karn (01/08/83)
UOSAT SPACECRAFT CONTROL CENTRE
UNIVERSITY OF SURREY, GUILDFORD, SURREY, ENGLAND
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UOSAT SPACECRAFT OPERATIONAL STATUS:
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** UOSAT BULLETIN-11 1400 GMT 7 JANUARY 1983 **
* S/C ATTITUDE *
THE EFFECTS OF THE INCREASE IN Z-SPIN PERIOD PERFORMED BEFORE
CHRISTMAS TO ENSURE THERMAL STABILITY DURING AUTONOMOUS
OPERATION OVER THE LAST TWO WEEKS HAVE BEEN MEASURED.
THE Z-SPIN PERIOD FELL FROM 153 SECONDS TO APPROX 60 SECS, AS
THE PRECESSION CONE ANGLE DROPPED FROM 55 DEGREES TO AROUND
15 DEGREES. THE NUTATION ANGLE IS ALSO MUCH REDUCED. THIS
ATTITUDE EFFECT COULD BE READILY OBSERVED BY MONITORING THE
SPACECRAFT BATTERY TEMPERATURES, WHICH CHANGED FROM AN INITIAL
CYCLIC VARIATION BETWEEN -17C AND 2C TO A STEADIER 7C DURING
THREE WEEKS.
* S/C OPERATIONS SCHEDULE *
MAGNETORQUER MANOEUVRES TO INCREASE THE Z-SPIN PERIOD TO 108
SECS HAVE ALREADY BEEN PERFORMED, AND THIS WILL BE FOLLOWED
SHORTLY BY THE RESTORATION OF THE PRECESSION ANGLE IN
PREPARATION FOR GRAVITY GRADIENT STABILISATION. COMPUTER-
GENERATED MAGNETOMETER DATA WILL BE HEARD ON THE 435 MHZ
DOWNLINK WHEN IT IS ACTIVATED OVER EUROPE.
* THANKS FOR FEEDBACK *
DATA RECEIVED FROM: W4FJ, BRS 34348, PD0JCY, G6HRH, G3VYV,
W4AUZ, DC7BZ, G3EMU, G8EDG, VK5AGR ET AL, K1KSY.
*SPACECRAFT ORBITAL DATA*
UOSAT OSCAR-8 NOAA-7
ORBIT NO: 6937 24681 7950
EQX TIME: 15:25:31 13:47:26 14:02:16 GMT
EQX LONG: 4.5 284.4 346.1 DEG.W
MEAN HGT: 509 905 854 KM
PERIOD : 94.787436 103.233288 101.98 MINS
P-DRAG : 8.95919E-5 -2.6112E-6 -8.0E-6 *N
LONG INC: 23.696487 25.811037 25.49 DEGS
L-DRAG : 2.254152E-5 -7.028E-7 -2.0E-6 *N
N=ORB.NO- 6937 0 0
QSL/POST CARDS CONFIRMING RECEPTION OF UOSAT DATA INCLUDING
STATION DETAILS WOULD BE APPRECIATED FOR SURVEY OF NO. AND
GEOGRAPHIC DISTRIBUTION OF ACTIVE STATIONS
SEND TO: DR.M.N.SWEETING, UOSAT CONTROL CENTRE - THANK YOU