The Russian military claims it’s making progress on a space plane similar to the U.S. Air Force’s secretive X-37B robotic mini-shuttle. That in itself isn’t terribly surprising or even, for the United States, particularly worrisome. Lots of governments and even private companies are working on space planesthat can launch from rockets or runways, boost into orbit for a period of time then return to Earth for quick refurbishment and re-use.The tech is pretty basic. But alone among space-plane developers, the Kremlin is proposing to arm its space plane. With nukes.