Created: 1/19/1959

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L The Director of Central Intelligence, with the participation and the concurrence of the United States Intelligence Board, haseview of all evidence relating to the accuracy of the Soviet ICBM as set forth in, "Sovietin Guided Missiles and Space9 (TOPnd has concluded that paragraphs9 and the Summary Tablehould be revised to read as follows:

e estimate Sovietuidance al IOC dateombination radar track/radio comrnand/lnertial syslem which Ls calledlthough an all-inertial system is possible. Soviet capabilities in related components at IOC pointheoretical CEP ol. with the radlo-inertial system. The Soviets probably will incorporate the all-tnertial system in their ICBM sometime duringeriod and, should they adopt this systemhey couldheoretical CEP ofhe data available for estimating both the above theoretical CEPS are far from exact. Tbe precise amount o( degradation which would be Introduced by operational factors Isbut weEP under operational conditions at IOC date of. with the radko-lnertUl system; with an all-inertial syslem the operaUonal CEP0 would bem We further believe that the Soviets will be able to itrprove thc accuracy ol their ICDM following IOC, and that over lhe next few years, and probably not later thanhe operational CEP for an all-inertial system could be reduced tond the operational CEP of thc radio-inertlal system would be somewhat better."

* The Assistant Chief of Staff (or Intelligence. Department of the Army, believes that ihis re-examiniUon which resulted tn the estimated belter Sovieteeuraey either reflects, or was sueeeated, by recenl US ICQM test experience which caused certain members of the USIB lo revise Uicir Judgment as to the validity of the most rcccni Intelligence Study of thisconducted foe Ihc US ID by the Guided Missile and AstronauticsCommittee (OWAICI The AssuUnl Chief of SUIT for Intelligence. Department of the Army, reeogniies Uiat ll ts prudent lo estimate lhat the SovieU would sooner or later, if not cuirently. possess an ICBM syslem Of an accuracy comparable lo (hat of the US IC8M. However, at present, lie perceives no justification for abandoning lhc estimates derived from so recent an analysis of all available technical Intelligence Information A fartherlea nt consul era Uon li lhat estimates ofccuracy are Based on theoietUal degradsUon of lest range performance which further Increases the uncerUinUes In such estimates. Accordingly. It Is believed that there Is mt present intelligence basis for changing theas lo operaUonal accuracy as contained In the OMAIC report and. therefore, lhat the more likely range of operational accuracy lor Soviet ICBM al IOC. using "radto-lnetUal- guidance. Is on the orderjn CEP; lhal by sometime Inith ine ail Inrrual system, the CKP could be reduced tom, allhouch the operational CEP ot Ihr -radio-inertlal" sysUm would be somewhat better.

estimate ICBM guidance at IOC dateombination of radar track/radio command/inertial which is calledlthough an all inertial system is possible. Soviet state ol the art in precision radars, gyroscopes and accelerometers leads us toheoretical CEP at IOC.. range lor the radio-inertial system. We believe thc Soviets probably will Incorporate the all-inertial guidance system into their ICBM sometime duringeriod (seend could0 achieve with thisheoretical CEP ol. The data available for estimating both the above theoretical CEPs arc far from precise. Further, under operational conditions the theoretteal CEPs will be degraded by several (actors, such as (a) re-entry errors induced by undeterminable winds and air density over the Impact area; (b) geophysicalnd (c) human and experience factors. The amount of degradation which would be introduced by such nonguidancc system errors cannot be firmly fixed, but we estimate that the operational CEP'at IOC date. lor the radio-inertial system would be. Should thc all-inertial system bc introducedt could have an operational CEP of

We further believe that thc Soviets will be able to Improve the accuracy of their ICBM following IOC, and that over the next few years, and probably not later thanhe operational CEP for and all-inertial system could be reduced tond theCEP of the radio-inertial system would be somewhatnits already equipped with radio-inertial guidance probably would not be retrofitted with all-inertial system.

Change to Summary Table: delete present entry on ICBM accuracy and insert new statement, "See paragraphs"

A similar review of the evidence relating to ICBM reliability has led to the conclusion thatf the subject esUmate should also be revised. We have concluded that the inflight reliability, that is, the missile's reliability after leaving the pad, lies in the range betweenercent andercent at IOC as opposed to theercent now appearing in the Table. We further conclude that inflight reliability at IOC plus three years lies in the range betweenercent andercent as opposed toercent now in the Table. Within these ranges the Assistant Chief of Staff for Intelligence. Department of the Army and the Assistant Chief of Naval Operations forDepartment of the Navy believe the reliabilities inlie at the lower ends; the Assistant Chief of Staff, In-

' Geophysical errors Include gravitational anomalies, gcoldal uncertainties, and uncertainUcs o( target location relative to launch point and local vertical*.

'See Uie Assistant Chiel ol Stall lor Intelligence. Department ol the Army, footnote to paragraph fl.

* Sec the Assistant Chief of Staff for Inielligence. Department of thc Army, footnote to paragraph 6



tclligence, USAF estimates that the reliabilities lie at the upper ends and herewith withdraws his footnote on pagef the subject estimate. Note that figures in the Table regarding "in commission rate" and "on launcher reliability'" are unchanged.

Original document.

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