[0] https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation
But bigger rockets can get closer to that theoretical optimum because some dead weight components remain fixed-size and because some masses scale with surface instead of volume. Rockets can scale better than linearly with size, but they will never exceed the rocket equation.
What am I missing here -- I'm sure I'm overlooking something.
The R7 rocket
- mostly to avoid engine ignition in flight & due to having a lot of nozzles you need to fit on a rocket
- this was then kept for Soyuz even after an additional stage has been added that is started in flight
- Soyuz 2V uses a more efficient engine & uses only the central stage
The proton Rocket
- the central tank has the maximum diameter you can ship via rail from the factory to Baykonur
- by mounting smaller tanks around it that are shipped separately you can avoid building an overly long rocket, that could be fragile and unstable
Saturn 1/1B
- basically a stop gap using existing Jupiter and Redstone rocket tankage tooling
- strap 8 Redstone tanks around 1 Jupiter tank and you get the S-I first stage
Delta IV Heavy/Falcon Heavy
- you have a rocket that can launch by itself with smaller payload or by strapping 3 first stages together can launch a bigger payload
- better economies of scale as you can doe more with a single rocket design instead of maintaining 2 separate one (big and small)
- in Falcon Heavy case you can also save all the first stages from more demanding trajectories where you would otherwise have to expend the regular F9 first stage
OTRAG
- make dirt cheap and as simple as possible standardized "rocket tubes"
- strap a lot of them together
- fire and jettison in the right order to achieve orbit (check your staging! ;-) )
Poorly for the current market using a FH makes sense, but to break to another level, building one big rocket is better. Both the US Saturn 5 and the Soviet N1 were big single tube vehicles.
¹ Superlinear because tank mass scales with a lower exponent than tank volume.
I'm confused here. How are they not both cubic?
On the other hand, ten fuel tanks will mass more than a single fuel tank with ten times the volume.
