karn@allegra.UUCP (Phil Karn) (02/28/84)
**** UoSAT Bulletin-63 00:00 28th February 1984 ****
** UoSAT-Oscar-9 Status **
Following major breakdowns in the Oscar-9 ground station at the
University of Surrey shortly before the team left for the
UoSAT-B launch campaign, it was impossible for any remaining
members of the department to activate the spacecraft during our
absence. We apologise for the disruption at this crucial time.
Until the launch of UoSAT-B on March 1st, daily bulletins will
be used to describe the basic telemetry and modulation formats
and give launch information. Following launch, Oscar-9 will be
used for bulletins and information and to answer queries
received to the largest possible audience. Eventually, it is
anticipated that UoSAT-1 will continue to carry mostly bulletin
material while UoSAT-B will generate housekeeping and
experimental data, combined with Digitalker and other formats.
** Oscar-9 Schedule **
Tuesday 28th February 03:00 load bulletin-63
Wednesday 29th February 14:00 load bulletin-64
Friday 2nd March 14:00 load bulletin-65
The above schedule will allow users to receive one afternoon
and one night pass of each bulletin up to launch.
** UoSAT-B Spacecraft status **
The UoSAT-B spacecraft was shipped to the Goddard Space Flight
Centre on Thursday 9th February for two days of magnetometer
and magnetorquer tests and calibration. These tests were
performed most successfully and the spacecraft left for
Vandenburg Air Force Base, California, on Saturday, 11th
February, arriving there late Sunday. After installation in
the clean room, 10 days were spent on final tests and
calibration, rectifying a few interface problems and generally
getting to know the complete system. Two days were spent in
this period shipping UoSAT-B to MacDonnell Douglas at
Huntingdon Beach for a brief period of thermal vacuum testing
following inconclusive tests which indicated an unacceptably
high level of contamination following thermal vacuum in the
U.K. These indications were proved unfounded and the
spacecraft returned to Vandenburg with a clean bill of health.
(Sorry!) Pre-mate on Thursday 23rd February and final mating
with the Delta launcher on Friday were both long, worrying
affairs with a number of problems which were eventually all
overcome. The UoSAT team returned, less all our freight, on
Saturday and Sunday 25th & 26th February, to finalise the
groundstation organisation. The lack of all microcomputers and
calibrated modulators and demodulators is likely to cause
problems, however we are confident that all will be ready in
time for launch on 1st March at 18:00 GMT.
** UoSAT-B Telemetry **
Below is a list of telemetry equations and modulation details -
more will follow in our next bulletin when we have unpacked the
rest of our documentation. Thanks are due to Harold Price,
NK6K, who used his computer systems at Vandenburg to help
generate the initial versions of these lists.
Checksummed TLM format. Channel format is:
nnvvvc
nn - channel number
vvv - value
c - To compute checksum, convert each ascii
character into the binary, e.g. 'A', which
comes in as 41H becomes 0AH. Exclusive OR
all 5 values. Convert the lower four bits
of the XOR answer to an ascii hex digit, e.g.
0BH becomes 42H, this character is the checksum.
A 1Eh cursor home character preceeds UOSAT-2 in each frame
The number after UOSAT-2 on the header line is the date
in YYMMDDWHHMMSS, W is day of week, 0-6. The date below
is bogus, it wasn't initialized after the s/c was powered
up. The s/c was in the Bldg 836 clean room when this
frame was taken. Some of the data is thus nonsensical,
although the format is correct.
UOSAT-2 0000010040621
00515101039B02011203010204023505028F06025107031508032909026D
10515011000012005613010314000515000416000717736418736B19736A
205153210322226677230001240017250007260774277367287368297369
30515231016532284F33000034000735030536000537736638353E39353F
40763641000542688043000744000045056246000247736148353949346C
50561751017252661653263154111055852F56000357306758736F593539
602105617BC762800C630041641003651C0E66140567340668000E69000F
Non-checksummed frame. Everything is the same as above expect
that the checksum character becomes a space. This format is
more pleasing to the human eye.
