Whilst the major policy issues were the province of the politicians, the day-to­day or month-to-month work was carried out by officials at the various Ministries. One of the most influential, by virtue of his post, was CGWL, or Controller of Guided Weapons and Electronics at the Ministry of Supply and its successors. For almost all the period, with a break of two years, Sir Steuart Mitchell held the post. From the Ministry papers he appears to be a sensible and capable administrator. Dr Robert Cockburn filled the break.

However, delving deeper into the Ministries, one drowns in a soup of alphabetic titles: in the RAF there was VCAS (Vice Chief of the Air Staff, who dealt with nuclear matters); DCAS, the Deputy Chief; DCAS (OR) Deputy Chief of Air Staff (Operational Requirements). There was DRAE (Director of the Royal Aircraft Establishment); DDRAE (his deputy); DAWRE (Director of the Atomic Weapons Research Establishment) and DDAWRE, his deputy. Then there are all the Ministry and Establishment departments with their heads: Guided Weapons, Space Department, and so on. Ministries have Private Secretaries (PS), Permanent Under Secretaries (PUS), and varieties of subordinate secretaries. It was part of their job to turn policy into hardware. But they were also responsible for the papers that went to Ministers, and, as a result, a good deal of the policy was made at a lower level than is often supposed.

Blue Steel

Blue Steel

If Britain had built the V bombers as strategic bombers which were capable of launching a nuclear attack, then it was logical to think that the countries threatened would take care to defend their cities against such an attack. In the Second World War, this had been done by means of night fighters equipped with radar, searchlights and anti-aircraft guns. But a new weapon was appearing on the scene: the guided missile, such as the Bristol Bloodhound, which would be deployed from 1958 onwards. Bloodhound was radar controlled, used a ramjet engine and had a range of up to 50 miles. There were even proposals at one stage to equip them with nuclear weapons to increase their destructive power. But threat implies counter-threat, and the Air Staff was working on the assumption that from about 1960 onwards the V bombers would be unable to penetrate the

Moscow air defences – in other words, that Moscow would be protected by guided weapons similar to Bloodhound.

The next question was then how to deliver the Bomb from the time the defences became too formidable for the V bombers to penetrate. In the early 1950s, ballistic missiles were not yet an option. Britain had invested heavily in the V bomber force, so that any ideas to prolong their active life would be very welcome. Hence the idea of a ‘flying bomb’ evolved. Initial ideas in the late 1940s had centred on a system called Blue Boar, which was a television guided glide bomb. This proved too limiting, since cloud and bad weather could obscure the television picture, whilst the radio link between missile and aircraft could easily be jammed. Instead, thoughts turned to a longer range powered device. This was not a flying bomb in the V1 sense, whose guidance had been extremely limited, but one that would be able to deliver its payload with considerable accuracy. Nor would it be a cruise type missile, since the technology for long- range guidance, terrain following radar or satellite navigation also did not exist at that time. Instead, inertial guidance would be used, which could be accurate enough at relatively short ranges. The missile would be released from the aircraft, immediately climb to a considerable height, cruise at high speed – around Mach 2 or so – then dive down onto the target.

The theory was all very well, but in 1954 reality was something else. Britain was still working on its first fusion bomb, so it was difficult to estimate what payload size and weight would have to be carried. The next problem was the inertial navigation. As the US was discovering with Snark, Matador and Regulus, navigation over considerable distances was a problem. This was one of the reasons why a range of 100 nautical miles was chosen for Blue Steel. The problem was made more difficult since it would be launched from a moving aircraft whose own position might be uncertain. A further problem with cruise type missiles is their relative vulnerability to enemy defences unless they fly at a very low level, which was, again, not possible in 1954. Hence OR 11321 specified a speed of Mach 2.5 at 70,000 ft or higher for the vehicle, although in 1954 supersonic speeds were an area still fraught with unknowns, and supersonic wind testing was still very difficult. Yet another problem was that at these speeds the skin of the vehicle would start heating up as a result of friction with the air. Aluminium airframes would not be suitable at high Mach numbers (this is one of the reasons why Concorde and similar aircraft are limited to around Mach 2.2) and the only real alternative was stainless steel, which was difficult to work with. This was more unknown territory.

All of this was summed up by a memo from the Ministry of Supply, appropriately enough on 5 November 1954, by saying:

Present estimates are that medium range GW defences will make it excessively dangerous for the V bombers to fly over, or within about 50 miles of the target in I960… The requirement is therefore for a flying bomb which will have its maximum use between 1960 and 1965. It is expected that a fusion warhead will be available by 1960 and it seems generally agreed that the bomb should be designed to carry this warhead.2

[GW = Guided Weapons. In this context, the reference is to surface-to-air missiles.]

The time period is significant – it is assumed that by 1960, the V bombers will no longer be able to attack the target directly. The next assumption is that by 1965 some other form of delivery will have taken over, although this is still too early for the Air Staff to be thinking specifically of ballistic missiles.

The early files note that in some respects the project is almost equivalent to building a fighter aircraft. It would have no instruments and so on, but certainly was aerodynamically novel, and with an autopilot connected to the inertial navigator in place of a human pilot. As a further minute of November 1954 put it:

This bomb is indubitably much simpler than a fighter aircraft in the range of equipment that has to be provided. On the other hand it is a big step to go from the present speed range to Mach Numbers of 2 and above and again in comparison with the development of a manned fighter, it is to be expected that the production of the many vehicles required for firing trials will lengthen the development time.

Blue Streak with a Centaur Upper Stage

Late in the Blue Streak saga, HSD published a brochure which was interesting technically, even if the chances of the British Government being interested in it were remote. The brochure has the look and feel of one put together in a hasty or cursory fashion – all the text is in block capitals – and does not really do justice to the proposal, except in the artwork.13

The proposal was for a Blue Streak launcher with an American Centaur D1 upper stage, built in Europe under licence (rather cannily, the brochure says ‘Europe’ rather than ‘Britain’!). Optional French L17 strap-on boosters were proposed as an optional extra. As to the payload, the brochure states:

Performance in geostationary orbit

Подпись:without strap-on boosters

– with two L17 boosters

– with four L17 boosters

(grouped in two pairs)

More tellingly, it goes on to say ‘Typical payload ranges are quoted – actual capability for specific payload requires detailed study of optimised trajectory and earliest permissible fairing jettison time’ – in other words, the figures quoted are estimates rather than being the result of any precise calculations. They do seem reasonable, and the brochure says ‘performance capability is higher than the proposed Europa III’ – which was true up to a point. There is a drawback in the sense that the vehicle has been stretched as far as possible, and had really reached the limit of its performance.

The proposed launch site was Kourou in French Guiana, which, like the rest of the proposal was technically feasible but politically completely impractical.

