published in Moscow.

biti Thi ty |

| BEGINNING A=NEW SERIAL

os is the first of a series of extracts, appearing exclusively in the Pacific Tribune,

from a remarkable new Soviet book, Interp

lanetary Travel, by A. Sternfeld, recently
An English edition of the book’is to be published in, Britain soon.

This first extract deals with the problems of overcoming the earth’s gravity, already suc-
cessfully solved by Soviet scientists.

HE EARTH, one of the nine
large planets of the solar
System, travels at a great speed
in airless space along an. al-
Most circular orbit around the
Sun, at a distance of over 90
Million miles from it. This dis-
tance is taken a sone astronmi-
Cal unit.
TThe other eight large plan-

ets — asteroids — travel ap-

Provixately in the plane of the
Same orbit.

Interplanetary space is limit-
€d by the orbit of Pluto, the
Outermost planet of the solar
System, which is separated
from the sun by a distance of
Nearly 3,750 million miles.

It is this bounndless. ex-
Panse that space ships will
Cross, making use of the sun’s
attraction, or struggling
against it and evading collision
With’ wandering meteors and

Swarms of asteroids.

What prevents us from
lauching a rocket into space?

The major obstacle is the
force of gravity.

All things around us pull at
ach other, but we do not feel
It because their power of at-
traction is too weak. On the
ther hand we always feel ter-
Testrial gravity.

Ts it possible for a rocket to
leave the earth and never to
Teturn?

_per second the

Yes, it is. Let us imagine
that a horizontal launching site
has been constructed on a high
mountain, where air is no
longer an obstacle to the roc-
ket’s flight. :

A rocket launched from such
a site at a certain speed would
follow a steep trajectory and
fall at a certain distance from
the mountain.

The speed of the rocket can
be increased to a point where
the curve of the rocket’s tra-
jectory is the same as that of
the earth’s surface.

As soon as this point is
reached the rocket can fly
around the earth and circle it
again and again.

Why does a body not fall to
earth at this speed?

When an aircraft flies around
the earth, along the equator
or a meridian, it is affected by
a centrifugal force which in-
creases in proportion to its
speed.

This force is in opposition to
the pull of gravity and strives
to lift. the aircraft away from
the earth.

At low speeds it is almost
unnoticeable, but when the
speed reaches almost five miles
centrifugal
force equals the force of
gravity and neutralizes it. This

a

from the

Like Smoked Salmon?
Here's a Bargain

to You
(No Middleman)

Fisherman

FROM OPERATION
‘STRIKE RELIEF’

ORDER NOW

TAtlow 3254
UNITED
FISHERMEN
and ALLIED
WORKERS UNION

- ~

is what we call the first astro-
nautical speed.

And at what speed must a
body travel if dt is to over-
come the earth’s gravify and
fly off into space?

The earth’s gravitational pull,
like that of the other celestial
bodies, decreases as one moves
away from its centre.

In order to free a body from
a planet’s gravitational field,
the same amount of work has
to be performed as for lifting
it to a height equal to the
planet’s radius, assuming that
the gravitational force does not
change as the body recedes
from the planet’s centre.

We can accomplish that by
giving the body a certain speed
near the surface of the earth.
A body going at that speed
would travel along a parabola,
and this is the origin -of the
term parabolic speed, which is
also known as the second astro-
nautical speed or “the speed
of escape.”

At the earth’s surface it is
seven miles per second.

To facilitate calculation I
have assumed that the body is
attracted only by the earth.

Actually, however, it is also
affected by the sun’s gravita-
tional field.

Calculations show that a
speed of not less than ten
miles per second is required to
set a body free from the gravi-
tational fields of the earth and
the sun. ‘

This is called the third astro-
nautical speed.

Bx

It is generally accepted that
any future space ship will be
rocket driven.

Travelling by rocket is quite
safe because the rocket, as dis-
tinct from an artillery shell,
gains momentum gradually.

Since the speed of a rocket-
propelled spaceship through
the atmosphere will be rela-
tively low, the ship will not
with much air resistance, and
heat due ta friction will be in-
significant.

