The ET would have provided a huge working space, and one major problem with various wet workshop designs is what to do with all of it. The oxygen tank, the smaller of the two tanks inside the ET, was itself much larger than the entire Space Station Freedom. Additionally, getting access to the interior was possible though "manholes" used for inspection during construction, but it was not clear if realistic amounts of building materials could have been inserted into the tank after reaching orbit. Nevertheless, the problem was studied repeatedly.