NASA & World Space Exploration...News, Views, Photos & videos


ZeEa5KPul

Senior Member
Registered Member
It's going to blow up, deform then blow up or crash then blow up.

There's a reason why stainless isn't used for rockets.

There's another reason why why propellent tanks don't share a common wall.

Then there's another reason why it's better to have few powerful engines than 10+ small ones.

But it's just taxpayer and Gulf Arab money so whatever lol.
I have to admit that I'm pretty jealous of Elon. He grifts American investors and then uses their money to bomb America. Dude's living my dream.
 

panzerfeist1

New Member
Registered Member
Someone wake me up when these private US companies start making fly wing methane rockets, aerospike engines, detonation engines, closed circuit engines, nuclear reactor powered ion thrusters and possibly quantum engines if Roscosmos doesnt choose to ignore their physicists while Energomash gave attention to their concepts.
 

gelgoog

Captain
Registered Member
SpaceX taking Gulf Arab money is well known and so is the fact that they have billions in taxpayer subsidies.

Atlas 5 upper stage uses stainless steel tanks, not stainless steel structural components. The tanks are not weight bearing structures but rather balloon tanks that are pressure stabilized; structural components are still aluminum. This is straight from the manufacturer itself.

Common bulkheads are a less reliable design because 1. weld seam is a weakpoint and 2. it cannot simultaneously be strong against pressure from both sides since the concave side will be weaker to pressure than the convex side.

And just because Centaur stage originally designed in the 1960's uses it doesn't mean that it's a good idea.

Subsidies? SpaceX got contracts. In fact they persistently get paid a lot less than Boeing or Lockheed Martin and yet deliver more.

The original Atlas rocket used steel construction not just in the upper stage. As for the Centaur stage you are so disparaging, it is probably one of the oldest upper stage designs still in use today. If it was that bad no one would still be using it. It achieves one of the lowest mass fractions of any upper stage.

The common bulkhead saves space and weight. It can be used because you can store Methane and LOX at roughly similar temperatures and pressures. This is not the case with Hydrogen and LOX. Or Kerosene and LOX.
 

ougoah

Colonel
Registered Member
Someone wake me up when these private US companies start making fly wing methane rockets, aerospike engines, detonation engines, closed circuit engines, nuclear reactor powered ion thrusters and possibly quantum engines if Roscosmos doesnt choose to ignore their physicists while Energomash gave attention to their concepts.

What on earth is a quantum engine? Some "anti-gravity" sci-fi stuff or hoax?
 

FairAndUnbiased

Junior Member
Registered Member
Subsidies? SpaceX got contracts. In fact they persistently get paid a lot less than Boeing or Lockheed Martin and yet deliver more.

The original Atlas rocket used steel construction not just in the upper stage. As for the Centaur stage you are so disparaging, it is probably one of the oldest upper stage designs still in use today. If it was that bad no one would still be using it. It achieves one of the lowest mass fractions of any upper stage.

The common bulkhead saves space and weight. It can be used because you can store Methane and LOX at roughly similar temperatures and pressures. This is not the case with Hydrogen and LOX. Or Kerosene and LOX.
But Centaur uses LH and LOX in their common bulkhead.

Please, Log in or Register to view URLs content!
This is an indirect subsidy.
 

gelgoog

Captain
Registered Member
Please, Log in or Register to view URLs content!
This is an indirect subsidy.

Did you even bother to read the article you linked to? ULA got separate money for facilities upgrades which SpaceX never got.
The money Boeing got for Starliner vs what SpaceX got for Crew Dragon is another good example.

You can make a common bulkhead for fuel with dissimilar temperatures and pressure but it requires extra insulation and is much more difficult. LOX/Methane in comparison is easy.
 

FairAndUnbiased

Junior Member
Registered Member
Did you even bother to read the article you linked to? ULA got separate money for facilities upgrades which SpaceX never got.
The money Boeing got for Starliner vs what SpaceX got for Crew Dragon is another good example.

You can make a common bulkhead for fuel with dissimilar temperatures and pressure but it requires extra insulation and is much more difficult. LOX/Methane in comparison is easy.

I did. They CLAIM all that is for facilities upgrade like... For a bigger payload fairing per her statement? Just so we're clear, the payload fairing is the metal shell around the payload at the top of the rocket. Seems to me like expense bloat to me.

Anyhow, this is about end proof of Starship viability. If it was so good it wouldn't be blowing up every time. It is typical trial and error engineering - that was phased out because prototypes are expensive and slow without pouring money into it.
 

gelgoog

Captain
Registered Member
It is not just the payload fairing. They are upgrading the launch pad facilities at Vandenberg. Including a facility for vertical integration of satellite payloads.

As for Starship, what they are trying to do is make a rocket with really low mass fraction. This means they need to use new materials and new construction techniques. Of course that is complicated. They already tried with composites and had to give up. The steel construction in my opinion will work even if they have to reduce the rocket performance a bit. Since it is a two stage rocket it will still have a huge payload.

There is no established method of doing what they are trying to do. So of course it will involve a lot of trial and error.

Even if for whatever reason they can't get it to work as a reusable, they can just use the same technology with a smaller rocket with the same engine types, just less of them, and make it an expendable.
 
Last edited:

subotai1

Junior Member
Registered Member
But Centaur uses LH and LOX in their common bulkhead.

Please, Log in or Register to view URLs content!
This is an indirect subsidy.
You can spin this anyway you want. However, here is what you cannot deny. SpaceX takes the conventional wisdom (which evolved at a time of lesser technology) and then asks whether its accurate, develops their own hypothesis and tests it to destruction. They are not afraid to watch their rockets blow up, fail to perform, have accidents, just so they can learn. In the end, the fail fast approach leads to a better system, quicker and with a new way of doing that.

They do/did all of that on their own dime. Whatever they have been awarded has happened afterwards and because of that. ULA behaves in the opposite manner; they don't design, build, test anything without the subsidy up front. That willingness to spend their own money first is why SpaceX is ahead and will stay that way.
 

Crang

Senior Member
Registered Member
You can spin this anyway you want. However, here is what you cannot deny. SpaceX takes the conventional wisdom (which evolved at a time of lesser technology) and then asks whether its accurate, develops their own hypothesis and tests it to destruction. They are not afraid to watch their rockets blow up, fail to perform, have accidents, just so they can learn. In the end, the fail fast approach leads to a better system, quicker and with a new way of doing that.

They do/did all of that on their own dime. Whatever they have been awarded has happened afterwards and because of that. ULA behaves in the opposite manner; they don't design, build, test anything without the subsidy up front. That willingness to spend their own money first is why SpaceX is ahead and will stay that way.
It always brings a chuckle to my head when I realize Elon Musk is African American
 

Top