To hold down costs, engineers and entrepreneurs are working to make space launch vehicles as reusable as airplanes, from bottom to top. But reusability does not come free, and they conceded the search for financing may apply more drag than gravity as developments continue.

“It costs money to put the systems on a bird to make it reusable,” says former NASA Administrator Michael Griffin. “It costs money to use that system because it cannot weigh nothing. It has to have a mass penalty that is a positive number. And whether the system is on the first or second or any other upper stage, it will be a gear-ratio effect through the rocket equation onto payload. We sell payload.”

It is probably no surprise that the top two contenders in the race for reusability are billionaires with pockets that may be deep enough to get the job done. Even the U.S. government was not able to achieve true reusability with the space shuttle, and so far publicly traded corporations have not done any better. Blue Origin’s Jeff Bezos and Elon Musk with SpaceX have made impressive strides toward aircraft-like operations, but neither has closed the loop yet.

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