baalke@mars.jpl.nasa.gov (Ron Baalke) (11/10/90)
Voyager Status Report
November 9, 1990
Voyager 1
The Voyager 1 spacecraft collected routine UVS (Utraviolet Spectrometer)
data on source SS CYGNI. On October 29, one frame of high-rate PWS (Plasma
Wave) was recorded. On November 1, there was a slew to a position pointing
toward Voyager 2 to observe interstellar hydrogen levels between the two
spacecraft.
On October 30 a DTR (Digital Tape Recorder) Maintenance sequence was
executed. The X Band TWT (Traveling Wave Tube) was also commanded to the
high power mode and the Bay 1 heater was turned off in preparation for
Playback #4.
On October 31 Playback # 4, containing PWS data, was executed; DSN (Deep
Space Network) performance for the playback was nominal. Following the
playback, the X Band TWT was returned to the low power mode and Bay 1 heater
turned on. A TLC (Tracking Loop Capacitor) test was also performed by the
Goldstone 34 meter station.
On November 1, real-time commands to reset the CCS (Computer Command
Subsystem) Status Telemetry, change the FDS (Flight Data Subsystem) data mode,
load the AACS (Attitude and Articulation Control Subsyste) and CCS Memory
readout mini-sequence for execution on November 2, load the AACS software fix
(Gyro Drift Turn), Reset the Command Loss Timer, perform a CCSTIM (CCS Timing)
Test, perform a CCSCAL (CCS Calibration) Test, and return the FDS to its
original mode, were transmitted to the spacecraft. Many problems were
experienced while attempting to command which caused all but the first command
to be delayed, and some to be transmitted out of the planned order. The
second element of the CCS Status Telemetry Reset command was aborted at the
first attempt and was not retransmitted as it was redundant. Delays from one
hour and twenty five minutes to four hours and forty seven minutes were
experienced in the command file transmission. All transmitted commands were
eventually successfully received by the spacecraft and executed; CCS checksum
verification was received. The CCSTIM and CCSCAL tests were executed and
analysis indicates there has been no change in the time offset between the FDS
frame start and the CCS timing chain in each CCS processor nor in the CCS
instruction cycle timing when compared with the sequence timing derived from
the FDS oscillator.
Voyager 2
The Voyager 2 spacecraft collected UVS background in the anti-Voyager 1
direction. On November 1, the scan platform was slewed to point towards
Voyager 1 to observe interstellar hydrogen levels between the two spacecraft.
Background levels will be removed by subtracting out the data from when the
spacecraft were pointed away from each other. On October 30, one frame of
high-rate PWS data was recorded.
CONSUMABLE STATUS AS OF 11/9/90
P R O P E L L A N T S T A T U S P O W E R
Consumption
One Week Propellant Remaining Output Margin
Spacecraft (Gm) (Kg) Watts Watts
Voyager 1 5 36.3 + 2.0 367 55
Voyager 2 6 39.3 + 2.0 370 61
___ _____ ___
/_ /| /____/ \ /_ /|
| | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov
___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov
/___| | | | ___/ | |/__ /| M/S 301-355 |
|_____|/ |_|/ |_____|/ Pasadena, CA 91109 |wayne@csri.toronto.edu (Wayne Hayes) (11/11/90)
In article <1990Nov10.001052.28690@jato.jpl.nasa.gov> baalke@mars.jpl.nasa.gov (Ron Baalke) writes: > Voyager 1 > On November 1, there was a slew to a position pointing >toward Voyager 2 to observe interstellar hydrogen levels between the two >spacecraft. > Voyager 2 > The Voyager 2 spacecraft collected UVS background in the anti-Voyager 1 >direction. On November 1, the scan platform was slewed to point towards >Voyager 1 to observe interstellar hydrogen levels between the two spacecraft. >Background levels will be removed by subtracting out the data from when the >spacecraft were pointed away from each other. Does this mean that they beamed some radio waves at each other to measure the absorbance at 21.1 cm? Do the spacecraft actually have powerful enough transmitters and sensitive enough receivers to actually detect each other? Or is it something to do with the absorbancy/emmission seen in all directions, and we're trying to measure a teensy-weensy delta between the background measured by spacecraft X minus the same background from the same direction measured by spacecraft Y? -- "Dad, what should I be when I grow up?" "Honest." -- Robert M. Pirsig, _Zen and the Art of Motorcycle Maintenence_. Wayne Hayes INTERNET: wayne@csri.utoronto.ca CompuServe: 72401,3525