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Aviation History
1959
1959 - 2067.PDF
no FLIGHT, 4 September 1959 Missiles and Spacefiight... TO SPACE BY BLUE STREAK o, NE of die most in-formative paperspresented to the Commonwealth Space-flight Symposium, which met in London last week,was written by G. K. C. Pardoe, Chief Co-ordinator (Ballistic Mis- siles) of de Havilland Pro-pellers Ltd., and entitled General Review of aBritish Spacefiight Pro- gramme Based on BlueStreak. It outlined a num- ber of valuable types ofmission, particularly of the orbital variety, whichcould be accomplished by devices launched initiallyby a first-stage based upon a Blue Streak long-range ballistic missile (photograph above). At the outset Mr. Pardoe emphasized his intention of presenting asbroad and comprehensive a review as possible; moreover, he stressed the impracticability of planning any spacefiight programme without carefulstudy of the past achievements and future intentions of the U.S.A. and Russia. After briefly recapitulating the present space situation, andproducing telling arguments in support of a national space programme (for any country), he dwelt upon the awesome cost involved in anyspacefiight system (which inevitably included far more than just a vehicle), and suggested co-operation throughout the Commonwealthwith a view to producing an integrated system, including launching sites and tracking devices favourably disposed throughout the globe. Turning to consideration of desirable objectives Mr. Pardoe suggestedconcentration upon orbits essentially within that of the Moon, the lowest being perhaps 50 miles up and the highest being a very ellipticalorbit encompassing the Moon. From the military viewpoint orbits between 50 and 150 miles might be particularly suitable for varioustypes of surveillance, although some form of propulsion system might be required to sustain such an orbit, making for a limited duration.Between 150 and 450 miles resolution would be poorer, although the fact that atmospheric drag would be virtually zero should enable such anorbit to be sustained indefinitely. At higher altitudes out to about 22,000 miles (the approximate height for a 24 hr orbit) military applicationsappeared doubtful, but scientific and commercial functions could be extensive. After underlining the necessity of providing a properly integratedsystem for each type of vehicle, and drawing comfort from the fact that the major part of the equipment required for the first stage wouldalready be in existence as a result of the Blue Streak military project, Mr. Pardoe went on to talk in general terms of the performance whichwould be required depending on the orbit chosen (within the limits specified above). For the lower orbits about 25,000ft/sec would beadequate, but for the outermost orbits the total velocity requirement for the complete vehicle would be of the order of 37,000ft/sec. Althoughcomprehensive instrumentation could be packaged within a total weight of 150 1b, a payload of some 500 lb was desirable from the viewpoint offorward planning. Improved reliability, endurance and further informa- tion might call for weights of the order of 1,500 lb; moreover, the latterwas likely to be the minimum for a capsule containing a man. It could be shown that approximately 2,000 1b would probably be the upperlimit which could be sent into space using the existing Blue Streak as a first stage; therefore, within the present objectives, it was not reasonableto consider manned missions. Aiming at an initial simple mission, Mr. Pardoe first outlined thepotential of Blue Streak carrying a rudimentary solid-propellant second stage. The latter comprised twin motors carrying a payload dividedbetween two canisters located between the motors (right). In order to reduce drag and kinetic heating during the ascent, the complete payloadwas shrouded beneath a light fairing, which could be jettisoned either at first-stage burnout or on leaving the atmosphere. Such a vehiclewould be restricted to lower orbits; and it was suggested that, in view of the simplicity of the second stage, it should be placed in orbit underthe guidance of the first stage, coupled with stabilization of the second stage by rotation effected by canting the motor nozzles. If desired, thepayload could finally be separated by a small H.T.P. rocket, in order to effect vernier adjustment of axial velocity (and possibly attitude) aftersecond-stage burnout. The beauty of the overall system was that, with virtually no mechanical or system changes to Blue Streak, the latter, From Mr. Pardoe's paper, these diagrams illustrate the simple solid- propellant second stage and (far right) the modified Black Knight. 