41.   This is something new for Delta III because it is heavier than Delta II and needs more control capability than just the main engine.

42.   Today in the West, only the main engines of the space shuttles use this advanced technique.

43.   While strap-on boosters have long been reused, the space shuttle is the only vehicle that reuses its main engines.

44.   Propellant for the main engines on the space shuttle, for instance, is hydrogen and oxygen.

45.   Pessimistic earnings forecasts by some technology companies have raised fears of declining demand for the computer components that are a main engine for economic growth in the region.

46.   At Kennedy, technicians closed the cargo-bay doors of each shuttle and bagged the main engines on the tail to protect against water damage.

47.   Consumer and business investment has been a main engine of economic growth in the past.

48.   Every Space Shuttle main engine is tested at the site, located in a remote part of southwest Mississippi near the banks of the Pearl River.

49.   Every Space Shuttle main engine is tested at Stennis.

50.   Germany, the other main engine behind the euro, is also struggling with high unemployment and budget restrictions and faces an election this fall.