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Aviation History
1961
1961 - 0936.PDF
2,600 2,400 2,10O 1,600 - UOC 1,000 MO 600 400 too 1 POLA* v EQUATORIAL ORBIT (EASTERLY LAUNC FROM EQUATOR) \ \V CIRCULAR ORBITS'' s. ^^ >\ \K \ ^^ ELUIPTl -% nftfciT* , N f / J NO \K STA6E IMPA ^RESTRICTION STAGE C (.PCSI^r AT 500 N MILti) EQUATORIAL ORBIT (EASTERLY LAUNCHING, FROM EQUATOR.) MM 400500 we t,ooo ifiMipttipto IO.OOO 24000 APOGEE HE«HT OR CIRCULAR HEIGHT (kl. MILES.) KK^OOO MO 400 500 1,000 ipon 1,000 fooo spec ORBIT HEIGHT (N MILES.) IftOOO Left, nominal payhads for circular and elliptic orbits, assuming HTP/kerosene third stage in the three-stage vehicle. Right, higher performance is obtained by introduction of liquid hydrogenjlox third stage; circular orbits are shown Missiles and Spaceflight. .. A timely description of the proposed three-stage vehicle wasgiven on the day of the announcement of the West German decision by Mr D. J. Lyons, Acting Head of the Guided Weapons Depart-ment of the Royal Aircraft Establishment, Farnborough, in a paper presented at the Oxford convention of the British Institutionof Radio Engineers (reported on pages 37-38). Concerning the third stage, Mr Lyons said:—"No firm joint European proposals have been made regarding the design and construction of a third, end stage, for final injectioninto orbit, but in order to demonstrate the capabilities two pro- pellant combinations have been considered in assessment of apossible third stage. The first, hydrogen peroxide (HTP)/kerosene, a conventional, relatively low-energy propellant combination, wasconsidered for its comparative ease of development. The second, liquid hydrogen/liquid oxygen, yielding a greatly improved per-formance in terms of payload, especially in distant orbits, demands more extensive development. "Only the final stage need be varied to meet a widely variedseries of orbit requirements without significant departure from optimum staging conditions."On the subject of performance the speaker stated:—"It is possible to meet the varying orbital requirements by exchangingpayload weight for propellent weight in the third stage whilst maintain-ing constant the overall weight of the third stage plus satellite payload atsome 5,0001b, that is, the third stage incremental velocity can be increasedat the expense of payload. The tank volume, only, is altered to suit theorbital mission, allowing the remain- der of the third stage, including theengine and all equipment, to remain sensibly unchanged. "The figure (above left) shows theestimated payload capability of the launcher with the illustrative HTP/kerosene end stage. These are based upon the indicated weight break-downs, and a sea-level take-off thrust of 300,0001b (i.e., 2 x 150,0001b), and with exchange betweenpayload and propellent weight with mission in the third stage, as mentioned earlier. As will be seen, the payloads vary from 1 tonactual payload in a 300 n.m. circle to 5001b in a 6-7,000 mile circle or in an elliptical orbit out to about 50,000 n.m. from a 300-mileperigee. "In obtaining these results, stage weights and flight programmeshave been optimized as far as possible. In general the stage weight/ payload curves are fairly flat around the optimum point, and it hasbeen found advantageous to choose end weights slightly off opti- mum on the "light" side for a number of reasons, such as, forexample, the location of the impact point of the discarded first stage in an acceptable area. "The 'payload into orbit' figures are considerably improved, aswould be expected, using a liquid hydrogen/liquid oxygen third stage, as will be seen from the second figure (above right). This isespecially marked in distant orbits, where the third-stage effective incremental velocity becomes a much larger proportion of thewhole mission characteristic velocity. A payload of about 1J (Concluded at foot of page 38) Although torget dates have presumably slipped becouse of the delay in making the final decision to go ahead, this development programme, put forward at Strasbourg by the French and British Governments, outlines the main phases in the initial launch vehicle development plan. Costing some £70m, this pro- gramme would result in three firings of the complete vehicle in 1965. Firings Fl and F2 are of the first stage only, with F2A and f2B as back-up launches; F3, F4 and FS would carry a dummy second stage and live third stage; and F6, F7 and F8 represent the three-stage vehicle 1ST STAGE MANUFACTURE TRIALS SEA TRANSPORT PREPARATION WOOMERA FIRINGS PREPARATION AIR TRANSPORT TRIALS 2ND STAGE 3RD STAGE MANUFACTURE KEY DATES 1961 F1 1962 F2A F2© CD 1963 F2B F3 DEC. 621 JUNE 63 2HD* JRDSTAGE STRUCTURAL DUMMIES 1ST FLIGHT ENGINE FOR JwSTAGE F0RF3 DUMMY 2ND STAGE F0RF3
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