Voyager 2 Power Cycled in 2020
Last update 2026-08-12 10:23
Low Voltages,  Rates

Timeline

After the PWRCHK anomaly all V2 science instruments were powered off for ~ 15 seconds and then were powered back on. The power supplied to some or all of the instruments for the next 54 hours may have been low or off nominal. LECP needed a reconfiguration to turn the LEPT bias and discriminator power supplies back on.

Temperature Plots

There is no mrt data when the spacecraft is in SM-40 and EL-40 modes. The JPL values in the plots below are extracted from LECP plots in the file
20-023.033_PWRCHK_ANOMALY_32_TEMPS.pdf That file contains other temperature plots, including plots of bay temperatures. The LEMPA telescope temperature in the mrt files does not agree with the JPL values for Voyager 2, so the LEMPA telescope plot below uses E-0453 raw DN values converted to temperatures. The conversions of DN to temperature are based on only a few points.

From "Spaceflight Telemetry Dictionary LECP Channels.pdf":

• E-453 LECP LEMPA TEL TEMP
  This measurement is sampled by a transducer mounted on the LEMPA telescope and measures the overall temperature of the telescope. The measurement is used to monitor the controlled temperature of the telescope Expected Range: -14.24°C to -12.01°C MEASUREMENT RANGE: -78°C to +l00°C
• E-461 LOG AMP TEMPERATURE
  This measurement provides temperatures of the critical log amplifiers. The temperature transducer is mounted on the mother board near the log amplifiers. The nominal analog output range is 0-1.6 V. Expected Range: 15.01°C to 13.67°C MEASUREMENT RANGE: Not available
• E-459 MOTOR TEMPERATURE
  This measurement provides the stepping motor temperature. The temperature transducer is mounted on one of the legs of the motor support. The nominal analog output range is 0-1.6 V. Expected Range: -14.11°C to Not Available MEASUREMENT RANGE: Not available

Low Voltages

E-0454 (LP LEPT-6), E-0474 (LP LEPT+6), E-0466 (LP BILOW), E-0468 (LP BIHIGH), and E-0467 (LP LEP+12) were zero for several days after the PWRCHK anomaly. The remaining low voltages changed but did not go to zero as shown in the LECP plots in 20-023.033_PWRCHK_ANOMALY_32_PWR_Sci-Instruments.pdf The file "Spaceflight Telemetry Dictionary LECP Channels.pdf" has explanations of the low voltage engineering values.

• E-454 LP LEPT-6
  This measurement measures the voltage (nominal -6 V) to the LEPT discriminators, identification circuits, and coincidence logic. The nominal analog level is 1.2 V. MEASUREMENT RANGE: 0 to -15 V, RESOLUTION: 0.0586 V/DN, FDS RANGE: 0 to 3.0 V
• E-474 LP LEPT+6
  This meaeurement measures the summation of the voltages (nominally +6 V and +12 V) to LEPT low. A summation is used because both voltages can then be read using only one channel. The nominal analog level is 1.2 V. MEASUREMENT RANGE: Not available, RESOLUTION:, FDS RANGE: 0 to 3.0 V
• E-466 LP BILOW
  This measurement measures the input voltages to the bias network. The nominal analog level is 1.5 V. MEASUREMENT RANGE: Not available, RESOLUTION:, FDS RANGE:
• E-468 LP BIHIGH This measurement measures the detector high voltage bias values. Nominal analog level ie 0.32 V. MEASUREMENT RANGE: Not available, RESOLUTION:, FDS RANGE: 0 to 3.0 V
• E-467 LP LEP+12 This measurement measures the summation of the voltages (nominally +6 V and +12) to LEPT high. A summation is used because both voltages can then be read using only one channel. The nominal analog level is 1.5 V. MEASUREMENT RANGE: Not available, RESOLUTION:, FDS RANGE: 0 to 3.0 V

Rates