Osiris rode on an Atlas V 411. Why not use a larger rocket and skip the gravity assist flyby?

  • $\begingroup$ Because larger rockets cost a lot more? Any particular reason "cost" isn't enough? $\endgroup$ Oct 27, 2016 at 1:43
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    $\begingroup$ If launches were free, using a higher performance launch vehicle would make sense because the extra year needed to perform the Earth gravity assist would have unnecessarily added a few million dollars to to the cost of the Osiris-REx mission. Launches of course aren't free. Using a sufficiently capable rocket to avoid that gravity assist would have added a few hundreds of millions to the cost of the Osiris-REx mission. $\endgroup$ Oct 27, 2016 at 5:14

1 Answer 1


Money. Why spend more if you don't have to? Especially if you're in a competition with other similar proposals. Which it was.


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