SpaceX will be doing a Pad Abort test at LC-40 in Florida for the Dragon V2 vehicle to close out the CCiCAP criteria.

They will not be using a real first or second stage, instead building some kind of truss to hold the Dragon V2 at about the right height and then trigger the abort from there.

Perhaps the test would destroy the second stage, but why not use a real first stage, mount an appropriate space to represent the second stage, and then do the abort?

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    $\begingroup$ Blowing up a first stage could well detract from the test. There's always a point of no return in aborts. Wait until the last nanosecond prior to explosion to escape and the crew has two choices: Die with the explosion, or die as the LAS whisks them away at 30g (as if the LAS could achieve that kind of acceleration). The abort stage has limited acceleration and thus has to act at some time prior to the imminent disaster, which means that the actual disaster is not needed to test the LAS. $\endgroup$ Dec 30 '14 at 6:08

It's got to be hugely expensive to transport and erect a Falcon even if you don't intend to launch it. The potential for damaging part of the rocket in the test makes it even less attractive.

Why use a real rocket if a truss suffices?

After Apollo's first abort test from a low platform in the desert, they also did several in-flight abort tests by launching a boilerplate CSM on a stubby Little Joe II rocket.

Given SpaceX's demonstrated preference for combining non-critical-path R&D tests with commercial missions, I wouldn't be surprised if they combine a Dragon V2 in-flight abort test with a Falcon first-stage powered landing and/or flyback test at some point in the future.

  • $\begingroup$ But they have so many in the flow. The superDraco thrust is offset, not straight down. So it might destroy the second stage, but that is something like 30-40 feet down + interstage to the first stage... Use the F9R-Dev2 core stage, etc... The more real the better? $\endgroup$
    – geoffc
    Dec 29 '14 at 20:13
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    $\begingroup$ I wouldn't expect any damage to the second stage, apart from blown explosive bolts, but even so I wouldn't bother with the expense if certification didn't require it. What is it about having a real rocket underneath do you think would make for a more realistic pad abort test? $\endgroup$ Dec 29 '14 at 20:15
  • $\begingroup$ @RusselBorogove Well honestly, blowing up the first stage, would be a better abort test. I.e. Not a software abort, make it real. But that would be ludicrous I concede. $\endgroup$
    – geoffc
    Dec 29 '14 at 20:17
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    $\begingroup$ Again, if you wanted to test abort in a dynamic situation, it would be vastly cheaper to build a platform that just tilts rapidly as the abort test starts. Interestingly, Apollo's first pad abort test was done from a very low platform in the middle of nowhere rather than from a tower in Florida: en.wikipedia.org/wiki/Pad_Abort_Test_1 $\endgroup$ Dec 29 '14 at 20:24
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    $\begingroup$ @geoffc, abort stages aren't there to take you away from an explosion. They're to take you away from a detected problem before it explodes. Blowing up a first stage wouldn't add anything to the test. $\endgroup$
    – BowlOfRed
    Dec 30 '14 at 0:54

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