> Why do they need to develop new engine for instance? "Need" is interesting. There are two key goals with the Raptor engine. #1- Switch to Methane burning. Me

> Why do they need to develop new engine for instance? "Need" is interesting. There are two key goals with the Raptor engine. #1- Switch to Methane burning. Methane is available much more easily everywhere in the solar system- Mars especially. So we can make fuel wherever we are instead of bringing it. #2- Make it much more resilient to re-use. Those Merlin engines are great, but they need a lot of work to get them ready to go again. Lots of inspection. Raptor is a Full-flow staged combustion engine[0]. Everyday Astronaut does a great write-up (and video) on the topic[1]. > why they didn't just iterate on the Falcon design and what necessitates a "full stack" clean slate approach Falcon is big, but it isn't huge. It's got a 3.7m diameter. Starship has a 9m diamater, almost 2 and a half times wider (meaning more than 5 times larger circumference). When you scale up that much, you're basically starting over. This size increase also means Starship should be able to lift something like 6 times more to orbit. And because it's so huge, it won't need a booster to launch itself from Mars or the Moon. Materials also matter. Falcon is made of carbon fiber: carbon fiber is expensive and hard to work with. It's slow. Iteration is slow. If you want to blow up 1 rocket per month in testing, that's going to get expensive and take a lot of work to make happen, especially given the larger size. Steel, on the other hand, is cheap and fast. So Starship is based on steel. Starship is also fully reusable. Falcon 9 isn't- the second stage is expended. They looked into how they might bring those back, but it just wasn't worth the R&D effort. When it's all done, Starship is going to be a fully-reusable system that is cheap to build, cheap/easy to operate, can be refueled easily, anywhere (like Mars), can launch itself from the Moon or Mars without a booster. It will be cheaper to launch per kg than any other launch system out there by probably an order of magnitude. It will dominate the competition and likely claim a monopoly on the private launch market until someone gets their shit together and competes. [0]https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-flow_staged_combustion_cycle https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-f... [1]https://everydayastronaut.com/raptor-engine/ https://everydayastronaut.com/raptor-engine/