1, dual package powered by twin solid motors; 2, launch rails; 3, nosecone ejected in two halves- 4, two attitude correctors and spin stabilizers; A, separation line; 6, final separation; C, payload, 53.4 cu ft; D, nosecone ejected in halves; E, ground connections and release; F, kerosine tank; G, H.T.P. tank; H, service tube through inner tank; J, external frame with release mechanism and fairing; K, electrical ground connectors; L, second-stage probe separation; M, ground connectors for propellants (H.T.P. shown); N, work platform together with an extremely simple second stage based on equipmentalready undei development, could place a payload of some 1,000 lb in a 300-mile circular orbit.Still adhering to the theme of availability, the author next turned to the obvious combination of Blue Streak with Black Knight. This hadthe advantage of using highly developed equipment, Black Knight having demonstrated a remarkably high state of reliability. Carriage ofso slender a vehicle sitting on top of Blae Streak would necessitate careful design of the inter-stage adaptor; obviously new dynamic bendingloads in the forward tank section of Blue Streak might demand structural modification, and revised flexural characteristics during first-stage burn-ing might involve changes in the autopilot system and larger excursion angles of the first-stage motors. Moreover, the H.T.P. tank of theBlack Knight would be directly exposed to kinetic heating and, although the problem with H.T.P. was milder than with other oxidants, anattitude-control might be required to reduce radiation heat from the sun while the vehicle was in a transfer or parking orbit. Clearly itwould be possible to effect substantial improvements over the basic Black Knight, and a very attractive solution combining the best of bothworlds might be to retain the complete propulsion bay of Black Knight [Bristol Siddeley Gamma engine—Ed.] together with an accurate andreliable control system. Below, right, is illustrated a suggested second stage based upon thispropulsion bay, but with entirely new tankage in the form of two hemispherical domes separated by a parallel section of tank determinedby the limiting volume or weight which could be lifted by Blue Streak. The author went into some detail in describing this complete secondstage, and showed that an inertia! guidance system could be located in a transition bay in front of the upper tank of the Blue Streak. Altogether,the second stage could well be lighter than a longer structure. Thrust/ weight ratio at the beginning of second-stage ignition might be 0.8 oreven less, implying a second-stage weight of at least 22,000 lb. Thus a payload of some 7,000 lb could be placed in a 300-mile circular orbit,or roughly double the weight which could be handled by an unmodi- fied Black" Knight. Having studied three technically attractive concepts (Blue Streak asso-ciated with a simple solid second stage, a basically unmodified Blue Streak, and the new device shown below) it was essential to investigatesuch basic factors as technical capability, organization, finance and timing. Regarding the time-scale of Blue Streak, security allowedMr. Pardoe only to suggest that the first flight-trial of the system "cannot be far away in the future." A major military project of this nature couldnot suffer in order to enable a purely scientific project to go ahead— although this situation could be reversed if primary military spacefiightobjectives became apparent. It appeared, therefore, that we were some two to three years from the time at which the projects proposed mightmaterialize. Regarding cost, it should be borne in mind that the entire concept discussed involved minimum modification to equipment alreadyin use; and it could be shown that the additional expenditure was com- paratively small and reasonable "bearing in mind the implications to thefuture of our country." In conclusion, Mr. Pardoe said, "The existence of Blue Streak as apotential main stage vehicle for European countries is significant. European nations who do not possess a main stage booster facility,could well consider planning a programme using Blue Streak as then- booster for either their upper stages or payload, since the design team ofthe vehicle would be on their doorstep. "Earlier in this paper, an attempt has been made to demonstratethat we as a nation are bound to embark on space Sight at some time. In the time-scale which I have discussed, we would be 4 to 5 years late inour early experience of these new things—this must surely be relatively unimportant when we look back in 50 years' time to the present age.What does seem vitally important is that, as a nation, and as individuals, we should have a firm plan and conception now of where we are going,and what we can do."
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