Here is a thought.SpaceX is investigating use of carbon composite tanks for ITSy. But what if they changed over to its use on F9/FH prior to the ITSy being operational. What would that up to 30% weight savings on tank weight do to the F9/FH payload capability?What would that do to the capability of doing RTLS for a size of payload?Impacts for life (number of reuse flights)?Just using a reduction of 1mt of tank weight for example in US that translates directly to a increase of 1mt of payload weight to any orbit. Instead of just 6mt for an EXPD F9 it would be 7mt for a EXPD F9. For FH those TLI and Mars payloads would increase by that same 1mt for example.By reducing the booster weight the boosters would have more prop and more DV due to the available prop to be able to do RTLS in situations of much larger payloads where now the F9 would have to be ASDS recovered.Then there is the final item about this is that SpaceX would gain the needed extensive flight data on the reuse of carbon composite tanks. This without the need to do an extensive test program of the ITSy to get this same data set.
Part of their challenge with carbon fiber tankage is the effects of hot oxygen from autogenous pressurization on the lox tank. If they go linerless, how do they keep the fibers from combusting. If they go with a liner, how do they keep the liner from separating in cryogenic temps. With Falcon based design, they won't be able to test that aspect out.
They explicitly said that they'd stop major revisions of Falcon family after Block 5. So no. Lock thread?
Their revenue source is the rising launch rate of F9, especially after Block 5 starts flying. Doubt that GS would support R&D on their breadwinner. ConnX isn't going anywhere without F9 high flight rate, ITSy discussions and possibilities notwithstanding.If they want to test carbon composite tankage, they can do it many other ways on 'Test Articles' -- when one fails, testing and operational flights are uninterrupted.
I guess it worth to keep it open until question from title (Impact on payload capability) and from 1st post are reasonably estimated and answered. I find it interesting. - Impacts for life (number of reuse flights)?
Here is a thought.SpaceX is investigating use of carbon composite tanks for ITSy. But what if they changed over to its use on F9/FH prior to the ITSy being operational. What would that up to 30% weight savings on tank weight do to the F9/FH payload capability?What would that do to the capability of doing RTLS for a size of payload?Impacts for life (number of reuse flights)?Just using a reduction of 1mt of tank weight for example in US that translates directly to a increase of 1mt of payload weight to any orbit....
Since when is the interstage a single use object?
Quote from: Nomadd on 08/08/2017 03:41 pm Since when is the interstage a single use object?It is most definitely not a single use object.
It was my understanding it separated from the first stage to let the US go free.
Quote from: john smith 19 on 08/08/2017 04:14 pmIt was my understanding it separated from the first stage to let the US go free.No, it stays attached to the first stage until landing.
Quote from: envy887 on 08/08/2017 04:03 pmQuote from: Nomadd on 08/08/2017 03:41 pm Since when is the interstage a single use object?It is most definitely not a single use object.It was my understanding it separated from the first stage to let the US go free.
If they decide to use and expendable carbon fiber second stage on say a multiple used first stage to improve GTO performance, would it be worth going to carbon fiber?
That's an interesting one. Impact tests on composite tanks have show a 30% reduction in maximum load before failure but without visual signs of impact damage.