Evening star., 1946-12-01
Boiling Temperatures
Pose Flight Problem
Weather Scientists Report 2l6
Degrees at 75-MiIe Altitude
su Thonlas r. Henru

By Thomas r. Henry
Seyenty-five miles above the earth's
surface-in a region which may be
trayersed regularly by space ships In
few years-the average daytime temper
ature stands at 2l6 degrees FahrenheiD
above zero, higher than the boiling
point Of water.
This is the figure calculated by o
committee of experts headed by Or.
Harry Wexler of the United States
Weather Bureau, working under the di-
rection of the National Committee on
.Aeronautics to determine physical con-
ditions in the upper atmosphere as q
basis for stratosphere and troposphere
weather predictions which may be re-
quired in the near future.
They have arrived at an approximate
table, as follows:
The temperature goes down steadily
with increasing altitude until 1t reaches
an average of minus IS degrees cent?
grade some miles up.
It remains constant at this figure to
a height of approximately IA miles.
Then 1t goes up again until it reaches
close TO 110 degrees Fahrenheit at 20
miles. At an altitude of 80 miles the
temperature is about I'll Fahrenheit.
1t remains constant again until an
altitude of little over 35 miles is
reached Then it drops sharply up TO
48 miles, where it is little less than 100
degrees Fahrenheit. This remains fairly
constant up to about so miles.
From this point up the temperature
mounts very rapidly at least
ZIG degrees Fahrenheit somewhat above
the boiling point of water-at an alti-
tude about go miles.
Conditions at any greater attitudes
remain completely unknown. DR.. Wexler
says. Presumably the temperature con-
tinues to go up as far as the utmost
limits of the earth's atmosphere.
These figures were calculated from
compilations of all existing data and viii
be official until they are changed by
actual observations. The highest direct
measurements which have been made
extend only to above 20 miles, the limit
to which it has been possible to send
radiosondes. the robot balloon-carried
weather observers" which automatically
radio their recordings of temperature,
pressure, ETC., back to observers ON the
ground. Up to this height they confirm
theoretical calculations.
x4*
A great deal can be deduced, however,
from observations of shooting stars,
sound echoes from layers Of the high
atmosphere and radio probes Of the elec-
trical layers at various attitudes.
The figures leave little doubt that a
troposphere trip across the top of the
world will be much like flying through
a hot furnace. 1t may be possible, how
ever, to provide appropriately air-con-
ditioned cabins. There will be far
greater differences between day and
night temperatures than at the surface
of the earth
The situation is complicated by many
factors. Rough calculations indicate,
however, that human being exposed to
full MONDAY sunlight about 10 miles
above the earth-the season would make
no diference-soon would build up q
body temperature OF nearly 1000 degrees
Fahrenheit. This would mean that he
would almost Immediately boil to death.
His means of losing heat by aridiation
through the thin air would be close to
NIL.
The figures admittedly are crude and
preliminary. The committee still con-
Siders the day of rocket ships some
years in the future. They want to have
a reliable forecasting ready when the
demand comes. Already, however,
planes have reached heights where air
conditioning of cabins against heat is an
important problem.
North American Newspaper AIlianee)