This mission profile seems like a no-brainer to me, but I don't recall seeing it mentioned in Orion coverage. I know this may have more to do with politics than anything else, but I'm more interested in technical points such as:

Have ISS missions been discussed internally by the Orion design team?
What remains to be done to achieve a manned rating for Orion?
Are there any current US man-rated launch vehicles capable of sending it to the ISS?
If not, what would qualifying a suitable launcher take?

Or is there some sort of non-compete clause in the CCtCAP program?

  • 2
    $\begingroup$ You are asking multiple questions, some of them already answered. When you have multiple questions, it is better to ask them separately. $\endgroup$
    – Philipp
    Dec 6, 2014 at 15:05
  • 1
    $\begingroup$ Monstrous buckets of money. Obscenely large buckets of money. It would take years, burning 100 dollar bills, one a second to burn that much money, to use Orion for ISS ferry duty. $\endgroup$
    – geoffc
    Dec 7, 2014 at 0:26
  • $\begingroup$ Orion is definitely more spacecraft than you need for the ISS ferry mission, but if it were actually used in that role, it would go a long way toward amortizing its development cost. I'm not saying it's the best solution, mind you. $\endgroup$ Dec 7, 2014 at 1:11
  • $\begingroup$ @Philipp which of the subquestions have been answered? I have no problem editing to narrow the scope. $\endgroup$ Dec 7, 2014 at 1:19
  • $\begingroup$ Orion could do it, but that's not what it's designed for. It's made for longer lunar missions. Using Orion as a simple ferry would be like buying a car to cross the city when a regular taxi or public transit would work just as well. $\endgroup$
    – Dragongeek
    Mar 12, 2020 at 10:07

1 Answer 1


According to wikipedia, when Orion was conceived as part of the Constellation program, the ISS ferry role was considered; I would be surprised if that role wasn't kept in mind throughout development since then. In particular, Orion uses the ISS-compatible NASA Docking System.

Some of the excitement around the Orion EFT-1 flight was that it was "the first human-rated ship to leave LEO since Apollo"; it's not clear to me whether than meant that Orion was actually, currently human-rated or if that was stretching to cover the Orion program's overall design. In any case, human-rating is mostly a matter of "we are incorporating these necessary design features", so I would guess there's not much more to be done there.

As of this article (possibly from 2008?), the Atlas and Delta launchers are very close to being human-rated, with Delta mostly needing automatic fault detection systems that could trigger an in-flight abort. Delta IV Heavy definitely has the capacity to send Orion to ISS, Atlas V probably not.

  • $\begingroup$ Is D4-H really powerful enough to launch Orion, with a Service module? I do not think Orion by itself has sufficient impulse and control to dock to the ISS. If you need the SM, D4H is not powerful enough. $\endgroup$
    – geoffc
    Dec 7, 2014 at 0:28
  • $\begingroup$ Looking at Wikipedia, I think it just barely adds up; 28t to 200km LEO on D4H, Orion is 21t CM+SM and takes up to 8t service module propellant -- so we can't quite bring a full tank. Only a couple hundred ms of delta-v are needed to raise from 200km to ISS at 400km, though. $\endgroup$ Dec 7, 2014 at 0:49
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    $\begingroup$ You know, you could do the orbital insertion with the service module engine. Makes getting rid of the booster more predictable. $\endgroup$
    – Joshua
    Aug 26, 2019 at 3:39

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