Comment Re:"reached orbit" is a misnomer (Score 1) 56
Exactly. You can test each component on the ground like NASA does but it's very expensive and very slow. I think the "test flight hardware by flying it" philosophy practiced by SpaceX is superior for actually producing results in a timely and cost-efficient manner.
One result of this is that a single SLS engine probably costs more than an entire Starship/Super Heavy stack. Even the ones that were taken off Space Shuttles and refurbished.
Yep, even the "expendable" version (the RS-25E) is hugely expensive. From wiki:
On 1 May 2020, NASA awarded a contract extension to manufacture 18 additional RS-25 engines, with associated services, for $1.79 billion
So these engines are costing the taxpayer 100 million EACH, the 4 of them needed for an SLS booster is 400 million. And this is for the less-capable expendable version, which was supposed to be cheaper than the original. All to just manufacture an engine that has already been designed and has been optimized for decades, no research and development required. Meanwhile SpaceX is producing hundreds of Raptor engines, which they had to develop from scratch, and doing it at a much lower cost. As a bonus, the Raptor is a reusable engine so they don't need to make a new set for each rocket they need to fly (presuming their reuse plans come to fruition).
