Saturday, 24 October 2009

Unlikely Characters

From time to time I try my hand at writing fiction. It is advisable, they say, to create convincing characters, to describe real people doing plausible things. Hollywood actress Hedy Lamarr, and composer George Antheil, seem to have taken that rule and stamped on it, and these two are real life characters.

Hedy Lamarr starred in the controversial 1933 Czech film, Ecstasy. This movie, which depicts a frustrated young woman married to a much older man, swept her to fame. Helped by nude scenes and depictions of her orgasm. Which, she says, was cued by being pricked in the bum by the director wielding a safety pin. This led to the film being banned in various countries and after this it became a must see.

Hedy subsequently became the trophy wife of a wealthy European arms manufacturer, Friedrich Mandl, who counted Hitler and Mussolini among his chums. Mandl wanted to control Hedy’s life, he tried to buy up all existing prints of Ecstasy and destroy them. Hedy says she hid out from Mandl in a brothel and ended up having to ‘entertain’ one of the clients in order to maintain her cover. The marriage didn't last, she met Louis B. Mayer and moved to Hollywood.

George Antheil was an American who traveled around Europe pre war living in Paris and Berlin and achieved fame as a composer of avant-garde musical works. He wrote  Ballet Mécanique which was to be performed by an orchestra of some 16 player pianos, see Essential Music. In the era before electronic amplification Antheil wanted to achieve very high volume levels, rock concert levels, and using 16 player pianos was how he chose to do it.

George turned up in Hollywood in 1938, then tried his hand at novel writing, he wrote an advice column for Esquire, and eventually wrote the musical scores for a number of Hollywood movies. He also authored a number of books of male interest including one called "The Glandbook for the Questing Male" which was intended to give men an insight into identifying the sexual availability of women. Hedy contacted him when she was looking for a non-surgical means to increase her breast size.

So, in 1940 George and Hedy met and the conversation turned, somehow, to the radio control of torpedoes! Most popular accounts say that Hedy brought, from her time married to her first husband, knowledge of the potential control problems of torpedoes. George brought a knowledge of player piano technology.

At the time torpedoes were mainly free running devices and homing systems were still a little way in the future. When Hedy and George were getting their heads together radio control had been tried. They knew that a radio control system would be subject to jamming, (transmissions on the same frequency which would scrabble the control signals) They decided that in order for radio control to be viable the control system would need to hop quickly between different frequencies. The idea was that the controlling transmitter would constantly change frequency and that the receiver in the torpedo would  change its frequency, to follow that of the transmitter.

The diagram, from the patent, shows the transmitter and receiver. Hedy has signed it 'Hedy Hiesler Markey', which was her married name at the time.

The system is controlling the rudder of a torpedo and a tone corresponding to 100 Hz will drive the rudder left and 50 Hz will drive it to the right. At the same time, the transmission frequency, which on a conventional broadcast transmitter is fixed, is made to change under the control of a player piano type roll. A motor is driving the piano roll, and as the piano roll perforations pass over switches different capacitors are switched into the master oscillator circuit of the transmitter.

The switched capacitors change the frequency of the transmitter, if you were listening to the transmitter on a radio you’d need to constantly re-tune, as to a different station. If you were trying to jam the system, you’d need to retune your transmitter as well. Of course, in order to maintain control, the receiver in the torpedo  has to switch to the new frequency automatically. It also has a piano roll, punched identically to that in the transmitter, this would retune the receiver so that it stays in tune with the transmitter.

The transmitter and receiver need to stay synchronized in order for continuity of communications to be maintained. George had already encountered synchronization problems with his work Ballet Mécanique and those 16 player pianos. Lack of synchronization between the instruments had turned the first attempts into a cacophony and the 16 pianos had been reduced to four. The patent recognizes the synchronisation problem and although they do not illustrate a synchronization method they suggest it is prior art, and already in use in telegraphy and television.

