Project Cyclops, A Design... - Department of Earth and Planetary ...

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At this very minute, with almost absolute certainty, radio waves sent forth by other intelligent civilizations are falling on the earth. A telescope can be built that, pointed in the right place, and tuned to the right frequency, could discover these waves. Someday, from somewhere out among the stars, will come the answers to many of the oldest, most important, and most exciting questions mankind has asked. -Frank D. Drake, (Intelligent Life in Space The MacMillan Co.) iii
FOREWORD In addition to the findings of the Cyclops summer study, this report contains much tutorial material added for the benefit of those readers unacquainted with the subjects of exobiology and interstellar communication. This introductory material is found in Chapters 2, 3, and 4 and parts of Chapters 5 and 6. These chapters may be omitted or skimmed by readers already familiar with the subject. Parts of Chapters 5 and 6 together with Chapters 8 through 14 contain the main results of the summer study. Chapter 7 is a condensed description of the Cyclops system, while Chapter 15 presents some conclusions and recommendations that are the consensus of the System Design Group but do not necessarily reflect the unanimous opinion of all the fellows. In my opinion, the major contributions of this study are: 1. The reaffirmation of the microwave window as the 2. 3. 4. most suitable part of the spectrum for interstellar communication and search. The identification of a particularly likely band in the microwave window. The design of a data processing system capable of simultaneous search of at least half of this band and the detection of coherent signals 90 dB below the total noise power in the band. The design of an improved local oscillator distribution system, an IF transmission and delay system, and low-noise remotely tunable receivers that appear to guarantee the feasibility and practicality of an array with several square miles of collecting area. 5. The identification and estimation of the major costs of a search system and program. Taken together, these contributions indicate that we now have the technological capability of mounting an effective search for extraterrestrial intelligent life. Before any major commitment is made in this direction a great deal of additional study should be devoted to all aspects of the problem. It is hoped that this report can serve as a basis for that further study. Although the editing of some sections and the writing of other sections of this report have consumed all my spare time for several months since the summer program formally ended last August, I have found the effort both fascinating and challenging. I only regret that I did not have the time nor skill to do a better job, and I must ask the reader to be forgiving of inconsistencies, poor organization, and errors that have eluded me. Finally I want to express my gratitude to Hans Mark, Director of Ames Research Center and to John Billingham, Chief of the Biotechnology Division, for having conceived the idea of a summer engineering systems design study on this subject, and for having invited me to participate. I am also grateful to Hewlett-Packard for granting me a leave of absence and for excusing many hours devoted to the program both before and after. The summer experience was in itself exciting and rewarding, but if the Cyclops report stimulates further study that results in a full-scale search, I shall consider this to have been the most important year of my life. Preceding pageblank Bernard M. Oliver
Page 1 and 2: (NASA-CR- 11_5) PROJECT CYCLOPS: A
Page 3 and 4: CR 114445 Available to the public A
Page 8 and 9: ACKNOWLEDGMENTS The Cyclops study w
Page 10 and 11: COMMUNICATION BY ELECTROMAGNETIC WA
Page 12 and 13: APPENDIX A - Astronomical Data ....
Page 14 and 15: t _ 2
Page 16 and 17: of the living beings evolved by the
Page 18 and 19: Figure2-1. M3I,the great galaxy in
Page 20 and 21: self.Thus,wecaninterpretFigure2-2as
Page 22 and 23: magnitude (low brightness) end, the
Page 24 and 25: Red Giant. The transition from main
Page 26 and 27: tion, as the central part of the cl
Page 28 and 29: TABLE 2-4 SELECTED NEARBY STARS WIT
Page 30 and 31: tideraisingforcesasr--_ where ,v =
Page 32 and 33: 3. Is it possible that living syste
Page 34 and 35: lawsof natural selection, more like
Page 36 and 37: starsthroughout the Galaxyhave also
Page 38 and 39: if the longevity of that life is ty
Page 40 and 41: The imaginative reader will have no
Page 42 and 43: Lookingfar ahead,supposewe aresucce
Page 44 and 45: usuallyterritorial expansion by the
Page 46 and 47: IOO IO 1 [ [ J [ J I J i [ i I i I
Page 48 and 49: order with what Morrison has descri
Page 50 and 51: The quantity gtPt is often called t
Page 52 and 53: which might result from synchronous
Page 54 and 55: 1. Wewillnothavenough resolving pow
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normalwith the meanat o x/--2. When
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Chapter11 in analyzingthe dataproce
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Therangelimitisthenfoundbyequating_
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TABLE 5-3 PARAMETER Wavelength Tran
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angeanddirectlyasthesquareof antenn
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"_ i i i i i p = STELLAR DENSITY AT
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I-- g u. O >- I--- .d tit (]O 0 0.
