Sunday, 22 July 2012

Flights into the Future Pt. 02: Can Man Reach the Moon?

This fascinating question is here asked and answered by one who has had a life-long interest in the conquest of the air,  who has studied closely the technical aspects of space-flight, the man who was Britain's first air-reporter,
Harry Harper

One of the finest of all stories is the story of adventure - the story of the men who risked their lives in reaching the North and South Poles; the story of those who struggled to scale the hitherto unconquered mountains; the story of those air pioneers who risked their live in making blazing-the-trail ocean flights.
Epics, these; stories we shall never forget.
Yet man's greatest adventure still lies before him.
Though we have conquered land and sea, and the lower zones of the air, and have even begun to penetrate the stratosphere, we have still to conquer outer space.
We have still to send a great space-ship on that most thrilling of all adventures of a voyage to the Moon.
Can it be done?  Is it possible?
Well, listen to the words of one of the greatest pioneers in the fascinating study of space-flight and of interplanetary communication - that famous French scientist and engineer, M. Robert Esnault-Pelterie.
It was just after he had given a brilliant lecture in Paris on the possibility of a flight to the Moon that he and I were talking together out on the big flying-ground at Rheims, in France.
Above us, as we talked, flew the pioneer aeroplanes which were taking part in the world's first air meeting and aviation display.
"Can we reach the Moon?" said Esnault-Pelterie.  "Just listen to me, my boy.  What getting a rocket out across space from Earth to Moon really means it this.  You've got to have some form of fuel which will give out a huge amount of energy, and yet which will produce all this tremendous power in some form of apparatus which is not too heavy or too big.
"That fuel, whatever it is, must give you enough energy to drive a rocket carrying two or three men up and up through the 200 miles of the Earth's atmosphere and out into those great zones of space beyond; and all the time, don't forget, that rocket as it rushes upward will have to overcome the constant pull of the Earth's gravity, which will be trying to drag it back."
While he was talking, out there on the big plain at Rheims, the world's first flying machines were still droning away overhead.  Esnault-Pelterie, I remember, pointed up to them.  Here, he said to me, was the first stage in that great quest which would take men up through the lower zones of the air into the stratosphere beyond, and then even above that into those vastnesses of outer space.
Presently we were joined by some of the other  pioneer airmen who were flying at that first air meeting - Henry Farman, Louis Bleriot, Alberto Santos-Dumont, and others.  It was so fascinating, that talk of ours, that afternoon passed and evening came, and still we talked on and on.
Science, I remember Esnault-Pelterie saying, should never allow that there was any such word as "impossible."
"People used to declare," he said, "that it would be impossible for man ever to imitate the birds and go sailing through the air in a winged machine.  But now look overhead today.  Here above us, now, we have an answer to that.  In this first flying meeting we see the beginnings of our great age of the air.  Nor will science be satisfied with that.  Far from it.  We shall go on until we reach that further and bigger conquest that will bring us to the great space age."
It all sounded very wonderful to me; but I must say that - at any rate, at that time - it also sounded as though it was just a bit fantastic.
I could grasp all right the stages by which men had built their first aeroplanes, but this business of rushing out thousands and perhaps millions of miles across space - well, that seemed something quite different, something it was hard to believe would ever come about.
But, all the same, a seed was sown in my mind out there on that flying-ground years ago; and it has grown in my mind ever since.  I found myself reading everything I could lay my hands on that told me anything about rockets and the navigation of space.
I remember one of the things I did was to take down from my bookshelves again that famous yarn Jules Verne wrote about an imaginary voyage from Earth to Moon, and which is retold as a short story between these covers.  Full of stuff to stir one's imagination that book was, but the author dropped one "brick" which my friends who are technical men have not failed to point out to me.
What Jules Verne did, in this story of his, was to put his space-voyagers inside a giant projectile, and then fire them up into the sky from an enormous cannon.  That looked all right at a first glance - a jolly good idea, in fact - but when Jules Verne was writing that book there had been no experience gained as to one very important question - acceleration, or abrupt starting-off from a standstill.  Since those days our fast-flying aeroplanes, with the sudden manoeuvres pilots are called on to make, have told us quite a lot about what sudden accelerations - or "g" pressures, as they are called - can do to the body of any human being who is sitting in a machine that may be carrying out "aerobatics" in display flying, or doing ultra-rapid manoeuvres in war-flying.
