Category A VERTICAL EMPIRE

Rippon and Strath will have told you how things have been developing in your absence.

The first development is that WS.138A seems to be doing well. You will have seen the messages sent to your Ministry by the Mission, which show that it has now been approved by the Department of Defense…

This leads on to Blue Streak. The Chiefs of Staff have been considering their attitude to Blue Streak and have now given me their unanimous advice that they find Blue Streak, as a fire first weapon, unacceptable. I am afraid Dermot sold the pass here to begin with.

If then it is open to us to obtain an American weapon on acceptable terms, we are faced with a disagreeable choice. Either we must go on with Blue Streak in the knowledge that the Chiefs of Staff advise against it as a weapon. Or we must cancel it in favour of an American weapon, with all that may be involved in the way of losing the ability to develop missiles on our own. No intermediate course seems to be feasible as I understand from your department that if Blue Streak is to go on at all there is no sensible way in which any significant sum could be saved. I am not sure that they have really thought this out enough, but you will know better than I about this.

This then is the choice so far as spending defence money is concerned. It may be that the Minister of Science will conclude that he can justify financing the development of Blue Streak and converting it into a project for space research, primarily from civil funds. I have put this proposition to him but I should doubt whether he can find the money.

All this presents us with a difficult choice and I am not yet clear what it is best to do in the national interest. In order to help me to form an opinion I have been asking your department for information about the consequences of stopping Blue Streak. Your department is directly in touch with the Minister of Science’s office about the cost of the space research programme.

I should very much like to know what you think, as soon as your people have finished setting out the consequences of stopping Blue Streak, or any possibility of saving something from the wreck.22

‘Dermot’ referred to in paragraph five was the Chief of the Air Staff, Sir Dermot Boyle. Blue Streak was intended for service in the RAF, yet even the head of that Service had rejected it. Watkinson’s implication is that Boyle’s withdrawal of support for Blue Streak was the precipitating factor. The phrasing of the letter is also interesting: Watkinson realises the implications for Sandys, yet cannot argue against the advice given to him by the professionals.

What were the motives of the Chiefs of Staff? Crudely, they could be summed up as follows.

The Army had no real interest one way or the other. Their only real interest was to keep the cost of the deterrent as low as possible to allow more room in the military budget for new equipment (tanks and the like) for conventional forces. If a cheaper alternative to Blue Streak were available, they would vote for it.

Mountbatten, as mentioned, had other motives. He was, in addition, Chief of the Defence Staff and a man with a considerable Whitehall network. Cancelling Blue Streak, to which he was opposed anyway, opened the way for the Navy to acquire Polaris submarines, which they did in the mid-1960s. His successor as First Sea Lord, Sir Charles Lambe, was also pushing hard for Polaris.

Boyle, of the RAF, also saw new opportunities for his service. Not only would the V bombers be given a fresh lease of life, there was a window of opportunity for the RAF to acquire further aircraft to supplement and replace the V bombers. Proposals were well advanced at the time of the cancellation of Skybolt to modify the VC-10 airliner to enable them to carry the missile.

Apart then from the Ministry of Aviation, Blue Streak had no Whitehall or Service support. Hence it was to go.

But there were other political considerations to the cancellation. Two of the most important were the political dimension of the cancellation, particularly given the cost to date, and the implications for relations with Australia.

Since the late 1940s, there had been considerable co-operation between the UK and Australia in matters of weapons development. The UK had devices to test but no room in which to test them; Australia had the room but did not have the devices. Thus Australia provided testing sites for atomic weapons (the Monte Bello Islands, Emu Field, and Maralinga), as well as the Long Range Weapons test site at Woomera. All Blue Streak test firings were to have been carried out at Woomera, and many facilities, funded jointly by the UK and Australia, were nearing completion. Thus the Foreign Office in particular was concerned about the impact of the cancellation on the Menzies Government and on Australian public opinion.

As to the cost of the project so far, there was a salvage option: to continue Blue Streak not as a military weapon but as a satellite launcher. This would help deflect much of the political criticism, but it was an option that had not been thought through very clearly – in particular, the cost implications.

Now the decision went to the Cabinet Committee on Defence, and the minutes of its third discussion on 6 April concerning Blue Streak read as follows:

THE PRIME MINISTER said that the first question for consideration was whether

the provisional decision… to abandon the development of BLUE STREAK as a

weapon should now be confirmed. There were two main issues to decide:-

(a) Would it be militarily acceptable to rely on the V-Bombers, with SKYBOLT, rather than on BLUE STREAK, as our strategic nuclear force from about 1965 onwards?

(b) Was it reasonable to assume that SKYBOLT and eventually POLARIS (if we needed it) would be made available to us by the Americans on satisfactory terms?

THE MINISTER OF DEFENCE said that… the general consensus of opinion was that, in circumstances other than a surprise saturation attack, the V Bombers equipped with SKYBOLT would have certain advantages over BLUE STREAK. The main considerations leading to this conclusion were political rather than scientific or technical. The Bomber force had qualities of mobility and flexibility which were useful for conventional operations as well as for the nuclear deterrent. It had the advantage that it could be launched on a radar warning without an irrevocable decision being taken to launch the nuclear attack itself.

THE MINISTER OF AVIATION agreed that there would be certain financial and political advantages in depending on the V-Bombers and SKYBOLT rather than on BLUE STREAK for our strategic deterrent force in the later 1960’s [sic]. From the military point of view, there was no marked advantage one way or the other. In these circumstances he would concur in the decision that the development of BLUE STREAK as a weapon should be abandoned.

… The Americans had indicated their willingness to make SKYBOLT available unconditionally, except for the suggestion, which we might be able to persuade them to modify or abandon, that specific reference should be made to its use for North Atlantic Treaty (N. A.T. O.) purposes. It should be possible to reach a similar understanding as regards POLARIS (on which, however, no immediate decision was required) .

THE PRIME MINISTER said that the Committee’s discussion showed that their provisional decision to abandon BLUE STREAK as a weapon could now be confirmed. The next question to be considered was whether its development should be continued for scientific and technological purposes. The officials’ Report showed that there were only two alternatives:

(a) to cancel BLUE STREAK completely; even if this were done immediately, there would be unavoidable nugatory expenditure of about £72.5 millions, of which £22 millions would fall in 1960/61.

