Towards routine, reusable space launch.

In article ,
says...

On 2018-06-15 07:52, Jeff Findley wrote:

True, but that's essentially still the state of the art today.
Composite layup machines have been around for decades.

Wasn't aware of that. If that is the case, then you are correct.

fiber layup, so I'd count that as new, whenever it was first done. I'm
not a materials engineer, so I don't know when that would be for glass
fiber and aluminum.

Developped by/for Airbus as part of many years og R&D un mid/late 1990s
when Airbus wanted to make the A380 but knew it woudln't be economical
(too heavy) with current tech. It wasn't till they solved a number of
weight and landing gear problems that they could launch the project
formally.

BFR/BFS may have similar scalability problems since weight is also a big
issue. But they won't have to worry about landing pad being strong
enough for it since they can build their own.


X-33 attempted to do just that. It failed due to the complex geometry.
BFR/BFS is sticking with traditional cylindrical tanks, which is a
proven geometry for carbon fiber composites. They're being pretty
conservative as far as their use of carbon fiber goes, IMHO.

Had forgotten about the odd shape for X33 tanks being reason for failure.

From what I've read, they'll be sticking with traditional techniques to
minimize development risks. I fully expect them to cure it in an
autoclave.

Yet, that BFR all composite tank is at a scale nobody has productized
before. Just because they seem to have been able to build/test it
doesn't mean that it is "conventional" in design or using off-the-shelf
resin.

They already built the thing and it's stitting inside a tent at the
BFR/BFS production facility:

SpaceX moving fast on Mars rocket development, BFR tent spied with more
tooling

https://www.teslarati.com/spacex-bfr...ocket-tooling-
molds/

It's big, but others have build quite large autoclaves:

ASC Process Systems Manufactured the World's Largest Autoclave System.
http://www.aschome.com/index.php/en/...rol-systems/2-
uncategorised/327-world-s-largest-composites-autoclave

From above:

Inside working diameter: 30ft. (9.26M)
Inside working length: 76 ft. (23.5M)

From Orbital ATK's arsenal:

https://en.wikipedia.org/wiki/Castor_(rocket_stage)

Scroll down to Castor-600, which is to be used for OmegA:

Based on a 2-segment Space Shuttle SRB, the Castor 600 measures
860 inches (22 m) in length and 146.1 inches (3.71 m) in
diameter, and it weighs approximately 600,000 pounds (270,000
kg). Instead of using a D6AC steel case and PBAN binder like
the Space Shuttle SRB, it will instead use the technology
derived from the GEM motors which have carbon composite cases
and HTPB binder. The carbon composite design eliminates the
factory joint common on all Space Shuttle SRBs.

If Orbital ATK can made SRB casings out of carbon composites (very large
size and pressures inside an SRB casing), then making a few tanks for
BFR/BFS out of carbon composites will be a lot eaiser.

This stuff really isn't as uncommon as you think.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.