What we know, now, is that if the human body is given an acceleration which is too violent it may produce very nasty physical effects indeed, and may even prove fatal.  This shows us that Jules Verne's voyagers would never have reached the Moon alive, seeing that, if they had been shot out into space with the terrific force which that cannon-discharge would have given the projectile in which they were travelling, they would all have been killed in the first few seconds of their ascent.
This shows you that what may be quite all right in fiction may be quite all wrong in fact.  It is this which makes me careful to talk over with my expert friends everything that I myself write about the fascinating, but very tricky, subject of space flight and of interplanetary travel.  Here I am lucky in being a member of our British Interplanetary Society, whose job it is to go into every question of the conquest of space.  Among our members we have aeroplane designers, chemists, experts on metals, wireless engineers, and many other technical men who are now making a careful study of those questions to which we must find answers if we are ever to travel out beyond this Earth.
One of my friends in this romantic world of space-flight is Mr. Kenneth W. Gatland.
He is in the design department of one of our great British aeroplane organisations, and it was he who was one of the founders of our British Astronautical Societies; while, with another of our British space-flight experts, Mr. E. Burgess, he has written an account of the whole history of the rocket.  And it is to the rocket, as Mr. Gatland said when I was talking over with him this piece of writing I am doing here, that we must look if we are ever to get men out across space to the Moon, Mars, or Venus.
What Jules Verne ought to have done, in that Moon-flying yarn of his, was to put his crew into some big rocket fitted with its own power-unit, and which did not have to rely on being shot out of any cannon.  In any case, by operating controls inside their rocket, they could have kept their rate of ascent, just after leaving the ground, at some speed which would not have meant any physical discomfort and which would have prevented there being any risk whatever of injury to the organs of their bodies.
A point that an expert like Mr. Gatland makes, when you talk over space-flight with him, is that apart from being able to control the pace of one's ascent, the rocket is the machine for space-navigation in another very important way.  What you have got to reckon with is that when any machine is in outer space it will be in completely airless conditions, with no atmosphere whatever to draw upon.  This means that any form of power which calls for a mixture of air is ruled out of the question when we come to driving a machine through the outer airless void that exists above the belt of our Earth's atmosphere.
A petrol engine, for example, such as we use in our aeroplanes, has of course to draw in a supply of air to make its fuel work.  The same applies to our newer jet method of flying, in which air is sucked in at the front of an aeroplane, and then, after being compressed, heated, and expanded, is shot out rearward in such a powerful blast that it gives a driving force to the machine.  Take their air flow away from them, and neither of these methods would give their power; which means that they would be useless to us in any of our attempts to rise into the void above the Earth's air belt.
It is here the rocket really scores - and it is a point which, in fact, makes the rocket the only machine we know of, at present, which would work really well in conditions where no air exists.  A rocket power-unit does not call for any mixture of air of air at all.  You can just take any form of liquid or solid fuel - or we hope, later on, an atomic fuel - and feed it into a combustion chamber inside the rocket.  Here, without needing any air with it at all, it can be ignited, expanded, and ejected from a nozzle at the back of the rocket.  And it is of course the reaction on the part of the rocket to this rearward discharge of gas, moving with a tremendous speed, which thrusts the rocket itself forward.  The gas goes pouring out one way; the rocket moves forward in the other.
There you have the crux of rocket flight - which is the reaction of the machine to the shooting out of the gases from its combustion chamber.  And one should add, here, that the greater the rate at which these gases are forced out from the nozzle at the back of a rocket the faster will be that projectile's forward or upward speed.
There is yet another point which my friend Gatland and other experts make.  This is that not only does a rocket work well in airless conditions, but that it actually works better in a void than it would in atmospheric conditions.  This, without going into details, is due to the fact that the atmosphere has a slowing-up effect on the rearward rush of the gas discharge; whereas when there is no atmosphere to be reckoned with the "kick" which the gas exhaust gives to the rocket is much more effective.
