SETI bioastro: Pioneer 10 Status Report for May 1, 2000

From: Larry Klaes (
Date: Wed May 03 2000 - 13:43:32 PDT


Pioneer 10

(Launched 2 March 1972)

Distance from Sun (1 March 2000): 75.10 AU
Speed relative to the Sun: 12.24 km/sec (27,380 mph)
Distance from Earth: 11.37 billion kilometers (7.065 billion miles)
Round-trip Light Time: 21 hours 04 minutes

>From a recent tracking report:

Deep Space Station (DSS): 63 Madrid, Spain

Spacecraft: 23 [Pioneer 10]

Date of track: 3/21/00 Day of Year (DOY)=081

Beginning of Track (BOT) = 21:15 (Universal Coordinated Time)

End of Track (EOT) = 23:50

Spacecraft Health: Thermal, Power, RF, Science all nominal.

The Radioisotope Thermoelectric Generators (RTGs) continue to provide
sufficient power to support the current spacecraft load of transmitter,
receiver, command and data handling as well as the Geiger Tube Telescope
(GTT) science instrument.

The RTGs are currently providing approximately 65 Watts of power (about
42% of the 155 Watts launch value).

The science and transmitter are turned off to provide enough power to
fire the attitude control engines for the biannual spacecraft pointing
maneuvers towards the Sun (the latest maneuver was executed on 2/11-
12/00). The battery voltage is often discharged and charged. However,
the battery does not support any of the load, being charged to only
about 1 volt at its peak, down from its nominal value of 9 volts.

The Bus Voltage is at a steady 27 Volts with a Bus Current of about
1.3 Amps.

The platform temperature is still within acceptable limits at -41
degrees F (the nominal range is between -63 F to 180 F).

The Deep Space Network (DSN) continues to provide good data with the
received signal strength of -178 dBm (only a few dBm from the receiver
threshold of -180 dBm).

Although powerwise Pioneer 10 is operating OK with one science instrument
on, the DSN may not be able to get good telemetry lock as the signal-to-
noise ratio (SNR) continues to decrease. Even though in a year the DSN
may still be able to get good telemetry lock, being this close to the
receiver threshold and losing about 0.3 dBm/yr due to range, maintaining
contact will be a challenge.

(From update report by Ric Campo, Pioneer Operations Supervisor)

Larry Lasher, Pioneer Project Manager

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