There's a lot to like about this rocket: 1.) It's good to see ULA stepping up to the plate and actually innovating. SpaceX will need some competition by then,

There's a lot to like about this rocket: 1.) It's good to see ULA stepping up to the plate and actually innovating. SpaceX will need some competition by then, to keep the industry healthy. 2.) The name, "Vulcan", is pretty badass. Certainly far better than the other, embarrassingly jingoistic candidates they were considering. 3.) The inclusion of innovative NewSpace companies like Blue Origin and Xcor is pretty exciting, even if ULA hasn't actually committed to using their technologies yet. That said, there are ways in which the Vulcan seems like it was designed by a committee, and doesn't quite seem fully-baked. In particular: the "dial-a-rocket" approach of strapping on solid boosters is at fundamental odds with the economics of reusability. In an expendable rocket, solid boosters are used because you need a lot more thrust early in the ascent (to overcome gravity losses), and solid rockets are a relatively cheap way to achieve that. (Solids generate a lot of thrust during a short period of time, but their efficiency over long-duration burns is relatively poor, which is why they're generally not used all the way to orbit). You could accomplish the same thing by using more liquid fuel and more engines in the primary booster stage -- but turbopump-driven liquid engines are a good deal more expensive than solid boosters, so it doesn't make sense to do this if you're going to dump them in the ocean after a minute or two. On the other hand, if you're recovering the engines, then using more of them is absolutely the right thing to do. In that case, the tradeoff isn't between the cost of liquid engines vs. solid boosters; it's the difference between the cost of refurbishing liquid engines (and some extra fuel) vs. solid boosters. In this case, the latter is likely to be more expensive by an order of magnitude. So if your hardware is reusable, then it's better to have one or at most two vehicle configurations, and simply accept that most of the time your vehicle will be oversized for its payload. You also get some additional benefits from doing this, such as greater mass-produceability and engine-out capabilities, etc. I suspect that the problem is that aerospace engineers are used to doing high-level trade studies using a crude $$$/kg costing for the cost of a rocket -- at least, this is how I've frequently seen them do it. If this is how you think, then you want your vehicle to be no larger than the payload requires -- and that's what the dial-a-rocket approach allows you to do. But it's kind of like assuming that a truck costs $$$/kg, and therefore if you need to carry a load across town, you should build a truck which is as large as you need and no larger. This makes sense if you take it as a given that you will always be building your trucks by hand, and that they will be thrown away after every journey. But if both of those assumptions are false, then so too is the "build the truck to fit the payload" design philosophy. It doesn't look like ULA has figured this out yet -- but they've definitely realised that there's a fire under their tail, so hopefully they will do so eventually!