It was a hell of a lot cheaper to refurbish and reuse a shuttle than to build a new one each time. That's why 135 shuttle missions were flown with 5 shuttles i

It was a hell of a lot cheaper to refurbish and reuse a shuttle than to build a new one each time. That's why 135 shuttle missions were flown with 5 shuttles instead of 135 shuttles. It's true that refurbishment between use was far more expensive and time consuming than had been planned, however it was a hell of a lot cheaper than building a new shuttle each time. Refurbishing a shuttle took months but building Endeavour to replace Challenger took several years and cost several orders of magnitude more. There can be no serious question that the shuttle orbiters were mostly reusable. > cost effective That's another matter entirely. It would have been cheaper to use conventional disposable rockets. Even better than that is reusable conventional rockets; the economic sense of which has now been demonstrated by Falcon 9.