4 ms·
[TFA isn't loading up for me] 3% to 30% is a 10x savings, because it's a ratio. E.g., if it takes $1,000 of fuel to get a unit mass into orbit, then a 3% rati
by danielweber 11y ago
[TFA isn't loading up for me]
3% to 30% is a 10x savings, because it's a ratio.
E.g., if it takes $1,000 of fuel to get a unit mass into orbit, then a 3% ratio means $33K, and a 30% ratio means $3K.
I am always skeptical of "massive upfront investment but lower per-unit costs," especially for space-launch. It's the way most of us learn about space, because sci-fi novelists talking about space have to explain what finally got man into space, and a massive infrastructure seems such a nice logical explanation. But Musk has shown that Plain Old Boring Rockets can be done much more efficiently than traditionally done. And that doesn't make a good sci-fi backstory.
- deleted 11y ago[deleted]
- vidarh 11y agoI think you misunderstand me. Musk has stated fuel for current type launches is around 0.3%. If we assume that SpaceX cuts the overall cost of launches to 1/10th mainly by reuse of the first stage, that is indeed a 10x savings, but not on fuel (in fact, SpaceX uses more fuel because they need to be able to slow the first stage). 0.3% of x is the same as 3% of x/10. So my point was that even with SpaceX numbers, where fuel will (once they sort out reuse) make up substantially more than what it currently does (because they're aiming to massively slashed the non-fuel costs), a 30% cut in fuel costs will "best" case cut launch costs by about 1%. If these guys are going to achieve substantial cost cuts it will need to be elsewhere unless Musk' has been massively misquoted or is totally wrong about the relative cost of fuel vs. the rest. (I'm not going to bother being precise as all of these are handwavy estimates from people anyway).