/sci/ - Science & Math

>>16052638
yes, changing SRB inner geometry or fuel composition to burn faster is easier than building a mach 5 airliner sized jet

>>11130061
>SRBs can't be throttled
They can, with proper planning ahead by controlling how much of the surface area is burnt at any given second. As such, if you build a different structure of propellant into it, the thrust that you'll receive changes, giving you the choice to throttle the motor during its flight.
>but you can change liquid motor throttle freely in flight!
If you have an ascent flight profile, the engines will be throttled at specific times to specific levels. So as a booster for surface to orbit operations, SRBs are perfectly viable and cost-effective, hence their usage as boosters for the Space Shuttle and SLS

>>9517205
The only canceled project I see under SpaceX is the Falcon 5, sure plenty of things are years late but that is industry standard.

>>9517227
I'm a fan of the "Big Dumb Booster" SRB approach. Their main drawback is it's harder to configure the thrust curve but I can't see why you couldn't have half a dozen grain geometries that you mix and match depending on mission profile and a widely throttleable upper stage.