While a 5/5 indestructible beater sounds like a reasonable threat at first glance, considering that Historic will likely heavily feature Teferi, Hero of Dominaria, Teferi, Time Raveler, and Oko, Thief of Crownsall of which incidentally answer a 5/5 indestructible Darksteel ReactorI'm not sure the plan will actually be competitive
However, Alara is such a popular plane and Wizards constantly makes callbacks to it, I suppose they'd rather save that story for a main block instead
36 lands worries me, but with Hakbal in the command zone it's probably enough assuming we can explore a couple times
Once played, these cards remain in play until you or an opponent do something to remove it
Its got high synergies with spacecraft, so you can fetch one and help station it