Medical research? These poor creatures will end up being test subjects for cosmetics, tobacco, pollution,… You know, just so the people who pay know how much a living being (i.e. your future self) can take before collapsing. Implying most (or even a significant portion) of them are for “finding a cure for cancer” is PR washing.
Of all the resource- wasting human activities, why should we cut spacefaring? Can’t we start by dismantling AI, cosmetics, golf courses,… and then if some last minute precious resources are needed we can talk about not going to space?