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I'm having some trouble understanding the requirements for launch vehicle certification. According to NPD 8610.7D the requirements for a category three LV are "a demonstrated flight record of a series of 14 consecutive successful flights of a common launch vehicle configuration..."

The document hints that there are other reviews that go into granting a launch vehicle certification but it seems like 14 consecutive successful flights is the key item. The Delta IV has been fully successful on all flights except for the first flight of the Delta IV heavy which did not reach as high of an orbit as was intended.

What are the other requirements not made clear in this document and why aren't all the requirements spelled out specifically.

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The requirement is for the same configuration. The Delta IV is a highly configurable rocket, and has been flown in the following modes:

  • Delta IV-M 3 times, no failures
  • Delta IV-M+ 19 times, no failures
  • Delta IV Heavy- 9 times, 1 failure. 6 in a row success.

So, the Delta IV-M+ configuration has the required 14 consecutive flights. Assuming the proper instrumentation was on board as required per the NASA flight requirement matrix, the only thing that would be required is for ULA to present the data to NASA to get the certification.

And in fact, it turns out that the Delta IV is Category 3 certification for the Delta IV in 2007. I assume that is only for the M and/or M+ configuration, and not for the Heavy configuration. It, however, does not have Nuclear certification, which is explained in more detail in this answer.

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    $\begingroup$ Since the certification is configuration dependent why was MSL (Class A nuclear payload require category 3 LV) allowed to fly on the first flight of the Atlas V 541 configuration? $\endgroup$ – SpacePaulZ Jul 27 '16 at 17:38
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    $\begingroup$ @SpacePaulZ: I'm working on it. It seems that NASA will bend the rules occasionally for trusted partners. Still trying to get the details. At the very least, the Delta IV Heavy is almost certainly considered a different rocket than the Delta IV M, but I'm still trying to learn more... $\endgroup$ – PearsonArtPhoto Jul 27 '16 at 17:40
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    $\begingroup$ I'm pretty sure that New Horizons was launched on a Atlas 5 that was the first time that configuration had ever been launched. If there's only 1 rocket that can launch you, then it makes it a bit more required to allow for differences between launch vehicles. $\endgroup$ – PearsonArtPhoto Jul 27 '16 at 17:50
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    $\begingroup$ But in 2011 ULA claims that the Atlas V is the only U.S. vehicle to be certified to fly nuclear payloads. $\endgroup$ – SpacePaulZ Jul 27 '16 at 17:57
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    $\begingroup$ @SpacePaulZ Okay, I've got the difference at least partially identified, but it's not that easy. Short answer: Delta IV Medium is a Category 3 launcher per NASA, but not nuclear certified. $\endgroup$ – PearsonArtPhoto Jul 27 '16 at 18:34

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