What is the principle of the
rocket’s motion?

The type of rocket with a
gunpowder charge that is
launched at a carnival cannot
be used as a motor for the
spaceship, because of the very
high pressure set up by the
combustion of gases,

The liquid-fuel rockets ex-
tensively used nowadays are
superior to gunpowder rockets
in this respect.

Both gunpowder rockets and
liquid-fuel rockets depend for

the steadiness of their flight
on air fins and rudders.

But these are of no use once
the rocket has left the earth’s
atmosphere and emerged into
space. What are the astronauts
to do if the rocket is deflected
from its route?

This problem was solved by
K. E. Tsiolkovsky, who sug-
gested that rudders be placed
in the stream of gas emitted
from the nozzle in order to
change the direction of the
rockets flight in empty space.

w

On what factors does the
rocket’s speed of travel de-
pend?

In empty space, beyond the
reach of gravitational fields,
the velocity that can be at-
tained by a rocket depends on
the speed with which the gases
leave. the nozzle and the
amount consumed.

In view of this, use will be
made of those fuels which pro-
duce the greatest possible ex-
haust velocity, for example
oxygen and hydrogen.

Nitric acid and hydrazine (a
chemical combination of nitro-
gen) are more economical, in-
asmuch as these liquids are
easy to handle and can be con-
tained in small tanks.

Other liquid-fuel rocket pro-
pellents are benzine, turpen-
tine, paraffin, etc., with hydro-
chloric acid, hydrogen per-
oxide, etc., serving as oxi-
dizers.

Thermo - chemical (conven-
tional) propellents produce ex-
haust velocities of about one
and one half mile sper second,
but there are good reasons for
believing that a speed of two
and one half miles per second
can be reached, which would
simplify the problem of con-
structing a spaceship.

Another method of increas-
ing the rocket’s speed and
range is to launch it with an
auxiliary rocket. When ‘the
latter uses up all its fuel it
is automatically jettisoned,
the touch-down being by para-
chute.

The main rocket is fired only
when the auxiliary has done
its job — that is when it has
reached a certain height and
speed, and it can ‘therefore
climb higher than an ordinary
rocket.

To increase exhaust velocity,
conventional propellents
should be replaced by nuclear

propellents.

Modern physics has succeed-
ed in converting a number of
chemical elements into other
elements. In certain cases the
process is accompanied by a
release of atomic energy.

October 25, 1957 —

The conquest of space

A material that produces
such energy is known as a
nuclear propellent, a small
quantity of which contains
to convert certain liquids (for
example, liquid hydrogen or
helium) into gas and then to
expell it from the rocket.

Atomic energy can be used
enormous energy.

Nuclear propellent with a
liquid or gas is called “atomic
fuel.”

One must bear in mind that
the terms “nuclear fuel’ ’are
used here only conventionally,
since the release of atomic
energy and its transfer to an
inert body bear no resembl-
ance to the process of burning
as we know it.

In an atomic rocket the gases
will leave the nozzle at a speed
of several dozen miles per sec-
ond, and the greater the ex-
haust velocity the less fuel is
required for interplanetary
travel. This is a big advantage

‘of the atomic rocket.

Although the atomic rocket
does not differ in principle
from the ordinary types of
rockets, fhere are a number
of technical difficulties pre-
venting its construction.

In the first place the extra-
ordinary high temperatures
and pressures arising in the
atomic rocket must be reduced
because no metal can with-
stand them.

Secondly, measures must be
taken to protect the astronauts
from the radioactive radiations
which are released at the same
time as atomic energy.

To tackle the problem sec-
cessfully a material must be
devised that would absorb
such _ radiations and would,
at the same time, be light, be-
cause excessive weight would
considerably reduce the
rocket’s range.

® A second extract on space-
ship desgn will appear next
week.

Gcs Installations

FURNACES — STOVES
WATER HEATERS

Harry C. Weinstein
GAS CONTRACTOR

692 East Hastings
MUtual 3-5044
Res.: AL. 2991-L

FREE ESTIMATES

PACIFIC TRIBUNE—PAGE 9