Evening star., 1953-08-14
Navy on Second Trip
To Geomugnetic Pole
Group Seeks Spectrum
Of Cosmic Radiation
By Thomos R. Henry


The Navy's second expedition to the
north geomagnetic pole now is under
way.
It will proceed aboard the icebreaker
Staten Island to a point near Smith
Sound, West Greenland, at about lati-
tude 7S north and longitude SO west
the one point in the Northern Hemi-
sphere where there is the least deflec-
ton from the vertical Of cosmic rays
from outer space.
The site is quite different from that
OF the magnetic pole itself-the north"
to which compass needles point-which
is located far to the west in southern
Ellesmere land.
CoSmic rays-elementary particles Of
matter, mostly protons, some of which
come out of space at energies of bill
lions of volts-are DETECTED by the mag
netic field of the earth. The weaker
ones are detected to such an extent
that their path is curved into space
again without hitting the earth's at.
moSphere.
Purpose of Expedition.
A primary purpose of the expedition
will be to get as complete spectrum as
possible of this coSmic radiation, from
the lowest energies to the highest. This
can be fairly well accomplished near
the top Of the atmosphere over the
geomagnetic pole. Once the radiation
has passed any distance through the
atmosphere, the picture becomes quite
confused because of collision with at
mospheric particles. This results in
secondary radiation which reaches the
earth's surface.
An important part of the expedition
will be carried out by group of Scien-
lists from Iowa State University by
means of cosmic ray detection appara-
tus-Geiger counters and cloud cham
berS-carried by rockets which will be
launched from balloons at an altitude
Of approximately 10000 feet. 1t is hoped
that the rockets will attain attitudes of
at least 00,000 feet-Still far below the
absolute upper limits of the atmosphere.
Fourteen flights Of this sort will be
made.
A Naval Research Laboratory group
will attempt to measure atmospheric
pressure, density and temperature at
attitudes above 100000 feet by means Of
instruments mounted in the balloon
launched rockets. Similar experiments
have been conducted at the Army'S
rocket research station at White Sands.
N. Mex, but not in the Arctic, where
conditions may be quite different.
135-Foot Balloons.
Technicians from the research lab
oratories of General Mills Corp. Of
Minneapolis have the primary respon-
Sibility for furnishing and launching
the rocket-carrying balloons. Some Of
these are 135 feet long when inflated
and are made Of plastic material .
thousandth of an inch thick.
The balloon-rocket technique was de-
veloped by DR.. James A. Van Allen at
Iowa State and used for the first time
last summer aboard the Navy icebreak-
er Eastwind. A small rocket with the
essential instruments aboard is lifted to
attitudes around $4,000 feet by the
balloon. At a fixed altitude or time the
rocket is fired almost straight up 1t
enters an almost perfect vacuum where
the only obstacle to its upward flight is
the gravitational pull of the earth.
Last summer one of these rockets
reached a record altitude of 295,000
feet but it is hoped that this may be
exceeded this summer.
Several scientific institutions are pro-
viding instruments whose rcords may
help answer specific problems in which
they are interested. Among these is the
production of mesons, extremely short
lived particles created by the disintegra-
ton of atmospheric atoms, at the ex-
tremely high attitudes where they are
most abundant.
Another special project is the meas
urement of the nuclei of heavy atoms
in the cosmic rays. This may give some
better clue to the outer universe.