# The costs of a single SLS solid fuel rocket booster

Why didn’t Nasa cluster four solid fuel shuttle boosters around an Atlas V booster. The thrust would be substantially more than that of the SLS, with no fueling problem on the launch pad. It would be much less expensive and if using old technology anyway, why not develop new technology while building a base on the Moon which should have been done decades ago?

• Part of the answer will be about human rating, see e.g. this question and its answers and this other answer. I also doubt your design would meet the mission requirements for SLS, even if you did figure out a way to mount Shuttle SRBs to an Atlas core. Nonetheless, welcome to the site Nov 19 at 21:00
• oh also the title should align with the body of the question. Sorry for missing that; it's what I get for coming in from the review queue instead of the front page Nov 19 at 23:00
• So if human rating is a problem with Atlas V, why not change the question to 4 solid fuel boosters around the existing SLS core that already uses new tchnology ? The fueling problems seem now solved. Nov 20 at 11:53