The US Navy did not persevere with Hedy and George’s invention. Radio control of torpedoes was quite a difficult trick, and most torpedoes were straight runners, with simple autopilots to control direction and depth, or were controlled by wires. Eventually Germany introduced homing torpedoes which went for the acoustic noise of the propellers of the target.

However, the 50Hz, 100Hz modulators could easily have been replaced by a speech modulator, and this would have given secure voice communications much like the Havequick radios currently in use by the British Armed forces. In the Havequick the transmitter frequency comes from a pseudo-random algorithm which can be seeded by the current date and time. The sequence of the pseudo-random number is highly classified and knowing it would be like having a copy of one of George and Hedy’s player piano rolls. – It would permit an outside agency to know the sequence of frequencies which would still allow jamming or interception the transmission.

The mechanical system doomed the practicality of the system. The player piano roll needed a source of vacuum for the reader switches and the synchronisation system would have tricky to impliment. Although the principle described is sound, as with Babbages mechanical computer, proper electronics is much better. Hedy and George, like Charles Babbage before them, had a good idea that was just a little ahead of its time. They had to use mechanical methods, methods which were not totally impractical but would be better achieved using electronic switching techniques.

Hedy Lamarr, from nude scenes in Ecstasy to Time Domain Frequency Multiplexing. If you put her in a short story they’d laugh at you. Incredible characters, don’t you just love them?

Monday, 19 October 2009

The Long Shadow #1

Neil Armstrong said, “We went to the moon on world war two technology.”

It’s tempting to assume that he meant the technology that Von Braun had developed, the V2 rocket. This had been adapted by both the USA and the USSR, and quickly developed into technology for delivering nuclear weapons.

It’s remarkable to me that only 25 years separates the first V2 fired on London and the first landing on the moon, and 40 years have passed since then. The moon landing seemed, at the time, to be of another age from what I then knew of the war. That so much had been accomplished in such a short time suggested that by 2001 we would be dancing around the outer planets.

Rocket technology, which with the V2 had been little more than an expensive way of delivering a small amount of high explosive, had suddenly become a viable means of delivering nuclear weapons. This had surprised sceptics who had assumed that 1. nuclear bombs would remain physically huge and heavy and 2. that the problems of automatic guidance over intercontinental distances would be too difficult.

Electronics, which had previously only meant radio, had now spun off into a variety of other areas. Radar, control electronics used in guidance systems and numerous types of navigation system.

Even the digital computer had its roots in wartime code breaking technology. Although this information was not common knowledge in 1969.

Strictly speaking, the transistor is absent from the wartime development list. But even this had its origins in work done at the Bell labs in support of radar. Semiconductor diodes were developed in wartime and by 1947, based on this research, the transistor was developed.

Pilots like Armstrong had flown high performance jet aircraft and were trained in the sciences.

Space medicine had grown out of wartime studies, with data gathered in shameful experiments on prisoners in Germany and Japan. Yet the data was useful, and it did contribute to the knowledge base that marked the beginnings of space medicine.

Numerous technologies: precision engineering of gyroscopes, electro-optics, magnetic tape recording, these were all wartime developments. They had all been the subjects of intense development in the guided missile race that commenced as soon as WW2 was over. These developments were relatively mature by the time Kennedy made his first announcement about a moon landing in 1961.

In order to reach the moon, ‘state of the art technology’ would be used. This expression became a euphemism for the hottest technology going. In its original form it was meant to indicate a measure of caution. State of the art meant the design of the space craft would be based on existing techniques. Nothing in Apollo would be dependent on technologies unproven and propulsion, structures, electronics, and re-entry systems had already been used in existing missile systems.

Despite the commitment to 'state of the art', there was left an enormous challenge, the need to coordinate the numerous companies that manufactured the Apollo spacecraft and systems. Many different companies would be used and all must work together to make a single, common system. This was quite unlike the typical aircraft build process back then. Airframe manufacturers were used to working in splendid isolation. As long as they could make all their bits fit together, and accommodate the engine and electronics, they could complete a structure in any way they saw fit. Aircraft manufacture was like low volume, luxury car making, expensive and very labour intensive. It was dependent, not on rigorously defined engineering processes, but on skilled craftsmen who tailoring the pieces together. All that would change for Apollo where different suppliers had to separately produce different parts of a tightly meshing system.