(b) to adapt it as a space satellite launcher at a cost, including the development of a stabilised satellite, of about £90-100 millions.

The advantages and disadvantages of these two courses could not be wholly assessed in material terms. To cancel BLUE STREAK would involve dislocation of industry, difficulties with the Australians, heavy charges, the loss of the potential value of a large British rocket for space research or other purposes and the abandonment of that part of the work already done which was relevant to the development of a satellite launcher; but it would curtail expenditure in the longer term, and make resources available for other purposes. To develop BLUE STREAK as a space satellite launcher would be much more costly. and the Ministry of

Aviation had not been able to consult the firms concerned about whether the £90­100 millions launcher and satellite programme would in fact be practicable…

THE CHANCELLOR OF THE EXCHEQUER said that an immediate decision should be taken to bring all further work on BLUE STREAK to an end. The nation’s resources over the next few years would be inadequate to meet all our existing commitments. Since there was no suggestion that any other project should give way to the development of BLUE STREAK as a space satellite launcher, he did not see how the heavy expenditure involved could be met. The programme was estimated to cost over the next four or five years some £75 millions more than the cost of immediate cancellation; past experience suggested that this figure might be considerably increased and that other defence projects, for which no provision had yet been made, would eventually come forward to take the place of expenditure saved on BLUE STREAK. The national economy would benefit from the industrial and man-power resources made available by the complete cancellation of BLUE STREAK.

Summing up, THE PRIME MINISTER said that the Cabinet should be informed of the decision to cancel the development of BLUE STREAK as a weapon and invited to consider whether this decision should be announced in terms that all work on BLUE STREAK should cease completely or that further consideration was being given to its development as a space satellite launcher. If the latter alternative were adopted it would be desirable for a final decision to be taken if possible within the next few weeks.

The Committee took note that the Prime Minister would arrange for the Cabinet to be informed of the decision to cancel the development of BLUE STREAK as a weapon and of the terms in which this decision might be communicated to Parliament and to the Government of Australia on the alternative assumptions that –

(a) all further work on BLUE STREAK should cease;

(b) consideration should be given, in consultation with industry and the other interests concerned, to the adaptation of BLUE STREAK as a space satellite launcher.

The decision having thus been taken, it fell to Watkinson to make the announcement in the House of Commons on 13 April. He rose to read a statement which ran thus:

Single stage. Launched 29 June 1959 at 21:03. Apogee 275 miles.

BK05, a re-entry experiment using a double cone eroding head, was designed for greater penetration at high speed into the atmosphere with the object of obtaining much greater heating, particularly in the nose cone which was made of doorstops. A complicated parachute recovery system was built into the head in an attempt to prevent damage to the nose cone on impact.

Overheating in the propulsion bay, as in BK03 (unfortunately not confirmed until after BK05) again caused premature engine cut-out resulting in a reduced re-entry velocity.

A hitherto unsuspected long decay time of thrust at engine shut-down resulted in collision of body and head at separation. The body telemetry continued to function to re-entry but head telemetry ceased just after head separation. The head aerial was probably broken by the impact with the body. The head was recovered and it was found that the parachute had torn out the inner core of the head and the base dome had been pulled off. Early deployment of the parachute would have resulted in excessive drag loads and it can only be assumed that this happened.

Some supporting evidence is that the barometric switch used to deploy the parachute was found on recovery to operate at a pressure equivalent to 22,000 ft instead of the expected height of 10,000 ft. However, the trial was not a complete failure since recovery of the head yielded data on erosion, albeit at a lower re­entry speed than intended.

RAE had plans for yet another set of re-entry experiments after Dazzle, which were code named CRUSADE (derived, apparently, from ‘Co-operative Re-entry Undertaking, Signature and Discrimination Evaluation’). RAE also wanted to improve the performance of Black Knight still further. The Gamma 301 motor had been used at thrust levels of 21,600 lb, but up to 25,000 lb was quite feasible. Increasing the thrust meant that a bigger vehicle could be designed. Thus was born the 54-inch Black Knight6.

The original 36-inch Black Knight had been a long and slender vehicle – increasing its weight without increasing the diameter would have made it rather too long. The new vehicle would have tanks of 54 inches diameter, which made it shorter than the original vehicle, despite being heavier.

Saunders Roe produced a variety of schemes (Figure 103) presenting to them to the RAE at a meeting in July 1962. The first ideas were to keep the engine bay at 36 inches, and taper the HTP tank, although the result looked distinctly inelegant.

It was decided to change to a 54-inch bay and thus a parallel sided vehicle relatively late in the design process, and for aerodynamic rather than structural reasons. The parallel sided tank would have been marginally heavier, according to Saunders Roe’s calculations.

It was not only the main stage that could be enlarged: keeping the Cuckoo motor meant that despite the increase in size, performance was not that much better. Instead, a new motor was designed – the Kestrel. This was 24 inches in diameter – the first Westcott motor to exceed 17 inches diameter.

And comparing the two first stage configurations:

Weight empty Fuel Capacity Total 36 inch 1,380 lb 11,600 lb 12,980 lb

54 inch 1,480 lb 15,600 lb 17,080 lb

The last Dazzle flight took place in November 1965. The first flight of the 54- inch Black Knight was still some way away – perhaps 12 months or so – but the intention was to use BK22 for the first experiment in the Crusade programme. This was one of the last of the Gamma 201 engined vehicles, and had been an ELDO experiment back-up, upgraded to a two stage vehicle. Seven firings had been pencilled in, which included much heavier (250-300 lb) re-entry vehicles, and some decoys. Construction of a new engine bay and tank structure for BK26 had begun when RAE was given the choice between Crusade and Black Arrow, and Black Arrow won. Further re-entry experiments were dropped, although the US carried out further flights using old Redstone missiles, in a programme codenamed Sparta. One Redstone was left surplus to requirements at the end of the programme, and adapted to launch an Australian satellite.

History of the Saunders Roe SR53 and SR177

The SR177 is being built to OR337, issued by the Air Staff on 2nd December, 1955. This is a development of an earlier requirement, O. R.301, first issued in 1951. The aircraft being built to this latter requirement is the S. R.53.

