Ask A Scientist© Environmental Science Archive

Author:      bob w whitbeck
What kind of fuel do space shuttles use?

Response #:  1 of 1
Author:      jade hawk
It depends on what you mean by "space shuttle" -- the official name is Space 
Transportation System (ever wonder what the "STS" stands for in the mission 
names?).  For launch the STS uses 2 systems: the main engines in the orbiter 
that burn hydrogen and oxygen from the external tank (the great big orange 
cylinder that the orbiter is attached to for launch); and the SRBs (Solid 
Rocket Boosters) that burn a solid rocket propellant that is a mixture of 
powdered aluminum and ammonium perchlorate.  These are used only for launch.  
The orbiter (what most people think of as "the Space Shuttle") has two 
propulsion systems: OMS (Orbital Maneuvering System) used to change orbit and 
to return to earth, and the RCS (Reaction Control System) used for station-
keeping and attitude control.  Both systems burn hydrazine with oxygen.