If some SpaceX enthusiasts were wondering if the Starship super-heavy booster would be more difficult to design and build than the Starship that is to fly on top of it. Then this article will attempt to clear up some of the confusion.
In order to logically deduct the answer to this question, we can take a closer look at its predecessor. The Falcon 9, block 5 to be exact.
The Falcon 9 in its current first stage reusable configuration has gone through multiple iterations of improvement throughout its lifetime.
The SpaceX team made small and large modifications that enabled them to eventually make the first stage, the booster fully reusable for perhaps up to ten times without major refurbishment.
Reusing the first stage allows them to be much more cost-competitive in their launch prices. It also helps reduce the cost of launching their own Starlink network satellites more cost-effectively.
This is a feat never achieved by any other space exploration entity.
So needless to say that SpaceX has a lot of experience reusing their Falcon 9 first stage. There was once a plan to try to reuse the second stage as well, but this plan was dropped once realized it was not technically and economically viable.
Coming back to the topic of Starship, Elon mush did answer a Twitter question why he started with Starship first and not the booster. His answer was because Starship is the most difficult part.
The reason is that the booster stage does not need to reach orbit, nor does it need to reenter earth’s atmosphere at high velocities. So it does not need a heat shield. It also, of course, does not carry any cargo or passenger so it does not need a life support system or the likes. Basically the Starship booster is just an enlarged Falcon 9 booster made out of stainless steel.
SpaceX can just take the technology developed for the Falcon 9 booster and apply it to the Starship booster. Obviously the Starship booster will need to go through extensive testing even though it is based on proven and tested technology. It will need to have an impeccable safety record. Since Starship will not have an emergency abort system like the Dragon V2 currently has. So it needs to be as safe as possible if Starship is to be qualified for a crewed mission.
Once SpaceX manages to test fly the Starship prototypes reliably, it is suspected that they will start designer, building and iterating the Starship booster.
Luckily, we will not have to wait too long to see all these exciting developments happen. We suspect that we can see only booster test hops and flights in the first half of 2021. In the second half, we probably will see orbital test flights of the booster and Starship.
If you think this year is exciting with the rapid testing of the different SN prototypes, then next year is gonna be really epic and society changing when these colossal space ships take to the sky.