Some More Details on NanoRacks’ Centaur Wet Workshop Concept

Mike Johnson, Chief Designer at NanoRacks, in an interview with Evan Ackerman of IEEE Spectrum:

This is the original concept—we’d take a Centaur, add a docking hatch on it, put a Cygnus spacecraft on top of that, and staple it all to an Atlas V 500 Series rocket. We'd launch it into orbit, and then the Cygnus would take over and tug itself [and the Centaur] to the ISS. Cygnus would berth like it does normally, except it would have the Centaur upper stage hanging off the back end. At that point, we'd take the [station’s] robotic arm, grapple the Centaur, and move it over to another hatch.

I like how NanoRacks is approaching this—looking objectively at hardware that’s in use today to put things together in interesting ways. I’m not sure how they’d deal with the fact that Cygnus’ engine would be blocked by Centaur, but I don’t see that being a showstopper by any means.

I also really like the co-manifesting idea here—flying Cygnus above the habitat-capable Centaur makes this idea even more useful outside the context of the ISS. To that end, Johnson continues:

When we started working on the proposal for NASA, we saw that there were some additional requirements: they wanted additional docking ports, some form of airlock that could be used for crew EVAs, and an equipment airlock. You can't really put all of this on the Centaur without affecting its ability as an upper stage, so what we decided to do was put another module between the Centaur and the Cygnus: there's enough room under the Atlas V fairing to stack all this stuff up.

When you see how those requirements are addressed with their proposal—an additional node with several docking ports—you get the sense that this module could be the basis for a small, modular space station around the Moon or elsewhere.

As I’ve said before, my main concern with the NanoRacks proposal is that, positioned as open-ended and hardware agnostic, it feels less focused and more exploratory than the other competing prototypes which are based on hardware in space today or actively flying missions to the ISS.

NASA typically likes to pick the heritage choice when it comes to their exploration efforts, but the commercial cargo and crew programs have been pushing boundaries. This program seems to fit somewhere in the middle—it’s in support of their exploration goals but seems to be carried out like the commercial programs have been, even including the way the participants have to put up some of their own funding.