This, for all technical purposes, should be entirely doable right now as well. Hell, we did this in the late 60's, damnit!
The only real problem is getting the funding...
And actually, the far more interesting concept is the actual deployment and implementation of the vehicle itself. This project, if it gets the go-ahead, could possilby make for the first purpose built, non-orbital, manned spacecraft to be assembled... in space. Essentially, if the idea is research, then enough space to do research and deploy any possible test systems is essential. Rather than send up a single large space vehicle, which itself will be limited in volume due to launch vehicle power and size constraints, we might consider an approach similar to the building of the ISS and Mir themselves - we send up multiple space vessels with moduar components - then we assemble those components at the ISS.
When we're done, we lauch the vessel. When the vessel is finished with its mission, it returns to the ISS. And when we need it once more, we send it out on another mission.