It is here, by the way, that experts will tell you of a test which proved beyond question that a rocket works better in a vacuum than in conditions where there is atmosphere.
A big glass chamber was employed, the air being pumped out of it till it was completely air-tight.
A rocket charge had been arranged so that it could be fired inside the chamber, the thrust it gave being measured by instruments.  Then a similar test was carried out with the same kind of charge in atmospheric conditions just outside the chamber.  And what the instruments proved, beyond any shadow of doubt, was that the thrust by the rocket charge inside the air-tight chamber was greater than with the one carried out in atmospheric conditions.
So you can see, now, why it is that experts vote very time for a rocket unit when they are working on the design of any kind of space-machine.  It would not only work well away up there in outer space, but it would actually work better in space conditions than in the belt of atmosphere round the Earth.  Without any doubt, in fact, it will be space-ships with rocket power-plants which, in the future, will carry men on their voyages to those other worlds which lie away there in the vastness of the outer void.
Whenever you hear a group of experts talking about rocket power-plants, and the way they can be used in space-flight, you will realise that though the rocket ought to do everything asked of it in its actual operation there are many knotty problems that will have to be solved before we find ourselves in the age of space-travel.
Take the fuel problem.
That is a real headache for those who find themselves grappling with it.  What you must not forget is this.  When you start out on a 240,000-miles voyage across space to the Moon, you have no half-way places at which you can stop and pick up fuel.  Nor is that the worst of it.  When yo have finished your quarter-of-a-million-miles non-stop flight to the Moon, and have made your landing, you still have the problem of getting back again; and it is no use thinking you will be picking up any fuel on the Moon.
There is nothing on that bleak and cold satellite of ours in the way of help or welcome for the first visitors who may arrive there. On those ice-cold lunar mountains, and in those grim valleys, there is nothing in the shape of life - no air, no vegetation, nothing but a desolate, windless silence.  So that when you fill up your space-ship for its out-and-return flight to the Moon - 500,000 miles in all - you have got to have enough fuel on board that machine not only to carry you there, but also to bring you back again.
No small order, that!
What a tangle this fuel business can get you into was shown in one of the early designs I have been studying for a rocket-machine to travel to the Moon and back.  By the time its designer had worked out all he wanted to carry, including an immense fuel load as well as his crew and all their equipment, he found he needed a gigantic machine which would have weighed, when fully laden, something like 40,000 tons!
Just picture what it would have meant to launch such a gigantic the tremendously heavy machine on any lunar flight, to say nothing of the troubles which its crew might have been faced with when, assuming they had reached the Moon and had finished their observations on its surface, they wanted to launch their machine on a return flight to Earth.  No, it is no good - at any rate, with our present knowledge - to plan giant space-machines as big as battleships.
We have to learn to walk before we can run.  What we want is a machine carrying two or three men which will be easy to handle from the point of view of its size, weight, and general manoeuvrability.
Luckily the work of more recent years - and, more recently still, the wonders we now see dawning in the possible use of atomic power - have put a very much better aspect on things for those who are working out details for the power units and equipment of any first space machines.  It was here that splendid work was done in America by Dr. Goddard; while in Europe, apart from the experiments of Esnault-Pelterie, the French scientist I have already mentioned, there were the studies made by the Roumanian expert, Professor Oberth, who has been spoken of, more than once, as the "father" of space-flight.  Nor should one forget the work in Russia of Ziolkowsky and others.
What Dr. Goddard worked on was to improve the power units of rockets, and he did a great deal of work with liquid fuels of different types.  Professor Oberth's chief interest lay in evolving a big rocket which, after some first voyages into outer space, might be made to fly from Earth to Moon.  It was he who, when some of the German film people decided to do a big space-flight picture, designed for them a great rocket machine which was built according to his plans, and which played a big part in the film.
