A nyone who has ever been around children, or perhaps even been one, knows the different stages of growth that lead to adulthood. We begin with wonderment and exploration — usually in the form of play. New things are tried, tasted, tested and discarded as we grow. Each new toy, game and experience grows old quickly as we develop. Over time the things we learned yesterday through play begin to apply more and more to our lives, and we are not so quick to discard them. Eventually, as we move into adulthood, they become ever more permanent. We gain expertise in areas we need to survive and prosper. From games to hobbies to study to business and career, our horizons grow longer. Our material possessions go through this shift too, from toys to transportation, from shared bed to dorm room to renter to home owner. Eventually, we become adults, and are ready to start the next generation.

This analogy fits the opening of space well. Reaching upwards to touch its edges with tentative hands, ever higher we have risen to explore and experience its promise. With shiny complex toys we have ridden out into it, leaving trails of discarded parts behind us. With great excitement we raced each other to the Moon and tottered across its surface on unsteady legs, until that game grew old and we went home. With proclamations of seriousness we built ever more elaborate play forts, abandoning them when they grew boring. With endless patience our believing cultures bought us a stream of new toys, which we used and discarded, over and over again. And now we say we are serious yet again. Just as childhood flows into adulthood, perhaps we are now ready to shift from play to life beyond the protecting arms of mother Earth. Perhaps we are at last ready to move outside of our home to begin the next stage in the expansion of the family of man.

And there it is. The key and defining moment when a child becomes an adult, when toys are no longer toys, but tools, when games have taught their lessons and play becomes the work of survival and prosperity. But if this is so we must stop acting like children.

We are on the threshold, but to step beyond it, we must learn the harsh realities of life. We can no longer look to that endless stream of tax dollars from mom and dad to pay for our play. In particular, we must realize the only thing about the “expendable” space program that is “expendable” is the idea itself. Our job is to break free. To come up with the mortgage we need to lower costs and create wealth and jobs in space. We must create an industrial economy in orbit.

Instead of elaborate and expensive toys and forts made to be thrown away, we must design technologies and facilities that are useful and useable, robust and reliable. Instead of built in obsolescence, we must build for real permanence. We cannot leave trails of cast-off parts behind us, as if magic money will appear to buy us more. We must learn how to make machines and structures last for as long as possible, and go further, planning in advance how to recycle them once their first purpose is done, and how to pass them on to others for new purposes. A lunar lander, a space station, a Moon base — anything that is carried into space has immense value, simply by being there. And there is always someone ready to do something with it. This is the way of enterprise, the way of the frontier .

As I write this Americans and Russians are circling overhead in a space station I opposed. The international space station (ISS) cost too much, is imperfect, too complex, in a bad orbit and I am told it smells funny. But it is there.

Now I hear some want to throw it away. The folks gave us almost $100 billion to build it, and I don’t think they would like that. It holds air, has power and is made of tons of processed high-value material that if it isn’t up there already, someday someone else would have to carry it up or manufacture it. Once before I and others tried to save a cast-off toy from our childhood in space called Mir. We were too late, and faced too much opposition from those who wanted a shiny new toy. Now we have it. This time we have the time to make it useful. Let’s do it.

One building does not a community make, be it Mir or ISS or Bob Bigelow’s facility. Economies of scale apply, the more the merrier. There is much more to be said and decided regarding how to do it in a way that helps all, both public and private, but let’s decide to do it now before it is too late once again.

Keep ISS alive.

Rick Tumlinson is a founder of The Space Frontier Foundation.