One technical side note: Centaur was the only other rocket stage, apart from Atlas and Blue Streak, built using pressurised stainless steel ‘balloon’ tanks. Centaur was originally designed to go on top of Atlas, hence the similarity in construction. In that sense, Blue Streak and Centaur were well suited. The Centaur stage had some teething problems, but by 1970 was a well-tested and proven design.


Blue Streak with a Centaur Upper Stage
Подпись: 11049
Подпись: 12200
Blue Streak with a Centaur Upper Stage
Blue Streak with a Centaur Upper Stage
Подпись: 14558
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Blue Streak with a Centaur Upper StageBLUE STREAK VEHICLE PLUS 2xL17 BOOSTERS WITH


Figure 61. HSD’s proposal for mounting the American Centaur stage on Blue Streak.

The other major advantage of the proposal was that by comparison with the ELDO design, and any possible Europa III designs, all the components were flight-proven, and the bugs ironed out. But interesting though the idea might have been, it was a product without a customer. The UK was determined to have nothing more to do with launchers; any new European launcher would be French led, and use of an American stage, even built under licence, would have been a non-starter. [7] [8]


Two stage. Launched 9 May 1961 at 21:37. Apogee 258 miles.

BK14 was another two-stage vehicle with second stage and head similar to that of BK08. The initiation of the second stage light-up was to be by means of a Phillips ionisation gauge as on BK09. Upper atmosphere experiments carried out

Подпись: Figure 94. BK14 in its gantry - a night time photograph at Woomera. were a cosmic ray scintillation counter and electron temperature measurement.

The supply of kerosene ran out early, at 128 seconds, and this was followed by 14 seconds of ‘cold’ burning (i. e. HTP only). The final shut-down occurred at the correct time. Subsequent analysis of records indicated that a leak had developed in the kerosene supply system which accounted for the excessive kerosene flow rate.

Initiation of second stage separation was dependent on the operation of an inertia switch, and as a result of a drop in first stage performance, associated with cold burning, the acceleration was not high enough to operate the switch. Because of this, events following burnout, such as second stage separation, spin, ignition, head

separation and recording did not take

place. Had the second stage operated, the resultant re-entry velocity would have been adequate for a satisfactory experiment.

In view of this, alternative methods for arming second stage separation, not dependent on first stage performance, were subsequently employed.

R1 – 4 March 1970

R1 - 4 March 1970The cause of the failure of R0 was relatively simple, but it was decided to repeat the flight, so that the R1 launch was an exact repeat of R0. This time the vehicle behaved exactly as intended.

R2 – 2 September 1970

R2 was launched on 2 September

1970, carrying a spherical

satellite, christened Orba, as its

payload. This was intended to be

a very simple satellite (there was

no money in the budget for

anything more complicated) to

measure the atmospheric drag in

low orbits by observing its orbital Fgure 116 The Orba satellite on top of the

Waxwing motor.

decay. Figure 116 shows the

satellite on top of the Waxwing motor, whilst the payload shrouds are being fitted around it.

The first stage was completely successful, but the second stage shut down 15 seconds early, leaving 30% of the HTP unburned. This turned out to be due to a leak in the HTP tank pressurisation system, with the result that the nitrogen gas ran out early and so there was no pressure in the tank to help feed the propellants. With insufficient pressure the turbopumps cavitate and their effectiveness is much reduced. Hence the second stage thrust dropped to almost nothing. The third stage separated correctly, and fired, but the velocity was insufficient to reach orbit, and the payload crashed into the Gulf of Carpentaria. There were other problems which the subsequent RAE report describes:

Two other defects were recorded during the flight:

The solenoid start switch in the attitude control system failed to latch open on first initiation.

Only one of the two fairings separated correctly from the vehicle at the correct time – separation of the remaining section was delayed until third stage spin up.18

In addition to the drop in pressure in the HTP tank, either of these faults would have prevented the vehicle reaching orbit.

After this flight, an extensive review of the vehicle was set in motion, with eleven technical panels being set up. They began their work in December 1970, and submitted reports and recommendations by the end of June 1971. Relatively few deficiencies were found, and most of these related to the problems that had cropped up in the three development launches. Ian Peattie, who was the Project Officer at RAE for the launch vehicle, commented wryly that the review achieved its objective ‘once certain panel members were persuaded that a fundamental re-design of the launch vehicle was not within the terms of reference.’


De Havilland Propellers (later Hawker Siddeley Dynamics or HSD) was of course the largest contractor, building up to 18 flight models of Blue Streak (not all of which were completed) as well as several non-flight vehicles. Large test stands had also to be erected at Hatfield for proving purposes. Rolls Royce developed the prototype RZ 1 engines (copies of the American S3 engine) then designed and built the RZ 2.

De Havilland was also responsible for the Sprite and Super Sprite, designed to assist take-off for the likes of the Comet and the V bombers, and also the Spectre, used in the rocket interceptors and early test models of Blue Steel.

Armstrong Siddeley, which became Bristol Siddeley Engine (BSE) before being absorbed into Rolls Royce, was one of the first of the firms to be involved in rocket development, with the Snarler and Screamer motors. They were then chosen to develop the Gamma motor for Black Knight, the Stentor motor for Blue Steel and the later Gamma motors for Black Arrow. Their test site was at Anstey, near Coventry.

Napier was also involved in HTP work, producing the Scorpion, installed in Canberra reconnaissance aircraft, and a rocket pack intended for the Lightning fighter.

Many other firms were also involved as subcontractors, and in particular Sperry and Ferranti were responsible for inertial guidance platforms.

All these were mainstream aircraft manufacturers, and as such, their involvement in these projects is immediately obvious. What is less obvious, however, is the large part played by an otherwise rather obscure subcontractor and builder of somewhat indifferent flying boats: Saunders Roe (taken over by Westland in 1959, becoming the British Hovercraft Corporation in 1964, the Westland Aerospace in 1985, before being finally absorbed into GKN Aerospace).

Why Saunders Roe? Their previous history had been that of a small but enterprising firm, involved both in marine work and in aviation, and thus, not surprisingly, concentrating in the main on flying boats. It would be fair to say that many of the flying boat designs were rather indifferent. It would also be fair comment to say that later, from the 1950s onwards, throughout their existence as Saunders Roe and later in various Westland guises, they worked on idiosyncratic and often quite advanced projects that would reach prototype stage, but rarely ever reached production. A review of the projects they undertook reveals programmes with technological fascination, but which were often dead ends. These include:

• the SRA/1, a jet engined flying boat fighter. Three prototypes were built, the first of which flew on 16 July 1947.

• the Princess, a very large turbo prop passenger flying boat. Three prototypes were built, the first of which flew on 22 August 1952.

• the SR53, a mixed power plant (rocket/jet) supersonic interceptor. Two prototypes were built. The project had its inception in 1952, and the first flight was on 16 May 1957.

