totm nov 2023 SpaceX Discussion Thread

[RealKerbal3x]

 

[tater]

Toasty:

[JoeSchmuckatelli]

56 minutes ago, tater said:

Toasty:

I've often wondered - is that soot from the landing burn, or to do with the reentry heating?

[tater]

Just now, JoeSchmuckatelli said:

I've often wondered - is that soot from the landing burn, or to do with the reentry heating?

Soot I think.

 

[StrandedonEarth]

I wonder how much of the inspection process they've automated so far? I envision running the cores through a car-wash-style setup, with the booster going through a machine that automatically  locates, cleans, and inspects (X-rays?) the welds.

As for Starship numbers, at the rate they're already producing prototypes, it's easy to imagine them churning out thousands of airframes once the Alien Juggernaut in Boca Chica grows up, especially if they add another production line or two. Outfitting the interiors is a different matter of course, and will probably be by far the longest part of the build, but bare airframes look quick and relatively simple to build, and they're going to need a lot of tankers.

But that thin skin does concern me when it comes to crew. Sure, crew compartments can have extra shielding, but what about all that tankage? How resistant is 3mm or 4mm 304x stainless steel to MMOD damage, and what happens if it pierces a tank? I suppose that's one advantage of stainless; at least they can weld a patch over it. They'll need to work on their zero-gee-vacuum-welding skills. I wonder if plain vacuum welding aka cold welding could work, but probably not if propellants are trying to leak through. So hot welding (aka fusion welding) would probably be best.

That also makes me wonder if it would be worthwhile to store repair 'bots in  the tanks, so they can repair from the inside. Then when the tank is pressurized it helps push the patch against the puncture.

15 hours ago, Brotoro said:

There were 1,562 747s.

*Note: That's just 747s. Total "widebody" production, according to wiki:

Quote

Up to the end of 2017, nearly 8,800 wide-body airplanes had been delivered since 1969, peaking at 412 in 2015.^[14]

If one wanted to include the smaller airliners, the 737 family alone has produced over 10,000 units since it first entered commercial service almost exactly 53 years ago.

If the SS/SH model pans out, it's not hard to imagine thousands of Starships produced by 2170

[tater]

2 hours ago, StrandedonEarth said:

If the SS/SH model pans out, it's not hard to imagine thousands of Starships produced by 2170

Thousands of airliners are produced because there is a market for thousands of airliners.

[kerbiloid]

If force them all to evacuate from the Earth, there will be a market for thousands of starships, too.

[RealKerbal3x]

 

[Kerwood Floyd]

35 minutes ago, tater said:

Thousands of airliners are produced because there is a market for thousands of airliners.

A market is required  because the shareholders of Boeing and Airbus, etc. require it. Arguably, as long as Musk has the money, SpaceX can produce thousands of Starships without there being a market, but simply because Musk wants to.

[kerbiloid]

Yes, that's the plan.
 

Spoiler

 

 

Spoiler

Too bad for you to know it...

 

Edited February 7, 2021 by kerbiloid

[YNM]

46 minutes ago, Kerwood Floyd said:

A market is required  because the shareholders of Boeing and Airbus, etc. require it.

I don't recall those companies existed in 1920.

3 hours ago, StrandedonEarth said:

I suppose that's one advantage of stainless; at least they can weld a patch over it. They'll need to work on their zero-gee-vacuum-welding skills.

With propellant inside, in transit from Earth to Mars ?

[StrandedonEarth]

9 minutes ago, YNM said:

 

With propellant inside, in transit from Earth to Mars ?

By a repairbot inside the tank? Probably doable

[YNM]

2 minutes ago, StrandedonEarth said:

repairbot inside the tank

Seems like something pretty expensive. Then again might be something like TIG welding that just goes on a roller or something.

What about the floating propellant inside though ?

[mikegarrison]

1 hour ago, YNM said:

I don't recall those companies existed in 1920.

Boeing was founded in 1916. Airbus is of more recent vintage.

[tater]

SN11

[YNM]

1 hour ago, mikegarrison said:

Boeing was founded in 1916. Airbus is of more recent vintage.

Well they definitely weren't making airlines back then... Although even back then airmail was already a thing, so it's only a matter of time in a sense.

Starship would be similar, albeit we do need to establish something on the receiving side in the first place before doing them... which is a job the thing's meant for.

[mikegarrison]

1 hour ago, YNM said:

Well they definitely weren't making airlines back then...

The Boeing Model 40 first flew in 1925. While originally built as a mail plane, in 1927 they started selling the Model 40A, which had seating in an closed cabin for two passengers. (The pilot sat in an open cockpit. Many pilots of the day felt like this was necessary, because the feel of the wind was part of how they flew.)

Edited February 8, 2021 by mikegarrison

[tater]

 

Related to Starship and passenger safety. I will happily find a source for crow, and try to at least prepare it decently before I devour it should SpaceX fly people on SS at airline levels of safety, but I fully expect to expire before that happens.

