Mars rover, hypersonic flight show history moving forward

We may be going through one of those cycles where history doesn't so much repeat itself as pick up where it left off.

The successful expedition of the Martian rover Curiosity seems to have rekindled our interest in space exploration after first we allowed the lunar landings to lapse and then retired the space shuttles.

Now there's serious talk of a more aggressive exploration of Mars and even deeper space exploration, perhaps a landing on Titan, the most planetlike of the moons of Saturn. Private companies are seriously discussing mining missions to an asteroid.

In the late 1950s and early '60s, it was assumed that the next step in air passenger travel would be supersonic aircraft. The United States was well on its way to building such a plane, the SST, but concerns about noise and atmospheric pollution caused Congress to kill funding for the venture.

The British and French persisted with the Concorde, but the plane was cramped, the fares high and many destinations off-limits because of noise considerations. The Concorde was retired from service in 2003.

The U.S. Air Force is now testing the Boeing-designed X-51A WaveRider, which is designed to fly at hypersonic speed, about 3,600 mph.

According to the Los Angeles Times, NASA and the Pentagon are funding hypersonic-flight research at three sites. There have been several test flights of hypersonic craft, but each has encountered some kind of technical difficulty.

The current test calls for the WaveRider to fly at Mach 6 for 300 seconds.

The Pentagon is interested in the military aspects of hypersonic flight. Notably, Osama bin Laden escaped a cruise-missile attack in Afghanistan because it took the missile 80 minutes to get there. A hypersonic craft would have done it in 12.

Robert Mercier, deputy for technology in the high-speed-systems division at the Air Force Research Laboratory in Ohio, told the Times: "Hypersonic flight is one of those areas that is a potential frontier for aeronautics. I believe we're standing in the door waiting to go into that arena."

At 3,600 mph, a flight from Los Angeles to New York would take about 46 minutes. Of course, you would still have to arrive at the airport two hours early to find a parking place and allow enough time to clear security. And then there would be the inevitable delays because of bad weather at Chicago's O'Hare.