WHAT FUTURE FOR SPACE EXPLORATION, II. "To make a business out of flying reusable rocket-powered vehicles, you need to fly more than once a day, not just every couple of weeks." That sounds like a shuttle operation. It's XCOR chief engineer Dan Delong describing progress with Dick Rutan's E-Z Rocket. They're still a long way from a going commercial proposition. But it's time to think anew about the roles of rocketry, and the role of government in those roles. Paul Krugman is not the only commentator to suggest, "It's an open secret that the only real purpose of the International Space Station is to give us a reason to keep flying space shuttles." Here is a prescient 1998 column by Rocket Boy Homer Hickam: "What we will see in the next five years, then, is a NASA that is going to build the ISS, exhausting our shuttle fleet and its supporting personnel in the process. If we're lucky enough not to have a shuttle failure, or wholesale resignation of disgusted NASA engineers, the result of all of this expenditure of effort and money will be some linked trailers in space which we will grandly call a space station, a station, unfortunately, in name only. Its inclination will be too northerly to use for an efficient crewed flight to the moon or moving out along the plane of the solar system to Mars or anywhere else." He's not done: "These two programs [the space station and the shuttle] continue to dominate NASA and will, if we continue to let them eat our space agency alive, ultimately strand us as a space-faring nation as surely as the payloads aboard our recently misfired rockets." Ultimately, Hickam, also, would like to go to Mars, but with something other than chemical-fueled rockets.

But basic research and development, and interplanetary missions, are something different from placing satellites in orbit. Happy Fun Pundit, who has some thoughts on the role of government in space exploration, hasn't finished his argument. There are reasons to unbundle the interplanetary missions and the development of new rocket engines from the somewhat more routine placement of satellites, particularly commercial satellites, in orbit. There is no reason for the entire space enterprise to be a government monopoly.