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SpaceX and Blue Origin have demonstrated the feasibility of modern reusable rockets. Elon Musk claims that a reusable rocket is 100 times cheaper than a conventional one.

The average success rate of a rocket launch is around 94%. What will be the average loss in this reliability/success rate after each launch/reuse? How many times can they reuse a rocket(say falcon 9)? If SpaceX was to provide rocket launch service at a 1% of the actual overall cost(lets assume), will they make profits?

Lets assume NASA wants to launch a satellite to Earths low orbit. Will they trust a used rocket?

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    $\begingroup$ Reusable rockets will have to prove themselves the same as any new launcher. New protocols might apply to them, but it is far too early to say what those might be. There is no way to answer this except with speculation. $\endgroup$
    – kim holder
    Nov 29, 2015 at 0:24
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    $\begingroup$ @ShreyasBalakuntala: I have no idea why you'd assume they're not making any provision for launch failure risks. That would be ridiculous. $\endgroup$
    – Nathan Tuggy
    Nov 29, 2015 at 0:29
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    $\begingroup$ All launches are insured, which isn't cheap of course because failure rates on all launchers are not great. Companies that launch items into space inherently accept high risk. The fact remains that this is a technology in the early stages of development, and how it will be handled can't be anticipated. $\endgroup$
    – kim holder
    Nov 29, 2015 at 0:32
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    $\begingroup$ One could argue that in some ways a used rocket is more trustworthy than a new one. At least one knows that it hasn't got its gyros installed upside down from the factory, like that spectacular Proton rocket had in 2013. I think a large satellite operator (SES?) has already accepted reused launchers, when available. SpaceX added 50% launch weight to their reusable v1.1 Falcon 9, so some precautions for robustness seem to have been taken. The structure which failed on an F9 launch recently was in the non-reusable second stage AFAIK. $\endgroup$
    – LocalFluff
    Nov 29, 2015 at 0:50
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    $\begingroup$ The secret to reliability is simply to fly a lot. Looking at the list of all 125 launches of the Scout rocket 3 of the first 4 were failures; the last 25 were all successes. Same for other rockets. $\endgroup$
    – Alex I
    Nov 29, 2015 at 7:18

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Quoting an average success rate for rocket launches as a whole is not very useful. Atlas V has a near-perfect record, for instance, while Zenit and Proton have about 88% rates.

Presently, Falcon 9's partial success rate is 95% and its full success rate is 88% as an expendable, but it's still quite a young launcher. We won't know how it performs as a reusable until there's much more of a track record.

NASA has trusted not only satellites but humans to used rockets, many, many times. The space shuttles were used an average of 27 times each, and the two failures were not related to the reuse per se (although design decisions made in the name of reusability were major contributing factors). So it wouldn't be surprising for Falcon 9 first stages to manage 10 to 100 reuses, with some degree of engine overhaul or replacement.

If you mean provide rocket launch service at 1% of the per rocket lifetime costs, almost certainly not; that would be gambling on more than 100 successful reuses, a success rate which almost no expendable launch systems manage. It's much more likely that SpaceX will charge a large fraction of the price they would for an expendable rocket. Even charging half the current cost of a Falcon launch would be a win for the customers who currently pay full price and a win for SpaceX if they can use the first stage three or four times successfully.

Note also that Falcon 9 throws away its second stage, which is apparently around 25% of the total cost of the rocket (it accounts for half the guidance systems, half the tank assemblies, 1/7 of the dry mass, 1/10 of the engines, etc.) -- on that basis even a sixfold cost reduction would be a big challenge.

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  • $\begingroup$ Elon Musk publicly said that reusable rockets would be a 100 times cheaper. I was just assuming that he would actually provide the services at that price. $\endgroup$
    – Shreyas Balakuntala
    Nov 29, 2015 at 0:39
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    $\begingroup$ Musk: “There’s the potential there for, ultimately, a hundred-fold improvement in the cost of access to space." The words "potential" and "ultimately" are doing a lot of work in that sentence. It's not the same as saying "reusable rockets will be 100 times cheaper". The first 10 or 20 years of Falcon 9 reusables are not likely to reach anywhere near that degree of cost reduction. $\endgroup$
    – Russell Borogove
    Nov 29, 2015 at 0:48
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    $\begingroup$ @ShreyasBalakuntala Elon is an eccentric billionaire who has fun with making outrageous claims which mixed with his exceptional accomplishments make everyone unsure about what to believe. $\endgroup$
    – LocalFluff
    Nov 29, 2015 at 1:03
  • $\begingroup$ Reusability of the 2nd stage is also being worked on. spacexstats.com/faq.php $\endgroup$
    – kim holder
    Nov 29, 2015 at 1:07
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    $\begingroup$ The claim is only outrageous if you ignore the weasel words in it. $\endgroup$
    – Russell Borogove
    Nov 29, 2015 at 1:10

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