Explorer I Engineer Was 91
It is with sadness Aero-News learned
this week Homer J. Stewart, an aerospace engineer who helped
develop the first successful US satellite, died May 26 at his home
in Altadena, CA at the age of 91.
An early pioneer of rocket research, Homer Joseph Stewart was
born in Lapeer, MI, the son of a physicist. After graduating from
the University of Minnesota, the Dubuque, IA native came to the
California Institute of Technology for graduate study in 1936, and
became interested in the early pioneering rocket research that was
being carried out at the time by a small group of Caltech engineers
and scientists -- chief among them Theodore von
Kármán.
Stewart, von Kármán, and others began testing
rockets in a rugged foothill area of the San Gabriel Mountains
forming the nucleus of the research group that would evolve into
the Jet Propulsion Laboratory, according to CalTech.
In 1938, Stewart joined the Caltech faculty, teaching both
aeronautics and meteorology; but for many years divided his time
between his faculty duties and research at JPL. As chief of the
research analysis section, he participated in many rocket projects,
including the WAC Corporal, the Corporal, the Sergeant, and the
Jupiter C.
He was chief of JPL's liquid propulsion systems division when
JPL and the Army Ballistic Missile Agency (now the Marshall Space
Flight Center) developed and launched Explorer I, the first
artificial satellite launched by the United States
His research interests included rocket exhaust velocity
requirements for maintaining the exact trajectories of spacecraft.
He also conducted research in wind-driven energy, using his
knowledge of fluid flow to construct with von Kármán
a turbine known as "Grandpa's Knob."
Built in the mountains of Vermont in the late 1930s, the machine
generated up to a megawatt of power and operated through World War
II in cooperation with a local electrical company. The project was
abandoned after the war, in part because of the easy availability
of cheap fossil-fuel energy.
In the late 1950's, Dr. Stewart worked as the director of
planning and evaluation for the rookie agency, National Aeronautics
and Space Administration. He was in charge of research analysis and
calculating rocket exhaust velocities.
In 1959, he joined German rocket pioneer Wernher von Braun in
testifying before a Senate panel which included then-Senator Lyndon
B. Johnson. In their testomony, both scientists asserted Russian
space technology was a good 12-20 months ahead of the US -- and
that the USSR's missile guidance systems were far along enough to
strike an American city from 5,000 miles away.
This prompted the senate panel to order a "national approach" to
aerospace technology, according to The New York Times.
Stewart served continuously on the Caltech faculty from
1938 until his retirement in 1980.
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