and paying people ride on those jets and Boeing is a publicly traded company so the customers and shareholders should have lots of say.  Given their tight relationships one could argue taxpayers should have lots of say also.  But fundamentally I agree, Boeing should be the in pivotal position to solve Boeing's problems.  Within the law of course.

2 hours ago, CatastrophicFailure said:

“Solved” wrt to Starship and its reuse is the context here. SpaceX will be getting plenty of data from a similar atmospheric regime (hypersonic/translunar speeds in the upper atmosphere), enough to extrapolate to Mars, so it’s not reinventing the wheel, either. We’ve already seen from some of their earliest BFR renders that they already have some idea, carbon-Starship is shown flying a Mars entry inverted at times, using aerodynamic lift to actually hold itself down in the atmosphere. So, it’s an extension and further optimization of work they’re already doing. 

Dunning-Kruger… 

Indeed

1 hour ago, NFUN said:

They lack information, sure, but people who will likely fly on 737s definitely have skin in the game dude...

Yes, when you have paying passengers live streaming the big hole in the plane 1 foot away (and by "1 foot" I mean the passenger's foot) one could say they do have a lot of skin in the game.  Far more than than anyone at Boeing at that particular moment

Edited June 8 by darthgently

[magnemoe]

On 6/7/2024 at 6:58 PM, CBase said:

Starship and Raptor to convention rockets is more like cloud computing to mainframes.

One gains reliability by avoiding failures, the other compensates individual failures by controlling software stack. But both can support highly critical operations.

The center 3 engines are most critical part during final landing and do only allow for single failures. Which means you need 96.8% single reliability to have 99.9% against double failure. Is raptor currently up to this ? propably not. But again since the produce more than the 3 critical ones, they might be able to select best performing on final assembly control. So again just by collecting data, correlate to test performance they could get to a point that is acceptable.

This but landing of upper stage is just data points at this stage, if two engines fails you do not get the flip and simulated landing data. Not sure how they will land upper stage. As in unless almost polar orbit they will need to overfly Mexico. 
Even if Mexico allows it will the US?  You will get crashes down the line  where other countries could salvage parts. 

[JoeSchmuckatelli]

2 hours ago, magnemoe said:

will the US

We left a sekret helicopter in Pakistan.  So, yeah. 

Thing is - the US {SpaceFarce} might want SX to make damn sure a failed launch drops a payload into the drink... But they're not gonna give 2 Schneikies about SX's rockets. 

FAA and State might have some concerns, but not the Intel  community 

Edited June 9 by JoeSchmuckatelli

[mikegarrison]

1 hour ago, JoeSchmuckatelli said:

We left a sekret helicopter in Pakistan.  So, yeah. 

Thing is - the US {SpaceFarce} might want SX to make damn sure a failed launch drops a payload into the drink... But they're not gonna give 2 Schneikies about SX's rockets. 

FAA and State might have some concerns, but not the Intel  community 

Technically it might be a violation of ITAR and EAR laws.

[darthgently]

4 hours ago, mikegarrison said:

Technically it might be a violation of ITAR and EAR laws.

I would think the raptors would definitely be under ITAR

[mikegarrison]

1 hour ago, darthgently said:

I would think the raptors would definitely be under ITAR

ITAR specifically covers weapons and weapon systems. EAR covers "sensitive" technology, including "dual-use" technology.

However, the ITAR rules do include some things that are only weapon-adjacent. And for about 15 years the law specifically declared satellites to be covered under ITAR, even if they are not weapons. But in 2013 most satellite tech went back to be under EAR.

It does seem from this reference that rockets and launch vehicles are likely under ITAR.

The way it works is that ITAR has "first dibs", and then anything that is not subject to ITAR then has to be checked against EAR.

ITAR is under the Department of State. EAR is under the Department of Commerce.

Edited June 9 by mikegarrison

[Flying dutchman]

I just had a brainwave! Before the flight we learned that max-q would be 10 seconds later on ift-4 than on ift-3. I wonder if the engine out on ascent wasn't a failure but a planned test.

 

Probably not but i just wanted to share that.

[darthgently]

3 hours ago, Flying dutchman said:

I just had a brainwave! Before the flight we learned that max-q would be 10 seconds later on ift-4 than on ift-3. I wonder if the engine out on ascent wasn't a failure but a planned test.

 

Probably not but i just wanted to share that.

I doubt it.  Wouldn't they just decrease throttle rather than give the jeerleaders something to fret about?

[AckSed]

Perun, who normally follows military-industrial stuff, put out a vid on SpaceX:

 

[Geonovast]

10 hours ago, darthgently said:

I doubt it.  Wouldn't they just decrease throttle rather than give the jeerleaders something to fret about?

No, I don't think so.  If SpaceX wants to test the vehicle's behavior with an engine out (it's more than just decreased thrust), then they're going to do that.  I have no idea if the engine out was intentional or not, but they're not going to refrain from testing something just because they're worried about what armchair conspiracy engineers might say about it.

[darthgently]

34 minutes ago, Geonovast said:

No, I don't think so.  If SpaceX wants to test the vehicle's behavior with an engine out (it's more than just decreased thrust), then they're going to do that.  I have no idea if the engine out was intentional or not, but they're not going to refrain from testing something just because they're worried about what armchair conspiracy engineers might say about it.

