Dry storage space itself is already valuable. Maybe things are easier to relocate if there is no need to store them 3 layers deep.The big problem with wet workshop is that you just get an empty tank and then have to outfit it.I wonder what happens if the concept gets reversed. Start with a rather simple module including all the MMOD and external connections, strip the internals down, using it as tank during launch and reinstall gear on orbit.
...After listening to the podcast again and the concept to launch Ixion together with a Cygnus on top...A variation of that idea would be to revert to a variation of their first CRS round wet lab concept. Stick a docking adapter on the centaur H2 tank. Only use this contraption as trash truck.That should cut down exposure to MMOD and other risks nicely. Much less need to do interior work on orbit. Cygnus moves the stack to the ISS, both get captured and berthed. Open the wet and fill it what has accumulated for disposal, replace the access cover. Undock and reentry. Only then really start to work on the Cygnus cargo.Now that there is less need for disposal services extra points for upgrading the Cygnus pressure section to a full if somewhat empty module like some of the ATV concepts, the propulsion section to a detachable tug and recovering Centaur engine and avionics with SMART. Sounds roundabout enough for gouvernment work. After all why just play rocket lego if there are also ISS and transport addons aviailible.
Cue a small set of objections: But MMOD, but balloon tank, but thermal regulation, but interior of any kind, but attaching anything internally because balloon tank, but electrical connections, but fluids, but external handholds, but external attachment points, but radiation shielding, but .....
Quote from: Chasm on 04/17/2017 01:57 pmCue a small set of objections: But MMOD, but balloon tank, but thermal regulation, but interior of any kind, but attaching anything internally because balloon tank, but electrical connections, but fluids, but external handholds, but external attachment points, but radiation shielding, but .....There are answers to most of those objections... :-)~Jon
Quote from: jongoff on 04/18/2017 02:31 amQuote from: Chasm on 04/17/2017 01:57 pmCue a small set of objections: But MMOD, but balloon tank, but thermal regulation, but interior of any kind, but attaching anything internally because balloon tank, but electrical connections, but fluids, but external handholds, but external attachment points, but radiation shielding, but .....There are answers to most of those objections... :-)~JonThere are, but are they credible and practical. NOTE, no one has said that this is impossible. Just impractical.I finally got around to listening to the pod cast while driving yesterday, some notes from the interview:1. Mike Johnson clearly likes Centaur. A LOT. He is spent the last 15(?) years working on and off with proposals to adapt Centaur tanks as station components or cargo spacecraft. First as a "dry lab" (modified on ground), then now as a "wet lab" (modified in orbit). While he does admit that his concept could be applied to many other upper stages, I do find the single-minded obsession with Centaur stages somewhat baffling. He seems to have lots of connections with people at ULA, perhaps that is the explanation. But this single-mindedness does bring to mind the saying "if all you have is a hammer, every problem looks like a nail".2. The actual work of outfitting and modifying the Centaur on orbit is hand-waved away, aside from a brief mention of robots doing the work. I really do wish the host would have pressed him more on this.
There are, but are they credible and practical? NOTE, no one has said that this is impossible. Just impractical.
FYI, there will be a NextSTEPs panel at the Von Braun Symposium in Huntsville on Thursday morning (8:30am Central Time) with Jason Crusan and representatives from most of the NextSTEPs teams.http://astronautical.org/dev/wp-content/uploads/2017/10/2017-Von-Braun-Program-Website-3.pdfThere'll be a webcast at astronautical.org/live for those who're interested.~Jon
Jon, I see you representing Nanoracks on the panel. Have they contracted you for this project?
So now that ULA is moving to a 5.4m very wide body Centaur for all Vulcan flights, how does this affect this wet station concept? More volume is better, but changed construction techniques could add challenges, I would think.
Everything points to Centaur V and ACES still using stainless steel tanks, common bulk head. Also external Multi-Layer Insulation.More importantly ULA is a partner in development of this concept - so there should be no reason that Ixion's design isn't future compatible.
With up to 310 m3 habitable volume Ixion is the largest single element station since SkyLab