SR53

May 1951. Particulars of a proposed requirement for a rocket propelled fighter were circulated to the Air Staff… Because of the limitations of the early warning system and the likely scale of enemy attack, it was thought that a large force of high performance day fighters would be required. The ability of the fighters then being developed to deal with the very high altitude raider was doubted. The aircraft proposed was intended to fill the gap until effective Guided Weapons became available and to provide a strong backing for the day fighter force against mass daylight raids of B.29 type bombers. The operational role of the aircraft was to be based on an exceptional rate of climb, probably obtainable only by rocket propulsion. Target date for the first production aircraft was Spring, 1954. The aim was to combine simplicity and ease of manufacture with operational efficiency. Certain operational refinements were therefore to be sacrificed.

August. O. R.301 was issued for a rocket fighter with the following main features:

(a) Climb 60,000 ft. in 2 У2 mins.

(b) Speed. Aircraft of this type were required ultimately to be supersonic above 30,000ft. In the first instance, a maximum speed of M = 0.95 would be acceptable if this would shorten development time substantially.

(c) Landing speed. A low landing speed-this was more important than supersonic speed since landings would have to be made from the glide.

(d) Armament: Battery of 2” air-to-air rockets, with provision for fitting direct hitting air-to-air guided Weapon as an alternative.

November. Ministry of Supply accepted O. R.301.

1952

January. Ministry of Supply issued Specification (F.124T). This enlarged on

O. R.301 by specifying that provision should be made for carrying Blue Jay [an air to air infra-red homing guided missile].

February. Ministry of Supply circulated the specification widely to aircraft firms… Tenders were submitted by Bristol, Fairey, Blackburn, A. V. Roe, and by Westland and Saunders Roe.

While firms were preparing designs, the Air Staff decided to ask for an ancillary jet engine to assist the return to base phase.

July. The Tender Design. Conference decided to recommend to C. A. that three prototypes each of the Avro and Saunders Roe aircraft should be ordered.

October. Ministry of Supply raised a Technical Requisition to initiate contract action.

1953

May. Ministry of Supply awarded a contract for three aircraft to Saunders Roe. The history of the Avro design is not followed in detail hereafter.

June. Ministry of Supply issued Specification (F138D) calling for Spectre, (rocket) and Viper (jet) engines, supersonic performance above 40,000 ft. and a subsonic cruising ceiling of not less than 70,000 ft…

August. … The target date for the aircraft to be in service was 1957.

1954

January. For reasons of economy, the Ministry of Supply order was reduced from three prototypes each from Saunders Roe and Avro to two prototypes each.

June. The Ministry of Supply forecast the first flight of the first Saunders Roe prototype for July 1955.

1955

January. The D. R.P. C. decided that for reasons of economy, either the Avro or the Saunders Roe development should be stopped. The Ministry of Supply made a study of the relative merits of each aircraft and its development potential.

March. D. M.A. R.D.(RAF) concluded that the Saunders Roe aircraft was likely to be more successful and would have an attractive performance in its developed form.

July. A. C.A. S.(O. R.) recommended to D. C.A. S. that the Air Staff should support the Ministry of Supply’s proposal to abandon the Avro aircraft.

1956

The first prototype SR53 is expected to fly in July, 1956.

March. Delays have been due to two main reasons, each of which would have held up the first flight date.

(a) The fuel and designing a HTP system were more difficult than was first realised and required a large amount of testing.

(b) Development of the Spectre rocket has slipped and the engine has not yet been airtested. Tests with a Canberra are expected to begin in March, 1956.

S. R.177

1954

January. The Air Staff considered the further development of the aircraft to

O. R.301. A. C.A. S.(O. R.) suggested that the O. R.301 prototypes might be used to provide early technical information for building a more advanced aircraft on similar principles.

February. Saunders Roe submitted a brochure to the Ministry of Supply proposing that a jet engine of similar thrust to that of the rocket be fitted to the aircraft being built to O. R.301.

June. Ministry of Supply asked R. A.E to assess the performance of the aircraft proposed by Saunders Roe when fitted with a Gyron Junior engine.

1955.

February. Ministry of Supply raised a Technical Requisition for design studies of the possibility of using an engine of 7,000 to 8,000 lb. thrust in the P.138D.

August. Air Staff circulated Draft O. R.

September. Ministry of Supply issued a further contract instructing the company to proceed with fullscale design, pending a main contract, on the basis of the Draft O. R.

December. The Air Staff issued O. R.337. The preamble stated that the main threat to the country was still subsonic, but attacks by aircraft capable of speeds up to M = 1.3 at heights up to 55,000 ft. might be expected in 1960/62 …

The flexibility given by A. I. [Airborne Interception], navigation aids and auto­pilot facilities was essential.

The aircraft was required in service as soon as possible and not later than July, 1959.

1956.

January. The Ministry of Supply accepted the O. R. …

February. D. R.P. C. accepted the S. R.177 as a development project for RAF and Navy. Ministry of Supply sought Treasury approval to place an order for a development batch of 27 aircraft. As this was not readily forthcoming, in April the Firm was authorised the expenditure of a further £100,000 to maintain continuity.

February. The two S. R.53 prototypes are now regarded primarily as a lead in to the F.177, rather than as a research project.

July. Specification [handwritten: F177 to meet OR337] issued by Ministry of Supply.

Treasury agreed to a development batch of 27 aircraft, but authorised the build of only 9 aircraft with long dated materials being allocated to support the remaining 18 aircraft. The delay in Treasury approval being granted was due to reviews of patterns of fighter defences of the future, and the atmosphere of financial stringency and economy generally.

The S. R.53 has not yet made its first flight. The first F177 (SR177) is scheduled to make its first flight in April 1958, but this is likely to slip by 6 months.

September. Ministerial approval having been granted, O. R.337 is formally accepted for action by the Ministry of Supply. Design work has however been proceeding since September 1955. The main adverse effect of the delay in placing the final contract has been that it has prevented Saunders Roe placing sub-contract orders.

March. The first flight of the S. R.53 remained “imminent” until the end of 1956, but it has not yet flown and is scheduled for mid-April 1957. There have been troubles with the Spectre engine, but the airframe also is not fully ready.

[handwritten] 29th March. Air Staff cancellation of OR337 was formally sent to the M of S [Ministry of Supply] on the 29th March.

