Discovery...

Why did NASA send up Discovery instead of it's two newer shuttles, Atlantis and Endeavor?

Atlantis and Endeavor were designed differently from Discovery, especially in one area...

• Construction of the orbiter Atlantis began on March 3, 1980. Thanks to lessons learned in the construction and testing of orbiters Enterprise, Columbia and Challenger, Atlantis was completed in about half the time in man-hours spent on Columbia. This is largely attributed to the use of large thermal protection blankets on the orbiter's upper body, rather than individual tiles requiring more attention. Weighing in at 151,315 pounds when it rolled out of the assembly plant in Palmdale, Calif., Atlantis was nearly 3.5 tons lighter than Columbia. The new orbiter arrived at NASA's Kennedy Space Center in Florida on April 9, 1985, and over the next seven months was prepared for her maiden voyage.

Granted Discovery went over a major overall, I believe on a naive, common sense level that Atlantis and Endeavor would be better choices to avoid problems. Then again, the space shuttles have been operating since 1979 with one 2 major incidents. Airplanes have been in existance for over how many year? With how many incidents? Again, granted, there's more airplane flights, but still, the risk is low for incidents. I think you have to worry more about cousin Joey spilling spaghetti sauce on himself again at the family reunion then worrying about another shuttle problem. Significantly, though, it has to be done right as St. Vincent said. Those rocket scientists knows more than me about space shuttles, physics, and aerodynamics, so I'll leave the discussion and explanation to them.