Getting data on artificial gravity benefits

[sb]

Having been reading a lot of the exploration threads it seems there's two massive issues which will apply to any BEO mission and which we really don't have good data or a way forward on at the moment: 1) radiation 2) effects of long-term weightlessness.

I was looking at Robobeat's post here http://forum.nasaspaceflight.com/index.php?topic=18851.msg634944#msg634944 on an artificial gravity module, which seems to me to be a sensible idea, i.e.
- Only have spin in part of your habitat (and have that totally contained by the habitat itself)
- Only use it for some tasks (sleeping, exercise, or sedentary tasks).

This does seem to have some advantages as a near-term test set-up over spinning an entire habitat, to investigate 1) what levels of artificial gravity are needed 2) what activities/time spent in it are most useful.

But it's still going to be big and expensive, so what about using e.g. rabbits as an initial test subject instead?  It seems to me using these would make say 6-month+ tests fairly practical compared to the costs of a similar human experiment, due to the much lower weight, smaller size, lower space requirements, etc etc.  Obviously there are significant cardiological differences due to our upright stance but it might give some pointers as to whether e.g. 0.1g or 0.8g is necessary to prevent significant bone loss.

But how would it best be implemented? Human care and monitoring would almost certainly be needed so a free-flyer such as dragonlab is probably out.  Could an experimental module like this be added to the ISS or would vibrations be a problem?

Let me say also I'm against much animal testing (cosmetics etc) but this is basically their normal living conditions, just under different g, so I think ethically it's fine - it's nothing we wouldn't do to astronauts.

[Lampyridae]

Mars biogravity satellite was looking to do this. Animals can fly without human care (have done this since Laika). Getting them back is the problem. A Cosmos mission did use artificial gravity, for about a week (maybe a month). That's the only data point we really have. If you could fit a mini-centrifuge in an ISS rack with some rats in it you might get some useful data. Alternatively, a cargo Dragon with a centrifuge bolted-in would do nicely, with a nearly 2m rotation arm.