• the SR177, an extended version of the above. Prototypes were being built at the time of cancellation. Inception 1954, cancelled 1957.

• a design for the specification of F155, producing what would have been the very last word in rocket powered interceptors.

• a ‘hydrofoil missile’ for the Admiralty. This was a design for a large hydro-foil craft, powered by a jet engine driving a large wooden airscrew, under radio control, and carrying sonar and a torpedo. Design study 1957.

• the Black Knight research ballistic rocket. More than 25 built; 22 flown. Inception 1955, first flight 1958, last flight 1965.

• the design brochure for Black Prince (see Chapter 8) 1960.

• a design brochure for a liquid hydrogen stage for the Blue Streak satellite launcher (1961).

• the Black Arrow satellite launcher. Five vehicles built, four launched. Inception 1963, first flight 1969, last flight 1971.

• the SRN-1, Britain’s first hovercraft. Indeed, the firm for some years was known as the British Hovercraft Corporation, developing and building all the British hovercraft.

This is not an exhaustive list. Ironically, all these projects fulfilled their requirements. If Saunders Roe were asked to produce a design, they did so, and it would be fair to say that the designs were exactly what was asked for. If that is the case, then it has to be asked whether the requirements were reasonable to begin with. Hindsight is very valuable, but it is pointless to castigate others for not foreseeing the future. However, a more polite way of rephrasing this would be to say that the projects investigated possibilities which might have had a fruitful outcome, and which were worth investigating for their potential.

In addition, the firm undertook a large number of design studies for other projects. Any firm of this sort will always be thinking of new designs, many of which will never see the light of day, but the Saunders Roe team produced an astonishing array of ideas. Again, most of these, like the ones listed above, are noted as much as anything for their eccentricity. Highest on such a list, second only to the hydrofoil missile, might come a study for a nuclear powered flying boat undertaken for the US Navy.

Money values

It is almost impossible to convert from 1950s and 1960s prices to current prices. One measure is the Retail Price Index (RPI). The RPI in 1960 was 12.6; in 2009 it was 218.0, an increase of more than seventeen fold. At a very rough estimate, multiply by twenty. Thus, Black Prince at £35 million could be obtained for the price of the Millennium Dome!

It can be argued that inflation with regard to defence projects has been higher. The cost of deploying Blue Streak was put at perhaps £600 million, or perhaps £20 billion in today’s currency. On the other hand, the cost of replacing the present Trident system is put at somewhere around £80 billion over twenty years. [1]

That was certainly an accurate forecast!

Hence in September 1954 a letter was sent to the V bomber firms with data for a possible missile3. At this point the design had not been thought through in any detail, and there were up to six different possible configurations under consideration, some with ramjets and solid boosters, others with liquid fuelled rocket motors. The V bomber firms had then to start thinking how they were going to carry the missile on the aircraft.

Vickers, who made the Valiant, were the initial favourites for the contract, which eventually, despite misgivings, went to Avro. The extant papers of the Ministry of Supply give no real reason at all for the choice. Avro had no guided weapons expertise, and had to set up a special department for the purpose, headed by RH Francis, who had previously worked at RAE. His approach was the more measured one of a government department rather than the more urgent and commercial approach of a firm engaged on an urgent defence project.

The Air Staff had specified a missile to be available by 1960, and by about 1965 the missile would effectively have become obsolete since its range was only 100 miles. By this date, it was expected that the Russians would have developed defence in depth, so that a combination of missiles and interceptor aircraft would mean that the bombers would not be able to reach their release points unscathed. Hence its service life would be short. It need not be a particularly sophisticated design, but it did need to be in service on time. Given the performance limits, light alloy would have sufficed for the structure. Propulsion could have been by turbojet, ramjet or rocket motor.

Unfortunately the design produced by Avro was a good deal more sophisticated than was necessary. The airframe was to be built from stainless steel, a difficult material to work with, particularly when it came to bending it in two planes at the same time. A rocket motor was chosen for propulsion, and this would have a considerable impact on the serviceability and availability of the missile when it entered into service.

Blue Steel was not a ballistic missile, but instead was controlled like an aircraft. It was intended for release from the bomber at around 40,000 ft. The aircraft would be travelling at around Mach 0.7 or so. After release, it dived down, and after 4 seconds, at around 32,000 ft, its motors lit up. From there it climbed to around 59,000 ft, then increased speed to Mach 2.3. After that, the missile began a cruise/climb, using only the small chamber of the rocket engine, to over 70,000 ft. When it ran out of fuel or arrived at the target, the motor cut, and the missile dived down to its target.

The engine designed for Blue Steel was designated the PR94, which became known as the Stentor, built by Armstrong Siddeley (later to become Bristol Siddeley). Early test versions used the de Havilland Double Spectre engine until the Stentor became available. The Stentor had two combustion chambers, one of which was of fixed thrust of 25,500 lb at 45,000 ft, the other was to have a variable thrust of between 1,000 lbf and 6,200 lbf at 45,000 ft, and was capable of being throttled. Burning HTP and kerosene, it produced an S. I. of around 220. The large chamber was intended for the boost phase to high altitude; the small chamber for the cruise phase thereafter. The motor turned out to be reliable and effective; so much so that when reports of the failures of the early rounds stated that the rocket engine had failed, the chairman of Armstrong Siddeley wrote a sharp letter pointing out that this was not the case: the engine had been starved of fuel as a result of sloshing in the tanks. He did not want his company associated with the poor reputation the missile had at that time.

The Stentor chamber was the first HTP motor to be made from tubes braised together and formed into shape, rather than the double-walled chambers such as the Gamma or Spectre. The small chamber would, in the course of time, go on to power Black Knight and Black Arrow.

Avro tested the aerodynamics on a 1/8th scale model, moving up to a 2/5th scale model. These were tested by using solid fuel boosters to launch them at the RAE range at Aberporth in Wales, then variants made of light alloys rather than stainless steel were tested. For full scale missiles, the range at Woomera was brought into use, which entailed further delay as specially equipped Valiants had to be prepared (although the Valiant was not to carry the operational weapon, they were used in early trials). There was an attempt to speed up the testing by doing trials at both Aberporth and Woomera. This turned out to be a mistake. Two aircraft had been converted for trials purposes, and so one was based in the UK and the other in Australia. The problem was that they would frequently go unserviceable. If two aircraft had been available in Woomera, then the other could have been used as a back-up.

The problems were many and varied. The Auxiliary Power Unit, made by de Havilland, was particularly troublesome. The unit used HTP, which was catalytically decomposed, and the gases produced then drove a turbine that in turn drove the generator. Sloshing of the fuel caused problems as the missile went through some vigorous manoeuvring as it climbed, levelled off, then went into its final dive.

