The Space Shuttle’s new lift three
improved Main Engines – provided a flawless launch Monday
boosting Atlantis into orbit at 3:44 p.m. (CDT) on Mission STS-110.

The initial look at the data indicates the launch was smooth and all
three of the new engines performed as expected, said George Hopson,
manager of the Space Shuttle Main Engine Project Office at
NASA’s Marshall Space Flight Center in Huntsville, Ala.

This is the first flight with a complement of three enhanced engines.
The improved engines will make the world’s only reusable launch
vehicle safer and more reliable than ever before.

The enhanced engines – called Block II Main Engines –
incorporate an improved high-pressure fuel turbopump with a stronger
integral shaft/disk and tougher-than-steel bearings.

The new design also eliminates welds in the turbopump by
using a casting process for the housing. This makes the pump stronger
and should increase the number of flights between major overhauls,
according to


The new turbopump is not much larger than an automobile engine, yet it
generates 360 times the horsepower.

A single Block II Main Engine was demonstrated in July 2001 on the
STS-104 mission and again on the STS-108 mission in December 2001.

Pratt & Whitney of West Palm Beach, Fla., developed the new turbopump.

Boeing Rocketdyne is responsible for the manufacture of the Space
Shuttle Main Engine. NASA’s Stennis Space Center in Mississippi
tests the engines.

The Space Shuttle Project Office at Marshall oversees the Main
Engines, the Shuttle’s Solid Rocket Boosters and Reusable Solid
Rocket Motors, and the External Tank.