The Air Ministry, set up in 1919 to oversee the RAF, was represented in Cabinet by the Secretary of State for Air. Although both Winston Churchill and Harold Macmillan had held the post, during the 1950s and 1960s the position was occupied by ministers who were not destined for greater things, the office holders being respectively Lord De L’Isle and Dudley, Nigel Birch, George Ward, Julian Amery and Hugh Fraser. The post was abolished in 1964 when the Air Ministry was absorbed into the Ministry of Defence.

There was controversy over the procurement process for what would today be called weapons systems, such as Blue Streak. When the Air Staff had decided on the specification for a new project, they would issue an Operational Requirement (OR). The project would often have come through the DRPC – Blue Streak is a good example. In 1953, the DRPC had been studying missile development and had decided that both a ballistic missile and a defence against a ballistic missile should be investigated. This led to the issuing of the OR for Blue Streak in 1955 (and also one for an anti-ballistic missile defence, but this did not get very far).

The Air Staff might have issued the OR, but it was up to the Ministry of Supply to circulate the requirement to industry, take in the proposals, evaluate them and issue the contract to a particular firm. It would then follow the project through to service entry.

In principle, solid fuel motors are very simple. A tube is filled with the fuel/oxidant mixture, which is then ignited – but as always, there is rather more to it than that. Early motors used simple cordite, a mixture of nitroglycerine and gun cotton, and were end burning – that is, the cordite at the end of the tube is ignited, and the cordite burns upwards towards the other end. Cordite was

replaced by propellants based on ammonium perchlorate (NH4ClO4) and ammonium picrate (C6H2(NO2)3O. NH4) with small amounts of other material added.

A British innovation was that of centre burning. An empty cylinder runs the length of the tube. The igniter is at the top, and when initiated, the fuel burns from the centre out to the edges. One obvious problem is that the surface area increases as the burning spreads out, and one way to overcome this is to have a star-shaped cut out (see Figure 21).

From the military point of view, solid fuel missiles are vastly preferable to liquid fuelled ones. The solid fuel tube has to be very strong to withstand the high pressures and temperatures inside, thus making it
very robust when it comes to handling. Liquid fuelled missiles, however, have very thin tank walls, and in any accident there is the potential to spill a good deal of rather nasty liquid. With solid fuel motors, it is a question of point and fire; liquid fuelled missiles need a good deal of careful setting up.

Solid fuel motors have other advantages: by varying the geometry or the combustion mixture, motors can be made that give very large thrusts for very short periods of time, or smaller thrusts for a longer period. The Gosling boosters for the Bloodhound missile accelerated the vehicle to over Mach 2 in three seconds. The thrust is not uniform, as the graph below shows11. In particular, there tends to be a long tail off as the last slivers burn away (see Figure 23). For these reasons, the thrust and burning time given in reports are only approximations.

Solid fuel motors have two disadvantages in a satellite launcher: they tend not be very energetic (have a low S. I.) and have a poor mass ratio (mass full/mass empty). S. I. is related to the exhaust velocity of the gas (in modern units, they are the same), and final velocity of a rocket stage is given by:

Vf = Ve x ln(mass ratio)

Thus the first Black Knight rocket, BK01, had an all up weight at launch of 13,072 lb, and 1,424 lb when empty. Hence its mass ratio was (13,072lb/1,424lb) = 9.18. With an S. I. of around 220, its final velocity in the absence of any other forces would be (220 x 9.8) x ln(9.18) = 4,800 m/s. Performing the same calculation on the Cuckoo II motor, used as the second stage on later Black Knight vehicles, gives 3,750 m/s – quite a significant difference.

There are two obvious ways of improving performance: increasing the S. I. of the fuel, and making the case lighter. Hence later solid fuel motors became more efficient. The solid fuel boosters either side of the Shuttle have an S. I. of 242 at sea level (268 in vacuum). There is also another way to improve performance, which is simply to build them bigger. The mass ratio improves with size since the amount of material for the case is proportional to the radius of the tube, whereas the amount of fuel inside is proportional to the square of the radius.

Most British solid fuel motors were relatively small. The largest was the Stonechat, with a diameter of 36 inches. The Stonechat formed the basis of the Falstaff vehicle, which was used to test components of the Chevaline system. (Chevaline was a Polaris upgrade programme whereby one of the three re-entry vehicles and its warhead was removed to make way for an elaborate system of decoys.) Even so, its total impulse was only 1,700,000 lb. s as against Black Knight’s 2,300,000 lb. s.

It is interesting to compare Stonechat to the Algol 1 motor (first flown in 1960), which was used as the first stage of the original Polaris missile and also as the first stage of the Scout satellite launcher.

In terms of S. I., the two look equivalent, and the mass ratios compare quite favourably, being (23,600/4,100) = 5.8 for Algol and (10,300/1,800) = 5.7 for Stonechat. The later A3 Polaris missile had a first stage with a much better mass ratio: (24,400/2,790) = 8.7. The weight saving was achieved by using a fibreglass casing.

Several 17-inch motors derived from a motor called Smoky Joe, so named from the plume it produced when burning. These include the Albatross, Cuckoo, Goldfinch, Raven and Rook. The Raven and Rook motors were employed in a variety of different roles in the 1950s and 1960s.

The motor tube of the Rook and the Raven consisted of two wrapped and welded cylinders 90 inches long which were butt welded together. The tube was made of steel of thickness 12 SWG (0.104 inches or 2.64 mm). Head ends were welded to the tube: the top end had a threaded opening for allowing the charge former to be centralised during propellant pressing and allowing excess propellant to ‘bleed’ off. Later, the igniter would be fitted in the opening.

These two motors formed the backbone of the various solid fuel vehicles used for a variety of research purposes, with several hundred motors being fired. The Raven formed the basis of the Skylark vehicle.

Below is a table listing a few of the motors developed at RPE. This is taken from a manual of solid fuel motors which listed data for a total of 73 different types of motor12.

These data are taken from an index of solid fuel motors developed at RPE Westcott in the mid-1960s. The table shows only a small selection – 73 motors were listed in all. These rockets were used for a variety of different purposes:

Extra boost for first stage of Skylark.

Black Knight re-entry tests.

Skylark.

Black Arrow – stage separation and to settle propellants in tanks. Red Shoes, which became the Thunderbird SAM.

Falstaff vehicle for testing of Chevaline components.

Third stage of Black Arrow.

The most famous solid fuel rocket produced in Britain was Skylark, which had a remarkably successful career. First launched in 1957, from Woomera, its final launch took place from Esrange, Sweden, on 2 May 2005. In all, there have been 441 launches, from sites in Europe, Australia, and South America.