The weapon was supposed to have been ready to enter service by 1960. In April of that year, the first three rounds of the final version of the missile had been fired at Woomera and each had failed to follow the launch programme. The minutes of the second meeting of the Blue Steel Management board talk about Avro’s ‘dismal record at Aberporth’5 when talking of the delays in flight testing. The first round approximating to the final version was not successfully flown until 1962.

The problems led to the RAE being called in to assess Avro’s performance, and a series of Study Groups were set up. In December 1960 comments were made to the effect that the design of the missile was sound enough, but that ‘the standard of engineering is poor in a number of respects, with far too little emphasis on reliability studies’.6

In addition to work being done on the missile, a considerable amount of work had to be done on the V bombers to prepare them for the missile. The large size of the missile meant that it was carried semi recessed into the fuselage. One of the problems with the Victor bomber was that its ground clearance was quite small – there is a story (quite possibly apocryphal) that the only way to get the missile under the bomb bay was to deflate the tyres of the trolley carrying it, so as to give sufficient clearance.

That was certainly an accurate forecast!

Figure 34. A Blue Steel missile being serviced in a hangar.

Blue Steel came into service at a time when Britain’s deterrent policy was changing rapidly. It had been originally intended to extend the operational life of the V bombers until Blue Streak was deployed in the mid-1960s. When Blue Streak was abandoned in favour of Skybolt, the need for Blue Steel was far less acute, since the Air Staff hoped to have the first squadrons of V bombers equipped with Skybolt deployed by 1964. To the consternation of the British Government and the Air Staff, Skybolt was cancelled at the end of 1962. Some rather tense negotiations led to the Nassau Agreement, whereby the United States agreed to supply Britain with Polaris missiles. The drawback was that it would take some years to build the submarines and equip them with the missiles, and so Blue Steel would have to soldier on long past its ‘sell by’ date.

The Treasury was adamant that there would be no more money for Blue Steel and the V Force. The only way that the bombers could now penetrate Russian airspace was to fly as low as possible: a role in direct contradiction to the design of both aircraft and missile, which would now be launched at an altitude of 1,000 ft.7 This would halve its range, making the system even less viable.

This was not the only problem. The one advantage of choosing a rocket motor was that the missile did not need an air intake, and as a result its radar cross section was very much less – in modern jargon, it was ‘stealthier’. The use of HTP gave rise to a whole host of other problems. The first and unexpected problem was that aircraft de-icing fluids exploded when coming into contact with HTP, which necessitated a rapid change in procedure for de-icing during winter. The time needed to prepare a missile was of the order of seven hours. One option was to keep some missiles partly prepared, which might mean filling with HTP. The HTP had at some stage to be drained out of the missile, and the tanks were then flushed out with water and dried. Only one drying unit was provided for each station, so that after a full-scale exercise or sudden emergency, it could take as long as two weeks for the station to recover its normal peacetime preparedness!

The use of HTP also meant obtaining safety clearances from the Ordnance Board and Nuclear Weapons Safety Committee. Worries about safety meant that the Nuclear Weapons Safety Committee withheld the authority to fuel the missile on the aircraft when the warhead was fitted, the authority to fit the thermal batteries to readiness missiles and the authority to fly the aircraft with the warhead fitted to the missile to a dispersal base. Thus for a considerable part of its service life, Blue Steel could have fuel, or a warhead, but not both.

Blue Steel was only intended as an interim measure, and the Air Staff issued two further Operational Requirements, OR 11498 and OR 11599. These were for air-launched missiles, but ones with much greater ranges. The extra range effectively ruled out a rocket powered missile: the only way such ranges could be achieved was with an air-breathing missile using a turbojet or ramjet, and as such are beyond the scope of this book.

Various proposals were made for extending the range of Blue Steel, but such proposals were effectively just tinkering at the edges. This was summed up in a memo from the Deputy Chief of Air Staff to Watkinson, the then Defence Minister:

In considering Blue Steel and any possible developments of it we must take note of some pretty unpalatable facts. We first started thinking about this weapon in 1952. The OR was accepted by the Ministry of Supply in 1954 for an in service date of 1960 and events have I think proved that had this date been met the weapon would have had a useful and viable life. An in service date of 1963 for a weapon with a range of only 100 miles is however a different matter.

In our submission to the Treasury in 1955 the total R&D was estimated at £12.5M. This is now estimated to be £55M…

In all the circumstances I cannot see that we would be justified in pouring more money into the development of a weapon which has made unsatisfactory progress to date and which remains dangerously close to being a non-viable weapon at the time of its introduction into service.

There was also the fear among the Air Staff that if Avro were given the go – ahead to start work on any of the improved versions then there was a good chance that Mark I might be delayed even further.

Blue Steel eventually came into service with the RAF in a limited capacity at the end of 1962, although it was not until April 1964 that clearance was given for a filled and fuelled operational Blue Steel to be used with the Vulcan Quick Reaction Alert. However, its reliability was not good: in 1963 the RAF estimated that the chances of a powered missile being fit for powered launch at the target was around 40%, and of these, only about 75% would reach their targets. The Victor squadrons were operational until 1968, when they were retired from the Blue Steel role. The Vulcans continued with the missile until 1970, when it was withdrawn from service.

That was certainly an accurate forecast!

Figure 35. The Stentor rocket motor as fitted to Blue Steel.

It is difficult to avoid the conclusion that HTP/kerosene was a poor choice of propellants for Blue Steel, and that Avro, completely inexperienced in missile development, was a poor choice by the Ministry of Supply for its development. Both these factors extended an already critical development time and led to many operational difficulties. The delays in the programme, the cost overruns and the difficulties involved in handling the missile all conspired to reduce even further the reputation of the British aircraft industry. Blue Steel would be replaced by Polaris, then by Trident – both American-built. It is now half a century from Blue Steel, and Blue Steel was the last offensive British missile to be developed and deployed.

From the narrower perspective of British rocketry, the most useful contribution of Blue Steel was the two thrust chambers, which were the most successful part of the project. The smaller chamber went on to become the chamber that powered the later Gamma engines of Black Knight and Black Arrow. The larger chamber was suggested for various vehicles, but despite its apparent usefulness, was never exploited further. [3]

The European Launcher Development Organisation – ELDO

The political, technical and financial fiasco that would become ELDO grew from an act of political cowardice by the British Government. In an attempt to deflect some of the criticism that he knew would come its way after the Blue Streak cancellation, Watkinson had announced that development would continue as a satellite launcher. This was a disastrous move from several points of view.

Firstly, it deflected very little criticism. Very few people were interested in Blue Streak as a satellite launcher, but they were interested in the effect the cancellation might have on the Government’s defence policy. Secondly, the popular enthusiasm for a satellite launcher was small to non-existent. Thirdly, even civilian development was going to cost a great deal of money, and fourthly, there was no demand for a satellite launcher. It looked very much as though it might become a white elephant before it was even built.