That does make a lot more sense

Edited June 9 by darthgently

[mikegarrison]

I am certain that if they had been intentionally testing an engine failure, then they would have said so on the broadcast. Also, it would have had to have been in the approved test plan, and enough people seem to have gotten copies of that before the flight that it would have come out in the pre-flight news.

It's just wild to me how some fans seem to keep rushing to explain away any minor and even major issues as if it is somehow vital to themselves that SpaceX is infallible.

Edited June 9 by mikegarrison

[darthgently]

16 minutes ago, mikegarrison said:

I am certain that if they had been intentionally testing an engine failure, then they would have said so on the broadcast. Also, it would have had to have been in the approved test plan, and enough people seem to have gotten copies of that before the flight that it would have come out in the pre-flight news.

It's just wild to me how some fans seem to keep rushing to explain away any minor and even major issues as if it is somehow vital to themselves that SpaceX is infallible.

This also makes sense.  I'm back to doubting it was planned.  But to reiterate a previous post, when the payload is the data, it is far less important if an event was planned than how rich the collected data is and how much cognitive effort is expended mining that data.  They likely did not shut down an engine intentionally, but by using a double digit engine cluster with a comfortable engine out margin and collecting vast amounts of data it is easy for them to capture real world data on the event when it happens.  Which is as valuable as doing it intentionally when in an open minded learning phase.

Any skilled skateboarder or surfer out there will tell you that it is far more important when starting out to simply get on the board, and keep getting on the board, than to overthink about all the possibilities of what could happen prior to getting on the board and go into brainlock.  By simply repeatedly getting on the board, vast mountains of unplanned data are collected and necessarily processed as long as one keeps getting on the board. 

New space gets this.  Old space spends too much time sitting on the curb or beach contemplating the possibilities and not actually learning

Edited June 9 by darthgently

[JoeSchmuckatelli]

2 hours ago, mikegarrison said:

as if it is somehow vital to themselves that SpaceX is infallible

That is the part that makes the least sense. 

The best thing about SpaceX is that they are so confidently fallible. 

I wish more firms were like this 

[DAL59]

New info from some X gaming stream thing:

-Next flight in a month (Elon time of course)

-IFT5 will have a new heatshield, with tiles "twice as strong", and an ablative underlayer.

-IFT5 will attempt a chopstick catch

-Starship to Mars in 3 years (Elon time of course) (He can't keep getting away with this.gif) (Maybe for the Mars Sample Return?)

Edited June 10 by DAL59

[Minmus Taster]

12 minutes ago, DAL59 said:

New info from some X gaming stream thing:

-Next flight in a month (Elon time of course)

-IFT5 will have a new heatshield, with tiles "twice as strong", and an ablative underlayer.

-IFT5 will attempt a chopstick catch

-Starship to Mars in 3 years (Elon time of course) (He can't keep getting away with this.gif) (Maybe for the Mars Sample Return?)

I assume this is from the new NSF video? According to them the booster was on course and the ship was off a few kilometers on account of the damage.

[magnemoe]

24 minutes ago, DAL59 said:

New info from some X gaming stream thing:

-Next flight in a month (Elon time of course)

-IFT5 will have a new heatshield, with tiles "twice as strong", and an ablative underlayer.

-IFT5 will attempt a chopstick catch

-Starship to Mars in 3 years (Elon time of course) (He can't keep getting away with this.gif) (Maybe for the Mars Sample Return?)

Catch on the next is very ambitious. What is they was lucky this time. The risk is high, worst case they damage the tower but crashing outside of the launch side and they crash in an protected area and you get FAA on your neck. 
Dumping it in the ocean is fine until you have just two first stages left, as I understand they have many ready to use or close to. 

[cubinator]

2 hours ago, DAL59 said:

 

-IFT5 will attempt a chopstick catch

Hmmmm, watching out for an opportunity to go down to Texas...

2 hours ago, DAL59 said:

-Starship to Mars in 3 years (Elon time of course) (He can't keep getting away with this.gif) (Maybe for the Mars Sample Return?)

I'd honestly not be that surprised if they manage to throw at least one Starship at Mars in three years. They'll have done a fair number of test flights by that point, many of them orbital and probably cislunar, so I think they'd take the first opportunity to try to send something to Mars.

If refueling turns out to take extra time to fix problems, I can see it taking longer.

Maybe they could set down a tank of water with it, since there's no telling how long it'll be until anyone's there and that's a pretty universally useful resource.

[sevenperforce]

On 6/8/2024 at 1:00 PM, Exoscientist said:

 The problem is the Raptor is still exploding on relights, as happened on both booster landing burns.

What evidence do you have to suggest that any engines exploded on relight during either Superheavy booster landing burn?

[Ultimate Steve]

1 hour ago, sevenperforce said:

What evidence do you have to suggest that any engines exploded on relight during either Superheavy booster landing burn?

Probably the video footage of an engine exploding on relight during the IFT-4 Superheavy booster landing burn, a giant mass of fire remaining where the engine was, and chunks flying off.