The design first dates to 1955, when initial work was carried out by the RAE and the RPE. The first vehicles were ready less than two years later, and sent for testing to Woomera during the International Geophysical Year.

During the 1960s Skylark evolved into an excellent platform for space astronomy, with its ability to point at the Sun, Moon, or a star. It was used to obtain the first good quality X-ray images of the solar corona. Within the UK national programme, the frequency of Skylark launches peaked at 20 in 1965 (from Woomera), with 198 flights between 1957 and 1978.

Skylark began as a simple one stage vehicle, with three fins and a relatively long burn time of 30 seconds, using the Raven motor. This was to keep the accelerations within reasonable values. A series of different Raven motors were produced, each with a different filling as requirements changed. As a consequence of the low acceleration, a tower was needed to guide the rocket for the first few seconds. This was simple in construction and used components from Bailey bridges!

An extra boost stage was added to improve performance. Initially, this was the Cuckoo motor (so named, apparently, because its function was to kick the Raven out of its nest). Later versions used the Goldfinch motor in place of the Cuckoo.

The following description of how Skylark was used by the space science community was written by Professor Mike Cruise13, who has had a long and distinguished career in space science.

Many of the senior space scientists around the world were trained in space instrument design, data analysis and space project management on projects using the Skylark sounding rocket as the space platform. In the nineteen sixties and seventies over two hundred Skylarks were launched from sites in Norway, Sardinia, Australia and South America offering five minutes of observing time above 100 km and substantial payload carrying capacity. Many of the Skylark flights delivered data which ended up in Doctoral Theses, launching the careers of the students involved. A PhD gained by this route involved science, engineering, travel and exposure to many different professional cultures…

The scientific instrument was constructed on a circular bulkhead of magnesium alloy which was previously delivered from BAE as part of the Skylark ‘Meccano kit’ … The design of the Skylark provided great flexibility for the experimenter. Holes could be cut in the cylindrical bays or in the circular bulkheads provided the design was approved by BAE at Filton. The strength of the vehicle was in the magnesium alloy cylindrical skin. Generally four or five cylindrical bays would be mounted on top of one another containing the parachute, batteries, the control and telemetry systems and then the attitude control system if one were employed. Usually the experiment bay was mounted at the top under a conical nose cone which split longitudinally in two sections after reaching altitude.

A few hours prior to launch, the stack of Skylark bays with the nosecone at the top and the parachute bay at the bottom was mounted on a small trolley and taken by road to the Skylark launcher. The vehicle was rail launched – that is, there were three parallel rails mounted vertically in the launch tower and metal shoes were fitted at various positions along the length of the vehicle to engage with these rails. The fins extended outside of the rails, in the azimuthal spaces between them… The launcher tower was about 50 metres tall and the whole launching assembly could be tilted to angles of about 15 degrees from the vertical to adjust the trajectory for winds.

It was necessary to make calculations of the ballistic winds at various heights to predict the trajectory as the vehicle was only powered for 35 seconds of the ascent phase and had no guidance system.

Balloons were launched and tracked by radar for several hours beforehand to provide this data on the winds up to 10 or 15 kilometres altitude. In addition, there were various instrumentation checks and the firing of sighter rockets to check that all the radars and kine-theodolites were functioning correctly before a firing took place.

Figure 26. A Skylark launch from Woomera.

Normally the experimenters watched the launch proceedings from the block house, EC2, a concrete building below ground level, built into the edge of the concrete launch apron. All the control connections to the vehicle came to EC2 and there were telemetry receivers to check data from the instrumentation and the experiment. In a separate room in EC2, an Australian military technician did the actual firing by starting an automatic sequencer two minutes before launch. This counted down and issued the firing pulse to
the detonator in the booster motor at the pre-programmed time. Up to two seconds before launch the launch could be stopped using a line attached via a small snatch connector to the side of the instrumentation bay. Several people in EC2 had ‘Stop Action’ buttons which could abort the launch via this route. The snatch connector was left in place as the launch proceeded and the wires literally snatched from the side of the vehicle as it departed.

What did the Skylark programme produce in the way of benefits to the UK and the students concerned? Some very new science in most cases. Studies of the ionosphere, the middle atmosphere, X-ray sources, UV spectra of stars and, towards the end of the programme, some Earth observation data – all were progressed by Skylark experiments and contributed to the early development of space science. The Skylark engineering design was conservative to say the least, and most of the experiments were far in advance of the instrumentation that supported them. Mechanical switches were still being used to multiplex the telemetry while semiconductor storage was being employed to capture science data in the experiment. This conservatism was a lost opportunity for UK space companies who, given a freer hand, might have built more advanced equipment with consequent spin-off for the emerging satellite telecommunications industry. Undoubtedly the restraining hand of RAE Farnborough was at work in this respect.

The parachute failures dented the effectiveness of the whole programme and were a factor in letting the US pull ahead in many scientific fields. As the payloads became heavier and longer, the parachute design remained the same and success rates suffered. It must be recorded that, by the middle of the seventies, sounding rockets were losing their place to satellite borne equipment. Why spend three years building rocket borne equipment to gather five minutes of data when you could spend five years building satellite borne equipment that would deliver three years of data? The economics were against investing in new rocket technologies. The range at Woomera was extremely effective in the late sixties and the BAE team did their very best within the hardware limitations to ensure the experimenters gained the data they wanted.

The big contribution of the programme was the opportunity for young scientists and engineers to experience a space project from beginning to end within a PhD duration of three or so years. Vicarious benefits included seeing a snapshot of the whole British colonial experience in the space of a few days journey across the world and the opportunity to test oneself in management terms against time, technology and resource constraints. The nostalgia felt by those who experience a Skylark PhD is fuelled by the current lack of any replacement for the horribly realistic management training it provided.14

UCL in 1979 and became Deputy Director of MSSL in 1985. In 1986 he moved to the Rutherford Appleton Laboratory and became the Associate Director for Space Science in 1993. Moving to the University of Birmingham in 1995, he was appointed Professor of Astrophysics and Space Research and in 1997 became Head of the School of Physics and Astronomy and subsequently Pro Vice Chancellor for Research and Knowledge Transfer. 14 This section was published in an expanded version in issue 5 of the journal Prospero, published by the British Oral History Project.