One way round the problem was to try and find partners: Thorneycroft had tried the Commonwealth but had received little concrete help. The French, on the other hand, were very interested, as this note from Selwyn Lloyd, then Foreign Secretary, shows:

The French Ambassador raised with me on the 8th of July the question of Anglo-

French co-operation in the development of Blue Streak as a space project. He said

that the reply to the French aide-memoire had been communicated to the French

Government and that he himself had spoken about the matter to the French Minister

of Defence when he had been in Paris.1

Thorneycroft was anxious to find partners for the launcher, and so a draft document was quickly put together as the basis of an offer to the French:

1. All firings to be done at Woomera.

2. Offer to divide satellites for initial programme equally between partners, each paying their share of the cost.

3. The French to make the third stage boost.

4. French technicians to be associated with the completion of BLUE STREAK and

BLACK KNIGHT, and to be given all design information and know-how in a return for a payment of £X for five years.2

Not everyone was happy with a bilateral deal with the French; Edward Heath, then Lord Privy Seal, wrote to the Minister of Aviation thus:

Although I realise that the French are more likely than anyone else in Europe to make a useful technical and financial contribution to the development of a European launcher, I do not feel it is politically possible now, having made an approach to so many European countries to turn round and tell the Europeans that we propose to enter into an exclusive bilateral scheme with the French…

The French may of course try to steer us towards a bilateral scheme: if so, we should have to think again, and very hard: for I see substantial political objections to some exclusive Anglo-French scheme.. .3

Despite Heath’s objection, a party of French engineers visited London on 29 September, moving on to Farnborough on 30, September followed by a much longer four day visit in November, when the itinerary included Hatfield, Ansty, RPE, Spadeadam, Cowes and London.

Thorneycroft summarised the results of the visits in a note to the Prime Minister:

The French have replied on Blue Streak. Essentially they have said 4 things –

(a) That they will join us in an approach to other countries in Europe.

(b) That they remain uncommitted at this stage.

(c) That they want to make a good slice of the composite rocket themselves.

(d) That it will all take a long time to arrange.

(a) is excellent, (b) and (c) are understandable and (d) must be avoided at all costs.4

Then it was the turn of the British to go to Paris in January 1961. The record of the meeting begins with the sentence: ‘M. Pierratt opened the discussion by stating that the French had received instructions from top level on Wednesday last to work at a joint solution with the British for a European space launcher’ (‘top level’ being interpreted by the British in this context as meaning General de Gaulle himself).

The meeting then went on to discuss the details of the design. The French, at this stage, were leaning towards the idea of a solid fuel second stage deriving from their military programme. The British technical representative, Dr Lyons from RAE, was

… disappointed… not so much that the payload was less, but because it was less flexible in terms of a change in diameter. A 1.5 meter second stage would not produce a good three stage build-up if in later years a Hydrogen third stage was considered. The solid fuel motor would have been a cheaper option, since it was already being developed for the military. The liquid fuelled proposal would use

UDMH and N2O4, although the French admitted when asked what experience they had with these propellants: ‘… very little indeed. They had fired some engines of a research size for very short durations only’.

The most surprising point about the technical exchanges is how seemingly ill- prepared the French were. The first contacts had taken place more than six months ago, the first technical visits more than three months before, yet obviously no detailed consideration had been given to the design at all. If even such a basic point as whether to go for a solid or liquid fuelled design had not been considered in any depth, then there was a great deal of work still to be done. There was an interesting coda to the meeting. To quote:

French said they would try to work out these costs this evening and on Saturday morning. They would have to go carefully into the savings to be made on the military investment and the question of British help in this field was of major importance.

Twinn said we fully recognised this, and in order to be as helpful as possible we would like the French to define in more detail than previously just how we could help with the military programme.5

The items were listed in a separate table:

The European Launcher Development Organisation - ELDO Подпись: Methods of manufacture Damping Stage separation Fuel sloshing Coupling between structure and control: frequencies Comparison between inertia and radio guidance


Подпись: EquipmentRefrigeration and cooling

Re-Entry Head Stabilisation, orientation

Rate of spin, methods of spin control

Heat flux


Equipments concerned with operating the bomb

These are exactly the questions one might expect, although if the French were intending to produce a solid fuelled missile, some of the items such as sloshing would become redundant. It is unlikely that Britain could have given much help on large solid motors. Some of the other items were ones which had given particular difficulty to the British only two or three years before – inertial guidance and re-entry in particular.

Sir Steuart Mitchell’s comment on the re-entry head read as follows:

The design of re-entry head which we finally ended up with for Blue Streak is:-

(a) Of British origin.

(b) It is now joint UK/US information.

(c) It is agreed by the US to be much better than their designs as regards invulnerability and US has now copied it.

(d) As regards invulnerability it is so advanced that neither the US nor ourselves can conceive a counter to it.6

Writing to Solly Zuckermann in a memo entitled ‘Possible Transfer to French Government of Military Technical Information on Blue Streak’, he also notes that:

Re-entry head.

Radar Echo. Information on this is mostly Top Secret and would be of great value to the French. The most advanced work in this field is British and is acknowledged by the US to be ahead of their work. It is thought that future US warheads may be based on this British work.

Release of this information would be contrary to I and II of para 3 in that it could provide an enemy with a ballistic weapon against which we see no defence and it would prejudice American weapons. It is desired to draw particular attention to this point and it is recommended that this information should not be released.

To provide a line of defence on which any technical conversations might be conducted it is suggested that we take the line that –

Details of shape, weight, dimensions, etc. of the Blue Streak re-entry head cannot be discussed as they contain “atomic” information.

Decoys. Information on these would contravene I and II of para 3 above. This is a sensitive Top Secret field in which we are well ahead of the USA who accordingly would be apprehensive if we released information to the French.7

He also made the point that ‘… the re-entry head design is highly specific to the weapon parameters.’

It is clear, however, that the French regarded the military information as something of a quid pro quo:

… they wished to make a political point of associating the exchange of military information with the cost for the space launcher, and they wished to make the inter­dependence clear at Ministerial level by presenting both cost and military exchange papers to Mr Thorneycroft at Strasbourg.8

The British delegation was less than happy with this idea: ‘The representation at Strasbourg was not the channel at which we would prefer to deal with this.’ Mitchell wrote a minute (‘French Proposals for 2nd and 3rd Stage’) for the Minister, summing up the position to date. An interesting comment was that

‘since August [1960] no approach to UK firms to start design of the second and third stages has been permitted, partly to avoid compromising our negotiating position in Europe’. Using a French second stage would increase development time, and CGWL felt that this ‘now gives enough time to develop a liquid hydrogen 3rd stage’.

He also had these comments to make on the French proposals:

… if the French chose a liquid motor for the 2nd stage, and if they followed their present lines of development, the performance of their 2nd stage would again be appreciably lower than that of Black Knight.

