Polishguy":3k9ip1kc said:
Every NASA plan for a Shuttle-Derived Launch Vehicle with an in-line configuration, be it Ares V or DIRECT, has the same configuration: an engine bundle and only two SRBs. But why not add more SRBs? I mean, it could increase payload, so why not wrap six more SRBs around the External Tank?
One of the limiting factors is the capacity of ground processing systems. Solids are super-heavy because they are already loaded with propellant. The two Shuttle four segment SRBs weigh 1180 tonnes together. The 5.5 segment Ares 5 solids would have weighed 1580 tonnes together (and produced 3,400 tonnes of thrust). We're talking about something that weighs as much as a navy destroyer. Ares 5 would have meant building a new crawlerway, new mobile transporters, and new mobile launch platforms to handle the weight. The cost of all of that was already enormous. Adding more big solids was pretty much out of the question. This is one of the reasons NASA, or at least some in NASA, are leaning toward all-liquid super-heavy launch vehicles for the future.
- Ed Kyle