1. The Government have been considering the future of the project of developing the long-range ballistic missile Blue Streak, and have been in touch with the Australian Government about it, in view of their interest in the joint project, and the operation of the Woomera range.

2. The technique of controlling ballistic missiles has rapidly advanced. The vulnerability of missiles launched from static sites, and the practicability of launching missiles of considerable range from mobile platforms, has now been established. In light of our military advice to this effect, and of the importance of reinforcing the effectiveness of the deterrent, we have concluded and the Australian

Government have fully accepted that we ought not to continue to develop, as a military weapon, a missile that can be leached only from a fixed site.

3. To-day our strategic nuclear force is an effective and significant contribution to the deterrent power of the free world. The Government do not intend to give up this independent contribution, and therefore some other vehicle in due course will be needed in place of Blue Streak to carry British-manufactured nuclear warheads. The need for this is not immediately urgent, since the effectiveness of the V-bomber force as the vehicle for these warheads will remain unimpaired for several years to come, nor is it possible at the moment to say with certainty which of several possibilities or combinations of them would technically be the most suitable. On present information, there appears much to be said for prolonging the effectiveness of the V-bombers by buying supplies of the airborne ballistic missile Skybolt which is being developed in the United States. H. M. Government understands that the United States Government will be favourably disposed to the purchase by the United Kingdom at the appropriate time of supplies of this vehicle.

4. The Government will now consider with the firms and other interests concerned, as a matter of urgency, whether the Blue Streak programme could be adapted for the development of a launcher for space satellites. A further statement will be made to the House as soon as possible.

5. This decision, of course, does not mean that the work at Woomera will be ended. On the contrary, there are many other projects for which the range is needed. We therefore expect that for some years to come, at least, there will be a substantial programme of work for that range.23

The Opposition based their first attack on the grounds of waste of large sums of public money, which Watkinson was able to counter with the argument that Blue Streak would be developed as a satellite launcher. It was a useful point for the Opposition to seize on, as it was an issue which could cover its own internal divisions about the deterrent.

But the satellite launcher option was a useful defence, indeed the only defence open to him, which raises the question: how genuine a statement was this? Did Watkinson and the Ministry of Defence really want a satellite launcher, or was this statement merely a political fig leaf? Given the enthusiasm (or lack thereof) with which the subsequent Cabinet committee greeted the topic, the suspicion is that the fig leaf is the correct answer. Certainly the initial reaction among those in the House was quite vigorous: George Brown was the then Shadow Defence Secretary, and demanded an immediate emergency debate, which, however, was not forthcoming. (Sandys’ absence from the House was noted by Jim Callaghan, who seized upon it to say: ‘I was commenting that it was a little unfair that the Minister of Defence should have to face all this music, and I was wondering where the Minister of Aviation is and when he is going to resign.’)

Given the costs of the project at the time of cancellation, the Opposition managed to force a later debate. Whilst Brown might have been a good speaker, what he said at the debate does not read well today. This is partly because, like all Opposition speakers in any debate, he had not had the Civil Service back up and briefings that Ministers have. It is also interesting to note that he seems to have had some inside information on ‘fixed sites’, but although he makes a great show of saying that he himself had advocated dropping the system, he sidesteps making any justification.

Although Watkinson, as Minister of Defence, opened the debate, Sandys was obviously the target for the Opposition. He gave a very straightforward speech in reply, even if he might not have been entirely convinced by his own side’s case. He was able to undercut Brown by resurrecting a quote from the time of Thor, when Brown had said that what the UK needed was its own missile with its own warhead, which is what Blue Streak had been. The other notable part about his speech is that, by Commons standards, it was not particularly partisan: he laid down the facts as he saw them, and did not attempt to make political capital from the decision.

But with the cancellation now official, interest within the Ministries of Defence and Aviation turned swiftly to Skybolt. The Navy was still not happy that Polaris had not triumphed, as can be seen from another internal Admiralty memo. It comments of Watkinson:

Skybolt lay ready to his hand (he thinks) as a blood transfusion to keep the V bombers effective from 1965-1970. … Our trouble is that the Minister has been advised by interested parties, in very optimistic terms, about Skybolt’s state and prospects. I would almost say that he has been led up the garden path. I would warn you that some of the advisers he will bring to you with him are bitterly anti-Navy.

It is ironic that 20 months later, in December 1962, Skybolt itself was cancelled by the US (as predicted by Brundrett and CGWL), and the UK had to negotiate hard to obtain Polaris. This meant that the ‘deterrent gap’ was now stretched to the late 1960s, and while the Polaris submarines were being built, the deterrent was being carried by V bombers with free fall bombs and the short range Blue Steel stand-off missile.

From the outset, the British Government had been warned that Skybolt was very much in the development stage, and there was no guarantee that it would actually be deployed by the USAF. The veteran Labour MP, Sydney Silverman, referred to Skybolt in the House of Commons in June 1960 thus:

Would it be a fair summary of what the right hon. Gentleman has told the House to

say that the result of his negotiations in the United States is that what he has really

done is to buy a pig in a poke with a blank cheque?

Whilst Silverman was making his attack mainly on party political grounds, there was more than a grain of truth in his comment.

Polaris did serve the UK well for nearly 30 years (although its mid-life upgrade, Chevaline, was also a source of controversy), and carrying the deterrent offshore leads to the argument that the mainland itself is no longer a target. Given however the number of NATO and US nuclear bases in the UK, that argument rather falls down. The cancellation of Blue Streak, and the reason given, meant that land-based missiles were never again an option for the UK deterrent. As to what purpose the UK deterrent was to serve, however, is another question.

The Powell report may have been ingenuous in its conclusions, but in the end, Blue Streak was indeed cancelled as a military weapon. Was this the right decision?

The answer to this can only be ‘yes’. Skybolt, had it been deployed, would have been almost as effective a deterrent for a good deal less money. Deterrents are there for political reasons: the whole point of them is that they should never be used! Britain’s deterrent was a perfect example – there was no way that it would be used without America becoming involved, and indeed that was one of the points of it.

