Curtis L.
Hemenway, physicist, electronics researcher, educator
and space scientist, was born in Hope, Maine, in 1920, the son of
a mathematics professor father and a research chemist mother, his
own science career was slow to take off. A self described "goof
off" in high school and college, he only got serious while working
on radar during World War II. He went on to earn a B.S. from Colby
College, a doctorate in physics from Rutgers in 1949, and a
faculty position at Union College. Until 1955, his specialty was
electronics. He had focused on teaching, and had published a
textbook. Then, on sabbatical in 1955 at Harvard, he studied with
Fred Whipple, an astronomer specializing in the solar system.
In 1949, Whipple had made a stir by proposing that the earth
was being bombarded daily by many tons of particles from space
that were too tiny to burn up in the atmosphere. Their high ratio
of surface area to volume meant they radiated energy rapidly
enough to keep them cool enough to survive atmospheric entry.
Whipple named these particles "micrometeorites,"
a name that came to refer specifically to objects less than a
micron (millionth of a meter) in diameter. Here, it appeared, was
an inexpensive low cost supplement to space exploration. "The
writer heartily encourages the collection and study of
micrometeorites, as they may provide the only laboratory samples
of cometary material," Whipple wrote in 1949 If these particles
could be collected, separated from those of earthly origin, and
carefully analyzed for age, structure and chemical composition,
they might give clues about the primordial material from which the
solar system was made.
Hemenway saw micrometeorites as an appropriate research focus
for a new era. He got an opportunity to pursue this opportunity in
1956, when he was named director of the Dudley Observatory,
succeeding Benjamin Boss,
who had directed the observatory since 1912.
Hemenway proceeded to change the research emphasis of the
observatory from astrometry
to micrometeorite studies. Even before Sputnik was launched in
1957, the coming years seemed to be shaping up as a "space age."
He envisioned an institution that would not only do research in
space science supported by external funding, but would also assume
a growing educational role in the community and the academic
world. Within a few years he was being heralded in local
newspapers as "A Jet Age Astronomer". As a consultant to the
Defense Department he was warning that the Russians "are ahead of
us" in astronomy. "World War I made the chemist important in
society. World War II brought the physicist into his own, and the
preparation for World War III is making the astronomer important,"
he told the Schenectady Kiwanis Club in 1958. 5
His style as well as his message reflected the new era. "We
don't just look at the stars," he told the reporter. "We go out
and grab things."
Hemenway also helped found an Albany Astronomy Club (which
later merged with a similar group in Schenectady to create the
Albany Area Amateur Astronomers). With his wife Vivian, he formed
the Friends of the Observatory to solicit public support for the
Dudley. Vivian would also later write an astronomy column for an
Albany newspaper.
In 1963 Hemenway resigned from Union (giving up a tenured full
professorship), and added to his Dudley title the additional one
of head of the Department of Astronomy and Space Science at
SUNY-Albany. Dudley researchers might hold joint posts at both
institutions, receiving a salary from the university, and
obtaining external contract funding through the observatory.
Hemenway's space research was initially supported by the Air
Force Cambridge Research Laboratories. A high point of this work,
in June, 1960, was participation in an AFCRL effort that resulted
in the Dudley's first collection of particles from space by means
of a rocket.
By 1964 he had looked for micrometorites at successively higher
altitudes, published papers describing his results, and obtained
Federal funding for ongoing efforts. The search had begun on
mountaintops of the Adirondacks and then moved on to Hawaii. There
Hemenway had pushed air through fine filters, and analyzed the
trapped particles, seeking to separate those recently fallen from
space from those already long on earth. Failing to achieve
definitive results, he extended the search. In 1961, working in
collaboration with the Air Force Cambridge Research lab, he put
collectors on U-2 reconnaissance aircraft. In 1963, he put them on
balloons.
In 1963, he put collectors of a new design on rockets, in an
apparatus designed by the Air Force Cambridge Research
Laboratories called the "Venus flytrap". The detectors left the
ground covered by a metal hood that was programmed to open up at
high altitudes. This exposed pieces of metal or cellulose about
the size of microscope slides, with the intent of trapping or
registering the collision with any micrometorites that might be
encountered. Rival groups pointed out the possibilities of
contamination, and proposed a control method that Hemenway and his
team eventually adopted. In this "shadow" technique, metal
particles were sprayed from a filament at predetermined times,
providing markers for indicating the time interval, and therefore
the approximate altitude, when and where a particle was
encountered.
Hemenway went on to develop experiments carried on the Gemini
and Skylab space missions involving both the search for
micrometeorites and the study of the survival of living organisms
in space, and also carried out studies using rocket borne
apparatus on the relation of micrometorites to high clouds called
noctilucent clouds. . This reseach led to a controversial 1972
paper in Nature entitled "Stardust". "Heavy metal particles have
been detected in noctilucent clouds," the paper declared.
"Possible sources for these particles are considered and a solar
origin is suggested."
Hemenway's research also covered such topics as the development
of apparatus to study the tiny particles collected in space, and
the use of electronic cameras to photograph meteor tracks. He
continued to direct the Department of Astronomy and Space Science
at the State University of New York at Albany until 1976, and the
Dudley Observatory until 1977. After his departure from those
posts, he returned to his native state of Maine, where he died in
1982.
