I can recall when the first mission in Oracle, Arizona got started back in 1991. The idea was for a crew to enter a segregated structure for an extended period of time and create a functional closed-ecological system that was self supporting. If I recall correctly the first, two-year mission at Biosphere 2 never achieved much better than 83% efficiency, but even that it laudable since there were an endless list of assumptions prior to the start of the experiment.
Since then, it seems like there has been increasingly less support and interest in the development of functional space or Earth based closed loop systems. NASA seems content to pour research dollars into methods of providing explorer sustenance which essentially rehash ancient methods of food preservation with the addition of plastic bags and vacuum sealing techniques.
The first HI-SEAS mission is currently looking at ways to make dried, canned, and freeze dried foods palatable over a long period (120-days), but lacks any means to integrate fast crops, compost, or intensive gardening techniques into the mission diet. The Mars Society’s MDRS as well as this year’s FMARS missions will lack any substantive effort in this area as well.
Forgive me for being skeptical, but I cannot imagine a long term space mission that doesn’t involve at the very least a couple of hydroponically grown radishes. Humanity has evolved to take advantage of fresh produce. I’ve spent summers working into the fall and living on nothing much more than MREs. I can’t fathom doing this, even with some of the tastiest of these meals, for years on end.