This is due to the fact that the French have not developed high performance turbo pump fuel systems on UK or USA lines and, for their weapon development, are not prepared to face up to their technical complexities. They intend to use the cruder method of gas pressurisation of the fuel tanks as a means of pumping the fuel. The resultant penalty in tankage weight is considerable.

As a result of the above, the conclusions as to French 2nd stage performance are as follows:

The French agree that there would be a loss of performance, but argue that it would not be great… We, with much more experience, consider that the penalty would be considerable.9

There was a way round this performance loss: replacing the planned HTP/kerosene third stage with one using liquid hydrogen. His suggestion was:

Participation by other European countries in the Space Club is essential. Hence I suggest that development of the liquid hydrogen 3rd Stage should be offered to a consortium of European countries with some UK technical participation in the development teams.

His final conclusion was that

We are in favour of proceeding with a French 2nd stage and a European 3rd stage, recognising that by so doing the completion date for the European launcher will be delayed by perhaps Ш years and that the total costs may rise by perhaps 10-15%.

There followed some very rapid writing of proposals which would be put to other European countries. The end result was a long brochure, describing the vehicle and its missions in considerable detail10. The introduction provides a useful summary of the history of the project to that date:

After the British Prime Minister’s Statement in May 1959 that an investigation would be made of the adaptation of British rockets for satellite launching, extensive studies of the capabilities of Blue Streak, in combination with other rocket stages, have been made by the United Kingdom Ministry of Aviation at the Royal Aircraft Establishment, Farnborough.

The later proposal that a satellite launching vehicle system based on a Blue Streak as a first stage should be developed as a joint European and Commonwealth effort, has recently caused these studies to be extended by joint Anglo-French investigations into a design incorporating a French second stage.

The original British proposals were put to representatives of European nations at Church House, Westminster, London on the 9th and 10th January, 1961. At Strasbourg, during the week of 30th January to 3rd February, a preliminary description of a joint Anglo-French proposal was presented for the consideration of representatives of a number of European nations.

One of the guiding principles of the United Kingdom studies was the minimisation of cost, particularly capital cost, and thus the greatest possible use should be made of existing equipment and facilities, including the rocket ground testing and development facilities at Hatfield and Spadeadam, in England, and also the launching and other range facilities at the Weapons Research Establishment, Woomera, Australia.

France, on her side, has undertaken an extensive national programme of basic studies and development of ballistic missiles. The French proposal for a second stage, later to be described, is closely related to this programme in order, again, to minimise cost, delay and technical uncertainty.

This brochure contains outlines of the jointly proposed satellite launching vehicle and its systems as they stand at February, 1961. The opportunity has been taken since the Strasbourg meeting to bring the proposals into accord with the latest technical information. The assessment work which will lead to a full design study is by no means complete, depending as it does considerably on the parts of the work to be undertaken by the European nations involved. All aspects of the combination of the French second stage with Blue Streak have not yet been completely examined. The brochure, therefore, contains the joint Anglo-French proposals as far as they have gone, and where the necessary work has not been completed, the parallel work done on the original British configuration has been referred to. In the absence so far of an alternative proposal for the third stage, the third stage described is the original UK proposal.

The brochure went on to describe the capabilities of the launcher:

(i) A large satellite weighing between one and two thousand pounds in a near circular, near earth, orbit. This satellite would be space-stabilised with a primary purpose of making astronomical observations above the earth’s atmosphere.

(ii) A smaller satellite of several hundred pounds weight, moving in an eccentric orbit out to two or three earth radii, for the investigation of the earth’s gravitational, magnetic, and radiation fields, and the constitution of the earth’s outer atmosphere.

(iii) A satellite of the order of one hundred pounds weight, in a highly eccentric orbit reaching out to about 100,000 miles, to carry instruments for the study of the sun’s atmosphere.

These aims have been subsequently extended to cover the possible launching needs for Satellite Communication Systems and this has led to the consideration, in addition, of circular orbits at several thousand miles altitude.

Подпись: (18-75 M)

The European Launcher Development Organisation - ELDO The European Launcher Development Organisation - ELDO
The European Launcher Development Organisation - ELDO
Подпись: (3-04 8 M)
Подпись: (.31-4 M)
Подпись: CI9-9I M;
Подпись: Г25-5 MJ

The European Launcher Development Organisation - ELDO-BREAK UP CHARGES. CHARGES DE DESTRUCTION


The European Launcher Development Organisation - ELDO


Figure 62. The Anglo-French proposal. This is effectively the Black Prince design with a French second stage.

The first three objectives are taken from the Saunders Roe brochure for Black Prince, published a year previously. It does highlight an absurdity of the programme: £60 million for three satellites does seem excessive. The communications requirement is new, and the Saunders Roe liquid hydrogen stage was optimised for just such a role. The main problem was that even 5,000-6,000 miles was still too low an orbit for communication satellites. RAE and others tried looking at 8-hour or 12-hour orbits, but it is only the geostationary orbit which is of any practical use.

The European Launcher Development Organisation - ELDO

Figure 63. The French proposal for the second stage (the final version would be very similar, except that the one large chamber would be replaced by four smaller ones).

The brochure then went on to describe the vehicle in more detail:

The original British proposal for the second stage was to use a modified form of the ballistic research vehicle Black Knight. This has now been replaced by a proposed French second stage making use of techniques currently under development in that country. This stage will be propelled by a liquid propellant engine using Nitrogen Tetroxide and UDMH with, a sea level thrust of 25 tons (32 tons vacuum) and vacuum Specific Impulse of 276 seconds. The vehicle tanks contain approximately 7 tons of propellants and are pressurised by means of a solid propellant gas generator. The single thrust chamber is gimbal mounted for control in pitch and yaw. Roll control is achieved by means of auxiliary jets mounted at the top of the vehicle…

Studies indicate that it is possible to inject a satellite into orbit using the proposed two stage combination but this would necessitate a long coasting period after perhaps 90% of the second stage propellants had been burnt, followed by a relight of the second stage engine to inject both satellite and empty second stage into orbit. This approach introduces problems of relighting the engines under zero acceleration as well as the necessity for ensuring correct orientation of the second stage at engine relight.

Though such problems have been solved in other satellite launchings, the two stage vehicle would give considerably reduced payloads and would be unable to put any payload into higher orbits. The preferred approach is therefore to introduce a small third stage rocket. This is sometimes referred to as a vernier stage. The engine of this stage, working at a relatively low thrust level of between 1000 lb and 2000 lb would be started during separation from the second stage and would continue to burn through what would otherwise be the coasting period, cutting off when orbital altitude and velocity had been achieved. The low weight of the third stage structure and engines, compared with that of the relit second stage, affords considerable improvement in payload weight into low orbits and makes possible the injection of payloads into very high orbits.

