Toray carbon fiber to carry SpaceX's Mars ambitions • Hacker News Board

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#31

Post by arijun » Wed, Aug 17, 2016, 12:33 AM UTC

Animats wrote: post #7

In some ways, not a good sign. Space-X can't make and launch Falcon boosters fast enough now. They're not a big enough company to do many things in parallel. Their unfinished, and late, projects include the Falcon Heavy, the Brownsville TX launch facility, and the crewed Dragon, all of which were supposed to be working by now.

As a point on the FH, one reason it's delayed is that it has lower priority: now that the Falcon 9 has been upgraded to the full thrust version, it can take many customers who were originally envisioned to go on the Heavy

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#32

Post by hLHEDuYtSh » Wed, Aug 17, 2016, 12:34 AM UTC

planteen wrote: post #24

oliwaw wrote: post #22

Earlier quoted context omitted.

But cost is also at issue. For cargo, it might make sense to take on 0.5-1.0% risk versus the massive investments necessary for the development of a space elevator. And when we're talking about human spaceflight, consider the work SpaceX and Blue are putting into in-flight abort and propulsive landing - SpaceX's Crew Dragon should be much safer than the Space Shuttle, for example.

Yeah for cargo I agree. I was thinking more along the lines for human rating. Propulsive landing helps for some failure modes but not all. Like I don't think it would have helped the CRS-7 failure had that been manned.

It actually would have helped on CRS-7 -- That capsule was fine until it hit the water.

https://www.nasaspaceflight.com/2015/07/saving-spaceship-dra...

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#33

Post by [deleted] » Wed, Aug 17, 2016, 12:52 AM UTC

hLHEDuYtSh wrote: post #32

planteen wrote: post #24

Earlier quoted context omitted.

Yeah for cargo I agree. I was thinking more along the lines for human rating. Propulsive landing helps for some failure modes but not all. Like I don't think it would have helped the CRS-7 failure had that been manned.

It actually would have helped on CRS-7 -- That capsule was fine until it hit the water. https://www.nasaspaceflight.com/2015/07/saving-spaceship-dra...

[deleted]

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#34

Post by oliwaw » Wed, Aug 17, 2016, 1:00 AM UTC

fhrjchcjdnc wrote: post #25

Carbon fiber is a pretty weird choice for a reusable rocket. Unlike aluminum, it has basically zero tolerance to heat since the fibers are embedded in a matrix made of a polymer glue compound. That's why they call it fiber reinforced plastic.

It won't be used for the rocket but for the Mars transport spaceship.

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#35

Post by colechristensen » Wed, Aug 17, 2016, 2:17 AM UTC

matthewrhoden1 wrote: post #29

colechristensen wrote: post #14

Earlier quoted context omitted.

Aerospace aluminum isn't as easily recycled as beer cans. If you're building a space ship you have very tight tolerances and specifics needed for the alloying of the metals you use. The aluminum in aircraft is full of strange things that need to be removed for general use aluminum and definitely need to be removed for building new aircraft. You're right that melting and re-casting aluminum is really cheap and efficie…

I never thought about it but I became curious as to what the differences are, here's what I was able to find: [0] Aircraft grade aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper, and less than a half percent of silicon, iron, manganese, titanium, chromium, and other metals. [1] Aluminum cans are typically 1% magnesium, 1% manganese, 0.4% iron, 0.2% silicon, and 0.15% co…

>how well a metal cylinder can handle stress while staying light.

Are we talking beer cans or rockets? Maybe they are the same after all :)

All spot on. There are lots of alloys used for lots of different things and economics and availability play their part too. When you're designing your airplane every slight detail matters.

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#36

Post by jccooper » Wed, Aug 17, 2016, 2:23 AM UTC

fhrjchcjdnc wrote: post #25

Carbon fiber is a pretty weird choice for a reusable rocket. Unlike aluminum, it has basically zero tolerance to heat since the fibers are embedded in a matrix made of a polymer glue compound. That's why they call it fiber reinforced plastic.

SpaceX already uses carbon fiber on their rockets in the interstage and payload shroud. They do provide some insulation: they're covered in cork. But most of the rocket body encounters extra low temperatures more than high temperatures.

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#37

Post by stevenrace » Wed, Aug 17, 2016, 2:31 AM UTC

ori_b wrote: post #16

fredgrott wrote: post #6

Earlier quoted context omitted.

Maybe, we need to think about recycling carbon fiber as.. In recycling the fibers get shorter.. Could not that be re-applied to a different industry as far as re-using the carbon fiber? Body Armour for soldiers as the shorter fibers would be of use there?

The problem isn't fiber length. The problem is that the fibers are impregnated with resin, with strong chemical bonds.

The resin has a low Tg (temp at which it turns goopy again) - somewhere around 500*F even for 'aerospace' stuff. Whereas recycling aluminum requires roughly double that temperature to begin to melt aluminum.

The carbon fiber is then chopped and used as reinforcement in other material likes plastics. SGL Group, who supplies/partners in production with BMW, even uses reclaimed and production waste in it's production process for the new 7-series.

A more technical breakdown and state of the industry can be found here: http://www.compositesworld.com/articles/recycled-carbon-fibe...

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#38

Post by robryan » Wed, Aug 17, 2016, 3:59 AM UTC

arijun wrote: post #31

Animats wrote: post #7

In some ways, not a good sign. Space-X can't make and launch Falcon boosters fast enough now. They're not a big enough company to do many things in parallel. Their unfinished, and late, projects include the Falcon Heavy, the Brownsville TX launch facility, and the crewed Dragon, all of which were supposed to be working by now.

As a point on the FH, one reason it's delayed is that it has lower priority: now that the Falcon 9 has been upgraded to the full thrust version, it can take many customers who were originally envisioned to go on the Heavy

I think that they only have one customer lined up which actually needs the heavy? And hopefully being able to do the red dragon mission in 2018.

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#39

Post by anubisresources » Wed, Aug 17, 2016, 4:45 AM UTC

GregBuchholz wrote: post #11

Completely off-topic, but what's the latest thinking on space-elevators? Is there any active research on them? I thought that carbon nanotubes or diamond nanothreads were likely candidates for the cable material.

They make no sense when compared with alternate method like launch loops, which can be built with current tech

Re: Toray carbon fiber to carry SpaceX's Mars ambitions

#40

Post by _archon_ » Wed, Aug 17, 2016, 3:27 PM UTC

anubisresources wrote: post #39

GregBuchholz wrote: post #11

Completely off-topic, but what's the latest thinking on space-elevators? Is there any active research on them? I thought that carbon nanotubes or diamond nanothreads were likely candidates for the cable material.

They make no sense when compared with alternate method like launch loops, which can be built with current tech

80km high track supported by centrifugal force and belt momentum, and tethered by (the same type of cable necessary for a space elevator)? With a belt over 4000 km long capable of 14km/sec without flying apart or overheating?

Which part of this is current tech?