The Manhattan project, the wartime effort to produce the atomic bomb, had involved 130,000 people and cost, by today’s prices, an estimated 22 billion dollars. An international development, carried out in great secrecy, had successfully produced a weapon of unprecedented power. Kennedy and his contemporaries had seen what American science and industry could achieve when it set its collective mind to it.

Apollo would eventually employ over 400,000 people and numerous technology firms and academic bodies. Aside from its technical legacy it provided, at the time, a huge boost to an economy that was in recession. But this didn’t come cheap, it cost around $25 billion, or $145 billion in present day terms.

The legacy was an aircraft industry which achieved immense technical capability, working to hugely increased quality and production standards. It would subsequently decimate its European competitors and secure a technical lead that is still maintained 40 years on. European manufacturers eventually caught up in most areas, but it took much longer for them to recognise the need for the processes and standards that Apollo had demanded of the American aerospace industry way back in the sixties.

Apollo cost the US taxpayer plenty. Money up in smoke? I’m sure there were plenty who said so at the time. The tradition of public spending to jump start an economy, as used by Hitler with his public works program of the 1930s, is seen by some as backdoor socialism. The money spent on weapons, which gravitates towards a different set of rich capitalists, tends to be seen differently. With Apollo, the money trickled down and energised the economy, and consolidated a technical lead that the USA had made its first down payments on in WW2. It paid off with what Tom Hanks called, The exquisite achievement of landing a man on the moon, but it’s carried on paying back in jobs and capability ever since.

Now, at last, we have moved out of the long shadow of WW2, finally we are developing technologies which have only a tenuous connection to those started back then. The elements of our age, what Arthur C. Clarke called the Total Comm. Age, would have seemed incredible (in 1942) even to a visionary like Clarke. We haven’t made it to the outer planets, but things that are now essentials did not even have names back then, (the Internet is but one of them) and that is pretty amazing.

We have another great legacy of Apollo, the knowledge that when it gets the opportunity, science and engineering can quickly accomplish incredible things, and not just in the field of weapons of mass destruction. Yes, we needed to know that too.

Saturday, 17 October 2009

The Flight of the Phoenix

Flight of the Phoenix (original version) is one of the whole time great movies. I saw it when it was new in the cinema and I must have seen it fifty times on TV since, usually turning on half way in and getting drawn into it once more.

James Stewart plays a pilot who feels responsible for the deaths of several passengers after a forced landing in the desert. He and the rest of the survivors are eventually persuaded by Dorfmann (Hardy Kruger) to attempt to build an aircraft from the remains of the old one.

The movie says something special about the nature of machines, particularly aircraft. Although they may look refined, immaculate, often beautiful, in fact they are constructed of an extraordinary quantity of precisely worked components. Each part has been made to its particular shape to serve its particular purpose. None of it occurred accidentally, somebody sat down and designed every last tiny part.

Dorfmann, the aircraft designer, has to figure out how to make a plane from what’s left intact of the old. He must come up with a design that’s viable. He has to work everything out, how the old plane must be torn apart, how the parts of it will be moved around, and how they will be reassembled, how the controls must be rigged. In reality this would be an almost superhuman feat. Could a real life aircraft designer do such a thing? Would a real aircraft designer have covered ever step of the production life cycle.  But Dorfmann’s company makes model planes, and Dorfmann has always had to design everything on his projects. Still improbable? Maybe, but this is the movies, we don't take quite as much convincing!

Moreover, and most important of  all, Dorfmann must present the case for building the Phoenix, and see it through. Dorfmann demonstrates real steel, for a time he and he alone believes in the job and recognises the importance of seeing it through. Dorfmann is commited to the point of obsession, as true genius requires.

