Prototyping

 I recommend to students that they develop both hardware and software incrementally. A.s.a. H. software, for example, was developed incrementally and in modules*: inputing and saving cases, normalizing, comparing to past cases,** finding match(s)**, making any predictions, updating matching old cases and adding new cases, making extrapolations** and interpolations, etc., etc. Slowly adding functionality. For hardware like mobile robots I would develop chassis, arms, grippers, sensors, navigation, etc. as individual prototypes, get them functioning, and then seek to combine and coordinate them.

* each tested individually (I favor modularity whenever possible but I do not favor object oriented programming.)

** individually trying out and comparing various algorithms

When would we need humans in space?

 Military space stations like the American Manned Orbiting Laboratory (MOL) and the Soviet Almaz were rendered obsolete* by robotic spacecraft.** Studies are needed to determine what tasks really require humans in space.*** Any such list is presumably going to be reduced as AI and robotics technologies improve over time. 

* Have studies with Tiangong done anything to change this conclusion?

** Reconnaissance, communication, navigation, weather, intercepter satellites, etc. and, for example, today's Boeing X-37. Note the use of specialist robotic agents once again. Notice also that they are not of a  humanoid form.

*** If the Hubble robotic repair mission had been pursued purely as an experiment then it might have helped to establish some of these limits. And, if you ever wish to repair something (be it by humans or by robots) you should design it with that in mind from the very beginning. (Not to say that "single use" items should not exist. But they stay "single use.")