Lisa's First Word promotion due to the 1984 Summer Olympics boycott by the Soviet Union, as happened to Krusty. At one point in the episode, Dr. Hibbert refers to Olympic gymnastic medalist Mary Lou Retton. In its original American broadcast, "Lisa's First Word" was watched by 28.6 million viewers, the most-watched episode of the season. It finished thirteenth in the ratings for the week of November 30 to December 6, 1992, with a Nielsen rating of 16.6. The episode was the highest-rated show on Fox that week. It acquired the highest national Nielsen rating of the show since the season two episode "Bart
Liquid apogee engine The apogee engine traces its origin to the early 1960s, when companies such as Aerojet, Rocketdyne, Reaction Motors, Bell Aerosystems, TRW Inc. and The Marquardt Company were all participants in developing engines for various satellites and spacecraft. Derivatives of these original engines are still used today and are continually being evolved and adapted for new applications. A typical liquid apogee engine scheme could be defined as an engine with: To protect the spacecraft from the radiant heat of the combustion chamber, these engines are generally installed together with a heat shield. Apogee engines typically use one fuel and one oxidizer.