With Dorfmann's character, the movie teeters on the edge of credibility, but the introspective Dorfmann is something special, not only did he design the airframe of his world class models, but also the radio control. Improbable stuff? Perhaps, but the movie is saved by great story telling. The survivors decide to go for it, rather than sit on their arses and die, they take a chance on the 'toy plane' builder.

In fact, many full size aircraft designers have been model plane builders. Charles Fairey had a job as a power station engineer before selling, for a considerable fee, a model design of his to Gamleys Toy Store. Then he moved into full-size aviation and eventually ran a 'little' company called Fairey Aviation. Sydney Camm, responsible for the Hurricane fighter, was also a modeller, and most recently Burt Rutan, who even borrowed some his construction techniques from aeromodelling (hot wiring foam etc). As Dorfmann puts it, flying models are not toys, they obey the same physical laws as the full sized ones. Moreover, they don't have a pilot to keep them straight and level. Of course, Dorfmann would have preferred it if he could have managed without the pilot, James Stewart's character, Frank Towns.

Frank Towns must surrender his authority to Dorfmann, so that the new plane can be built. Towns doesn’t believe the plan is feasible but he is persuaded that engaging in the project is better than letting them sit around waiting to die. Throughout Towns rails against Dorfmann but always Dorfmann is right and Towns wrong, yet still Dorfmann knows he needs Towns’ skills to fly the plane.

After many problems the plane is ready and Towns must start it up and fly. The point where Towns climbs aboard and pulls the ladder up behind him is very sweet. This is where Towns takes the plane away from Dorfmann. Now he must use all his knowledge to get the engine started.

The engine can only be started with a Coffman cartridge starter. Dorfmann suddenly feels that Towns would intentionally fail to get the engine started, so he can't kill more of them in another crash. But if the engine doesn't start Towns will have failed as a pilot AND they'll all die of thirst.

Towns starts the engine and is seen to have knowledge that Dorfmann doesn't have. In one sense getting the engine going is the end of the story, Towns has made his choice, finally committed wholeheartedly to the project, and in doing so got his self respect back.

And now, with the motor going, the Phoenix has ceased to be a collection of useless parts, it’s become the difference between life and death and every one of them has made a contribution.

At the end Dorfmann's character, rather than fulfilling the stereotype of the soulless logician, has been the the crazy one. The logical thing would really have been to sit tight and wait to be rescued. Instead, the dry logical mind has persuaded them all to invest what remains of their lives in a totally madcap scheme. And this contradiction is what makes the story so watchable.

Paul Mantz, a veteran stunt pilot who had worked with Howard Hughes on Hell's Angels was killed flying for this movie. As a result the actual flying shots look a bit truncated. It's a great pity, but Mantz died doing the work he loved, and when you gotta go, that's not a bad way to do it. And this is a wonderful movie, Mantz could hardly have wished for a better final credit than Phoenix.

More comments on Phoenix

Wednesday, 7 October 2009

Doing More With Less.

I was delighted to see that Burt Rutan won the Robert Heinlein Memorial award for 2008. Other recipients have been Neil Armstrong, Chuck Yeager, Carl Sagen. So who the hell is Burt Rutan?

Burt Rutan first appeared on the radar back in 1980, his CV was a lot shorter then. Then known as an innovative designer of aircraft intended for home building. He’d designed a plane called the VariEze. (pronounced very easy) This plane was developed at a time when most commercially built aircraft were made from aluminium. VariEze was made from composite, foam plastics and glass fibre. Composite aircraft were not completely unknown, but these were largely European built gliders. These were factory made machines which required expensive tooling. Glass fibre was laid up in these fixtures and components were moulded, much like the parts for a model kit.

The VariEze and its successors, featured two Rutan design characteristics, an unusual configuration and a novel construction system.

The configuration features a canard. The canard serves the same function as the horizontal tail surface. It provides stability in pitch, but without the need to produce a lift reducing down force like traditional, aft mounted tails. The Eze also has swept wings, most unusual in slow flying, piston engined aircraft. They offer no aerodynamic advantages at lower speeds and make a conventional structure more complicated, but they do offer the more subtle advantage of inherent stability in roll.

