PUSH

Of course, the space programmes have absorbed billions of pounds and have solved particular technical and technological problems, the fruits of which Iound applications elsewhere.

Nevertheless, the development of high-speed, compact computing systems was not essential in convincing early sci-fic writers and early rocket pioneers of the feasibility of leaving the earth's surface and going into space.

Their convictions rested very firmly on a basic law of nature which had already been demonstra years bies rocket he cineme Firework Strange as it may . appear, stripped of the electronic minutiae; the mighty Saturn v or Soyuz launcher is nothing but a refined firework rocket in principle.

Yet, an obvious objection is often raised when such a parallel is made. We can accept that a rocket 'pushes' in order to rise, but what does it push against? While it remains within the atmosphere, the obvious answer is 'the air', but a spacecraft (we hope) soon finds itself in a vacuum. What then?

The objection is, in fact, based on a misconception.

The possibility of any form of propulsion depends on a very simple and almost self-evident principle recognized by Isaac Newton and embodies in his third law of motion-'To every action there is an equal and opposite reaction'.

When a man walks forward, the earth moves backward at each 1. step by an infinitesimal amount. If he attempted to skate on a completely frictionless ice, he would be unable to move parallel to its surface. FASCIST groups, financed from Greece and organized on military lines, are trying to create a 'climate of fear' in the great cities of Italy's industrial north, a young Italian socialist warned in London earlier this week.

Fill in the form below and SECRETARY, SOCIALIST 186A CLAPHAM HIGH ST, Name Address Here action and reaction are the equal and opposite frictional forces acting on the man (through his feet) and the earth.

The same applies to cars, ships and aircraft. They all react, through tyres, screws or propellors on the medium that supports them.

Example

We can best grasp the way a rocket operates through the following example:

Imagine a man standing on a light sled, and let us assume that he carries a pile of bricks. The sled rests on a sheet of frictionless ice.

The man takes one of the bricks and throws it horizontally to the rear of the sled. This action produces an equal reaction on the sled. But because the sled (plus man and load) weighs much more than the brick, it moves off at a correspondingly lower velocity.

THURSDAY'S MORNAHONAI that the Greek colonels' regime plays an important part in financing special combat squads known as squadri, composed of men recruited in the poverty-stricken South and paid to break strikes and attack left-wing meetings.

'Only a few days ago, when I was in Milan,' Franco said, 'a send to NATIONAL LABOUR LEAGUE, LONDON, SW4.

In fact, if the total weight was 1,000 times the weight of the brick, it would move at onethousandth of the brick's veloHowever, whatever happens to the brick after it leaves the man's hand, the sled will continue at the same speed.

If the passenger now repeats his performance with a second brick, his speed increases again but this time it will be a larger increase because the reaction is acting on a smaller mass (by one brick).

The last brick that is thrown has the greatest affect.

What is important is that this method of propulsion is independent of any external medium.

Continuous

The analogy with a rocket is clear, the main difference being that is ejected from a rocket continuously and not in separate lumps. Italian youth fight growth of fascism Babila, which is these gangs.' Mussolini used the same para-military system of armed gangs to break the labour movement, first in the Po Valley and later in the rest of Italy, during the early 1920s.

Policy

"This new tactic results from a change of policy on the part of the leaders of the fascist movement. Three years ago the MSI [Social Movement of Italy--the main fascist organization] had a parliamentary policy.

Its policies appeared to be watered down, and didn't disturb the revolutionary left very much.

"Then the big strike movement began in the factories, and the fascists' main stronghold in the universities was threatened by the students.

'After that they began to infiltrate into left-wing movements, and create provocations. In Milan, they organized bombing outrages which were If we want to close the analogy gap, we can provide our passenger with a supply of water, a pump and a hose pipe!

To emphasize the main point: in a car, ship or aircratt, matter is chemically changed (burned) to provide the energy for turning a wheel, screw or propellor which interact with road, water and air respectively.

The burnt residues appear as useless exhaust wastes.

In a rocket, fuel is burnt in order to provide the most energetic exhaust material which provides the continuous push required.

Mass is mass. No matter how thin the gas, if it's fast enough and in large enough quantities, it can lift a 3,000-ton Saturn vehicle into space!

Essentially, a rocket motor consists of an enclosed spacethe combustion chamber - in which the fuel burns and a nozzle through which the hot, expanding gases can escape.

That being the case, it becomes blamed on the anarchists. They were able to get into the anarchist organizations because these organizations had very little discipline.' Provocations organized in this way gave the government an excuse for a clamp-down on left-wing groups and in the witch-hunt that followed more than 20,000 people were arrested.

This was an attempt to prevent any link-up, between the militancy of the working-class -expressed in continual strike struggles, revolts like the rising in Reggio Calabria and in huge demonstrations-and the left-wing organizations.

Comparison

The centre-left government in Italy, Franco said, puts forward the idea of 'opposite extremisms' in order to justify their clamp-down. According to this conception, extreme left-wing movements are just as 'dangerous' as the fascists.

Of course, in practice, the fascist squadri are able to operate under police protecclear that the atmosphere, far from being necessary for the rocket's functioning, actually hinders it, by interfering with the expansion of the exhaust gases!

For this reason, the rocket thrust increases by about 10 per cent when outside the atmosphere.

Fuels

Clearly, from our example of the bricks, the speed which our rocket can attain will depend on our fuel supply and the exhaust velocity.

Contrary to , appearances, the firework rocket's black powder is a very poor fuel with an exhaust velocity (ev) of about 700 mph. • A modern solid fuel can provide an ev of around 5,000 mph and the hydrogen-oxygen mixture of the Saturn vehicles 8,500 mph.

(The experimental nuclear rockets that are now being developed have exhaust velocities of over 20,000 mph. Howtion, and are not subjected any repression, Franco said.

'In fact, the fascists always work in conjunction with the police, " he added. 'And they are able to get away with it because the Communist Party makes no attempt to organize workers to drive the fascists off the streets. moon and back.

Some of the useless cargo can be dispensed with and this has given rise to the concept of the step rocket which has made moon shots possible.

The modern rocket consists of a number of huge fuel tanks fitted together. Once the fuel in one is consumed, the tank is jettisonned and so on.

Store

In an Apollo flight, therefore, the largest proportion of the craft never leaves the atmosphere!

An obvious improvement on this procedure is to store fuel in orbit and this will be one of the reasons for building permanent space stations.

From all these considerations, it is clear that the space age has only just begun. The rockets of today are still unwieldly and lumbering monsters, unsuited to space exploration.

The breakthrough in rocket propulsion is not predictable, but it must provide a source of energy that outstrips our present chemical fuels many times over.