NASA in the 1970's: Let's build a really efficient engine for the Shuttle, it doesn't matter if it's expensive because we'll be bringing them back after each flight.
NASA in 2010: We need an engine for the SLS, let's use the RS-25. Who cares if we're throwing them away into the ocean after each use?
(They're planning to use ex-Shuttle engines for the first flights of the SLS. Taking what would otherwise have ended up in museums and dropping them in the Atlantic.)
Biting the hand that feeds IT
