Because you can't turn them off once they're ignited, and they're much more prone to disastrous accidents. And if you handwave away those problems you may as well handwave away the pollutant argument, which doesn't appear in Star Frontiers anyway.

The SRBs on the space shuttles were not disposable; they were designed to be retrieved and reused. Other missions have used disposable solid-fuel rocket boosters.

My main objection is simply that using disposable solid-fuel rocket boosters takes Star Frontiers technology backwards. This is the most primitive form of getting to orbit there is.

And just imagine the impossible atmospheric conditions at the spaceport where these SRB-using ships are coming and going daily, or even hourly! Solid rockets spew out a lot of smoke and pollutants!

How do all these ships using boosters land? I suppose they have wings and glide. But then how do they take off again? Ships are supposed to be able to do that, especially on planets without spaceports. Or are the environmental regulations relaxed on those planets? Even if you decide to use your regular chemical engine, how do you get your ship pointed up? Can you fire a chemical engine while horizontal to the ground, and expect your wings to work with your chemical engine like a jet plane? Are shuttles really just aerospace planes?

I really think you've got a solution looking for a problem.

My original thought was this, and I may have misremembered, but an atomic drive ship uses a fuel pellet to launch and achive orbit?  What if it used Boosters that dropped away? It alleviates the implied pollution problem of the atomic drive. It would save on swapping out a pellet and I believe an overhaul for ships with size A drives.

It is old tech but nothing to stop them from using it in the Frontier. That is how the Frontier was presented: slightly more advanced than today. 

I'm simply proposing and optional equipment rule. 

Sure today's SRBs have had problems but it's not outside the realm of possibility that most of those technical problems have been ironed out for for a situation where space flight is democratized. 

I assume that most space ports are serviced by a fleet of chem drive shuttles for ground to space and space to ground movement. So we're not talking about adding more to a situation. Simply using external chem drives instead of internal chem drives or atomic drives. 

Use of these would mean any ship, with size limits, can be built on planet and launched into space including ion although ion ships might not have their drives attached for until they get to orbit.

Why go to the expense of building a spaceship on a planet and then boost it to orbit, when you can just construct the ship in orbit? This is why spaceship construction centers are in space.

Ships with atomic engines don't use up a fuel pellet or require an overhaul after taking off from planets, only after making an interstellar jump. The amount of atomic fuel used in a takeoff is negligible according to the rules. House rules regarding intrasystem travel might introduce fuel consumption rates.

Chemical drives already account for take-off fuel: an in-system trip uses up one fuel load no matter where you go, or two fuel loads if you had to take off from a planet first. That second load is your booster rocket, without the detachable rocket. Same amount of fuel.

Star Frontiers technology is WAY more advanced than us, not just slightly more advanced.

Personally I would say any planet that has an Industrial based trade/economy should be capable of belting out system ships (Class III centers at the minimum). That would at least increase the number of such centers to just over half the Frontier worlds listed in AD. 

As far as starship yards, based on the AD pattern of utilizing "capital" worlds/systems for such SCCs I would at least add one more in Zik-kit (as it would appear to be the major Vrusk center in that sector, also supported by both industrial and resource trades), thus bringing the total Class I & II centers up to six...although I would probably still restrict the Class I centers to what is listed in canon (Prenglar & Cassidine).

Like I said, "Class III at the minimum". Any industrial based world in SF should be capable of constructing ships, whether they're system ships or star ships.

To that end I would further posit that the readily available technology & materials would define the SCC class more than anything. This availability and/or importing of goods & services neatly explains the significant cost increases at the lesser centers:

> If a system or world has both industrial and resource trade (such as my proposed Zik-Kit center) then a Class I center would be feasible for that setting...thus permitting said proposed center to be a Class I SCC.

> If resources need to be imported but the world has an industrial base then it's a Class II center...the world has the industrial capacity to design & build ion & atomic drives but they lack the resource production/refinery so they must import these (hence the higher cost over Class I centers). 

> The lack of industrial trade with the caveat of resource trade would make it a Class III center...the world must "import" design/manufacturing teams & facilities and as such they only get the "flunkies" that can't make it at higher paying gigs like the Class I & II centers. This also neatly explains why jump-capable drives are not available at such centers, the engineers & companies capable of designing & building these would not "stoop" to such conditions so the Class III centers can only hire the "little guys" that lack the capacity for supporting such design & production.

> The lack of both industrial and resource trade would restrict them to Class III ground based center, and we could go so far and call this a Class IV center (along with raising prices to boot since the resources must be ferried to the surface instead of in orbit). 
 

SCC Class I centers previously established in Prenglar & Cassidine (granted neither has resource production but being in the center of the Frontier AKA "core worlds" still has advantages other systems & worlds could never enjoy), then add one more in Zik-Kit while "promoting" the centers in Dramune & Truane's Star up to Class I. 

SCC Class II centers would be found orbitting Hentz, Terledrom, Kdikit, Hakosoar, Minotaur, and Lossend.

SCC: Class III (orbital) centers would be found over Hargut & Clarion while the rest of the worlds not listed (possibly even the outposts) would have the ground-based centers restricted to HS:5 hulls.

So this brings the Frontier up to five Class I centers, six Class II centers, and a slew of Class III centers in all the other worlds (14 IIRC). BTW this also neatly hand-waives the various explanations out there regarding the transport of system ships to worlds that don't have SCC facilities because now all the worlds have such facilities. ;)