Very much vital. If each week's food is 21 MREs, then there is going to be a lot of packaging.
MRE's involve a
huge amount of excess packaging, relative to shipboard use. This is because they are field rations. IMTU, the "TV Dinner" model is the norm for military or middle passage, and are optimized for low volume, variety, and ease of preparation. (Stick it into the warmer/cooler and each component is warmed/cooled/left alone, as appropriate).
Over 3 years, you will need changes of clothing. Over 1 week, probably just detergent (although these might be futuristic stay-clean clothes), and extra clothes would be the person's responsibility. Same with all sorts of other bits and bobs.
Yes. The cleaners appropriate for clothes, persons, and cabin are part of the "life support," which in CT was Cr 1,000 /person/week. That included, IMTU, all of these, plus the filters, supplies, etc. necessary for the life support of the stateroom. I figured this little bit of stuff for a week would all fit into a package of a nominal 32 liters, such that a 30 person/weeks of life support would fit into a nominal 1000 l (1 m cube) small shipping container/crate, along with some truly minimal sundry packs. If so packed, I would put 26 of such crates in a 2 dton shipping container, containing continuous life support supplies for 15 persons for a year. An additional crate would be for long-term issue items, such as replacement clothing, minimal recreational media, etc. Such a 15 person "long cruise" pack would cost MCr .78
I presume long-wear synthetics, washing done in a very small unit integral to the fresher; a space leaving on a long cruise would take all the clothing they anticipated needing, but the fabrics and washing cycle would minimize this. If I was packing clothes for a year I would be bringing much more, because of washing, weather, activity, fashion (slave to it!), etc. I personally would have to worry about various uniforms, civvies, casual, dirty work, professional work, etc. Naval and marine uniforms would be specifically designed to minimize these issues, and cultural norms adjusted accordingly.
On a long cruise, shore leave would be essential, of course, to minimize the effects on morale. Some field rations, cheaper but more bulky, would thus extend the length of the cruise, as would opportunities to eat locally, and stock up on a small amounts of local produce ("Oh, GRANPA.....").