Not saying SS won't work.

Not saying they won't fly people on it.

Just saying airline level safety is an astoundingly high bar.

[Silavite]

 

[Nothalogh]

56 minutes ago, tater said:

Just saying airline level safety is an astoundingly high bar.

Quibbling over safety and lack of guarantees of success, in a matter such as this, is insofar as my opinion, heresy.

And before you say I'm too harsh, consider that your ancestors, in matters such as these, took far greater risk, for a far lower payout, with little but a feeling of grim determination.

[RyanRising]

15 minutes ago, Nothalogh said:

Quibbling over safety and lack of guarantees of success, in a matter such as this, is insofar as my opinion, heresy.

And before you say I'm too harsh, consider that your ancestors, in matters such as these, took far greater risk, for a far lower payout, with little but a feeling of grim determination.

While it is worthwhile to engage on endeavours of great risk to further the reach of humanity, and that risk is definitely worthwhile for the purpose of space exploration, Starship is being proposed by SpaceX as a transportation system to compete with airlines. If they want to become a relatively popular means of mass transportation, the risk will not be balanced out by the payout of reaching amongst the stars, it will only be balanced by the payout of getting from point A to point B. That's where this airliner-level reliability idea comes from.

But a rocket is inherently less safe than an airplane, in the same way an airplane is inherently less safe than a car. (This is, of course, ignoring the safety attributed to the pilot, which is what makes cars more dangerous than planes in reality.) If your engine goes out while trying to park a car, you can put on the brakes, get out, and walk out alright. If your engine goes out while trying to fly a plane, you can glide down, hope there's a suitable landing area, land, and possibly walk out alright. If your engine goes out while trying to land a rocket, you die.

You can survive a lot of things going wrong in a car that you can't survive going wrong in a plane, and you can survive a lot of things going wrong in a plane that you can't survive in a rocket. Airliner-level reliability for a rocket would be incredibly difficult to achieve because they need to overcome the fact that the situation is more precarious with their system, but SpaceX needs to make it happen in order to for Starship to perform the functions they want it to.

Edited February 8, 2021 by RyanRising

[tater]

1 minute ago, Nothalogh said:

Quibbling over safety and lack of guarantees of success, in a matter such as this, is insofar as my opinion, heresy.

And before you say I'm too harsh, consider that your ancestors, in matters such as these, took far greater risk, for a far lower payout, with little but a feeling of grim determination.

?

Space travel is dangerous, and will be for a while. A subset of people are willing to take that risk. Current commercial crew requirement is a 1:270 LOC.

This will certainly improve, and I think reusable rockets, with higher cadence can do that.

A 100X increase in safety to LEO would be 1:27,000 flights is a LOC incident. That would be fantastic for a space program with 2 human flights per year, and even for a space program at 2 per week that's awesome.

It needs to be one every few million departures to be "airline level" safety, so it needs to be 10,000X safer than crew Dragon. That's a high %$@#in bar—and SpaceX talks about Point to Point. Mass use of rockets for P2P, or even mass flights of people into space requires a sense of safety that is substantially higher than 1:270.

[kerbiloid]

And Zoom + Skype + aerial pizza delivery will make most of those flights unnecessary much sooner and cheaper.

Together with p2p rockets.

[Scotius]

Then we'll build orbiting cities

Build a 'stock' Starship.

Furnish its interior as a living space comparable to apartment block.

Launch it.

Launch modular docking adapter.

Start stacking Starships together, adding docking adapters in quantity and configuration as needed.

Add infrastructure. Hospital Starships. University Starships. Factory Starships. Warehouse Starships. Agriculture Starships. Power plant Starships.

Ideally, organize everything in a configuration that can rotate, providing artificial gravity.

Have fun with you Space Lego City!

 

Seriously though - i think it is not bad way to build a space station, that is both permanent and temporary. If every module is a fully functional Starship, you can add and remove modules on demand. That should solve many problems with maintenance experienced with stations we've built so far.

Module is malfunctioning due to wear and tear? Land it. Launch and dock another module performing the same duties. Problem solved quickly and efficiently.

[sevenperforce]

On 2/6/2021 at 11:34 AM, tater said:

I assume the tiles are not light, either, though.

I’m pretty sure the tiles are VERY light. Like styrofoam and fiberglass light. 

On 2/6/2021 at 1:35 PM, grungar3x7 said:

Remember, the main reason for hex tiles in the first place, is to prevent hypersonic plasma being channeled in a straight line...

I'm not sure of a solution to the curvature problem, personally, but trapezoids and half hexes don't seem to be the answer, considering the reason for initial shape choice.

All the more reason to embrace the gaps. Trapezoids can work if you allow staggered positions. 

12 hours ago, tater said:

Soot I think.

Correct. Deposited primarily during the entry burn.