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andwidth that will still give near
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acquisitionphasefor otherraces.Supp
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1. They would transmit continuously
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and ¢-Ceti. No signals were detect
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vz .i g)mo PAGE NOr Ir[[,MZ 7. THE
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The price of incomplete sky coverag
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modest size.A largedatabaseontapeor
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THEAUXILIARYOPTICALSYSTEM Althoughn
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edetectedat 20,000light-years byCyc
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feeds must correct for spherical ab
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side of the dish and shade on the o
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TABLE 8-1 UNADJUSTED UNIT COST DATA
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7. Using huge specially designed ji
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9. THE RECEIVER SYSTEM The receiver
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whereP is the radiated power. Divid
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SHADOWED AREA SHADOWED AREA // // /
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Corrugatedhornssupportingbalancedhy
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o 50 ----- - _ T i 20 _,o 5 ,,,5 09
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TABLk ?- I A COMPARISON OF VARIOUS
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CENTRAL POINT STATION LSB LINE FREQ
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A02 .... + No (25) (i C 1 where No
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COAXIAL LINE DIRECTIONALCOUPLER FRE
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DeJager, J.T.:IEEETrans.onMicrowave
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pR_ING PA6E BLANK HOT FILMF_ 10. TR
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o-------------o_ _ o o o o ing of t
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addedto theother IF channel. The tw
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INPUT MHZ _PF 500 MHZ i : 575 T1 92
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azimuth _) has a delay (2a/c)sin 0
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stripline. For 2 _< k _< 6, appropr
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mation are common to all antennas i
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A cable pair costs about 20 cents/m
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11. SIGNAL PROCESSING The Cyclops s
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1.0 T t t I I r .9 -8 asynchronousl
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collimated coherent light. A simple
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power of the film and associated op
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samples simultaneously onto the sam
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outputs is assumed. COMPOSITE SIGNA
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SPECTRUM I n LINES M n LINES U SPEC
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signal andyet have a tolerable fals
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i --_- i i i i large values of n. T
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plottedin Figure11-15for various va
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All the1Fsignalswillarrivein phasei
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x:(1 +x) x 2 - _ -- (53) If we wish
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3's = unitcostof signal planelectro
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where0ma x is the maximum value of
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Roughestimates of the costs of buil
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12. CYCLOPS AS A BEACON Although th
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13. SEARCH STRATEGY The high direct
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distantgalaxies (oraninertialrefere
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wouldfollowtheuppermost linein Figu
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persquaredegreeof fieldwouldberequi
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starsfrom/'18 to G5 could support a
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14. CYCLOPS AS A RESEARCH TOOL Thro
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Only a few such galaxies have been
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15. CONCLUSIONS AND RECOMMENDATIONS
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perhapsdecadesand possiblycenturies
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APPENDIX A ASTRONOMICAL DATA DISTAN
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PLANETARY Planet ORBITS Semimajor S
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APPENDIX B SUPERCIVILIZATIONS AND C
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ABIOLOGICAL CIVILIZATIONS Many writ
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182
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tqOT APPENDIX C OPTIMUM DETECTION A
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to rmsnoise.Wenotethatthematchedfil
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APPENDIX D SQUARE LAW DETECTION THE
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If the output filter is very wide c
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if B/2 > T we can start instead wit
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Let us now introduce the normalized
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where h-- = expectation count of si
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APPENDIXE RESPONSE OF A GAUSSIAN FI
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APPENDIXF BASE STRUCTURES AZ-EL BAS
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ack,it shouldnotbenecessary to prov
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204
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206 i
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PAGE BLANK NOT APPENDIX H POLARIZAT
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APPENDIX I CASSEGRAINIAN GEOMETRY C
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APPENDIXJ PHASINGOFTHE LOCALOSCILLA
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APPENDIXK EFFECTOF DISPERSION IN CO
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APPENDIX L TUNNEL AND CABLE LENGTHS
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where r = "Ym/'rs- If we let o-_--o
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L-4 we see that the length of IF ca
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APPENDIX M PHASING AND TIME DELAY A
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andobtain V = 2 (Ps [! + _(Ar)] +Pn
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L" D 226
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APPENDIX N SYSTEM CALIBRATION The p
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APPENDIXO THE OPTICAL SPECTRUM ANAL
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232
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APPENDIX P LUMPED CONSTANT DELAY LI
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Thevalueofthefinalcoilonthelineis =
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APPENDIXQ CURVES OF DETECTION STATI
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I I I I LE :E oo
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APPENDIX R RADIO VISIBILITY OF NORM
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io 3 - l rlrllll I I I ]l+,ll_ I _f
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