Professor Oberth's interest in rockets was purely scientific, but the Nazi leaders and schemer, after they had managed to seize power in Germany, had very different and far more sinister ideas.  They shut down all private space-flight work, seized all the plans they could lay their hands on, and then went on to spend millions of pounds in secret work to evolve, not a rocket which would be a credit to science, but a horrible instrument of destruction which could be sent skyward with explosives and which could be made to dive at tremendous speed for brutal, death-dealing attacks on big centres of population.
It is not my business, here, to do more than condemn - as all the world has done - such a wicked misuse of a wonderful invention.
Upon those guilty of such infamies, retribution in the long run surely falls.
What does interest those of us in the space-flight world today is the fact that though the German V2 rocket was built purely as a weapon of destruction it is at the same time a type of machine which, when adapted to scientific rather than to destructive purposes, opens up many interesting possibilities for post-war research.
Here, for example, in one plan which has already been worked out, using a V2 design as the general basis of the project.
One would, of course, get rid of the explosive war-head of the rocket, and instead it would be so redesigned that it could carry up with it, in a climb that would take it through the Earth's belt of air into outer space beyond, a smaller rocket, which, when it "parent" had reached a certain height, would be released to go on voyaging still further across space.
It has been reckoned that by using this double rocket plan it would be possible for the smaller rocket, after leaving its "parent", to go on and till it had covered the 240,000 miles to the Moon.
In the nose of this smaller rocket would be a flashing signal which would be set-off automatically as soon as it struck the lunar surface, and this landing signal would be bright enough to be seen by observers watching from this Earth, who would thus be made aware of the fact that a first rocket voyage, although by a pilotless machine, had actually been made between this globe and our satellite the Moon.
I have heard some of my expert friends, in talking over this idea, say that one of these pilotless rocket flights should be made to the Moon before any attempt is made to send a manned machine across space on a lunar voyage.  There are others, however, who say that while we are about it we might just as well go the whole hog and send off a machine which has a crew on board, seeing that the members of this crew would be able to obtain personal experience in space navigation and in other matters, whereas of course no such personal data would result from the lunar trip of a pilotless machine.
As for myself, I favour the idea of a first pilotless attempt.
For one thing, there would be fewer problems about using some form of V2 for a pilotless flight; while for another, if proof was forthcoming that a first pilotless rocket had actually reached the Moon, this would kindle world interest in space navigation, with the result that it should be all the easier to organise some far bigger expedition in which a second flight would be attempted by a more powerful type of manned space-vessel.
This, however, is one of those questions that can be left for the future.
In the meantime, what interests our experts chiefly is the general design of a rocket such as the V2, which has shown, in a first and very striking way, man's ability to send a projectile 60 or 70 miles up into the sky, and to give it a speed as great as 3,000 miles an hour.  Actually, when you come to look into its performance, this V2 rocket has flown higher, and has moved at greater speed, than any other machine so far built by man.
One of the things our space-flight experts are interested in, when they study this V2 design from the point of view of using it in scientific experiments, is the method by which it is driven.
This is on the liquid-fuel system.
What happens is that a mixture of liquid oxygen and alcohol is fed under pressure into a combustion-chamber inside the projectile.  Here it is ignited, expanded, and then ejected in a gaseous stream from the rear of the rocket, which rushes skyward at an ever-growing speed in its reaction to this immensely powerful rearward gas discharge.
What our British experts are planning to do, banding themselves together in the Interplanetary Society, is to make a full study, which will naturally take some time,of every aspect of liquid-fuels, and also of systems in which solid fuels of different kinds are used, the idea of course being to find in due time a fuel system for rockets which gives the utmost driving force with the least possible weight.
Here a very special study will be made of the question of using atomic power.  Of course it is one thing to release the mighty energy of the atom in one terrific unleashing of power, as was done in the bombs which ended the Japanese war, and quite another another to find means by which this enormous and titanic power can be tamed and made to do useful rather than destruction work.
A great programme of research will be wanted, in which the world's scientists and chemists form themselves into groups to find ways of making that particular "isotope", or constitute of uranium, which is at present our source of atomic power, give  out its colossal energy gradually, in a controllable and practical form, rather than just in a single devastating outrush.