As to the vulnerability issues, the RAF was considering a follow on to the Vulcan as a Skybolt carrier – in the form of the Vickers VC10 airliner.24 This is not as absurd as it sounds: airliners are designed to stay in the air for long periods and to have very short turn round times. The point of Skybolt was that the carrier aircraft would not need to fly anywhere near the enemy defences – and so an airliner would have been an ideal vehicle for the purpose. Proposals were put forward for a system of standing patrols (not possible with the V bombers) using 42 modified VC10s.

As it turned out, Skybolt was cancelled and Britain was offered Polaris. The submarines were designed by the Admiralty, and the whole project was carried out exactly on schedule and within budget – an achievement that had eluded the Ministry of Supply for a decade (and is still eluding the Ministry of Defence today). Polaris served the country well in its function as a deterrent, staying in service until the mid-1990s.

Blue Streak, even in its silos, would have seemed outdated by around 1970, if not earlier. It would not have been difficult to have built and designed a substitute which was smaller and cheaper (warheads had become very much lighter in the interim), and which could also have been based in the same silos, but given the pace and cost of the project up to 1960, how much the silos would have cost, and when they would have been finished, is a very open question.

This may seem to be an extended exposition of the cancellation in what is, in the main, a book on the British rocketry programme, but it had a very considerable impact on the future of Blue Streak as a satellite launcher, and thus by extension, on any potential British space programme.

At the time of cancellation there was still a good deal of development work to be done on Blue Streak. If the missile had not been cancelled, then the cost of this would have fallen on the defence budget. Furthermore, there would have been a number of test and development launches needed at Woomera, and the facilities there would also have been charged to the defence budget. Building a launcher from a fully developed Blue Streak would have been relatively cheap. The upper stages would have been Black Knight derivatives, and the development of Black Knight itself had not cost a great deal. The major cost would have been in building the interface between Blue Streak and the upper stages (a further expense which would have been worthwhile would be the uprating of the RZ 2 motor from the 137,000 lb thrust for the missile to 150,000 lb – this would allow for heavier upper stages). Thus a quoted cost of £65 million for a Blue Streak satellite launcher in 1960 might have been reduced to a tenth of that by 1964, making such a launcher far more probable. What such a launcher might have been used for is the subject for later discussion!

Single stage. Launched 30 October at 1959. Apogee 455 miles.

BK06 was a repeat of BK05 with a similar head but using a tape recorder to record separation and re-entry data. Vehicle performance was good, a re-entry velocity of 11,220 ft/second being achieved at 200,000 ft. There was some thrust even after the eight seconds allowed between burn-out and head separation; this caused collision between main stage and head, initiated the ejection of the pyrotechnic flashes and deployed the parachute on the ascent instead of later, as intended, during descent. The tape recorder in the head was switched on correctly and covered the separation phase and later part of the re-entry. The tape cassette, with recordings intact, was recovered together with the eroded durestos nose cone.

The rocket itself had a relatively simple task to perform, which was to boost its payload as high as possible, from where the re-entry vehicles would fall with as great a velocity as possible. Some launches were completely successful in that the rocket and the experiments yielded all the data required. Sometimes the launches were successful, but the experiments failed, yielding little data. However, even when the vehicle’s performance was below optimum, the experiments could still yield good results.

Failures that would have jeopardised orbital attempts had less impact on re­entry studies. The very first flight of all, BK01, ended prematurely when the destruct system operated inadvertently. There were also problems with engine overheating leading to kerosene starvation and resultant ‘cold thrusting’, particularly in the second (BK03) and fourth flights (BK05), but again, these were solved relatively early in the programme. ‘Cold thrusting’ occurs when the engine consumes HTP in the absence of kerosene: decomposition still takes place, but the thrust is very sharply reduced. In addition, on many flights the kerosene was exhausted before the HTP, resulting in a few seconds of cold thrust after ‘all burnt’. The discrepancy between the calibration during test firing and the actual launch was never pinned down.

The first stage of the vehicle performed exactly as intended on 15 of the 22 Black Knight flights. Other launches had problems in one way or another:

BK01: the self-destruct mechanism was accidentally triggered near the end of the flight.

BK03 and BK05: overheating in the engine bay lead to a fuel lock in the kerosene pipes, resulting in a long period of cold thrusting.

BK07: one chamber reverted to cold thrust after 100 seconds. Over 80% nominal velocity achieved.

BK14: pipe failure caused loss of kerosene: cold thrusting after 130 seconds. 85% nominal velocity achieved.

BK12: 6.8% difference in mixture ratio between flight and calibration.

BK23: premature shut down of engine due to gearbox failure 3 seconds before expected flame out.

Of the 22 flights listed, seven would not have made it into orbit if they had been satellite launch vehicles. Most of these problems could be considered as developmental difficulties that occur with any new technology. As a very first attempt at a modern liquid fuel ballistic vehicle, this is a fairly good record, with no major failures at all. It is also a tribute to the engineers at Saunders Roe and at Armstrong Siddeley Motors.

However, Black Knight was a success in a different direction. It gave RAE the confidence in the basic design, and as a consequence, many further projects were proposed using Black Knight as a basis. One, of course, was the Black Prince launcher and its various derivatives discussed in the BSSLV chapter. Another was Black Arrow – the subject of the next chapter.

The paper that follows is the Air Staff description of the prototype Blue Streak underground launcher. The prototype was known as K11.

A drawing showing a full reconstruction of the launcher can be found in Chapter 6 (Figure 50).

K.11 prototype underground emplacement

(1) The potential attacker is believed to have the capability to produce an explosion of 1 megaton yield on the ground or in the air with an accuracy of xh nautical mile from his target. The launcher must be able to withstand such an explosion and successfully fire its own missile without outside assistance within 24 hours.

(2) The emplacement must be able to fire the missile in all weathers.

(3) The emplacement must contain the missile and the necessary facilities for operating and servicing it and for messing and accommodating the concerned personnel. Since an alert may be sounded when the outgoing shift is handing over to the incoming shift, messing facilities must be adequate for two shifts.

(4) Storage space for the missile propellant fuels, food and other stores and equipment must be provided.

(5) Adequate ventilation including the efficient and speedy expulsion of missile exhaust after firing, must be provided together with facilities for conditioning, purifying and circulating air.

(6) Insulation against the electro-magnetic effects associated with a nuclear explosion.

(7) The emplacement must be self-contained for an emergency period of four days (covering three days before an attack is expected and one day afterwards).

