sonicatio n suggests a potential strong bond of the  lubricant with the ste el. No phosphorous wa s seen on  any of the b all surfaces, suggesting that it wa s either removed  by surfa ce wear during the bea ring  operation or t he TCP treat ment wa s ina dequ ate. Race  surfa ces could not be examined for p hospho rous  due to limitation of physi cal size of the E SCA cham ber. 

Table 3.  ESCA Resul ts of Freon Flu shed Bearin g Balls [1]   Composition (Atom %)  Specimen  F O C Fe Cr N Other  #010 6A, First  flush 44 21 30 3.7 0.5 0.4   #010 6A, Second flush 21 27 42 6.9 1.6 1.0            #010 6B, First  flush 44 20 32 3.0 0.5 0.4   #010 6B, Second flush 21 24 48 4.6 1.7 0.9            #010 7A, First  flush 46 20 30 3.0 0.6 0.3   #010 7A, Second flush 17 30 42 6.8 3.2 1.0            #010 7B, First  flush 48 20 28 3.3 0.6 0.3   #010 7B, Second flush 23 24 45 5.4 2.5 0.9 0.1 Cu, 0.1 Cl   #010 7B, Sonicated in F reon 21 28 40 7.1 3.2 0.7 0.2 Cu, 0.3 Cl ,  0.2 Na, 0.1 M o           Braycote 8 15-Z 57 18 25     

A white -grain y material  was observed  on the shafts a nd clamp  rings of both motor/encoders. The bea ring  clamp ring i s machi ned beryllium S-200 E, with no co ating. The shaft material is also m achined be ryllium,   but with an electrol ess Ni coatin g. After removing a small p ortion of the re sidue, the cla mp ring s were   found to contain many small pits. Sa mples of the  white residue we re probed off both clamp rings,  dissolved in 1% ultra pure nitric a cid, and analy zed by ICP/MS (Inductivel y Couple d Plasma/M ass  Spectrometry ). High levels of bery llium were dete cted, howeve r, due to the diffi culty of isolating the white   residues, onl y minute sa mples we re tested th ereby limiting the  quantitative accuracy of the repo rted  results. 

During the in vestigation p rocess, a rep ort was found on a spare be aring set from  the same lot as the flight  units man ufacture d in the 1981 time fra me. In 1987, th is spa re set was sent ba ck to the man ufacturer for  refurbishment  (well after a ssembly of t he flight uni ts). Thi s refurbishm ent revealed contamination a nd  debri s particles in the bearing, roll ed fla t, of the sa me type found i n the FGS-1 M/E’s.  The b earin g races  also showed evidence of brinellin g. These sp are beari ngs were sub sequently cleaned, hone d, and  reassembl ed with n ew ball s. The refurbi shed spare bearin gs fun ctioned  withi n specifi cation  requireme nts.  It is thought that the metal  partial s described above were  rolled fl at prob ably d uring run-in at the beari ng  vendor p rior to shipme nt. The co ntami nation sour ce may have been the solvents (unfilte red) used to  clean the be aring s prior to lubri cation. It is surp rising that all torque traces recorde d during assembly of  the flight m echanisms were in family and within  require ment s and that  pre-d isassembly t orque traces  showed essentially no evi dence of the  extensive  debris in these be arings. Apparently, the d ebris was  pushed out o f the ball running track and content to stay in a reas that didn’t have mu ch of an effe ct on  torque. 

Conclu sions  

The compl eted in spection as d escribed herein resulted in seve ral ge neral fi nding s for th e FGS M/E  beari ngs and some specific to ea ch be aring. In gen eral, no eviden ce of the anti -wear additive (TCP ) was  found on th e beari ng balls. The bea rings appeared d ry (som e mo re than othe rs) with de graded, “bla ck tar  354