Rutan’s second major innovation, was the mouldless composite construction method. This allows a relatively simple implementation of swept wings, and much else. Borrowing ideas from surfboard and model aircraft construction, this entails cutting foam plastic cores to shape using an electrically heated wire. The foam blocks are carved and sanded to the required shape for the component, perhaps a wing or tail surface. Cardboard templates are used to devlop the shape to the required section and then the foam is covered in glass fibre and resin. The foam itself provides very little strength, most strength is in the glass fibre skin.

Other innovations are the ‘pusher’ engine and the twin, wingtip fins. Both these features offer aerodynamic advantages. With the VeriEzi Burt Rutan took the traditional aircraft configuration, as used on numerous aircraft from the Spitfire to the A380, completely changed it around and in the course of doing so, made it much better. The whole thing is a wonderful, organic creation. Balanced, logical and beautiful, a brilliant early effort from a man who has never stopped innovating.

Since the VariEze was prodced big aerospace manufacturing has adopted winglets as add ons to conventionally constructed wings. But this is just a 'bolt on' feature, in the VariEze the winglets also support the rudders and, because the rudders and other control surfaces are outside of the higher speed airflow developed by the propeller the aircraft is less directly subjected to changing its handling characteristics with different power settings. Rutan's winglets serve a dual purpose.

The image below shows SpaceShip One being carried aloft by its mothership. Tucked in close behind is the Beech Starship, another of Rutan's designs.

SS1, Space Ship One is Rutan’s greatest achievement thus far, (but he’s still only 66) and would have been sufficient to make him one of Heinlein’s people. Back in the day when Heinlein was writing his first stories, engineering was done very differently. In some respects it was all done the Burt Rutan way. Men such as Willy Messerschmitt and DeHavilland had their names on the aeroplanes they made, and their style all over them. As we moved into the 1960s aircraft design became institutionalised, immensely expensive and the work of huge teams. Aircraft were no longer designed by, or even especially associated with single individuals.

With the very high cost  came conservative configurations, design refinement, not revolution. Improvements, none the less, but expensive solutions to well understood problems. Rutan always been on the cutting edge.  “Any fool can find a difficult, complicated and expensive solution to a problem, but it takes somebody really smart to find a very simple solution.” For Burt Rutan. simplicate, and add lightness are mandatory.

Another Rutan hallmark is to design inherent stability into the aircraft's configuration, as with the swept wings of the VeriEze. On SS1 Rutan came up with a huge innovation for re-entry, the Shuttle is pedestrian by comparison.  He came up with a revolutionary way of turning a super streamlined hypersonic rocket plane into a high drag, stable, re-entry vehicle.

This image shows SS1 at apogee, adopting ‘Feather mode’. This mode is taken up after it has achieved its maximum altitude, and is outside most of the atmosphere. Re-entry, from similair speeds that SS1 achieves, was done the conventional way in the government funded X15. It used ablative heat resistant materials and precision guidance by an automatic flight control system. By contrast, SS1, in feather mode, is inherently stable, neither the pilot, or an automatic guidance system has anything to do while the aircraft re-enters the atmosphere. It decelerates from over 2,300 miles per hour, at 367,000ft, to a few hundred miles an hour by around 50,000ft. It is then 're-moded', out of feather, back to its standard configuration then glides down for a conventional, runway landng.

At a stroke Rutan knocked billions off the development budget. Developing automatic control systems is immensely expensive. It’s hard to overstate the value of this kind of innovative thinking.

Mike Melville, one of Rutan’s long time colleagues, someone who has worked with him since the VariEze days, became, the first SS1 astronaut. In the video below a system failure led to the loss of the primary attitude indicator, and this was during the boost phase. Melville maintained the craft in the correct attitude by monitoring the real world horizon in his peripheral vision. Now that's pretty hot stuff, even by the standards of one of Heinlein’s fictional heroes, it's seems that Rutan, as well as being a great innovator, can pick his pilots pretty well too.

Mike Melville