II. SITE CRITERIA

1. Rock mass (hard chalk, limestone or better) not less than 300 ft thick and preferably with no overburden. But if overburden is present, it must be soft and not more than 25 ft thick.

2. Easy and firm access from main road to emplacement for transport of missile, equipment and stores.

3. Ease of guarding.

4. Neighbouring inhabited property must be more than 3,000 feet from the emplacement (this may be reduced as experience is gained in K.11).

III. DESIGN OF EMPLACEMENT

1. Basically, the emplacement consists of a hollow re-inforced concrete cylinder, 66 feet internal diameter, extending downwards from ground level to a depth of 134 feet and divided internally into two main sections by a vertical concrete wall. One section houses a U-shaped tube, the arms of which are separated by a concrete wall and are, respectively, the missile shaft and its efflux duct. The surface apertures of this U-tube are covered by a lid which can move horizontally on guide tracks. The other main section within the cylinder is divided into seven compartments, each with concrete floor and ceiling, for the various storage, operating, technical and domestic functions.

2. The internal diameter (66 feet) of the concrete cylinder is determined solely by what is to be accommodated. Protection against an explosion as… above is given by the lid and by the re-inforced concrete roof walls and foundations. The wall thickness will depend on the geological characteristics of the surrounding rock and may well be of the order of 6 feet. The depth of 134 feet is arrived at primarily to give sufficient clearance below the missile (itself 79 feet long) to allow for de-fuelling and re-fuelling the missile into and from the liquid oxygen and kerosene storage tanks located on the 7th floor.

3. A nuclear explosion produces certain electro-magnetic effects which could gravely injure the electronic systems built into the missile and on which its efficient functioning depends. To screen the emplacement from these effects the concrete cylinder will be wholly encased in W thick mild steel plate.

Missile shaft

4. The shaft is octagonal in section, 25 feet across and has an acoustic lining. The octagonal shape, which has been proved by tests, will facilitate the mounting of the acoustic lining and of the four hinged platforms which are spaced at intervals down the shaft.

5. The purpose of the acoustic lining is to prevent damage to the missile from the extremely high noise level produced by the main thrust chambers in the confines of the missile shaft.

6. The missile rests vertically in the shaft on a launcher supported by four suspension limbs attached to the wall of the shaft.

7. Access to the shaft for servicing purposes is through blast-proof doors opening on to the second and sixth floor.

Efflux duct

8. This has an area approximately 60% of that of the missile shaft and in section is half-octagonal in shape. This gives symmetry in the structure and at the surface aperture. A series of deflector plates at the exit will take the exhaust gases away from the missile as it leaves its own shaft.

Storage, Operating, Technical and Domestic Section.

9. This is divided into seven floors, as below, connected by a lift and staircase running from the first floor (at the top) down to the sixth floor:

First Floor

This floor contains:

(a) lid operating mechanism

(b) generating equipment

(c) air conditioning equipment

(d) blast valves for all intakes and exhaust ducts.

All this equipment has been centred as far as possible on this floor to avoid large air trunking systems being provided throughout the site. In the event of contaminated air being taken in, arrangements will be made to close off this floor (other than the general access facilities) thus allowing the generating and air conditioning plant to continue to operate without risk of contamination of the rest of the site.

Second Floor

This floor contains:

(a) Upper storage and maintenance area for the missile, together with two magazine type stores for the payload and the pyrotechnic equipment of the missile, i. e. retro rockets, head propulsion rockets, etc.

(b) Certain items of heating and ventilating equipment for which space is not available on the first floor.

(c) The refrigeration supply for the missile guidance equipment

(d) Blast proof access doors to the upper portion of the missile shaft.

Third Floor

This floor contains:

(a) Auto-collimator equipment

(b) Radio and communications equipment

(c) Site and missile control and checkout equipment

(d) Azimuth bearing and general purpose telescopes.

This floor level is controlled by the relationship required between the auto­collimator and the inertial guidance unit in the missile.

Fourth Floor

This floor contains all the general domestic accommodation including kitchen, recreation and sleeping facilities, etc., together with a small battery room and a switch room.

Fifth Floor

This is intended as the main storage area for the site generally. It also contains one or two tanks which it is not practical to put in the tank room on the seventh floor.

Sixth Floor

This floor is the lower maintenance area and contains the blast proof access door to the lower portion of the weapon shaft. Small hydraulic units are installed on this floor to supply the auto-pilot and launcher services. A small mono rail is provided that can be extended into the missile shaft for maintenance purposes. Access is also provided into the lox and kerosene [‘and water systems’ crossed out in original and ‘rooms on the seventh floor’ handwritten in]

Seventh Floor

This floor is divided in two by a structural wall to separate the liquid oxygen and nitrogen systems from the kerosene and water systems.

The Lox room contains:

(a) Main Lox storage tank

(b) Main liquid nitrogen tank

(c) High pressure gaseous nitrogen storage bottles

(d) The Lox start tank

(e) Liquid oxygen topping up pump

Subsidiary rooms contain:

(a) Liquid oxygen recondensing units

(b) Liquid nitrogen recondensing unit

(c) Liquid nitrogen topping up pump

(d) Liquid nitrogen evaporating plant

The kerosene room contains:

(a) The main kerosene storage tank

(b) The main water storage tank

(c) The kerosene recirculating pump

(d) The kerosene start tank

The access doors from the sixth floor will normally be kept closed and ventilation shafts are provided from these two rooms through the main structure to the surface pipe systems are also provided in these vent shafts for filling these systems from the surface,

IV. DESIGN OF LID

1. The detailed design of the lid is about to form the subject of a special design study by selected firms.

2. The purpose of the lid is to protect the missile from the effects of attack and to remain fully serviceable itself after such attack. Since the missile is completely unprotected when the lid is open, the time allowed immediately prior to firing the missile for opening the lid must be kept to a minimum and has been put at 17 seconds.

V. DESIGN OF SITE

1. The main requirement is to achieve maximum security and this calls for both the site and its immediate surrounds to be enclosed by a security fence and to be clear of obstructions to visions. The cleared area extends also beyond the site perimeter. The need to camouflage the site is at present being considered. A simple road system with associated hardstandings must be provided within the site.

2. The site will be about 3 acres in extent.

3. The site includes the main entrance to the emplacement, consisting of three flights of steps, protected only against weather and leading down to a cylindrical air lock giving access to the first floor of the emplacement.