UOSAT-2 0000010040630
00515 01035 02010 03010 04023 05028 06025 07031 08032 09026
10515 11000 12004 13010 14000 15000 16000 17736 18736 19736
20515 21032 22667 23000 24001 25000 26077 27736 28736 29736
30515 31016 32284 33000 34000 35028 36000 37736 38353 39353
40763 41000 42688 43000 44000 45055 46000 47736 48353 49346
50561 51017 52661 53256 54111 55852 56000 57306 58736 59353
60210 617BC 62800 63004 64100 651C0 66140 67340 68000 69000
A dwell format is also available, in which only selected
channels are displayed. The channels can come out in any
order, in checksummed or non-checksummed format. The
UOSAT-2 and time stamp may or may not be included.
The blank columns will be completed when our freight catches
up with us.
Chan # Name Equation
00 Solar array current -Y I=1.9(516-N) ma
01 Nav mag X axis H=(0.1485N-68) uT
02 Nav Mag Z axis H=(0.1523N-69.3) uT
03 Nav mag Y axis H=(0.1507N-69) uT
04 Sun sensor #1
05 Sun sensor #2
06 Sun sensor #3
07 Sun sensor #4
08 Sun sensor #5
09 Sun sensor #6
10 Solar array current +Y I=1.9(516-N) mA
11 Nav mag (Wing) temp T=(330-N)/3.45 C
12 Horizon sensor
13 Spare (tbd)
14 DCE RAMUNIT current
15 DCE CPU current
16 DCE GMEM current
17 Facet temp +X T=(480-N)/5 C
18 Facet temp +Y T=(480-N)/5 C
19 Facet temp +Z T=(480-N)/5 C
20 Solar array current -X I=1.9(516-N) mA
21 +10V line current I=0.97N mA
22 PCM voltage +10V V=0.015N V
23 P/W logic current (+5V) I=0.14 (N<=500)
24 P/W Geiger current (+14V) I=0.21N mA
25 P/W Elec sp.curr (+10V) I=0.096N mA
26 P/W Elec sp.curr (-10V) I=0.093 mA
27 Facet temp -X T=(480-N)/5 C
28 Facet temp -Y T=(480-N)/5 C
29 Facet temp -Z T=(480-N)/5 C
30 Solar array current +X I=1.9(516-N) mA
31 -10V line current I=0.48N mA
32 PCM voltage -10V V=0.036N V
33 1802 comp curr (+10V) I=0.21N mA
34 Digitalker current (+5V) I=0.13N mA (N<=500)
35 145MHz beacon power O/P P=(2.5N - 275) mW
(valid when N>200)
36 145MHz beacon current I=0.22N mA
37 145MHz beacon temp T=(480-N)/5 C
38 Command decoder temp (+Y) T=(480-N)/5 C
39 Telemetry temp (+X) T=(480-N)/5 C
40 Solar array voltage (+30V) V=(0.1N-51.6) V
41 +5V line current I=0.97N mA
42 PCM voltage +5V V=0.0084N V
43 DSR current (+5V) I=0.21N mA (n<=500)
44 Command RX current I=0.92N mA
45 435MHz beacon power O/P P=(2.5N-200) mW N>175
46 435MHz beacon current I=0.44N mA
47 435MHz beacon temp T=(480-N)/5 C
48 P/W temp (-X) T=(480-N)/5 C
49 BCR temp (-Y) T=(480-N)/5 C
50 Battery charge/dischg curr I=8.8(N-513) mA
51 +14V line current I-5N mA
52 Battery voltage (+14V) V=0.21N V
53 Battery cell volts (MUX) See below
54 Telemetry current (+10V) I=0.02N mA
55 2.4GHz beacon power O/P P=((N+50)**2)/480 mW
56 2.4GHz beacon current I=0.45N mA
57 Battery temp T=(480-N)/5 C
58 2.4GHz beacon temp T=(480-N)/5 C
59 CCD imager temp T=(480-N)/5 C
60-67 Status points 1-96
The status points will be listed on the next bulletin. They
have been encoded so that the two-digit channel number is still
used as with channels 0 to 59, followed by three hexadecimal
digits giving 12 individual status indications.
