On Sunday, some friends and I rode from Los Gatos to Boulder Creek. It’s a more than 50 mile ride, made tougher because it’s hills all the way. According to the folks at Almaden Cycle Touring Club, the route has over 4000 feet of climbing. It’s good practice for our upcoming High Sierra Century in September.
The nice thing about turning around in Boulder Creek is that it gave us an excuse to get coffee and pastries at the cafe in town. Refueling and caffeinating made the ride back much easier.
As we all now know, the space shuttle’s return to flight was not the great success that NASA had hoped for. After spending over 2 years and a billion dollars, NASA still has not been able to solve the problem of insulating foam flaking off the shuttle’s external fuel tank. It was a 1.6 pound chunk of foam falling off the tank that punched a hole in Columbia’s wing, leading to the loss of that shuttle and all aboard in 2003.
As a result of hundreds of cameras and radar that NASA trained on Discovery’s launch, the agency knew that they had problems even before Discovery reached orbit. A piece of foam weighing almost a pound broke off the external tank, but did not seem to strike the orbiter. The astronauts then spent several days searching for potential problems on the orbiter. Fortunately, they were able to resolve the problems in a couple of space walks. Meanwhile, NASA suspended all further launches of the shuttle, until they can track down the cause.
What’s especially frustrating is that the biggest chunk of foam broke off the area around the external tank’s PAL ramp. The tank’s ramps had received special attention, since the chunk that doomed Columbia broke off one of the ramp areas.
In the days since, I kept wondering how NASA had miscalculated so badly.
- Why didn’t they test their tank insulation in a wind tunnel?
Actually, they did, but no wind tunnel can duplicate the extreme temperatures and pressures that the shuttle goes through in hypersonic flight.
- Then why not coat the foam in a hard shell, so that it can’t break off?
It turns out that on such a big tank, even a thin coating of paint adds a huge amount of weight. Apparently NASA even considered, and rejected, attaching some kind of netting to the outside of the insulation, to keep big chunks from flying off.
The agency has said they intend to retire the shuttle fleet by 2010. But they still don’t have a viable replacement. NASA needs something like the shuttle to carry large components of the International Space Station into orbit. Some aerospace companies have proposed alternatives that reuse shuttle components in new configurations. And the Russians recently demonstrated a mockup of their own shuttle design, the Clipper, to replace the Soyuz capsules that service the space station.
Yet despite all our efforts, it seems that manned space flight is a risky business. I remember talking to Dave Williams, one of Canada’s astronauts, at a reunion last year. He had flown Columbia into orbit in 1998. He described how he and the other astronauts helped search for and recover remains of the Columbia crew after the accident. It was a difficult task, made all the harder because it was their friends and co-workers that they were searching for. And yet, given a chance, he would love to fly into space again.
In Slate magazine, Timothy Noah outs Tom DeLay, Opera Buff.
Apparently, DeLay is no mere opera dilettante. He knows his spintos and his verismos and his ariosos, and I guess he must work overtime to keep that knowledge a tightly held secret lest his good-ole-boy constituents in Sugarland, Texas, conclude the Hammer is putting on airs. You probably think I’m kidding, but I’m not. The meanest man in Congress, who used to make his living killing insects, is … the phantom of the opera.
For years, one of the objections to observations of global warming was a discrepancy between ground-based and high-altitude temperature measurements. But as recently reported in Wired news, that discrepancy may have been caused by the way that sensors were installed on weather balloons in the 1970s.