There are the obvious things, like health insurance, immigration policy and the like. Whenever I cannot at all understand a certain action of the PotUS, like, for example, the scaling down (or closing) of two National Parks in Utah (Bears Ears and Grand Staircase-Escalante), I'll do a little research and find: the action is undoing some former act of Barack Obama.
Each day I get more and more convinced, that Mr Trumps only motivation is the extinction of the traces of his predecessor. As cited: it is not about Moon or Mars, it is about "abandoning plans set by his predecessor Barack Obama, to send humans to an asteroid near earth". Therefore it is absolutely unimportant, if the program gets funded or executed. The directive has fulfilled its purpse by rescinding an Obama act.
I am into archaeology and history. Extinguishing the traces of the predecessor is a very common pattern in history, you know, like chiseling away the former pharao's name from the temple walls. Alarmingly archaic, primitive and despotic.
Even the most absurd actions of the US president become completely reasonable, when seen in this context.