The British proposal for a third stage engine is a four chamber design, each chamber pivoted about one axis for steering. It would use hydrogen peroxide and kerosene. With low thrust and four chambers, very high nozzle expansion ratios, of 1000 : 1, are possible without undue chamber size and length…

The European Launcher Development Organisation - ELDOIt is possible to meet the several orbital requirements by exchanging satellite payload weight for propellent weight in the third stage whilst maintaining constant the overall weight of the third stage plus satellite payload at some 5000 lb; that is, the third stage incremental velocity can be increased at the expense of payload. The tank volume is altered to suit the orbital mission allowing the remainder of the third stage, including the engine, and all equipment, to remain sensibly unchanged.

For the configuration just described, with a take-off thrust of 300,000 lb weight a satellite of 2,160 lb may be put into a 300 mile circular polar orbit.

Corresponding payloads for elliptical polar orbits, both with perigee heights of 300 miles, and apogee height of 7000 and 100,000 miles, are respectively 910 lb and 320 lb.

For a typical high altitude equatorial orbit (launched near the equator) at, say, 5000 miles altitude; a payload weight of 700 lb is calculated.

These are ‘nominal’ payloads making some allowances for weight growth of the launching vehicle. It would be prudent, however, to assume that actual payloads would be perhaps 200 lb less than these nominal values to allow for unforeseen contingencies.

The negotiations were not easy. Enthusiasm for the project in Europe was very limited. Indeed, in May 1961, Thorneycroft asked Mitchell what needed to be done to go ahead with an all-British launcher, and received a reply saying that it would be quite straightforward with the original HTP design, with or without the liquid hydrogen stage. Even Australia seemed to be making difficulties, and Thorneycroft took the unusual step of writing to Mitchell to ask whether it was feasible to launch Blue Streak from Spadeadam!

The conclusion to his hastily written paper (the full version can be found in Appendix A):

Spadeadam is technically both feasible and attractive. From the cost point of view, it is approximately the same as Woomera, and is much cheaper than any alternative.

It must be accepted, however, that some cut-downs on to UK territory would inevitably occur if we fire from Spadeadam. The chance of serious damage to life and property from such cut-downs are numerically small.

The risk of damage to foreign countries, or to shipping, is negligible.

The crucial point is the political acceptability of the risk in the UK Hitherto this has been regarded as unacceptable, and it would be no less now than when previously considered. My advice is that the risk is appreciable and should not be accepted.11

As Mitchell says, the crucial point is political acceptability. The thought of launching a rocket as large as Europa from an inland site in Britain is one which should fill any politician with horror. The repercussions from an accident would be horrendous.

There is also another technical point. Mitchell describes the launch direction as ‘North 15 East’, or 015° in modern parlance. To be restricted in launch direction in this fashion very much reduces the value of the site (and this also applied to Woomera). Different satellites fulfilling different roles need different orbits. It certainly would be useless for communication satellites.

Fortunately, agreement was reached with the Australians, and Woomera would indeed become the launch site for the first ten launches.

Although several European countries sent delegates, most of Thorneycroft’s efforts were devoted to persuading the German and Italian Governments to join the project. Both countries were reluctant; the Italians wanting to reserve their money for their own national programme. Belgium and the Netherlands were willing to participate, but their contributions would be small. Denmark had taken part in the discussions but decided in the end not to join, but again any Danish contribution would not have been very significant.

After further protracted negotiations, Germany agreed to join, and would build the third stage; the Italians would provide the satellite fairings and the Satellite Test Vehicle (STV). Thus the final membership of ELDO consisted of the UK, France, Germany, Italy, Belgium and the Netherlands, with Australia making the seventh member.

The cost of the programme was split thus





West Germany:








Australia would make no direct contribution, but would instead develop the Woomera launch site.

Подпись: Figure 65. The inital design for the ELDO launcher. ELDO came into formal being in March 1962 by a Convention which was signed by the seven Governments and which came into force on 29 February 1964 after ratification by the signatory states. The headquarters were in Paris, and it was governed by a Council that had two representatives for each member state. The Council was assisted by an International Secretariat under the direction of a Secretary General, with two Deputy Secretaries General, one in charge of technical affairs and the other of administrative affairs. The staff of the Secretariat amounted to around 180 people in 1965.

But while design work for the new launcher had started, ELDO itself was already running into serious political trouble. Indeed, it would spend most of its existence staggering from crisis to crisis, either technical, financial or political.

By 1964, the design of the vehicle had finally been decided12, and work was beginning on the design and construction of the upper stages. The French then dropped something of a bombshell by stating ELDO A was inadequate, that it should be dropped, and that the organisation’s efforts should be directed towards a new launcher, ELDO B.

There were immediate objections from the other member states, mainly on the grounds that an entirely new upper stage would be technically demanding and take several more years to develop, whilst in the meantime, nothing else would be happening. Blue Streak had already been successfully tested, and work was proceeding on F4, which was Blue Streak with dummy upper stages. Under the French proposal, there would be no further launches for some years until the new upper stages had been designed and developed. To be fair to the French, if ever there was a time to go for a design that was far more capable, this was it, but given that it had already taken four years to get to the point of beginning work on ELDO A,

the reluctance of the other countries was understandable.

But the French took their objection to ELDO A one step further: they refused to provide any further funding. This did produce quite a serious crisis: without an agreed budget, all work would grind to a halt by the middle of 1965. Negotiations with the French proved difficult: the British representative referred to what he called ‘decisions handed down from Mount Olympus’ – in other words, a decision taken on high, and presumably a reference to General de Gaulle, which the French ELDO representatives could do little about. One junior minister, Austen Albu, described the situation thus: ‘Whatever the merits of the case we are in fact being blackmailed by the French.’13

The British Government had by now become actively hostile to ELDO, and there were hopes that French intransigence might bring about the collapse of the organisation.

From the economic point of view, the safest course would still appear to be to decline any further financial obligations beyond our share of the original £70 million on ELDO A, to which we are already committed. It has certainly not been demonstrated that a firm stand on these lines will involve serious dangers to those policies on which it is really important that we should have our neighbours’ support [referring to other members of ELDO]. Such action might indeed gain us enhanced respect in the more responsible sections of our neighbours’ administrations…

If however the feeling of Minister’s colleagues is against such risk of friction to neighbourly relations as a firm stand might involve, the next best course would be to take the line that on present evidence Britain

is not prepared to depart from ELDO A as originally conceived,

is unwilling to proceed to completion of the ELDO A programme until more

adequately costed,

as regards ELDO B no commitment could be considered until much more information was available.

