Forwarded from Dr. Larry Lasher, Pioneer Project Manager

STATUS UPDATED: 1 December 1997

Pioneer 10

(Launched 2 March 1972)

  Distance from Sun (1 December 1997): 68.85 AU
  Speed relative to the Sun: 12.24 km/sec (27,380 mph)
  Distance from Earth: 10.15 billion kilometers (6.310 billion miles)
  Round-trip Light Time: 18 hours 48 minutes

The Pioneer mission formally ended on 31 March 1997 at 19:35 GMT. However,
we still contact the Pioneer spacecraft on a non-interference basis to
other NASA projects for the purpose of training Lunar Prospector
controllers in Deep Space Network coordination of tracking activities. As
part of the training program, we successfully performed a CONSCAN maneuver
on 9 August, 1997, once again in the blind. The Iowa Geiger Tube telescope
instrument is operating nominally. The Chicago charged
particle instrument is cycled on for 4 hour periods once every two weeks
(when a round-trip light time (RTLT) opportunity is available). Three-way
Doppler data for Radio Science are obtained whenever a RTLT is available.
Current operation dips into the batteries, sometimes resulting in a low
value of 0.94 volts during a track. This indicates further degradation of
the RTGs.  Nevertheless, we anticipate the transmitter to continue working
until sometime in 1998. Also under the training program, Pioneer 6 was
tracked by DSS 43 on 6 October 1997. Both the MIT and ARC Plasma Analyzers
were turned on as well as the cosmic ray detector from University of
Chicago.



Pioneer 11

(Launched 5 April 1973)

The Mission of Pioneer 11 has ended. Its RTG power source is exhausted.

The last communication from Pioneer 11 was received in November 1995,
shortly before the Earth's motion carried it out of view of the
spacecraft antenna.

The spacecraft is headed toward the constellation of Aquila (The
Eagle), Northwest of the constellation of Sagittarius. Pioneer 11 may
pass near one of the stars in the constellation in about 4 million
years.