"stretching the limits of current human capacity - but not exceeding them"
That means "feasible".
As for inexpensive, it may be a poor word choice, but the alternative is launching rocket after rocket in to space, which is one of the most expensive things humans do.
That means "feasible".
As for inexpensive, it may be a poor word choice, but the alternative is launching rocket after rocket in to space, which is one of the most expensive things humans do.