ARC Pioneer Plasma Group Home Page

Last modified: 31 July 1995

[NASA Ames Pioneer Plasma Group]

The Pioneer 10 and 11 Spacecraft

NASA's Pioneer 10 spacecraft, launched in 1972, was the first spacecraft to
encounter the planet Jupiter (1973) and, as of this writing, is the farthest
man-made object from the Sun. A gravitational boost from Jupiter launched the
spacecraft onto a path leaving the solar system at approximately 3 Astronomical
Units per year (1 AU = 150,000,000 km). As of this writing, the spacecraft is
more than 62 AU from the Sun. It continues to send back useful scientific data,
adding to an enormous body of observations that now span more than 2 solar
cycles and 60 AU.

The Pioneer 11 spacecraft, launched a year after Pioneer 10, reached Jupiter in
1974 and was the first spacecraft to encounter Saturn (1979). Pioneer 11 is
also leaving the solar system, and as of this writing is more than 43 AU from
the Sun. By July 1995, exhaustion of the spacecraft power supplies had reached
the point that most of the scientific instruments could no longer be operated,
but over the preceding 21 years, Pioneer 11, like Pioneer 10, has provided a
very large body of interplanetary data.

For additional information on the Pioneer 10 and 11 missions, see the Pioneer
Project Home Page.

The Pioneer Venus Orbiter

The Pioneer Venus Orbiter and Probe were launched in 1978. The Orbiter
spacecraft was inserted into a highly eccentric and nearly polar orbit about
Venus on December 5, 1978. The spacecraft remained in operation until 1992,
when the natural decay of its orbit led to its entry into the planet's
atmosphere and subsequent destruction. The legacy of this mission is a vast
body of data concerning the plasma environment of Venus, as well as a 14-year
record of the state of the interplanetary medium at the heliocentric distance
of Venus (0.72 AU).

For additional information on the Pioneer Venus Orbiter mission, see Colin, L.,
The Pioneer Venus Program, J. Geophys. Res., 85, 7575-7598, 1980.

The ARC Plasma Analyzers

The Ames Research Center Plasma Analyzers aboard the Pioneer 10 and Pioneer 11
spacecraft measure the charged particles that comprise the solar wind. This
data is reduced to determine such parameters as the flow speed, density, and
temperature of the solar wind plasma. The ARC plasma group also maintains the
data set from the Plasma Analyzer aboard the Pioneer Venus Orbiter.

Instrument description: Pioneer 10 and 11 Plasma Analyzers

Instrument description: Pioneer Venus Orbiter Plasma Analyzer

Science staff

Aaron Barnes (Principal Investigator)
Paul R. Gazis (Information Contact)
John D. Mihalov
Romana Ratkiewicz

Publications

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The Pioneer Plasma Analyzer Data Sets

The data from these WWW pages are freely available. If you use these data sets
for detailed studies, we recommend that you contact us to inquire about
possible subtleties that might not be covered adequately in our documentation.
If these data are used in a scientific publication, please acknowledge their
source (the Ames Plasma Group), the ARC Pioneer Project, and the National
Aeronautics and Space Administration. We would appreciate receiving copies
(including pre-publication material) of any scientific papers that make use of
these data sets.

Pioneer 10 data is available for the entire mission. Pioneer 11 data is
available until mid-1992, when declining spacecraft power made further
operation of the plasma analyzer impossible. Pioneer Venus Orbiter data is
available for the entire mission.

Data Sets:

   *  Pioneer 10 (Trajectory, Summary, Hourly)
   *  Pioneer 11 (Trajectory, Summary, Hourly)
   *  Pioneer Venus Orbiter (Orbital parameters, Hourly)
   *  Pioneer Venus Orbiter Cruise (Trajectory, Summary, Hourly)

For further information contact:

Dr. Paul R. Gazis, SJSU Research Associate

phone: (415) 604-5704
fax:   (415) 604-6779
email: gazis@arwen.arc.nasa.gov

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[Go to] Top of page.

[Go to] The Pioneer Data Sets.

[Go to] Pioneer Project Home Page.

[Go to] NASA Space Physics Data System (SPDS) Home Page.

[Go to] NASA / Ames / Space Science Division / Planetary Systems Branch.

gazis@arwen.arc.nasa.gov
Last modified: 13 September 1995