There are many who consider that if Britain takes a position along these lines ELDO will die a natural death, without Britain having to plunge the dagger. First Secretary, however, will appreciate that such a happy outcome cannot be guaranteed and that the more moderate course must carry the risk of a lingering British involvement in these unrewarding activities.14

There were attempts at a compromise. One was to proceed with what was called ELDO A(1+3), to keep the programme going whilst work began on ELDO B. This was a proposal to put the German third stage on top of Blue Streak – hence the (1+3) designation. This, it was thought, could put 300 kg into a 500 km orbit. Use of an apogee motor would enable payloads to be put into highly elliptical orbits, which might suit some of the proposed European Space Research Organisation (ESRO) requirements. Given that the German stage was the least well developed part of Europa, this too was somewhat optimistic.

An ELDO document15 described the proposal thus:

The 1+3 programme would provide for development of basic techniques, establishment of facilities, and experience by personnel as a foundation for the ELDO B programme including proof of the first stage and engines; development of throttled engines, live-stage separation; instrumentation, safety, nose-fairing and STV separation, and inertial guidance. This is work which can only be carried out in a vehicle based on Blue Streak.

The studies so far undertaken, necessarily limited by time, give the Secretariat good grounds of assurance that the programme is technically feasible.

The payload performance of the 1+3 vehicle is strongly dependent on the 3rd stage performance and empty mass. Its round to round variation will be somewhat smaller than that of the original three-stage vehicle. For a 300 km orbit, the upper limit of payload performance is about 500 kg…

This payload performance would have application to:

a) missions requiring light satellites, e. g. for navigation, meteorology or geodesy,

b) ESRO requirements for the launch of small satellites, i. e. those within the launching capacity of Thor Delta.

It was a proposal that died together with ELDO B. A 500 kg payload is quite respectable, but whether it would be worth using a launcher as expensive as the (1+3) scheme is debatable. A sketch of the proposed vehicle is shown on the left.

Подпись: Figure 66. The ‘1+3’ proposal. The (1+3) programme was intended to run in parallel with the ELDO B development, but ELDO B was abandoned as a result of the Intergovernmental Conference in July 1966. Instead, a new five year programme was drawn up, starting in January 1967 at an estimated cost of 331 MMU. (1 MMU was effectively the same as 1 US dollar, so at the then rate of exchange this was a little less than £120 million.) 10 MMU were set aside for ‘studies and experimental’ work – ELDO B was not entirely dead yet.

On the other hand, the rejection of ELDO B left the organisation with a vehicle that had very little purpose. In order to salvage something from the wreck, the Perigee Apogee System (PAS) was put forward. This consisted of two solid fuel motors and a communications satellite. The system would be put into orbit by Europa, then the first solid fuel motor

would be fired to put the satellite into a highly elliptical geosynchronous transfer orbit. The apogee motor would convert the elliptical orbit into a circular orbit.

A geosynchronous orbit required a launch site close to the equator – and Woomera was too far south. The launch corridors from Woomera were very restricted by the centres of population below the flight path. ELDO set about finding an alternative site, and the two main contenders were Kourou or Darwin, and, as we shall see, Kourou was chosen.

So a new launch site for Blue Streak was built in the depths of the South American jungle. The last launch of Europa from Woomera was F9, after which Australia left the organisation. A non-flight model Blue Streak, known as DG, was taken out to Kourou to test the facilities. F11 (there was no F10) would be the first launch from South America, the first with the PAS operational, carrying a communications satellite for France, and the last ever launch of Blue Streak and Europa.


Two stage. Launched 7 June 1961 20:50. Apogee 362 miles.

BK17 was another two-stage vehicle but with a lighter low-drag eroding head to give higher re-entry speed. The first stage performance was very good. The kerosene level sensor and HTP probes worked well and propellant usage in flight was determined. Visual observation and camera records of re-entry were confusing, but it soon became clear that the second stage had not functioned correctly. The head and tape recorder were recovered, and subsequent analysis of head tape record and body telemetry indicated that second stage separation occurred at re-entry and not at the end of first stage burning. It was possible to deduce from the records that the failure of second stage separation at first stage burn-out was due to failure of one of the two explosive bolts. In later vehicles explosive bolts and associated circuits were duplicated. At re-entry the second stage was torn off, followed by second stage burning.

The tape of the recorder in the head ran out before re-entry. In subsequent heads, the speed of the tape in the tape recorder was reduced so as to run for a longer period and ensure recording re-entry.

R3 – 28 October 1971

R3 was dispatched to Australia early in 1971, and the second stage arrived at Woomera on 26 July, followed by the first stage on 17 August. Static firing of the second stage occurred on 1 September, and the two stages and the back-up satellite had been assembled by 1 October. The complete vehicle was given a static firing test on 8 October, and the flight model satellite was fitted by 22 October. A decision was made to delay the launch until 26 October, but systems checking delayed the launch further.

Derek Mack, one of the Saunders Roe launch team (Saunders Roe had by then become the British Hovercraft Corporation), remembers the morning of 28 October as a cool, fresh Australian spring day, with clear skies. The overnight crew had filled the HTP tanks and adjusted the kerosene levels, as well as arming the many pyrotechnic systems on the vehicle. The gantry was wheeled back at 11:00, but there was some alarm when the Attitude Reference Unit, which steers the vehicle, began to give erratic signals. There was relief when it was realised that this was due to the vehicle swaying gently in the light breeze. The vehicle lifted off smoothly, and the various telemetry stations north of Woomera reported that all events had been successful. However, this did not yet mean that the launch had been successful: it was only when the global satellite station at Fairbanks reported an operational signal from a satellite on a frequency of 137 MHz that the team knew that they had an orbiting satellite. The party could begin, but there was a sour taste to it.

R3 launched the Prospero satellite (X3) into orbit on 28 October 1971, in a text book launch.19 The programme had meanwhile been cancelled by an announcement in Parliament by the new Minister at the Department of Trade and Industry, Frederick Corfield, on 29 July 1971. The teams that had built Black Arrow and launched it were out of a job.

Prospero had a mass of 66 kg, and was launched into an orbit of perigee 557 km, apogee 1,598 km, and an inclination to the equator of 82°. It is still in orbit. It carried four experiments:

(a) To determine the thermal stability of a number of new surface finishes.

(b) To determine the behaviour of new silicon solar cells.

(c) An experiment in hybrid electronic assemblies.

(d) An experiment by Birmingham University to determine the flux of micro meteorites.

The satellite was formed from eight faces covered with 3,000 solar cells. Since the spacecraft would be in the earth’s shadow for part of its orbit, rechargeable batteries were also carried.

The flight sequence for the Prospero satellite launch was:

Event Time (seconds)

Lift-off 0

First stage engine shut down (HTP depleted) 126.9 Stage separation/second stage ignition 133.5

Inter stage bay separation 139.1

Payload fairing separation 180.0

Second stage shut down (HTP depleted) 256.9

Pressurise attitude control system 262.5

Spin-up rockets 575.0

Stage separation 577.0

Third stage ignition 590.0

Payload separation 710.1

The fifth vehicle, R4, was never fired, and is now on display in the Science Museum, London.