Naturally our space-flight experts will play their part in this programme, because they see in the harnessing of atomic power an ideal method of driving any man-carrying machine which is to explore the vastnesses of outer space.
What is seen, so far, is some kind of power-plant in which, after atomic power has been produced in a special apparatus in controllable quantities, the atomic particles which have been released are made to discharge themselves at enormous speed from the rear of the rocket; and it is already reckoned that this form of power should be at least a million times greater than that of any other form of energy known to exist at the present time.
One expert with whom I was talking about the possibilities of atomic power in driving a rocket on a voyage to the Moon put it in this way.
Years ago, he said, the mere idea of anybody being able to reach the Moon was looked upon as nonsense.  For a long time, in fact, it was just a subject to be used by people who wrote imaginative stories.  But then suddenly the world awoke to realise that this was not just a romantic dream, after all.  And the machine which gave them this jolt was the great V2 rocket, rushing up with a roar into the sky, and opening up an era of speed at height to which there seemed hardly any limit.  It was that V2 rocket which turned what had been a dream into something like a possibility.
Nor was this all.  Far from it.  Hard on the heels of the V2 came that even greater wonder of a first release of atomic energy.  This meant that what had already become possible now seemed to be something even more than that.
It seemed, in fact, to be growing probable.
My space-flight friends are not going to make the mistake that I remember being made by some pioneers in the days of aviation.  These built big machines before they had gained enough experience to be able to handle them properly - with the result that quite a number crashed.
No, that kind of error will certainly not be made in our conquest of space.  The programme now shaping is one in which this conquest will be made stage by stage, without an attempt to cut corners or dodge any of the many problems that will have to be faced and solved.  Nor will this programme have to wait until atomic power becomes available for driving our space-vessels up from the Earth.  What will be done at first will be to make every use of such liquid or solid-fuel power plants as can be obtained with the knowledge we have today.  Such forms of motive power, and more especially improvements in liquid-fuel systems, will be installed in special "sounding" rockets.
These will be designed and built to go up without pilots.  They will be gyroscopically balanced and will be controlled by wireless, and will take up with them, higher than any machines have reached before, a number of instruments which will record, automatically, many of the things scientists want to know about these zones very high above the Earth.
Such ascents by pilotless "sounding" rockets, going higher and higher above the Earth, will form a beginning to any attempt to reach into outer space with manned projectiles.
Actually such tests will do something more than help the progress of space-flight.  They should give us valuable fresh information for the use of those meteorologists, or weather experts, who have the difficult task of forecasting what sort of weather we are going to enjoy, or just put up with, down here at Earth level.
Already, in order to obtain data as to temperatures, wind strengths, and other conditions at considerable heights above the ground, special aeroplane ascents are made form different points, while small pilotless sounding balloons are also used regularly.
But our altitude rockets will begin where aeroplane and balloons leave off, and will probe into zones so far uncharted; and when one remembers that the conditions at these vast heights have an important bearing on the weather which reaches us in lower zones such a rocket-sounding programme should be of the greatest help to our meteorologists in making weather forecasts for longer ahead than is possible today.
Each of the sounding rockets will be equipped with a special nose compartment containing a parachute device.  This will be set to operate as soon as the rocket has reached its maximum height, the parachute being ejected automatically and bringing the rocket with its instruments back to Earth.
While these upper-air sounding are going on, technical committees of our Interplanetary Society will be working on all sorts of other problems, and will be designing the special instruments and equipment called for in space navigation.  After this will come the time for a first series of test flights into outer space by rockets big enough to bear aloft a crew of two or three men.
It will be the information gained in these first manned flights which will enable our experts to proceed with the design of a still bigger and more powerful type of rocket for a first attempt to traverse the quarter-of-a -million miles between Earth and Moon.
Will that greatest of all adventures succeed?
I believe it will.
Just as I have seen the work of our pioneers achieve the conquest of the air, so I believe that our science of today and of tomorrow will - aided by the tremendous power of a fully controlled systems of atomic energy - achieve the even greater wonder of the conquest of outer space, and that not only shall we see men from this Earth reach the Moon, but that in the end our space explorers will be voyaging out to the planets Mars and Venus.