Multiplexed Battery Scheme (channel 53)
Six consecutive TLM frames will carry the total volts, the
following ten frames will be individual cells, starting with
cell #10. Each cell has its own equation.
Cell Equation
ALL
10
9
8
7
6 (To be announced later)
5
4
3
2
1
The DCE currents will have small counts even when the DCE is
off. We think this is due to the +10 coming in from the Nav
Mag lines. If the Nav Mag is off (unlikely), the DCE currents
will be zero when both it and the Nav Mag are off.
By the way, beacons are:
145.825 MHz
435.025 MHz
2401.1 MHz
The tones are the same as for Oscar-9, but the sense of mark
and space have been reversed, to ensure more general
compatibility with many microprocessors, i.e. 1200Hz = logic 0
and 2400Hz = logic 1. Serial data uses logic 1 as the idle
level.
The deviation of the transmissions on 145.825MHz is greater
than that on UoSAT-1, which should be beneficial to the
majority of users. Special receivers optimised to receive the
UoSAT-1 low-deviation signals may require wider filters for
best effect on UoSAT-B.
** UoSAT-B Events **
The following events and keplerian orbital elements have been
supplied by Phil Karn, KA9Q. The circular period / precession
figures are from Jim Miller, G3RUH. The data is derived from
different sources and is not directly comparable.
The liftoff time assumed is 17:59:00 GMT on 1st March, 1984.
Event hh:mm:ss (relative to liftoff)
1st stage main engine cutoff: 00:03:47
Vernier engine cutoff: 00:03:53
Stage 1 separation: 00:03:55
Stage 2 ignition #1: 00:04:00
Stage 2 cutoff #1: 00:10:50
Stage 2 ignition #2: 00:54:04
Stage 2 cutoff #2: 00:54:17
Landsat separation: 00:59:10
Stage 2 maneuver start: 00:59:15
Stage 2 maneuver stop: 00:59:52
Uosat-B separation: 01:11:40
Stage 2 ignition #3: 01:30:53 distancing maneuver
Stage 2 cutoff #3: 01:30:58
Stage 2 ignition #4: 01:36:43 depletion burn
Stage 2 cutoff #4: 01:37:05
Satellite: uosat-b
Epoch time: 84061.79768519 (separation)
Thu Mar 1 19:08:40.000 1984 UTC
Element set: prelaunch
Inclination: 98.2596 deg
RA of node: 124.2426 deg
Eccentricity: 0.0004100
Arg of perigee: 174.4207 deg
Mean anomaly: 226.7604 deg
Mean motion: 14.61025794 rev/day
Decay rate: 0 rev/day^2 (none given)
Epoch rev: 0
Semi major axis: 7065.080 km
Anom period: 98.560888 min
Apogee: 690.030 km
Perigee: 684.236 km
Orbit No : 0
Eqx date : Mar 1st 1984
Eqx time : 18:59:25 GMT
Eqx long : 320.38 deg.w
Mean hgt : 687 km
Period : 98.5045 mins
P-drag : 8.3E-6 *N-ref
Long inc : 24.6251 degs
L-drag : 2.1E-6 *N-ref
Inclination : 98.26 degs
** Spacecraft orbital data **
Orbits for 27th February
UoSAT OSCAR-8 NOAA-7
Orbit no : 13266 30488 13825
Eqx time : 14:07:41 14:31:42 14:55:52 GMT
Eqx long : 337.7 293.9 352.2 deg.w
Mean hgt : 496.0 904.0 850.0 km
Period : 94.5234694 103.1632109 101.9582375 mins
P-drag : 2.477E-05 8.277E-07 7.500E-06 *N-ref
Long inc : 23.6297526 25.7899720 25.4896650 degs
L-drag : 6.233E-06 .000E+00 2.000E-07 *N-ref