I guess the notion here is that if you are going to use a stage forty times, materials that cost ten times as much and weigh less, or are more durable, might start to make economic sense.Matthew
Since they can begin to expect to recover engines and stages, and they can potentially spend more on each unit of the first stage and the next merlins, what types of more expensive materials might be used in F9 1.3?
carbon fiber doesn't like to be bent like that.
Graphene is supposed to be another very promising wonder material. It has a tensile strength which exceeds that of carbon nanotubes
Graphene is carbon laid out in a crystalline structure one atom thick. It can be layered in laminate form, but does it suffer from the same thing Robotbeat says about carbon fiber? Is it flexible, or will the bonds break in those one atom thick planes if flexed?
Conversely, there would be pressure to drive down the cost of the second stage and fairings if they continue to expend them. That's much harder to do with design since 1) second stages tend to push mass efficiency to the limit, and 2) the bulk of the cost is likely in the engine which would be just as optimized as the stage due to the need for high ISP. However I could see the manufacturing processes diverge rather sharply, whereas now they use a lot of the same tooling, materials, and components.
Quote from: Robotbeat on 01/31/2016 06:02 pmcarbon fiber doesn't like to be bent like that.Quote from: sanman on 02/09/2016 03:57 amGraphene is supposed to be another very promising wonder material. It has a tensile strength which exceeds that of carbon nanotubesGraphene is carbon laid out in a crystalline structure one atom thick. It can be layered in laminate form, but does it suffer from the same thing Robotbeat says about carbon fiber? Is it flexible, or will the bonds break in those one atom thick planes if flexed?
Recently, a new stainless magnesium-lithium alloy was discovered that weighs half as much as aluminium.
Recently, a new stainless magnesium-lithium alloy was discovered that weighs half as much as aluminium.See also: http://www.gizmag.com/corrosion-resistant-magnesium-alloy/40600/If it's possible for SpaceX to apply this new alloy, their rockets might gain tons and tons of extra payload capability just by making the first and second stage bodies from that alloy. I don't know if this specific material could qualify for rocketry, but it might well be worth testing this.To be on the safe side, they might try and use an innovative sandwich material with two 'traditional' relatively thin inner and outer metal sheets layers, and one appropriately thick MgLi alloy bulk layer to shave off perhaps 1000s of kg of the stage bodies.
Diamonds burn pretty easily compared to other material..
Why would they need to change materials?
3D printed plastic grid fins we currently use can't withstand the dynamic pressure and heating at supersonic. That's why we have started manufacturing titanium grid fins. They are cut from a single piece of titanium with a CNC machine: