Gov surplus for sale: Good airframes, high mileage, a bit tricky to operate

[Pangloss]

Given how much we've been spammed lately I thought the subject line might amuse. This thread is, of course, about NASA's announcement of plans to sell off the Space Shuttles after the program ends in 2010. Apparently they're exploring the idea of allowing a museum, school, or other institution to have a shuttle if they're willing to help pay for the cost of getting it there.

 

I think it's a great idea, and I think at least one of the shuttles should go to a little-known air museum in some rural backwater that's not even serviced by a major interstate highway. Something next to an airstrip with faded numbers, a beat-up Navion, and a place at the end of the runway where people sit around and watch the airplanes take off and land.

 

I don't mean that as a symbol of what I think of the space program, but rather as a salute to the true, almost forgotten spirit of aviation. That'll never happen, of course, because the idea of a shuttle -- the epitome of American engineering and accomplishment -- fading and forgotten under the elements will never even be considered. Ah well.

 

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On a related note (and just to add a little diversity to the thread), when I was coming here to post this and pondering the subject line, it occurred to me to wonder how much mileage these puppies actually have on them. "Billions", I assumed -- after all, they fly at Mach 25 for two weeks, surely a massive number, right? But then I got to thinking -- they don't exactly fly all that often, do they? Most of the time they're just sitting on the ground.

 

So I looked around a bit and found this information in the Wikipedia:

http://en.wikipedia.org/wiki/Space_Transportation_System

 

Columbia: 125,204,911 miles (1981-2003) (22 years)

Challenger: 25,803,940 miles (1983-1986) (3 years)

Discovery: 115,140,673 miles (1984-Present) (24 years)

Atlantis: 89,533,755 miles (1985-Present) (23 years)

Endeavor: 90,347,054 miles (1992-Present) (16 years)

 

Still quite large numbers, of course. But I thought it would be interesting to compare those values with those of typical commercial airliners, which of course fly a lot slower, but they fly on a daily basis for 20 years or more. Unfortunately I couldn't find a great source for this, but I did find one promising piece of information:

 

http://en.allexperts.com/q/Aviation-Flying-1651/shelf-life-aircraft.htm

A "service life of 20 years" is as generalization that figures 51,000 flight hours and 75,000 pressurization cycles for most aircraft. If an aircraft is used on long haul routes it experiences relatively few pressurization cycles in it's "life" it will last far beyond 20 years.

 

Working with that "51,000 flight hours" figure seems the most convenient. If we assume a speed of 600 mph (taking a high figure to get an outside value) we get 30,600,000 miles. Comparing against the shuttles with >20 years in service we see that the shuttles come out well ahead (especially Columbia -- wow!).

 

Now some airliners do fly for 30+ years, and could presumably produce much larger figures, but of course they're not always moving at 600mph -- takeoffs and landings, holding patterns, etc, all take place at much lower speeds. So I think it's clear that the advantage goes to the STS here. And by the time the shuttle program ends we're going to see at least 26 years (on Discovery) and possibly more. (Looks like Discovery could break Columbia's record, doesn't it?)