Pioneer 10 Mission Status 22 Feb 2001

PIONEER MISSIONS

February 22, 2001

Pioneer 10 distance from Sun: 77.21 AU

Speed relative to the Sun: 12.24 km/sec (27,380 mph)

Distance from Earth: 11.52 billion kilometers (7.16 billion miles)

Round-trip Light Time: 21 hours, 20 minutes

Pioneer 10 now has 5 one-way passes and 3 two-way round-trip light
time (RTLT) passes scheduled from March through May. This should
give us adequate coverage to contact the spacecraft or determine
the reason why if contact has indeed been lost.

We were able to schedule tracks on the busy DSN schedule to allow
uplink and downlink support (competition for time includes Galileo,
Cassini, and Ulysses).

We will have to wait until April for the two-way RTLT passes, which
allow the DSN to send up a strong stable signal to try to lock up
with a coherent downlink signal. The effort is further complicated
by the 21-hour RTLT.

There are other downlink-only attempts scheduled starting in a few
weeks. Project Phoenix is observing Pioneer 10 at Arecibo in Puerto
Rico through the auspices of the SETI Institute. Their observation
dates are from Feb 26 to March 5 and from March 8 through 18, about
one hour each night.

Larry Lasher, Pioneer Project Manager

llasher@mail.arc.nasa.gov