Order Code RS22283
September 26, 2005
CRS Report for Congress
Received through the CRS Web
NASA’s Voyager Spacecraft: A Fact Sheet

Mark Gurevitz
Information Research Specialist
Knowledge Services Group
Summary
Voyager 1 and 2 were launched in 1977 with the mission of returning data from
Jupiter and Saturn and other planets as they flew past them. Their current mission is to
extend NASA’s exploration of the outermost edge of the solar system and the region
where the sun’s influence ends. In the 28th year after their 1977 launches, they each are
much farther away from Earth and the sun than Pluto. These unmanned vehicles have
garnered broad congressional and public interest.
In light of funding constraints, the issue has arisen as to whether the National
Aeronautics and Space Administration (NASA) will opt to shut down the Voyager 1 and
2 spacecraft or any of several other spacecraft. NASA will decide which missions to
continue operating based on the level of funding available and NASA’s Senior
Management Review ranking of the science value provided by each of these spacecraft.
This ranking is expected later this year or early next year. This report is updated
regularly.
Background
Voyager 2 was launched on August 20, 1977, from Cape Canaveral, Florida aboard
a Titan-Centaur rocket. On September 5, 1977, Voyager 1 was launched, also from Cape
Canaveral aboard a Titan-Centaur rocket. The primary mission for both spacecraft was
the exploration of Jupiter and Saturn. After making a string of discoveries there — such
as active volcanoes on Jupiter’s moon Io and intricacies of Saturn’s rings — the mission
was extended. Between them, Voyager 1 and 2 explored the four giant planets of our
outer solar system, Jupiter, Saturn, Uranus, and Neptune, 48 of their moons, and the
system of rings and magnetic fields those planets possess. Voyager 1 was put into a
faster, shorter trajectory, so it reached Jupiter first and returned data about Jupiter and
Saturn. Voyager 2 returned data about Jupiter, Saturn, Neptune, and Uranus.
Both Voyagers continue to return data as they travel through the outer reaches of the
solar system. The current mission of the two spacecraft is designated as the Voyager
Interstellar Mission (VIM). Its objective is to extend NASA’s exploration of the
outermost edge of the solar system and the region where the sun’s influence ends. In the
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28th year after their 1977 launches, they each are much farther away from Earth and the
Sun than Pluto. Voyager 1 is farther from Earth than any other human-made object. The
Voyager probes are approaching the boundary region — the heliopause — where the
Sun’s dominance of the environment ends and interstellar space begins (Figure 1). Both
spacecraft are still sending scientific information back to NASA’s Deep Space Network
(DSN). NASA believes both spacecraft will continue to operate and send back valuable
data until at least the year 2020 when the plutonium power source will run out. Detailed
information on Voyager is available at [http://voyager.jpl.nasa.gov/].
Figure 1. Voyager Spacecraft Approaching the
Heliopause
Source: NASA at [http://voyager.jpl.nasa.gov/]
Voyager’s Future
Voyager 1 and 2 are funded as part of NASA’s Earth-Sun System theme in the
Science Mission Directorate. A total of 13 spacecraft in the Earth-Sun System category,
including the two Voyagers, are conducting “extended missions” — that is, they have
achieved their primary objectives, but continue to operate because they are still providing
useful scientific data. Initially, NASA indicated that it might not receive sufficient
FY2006 funding to continue operating all of these spacecraft, including the Voyagers. The
White House on July 15, 2005, submitted a NASA FY2006 budget amendment to
Congress, which includes approximately $16 million to maintain the continued operation
of the spacecraft conducting space and solar physics missions
[http://www.whitehouse.gov/omb/budget/amendments/amendment_7_15_05.pdf]. This
funding would enable the continued operation for at least part of FY 2006 of the
following seven missions: Voyager, Ulysses, Transition Region and Coronal Explorer
(TRACE), Fast Auroral SnapshoT Explorer (FAST), Geotail, Wind, and Polar. Detailed
information on these and other space science missions can be found at
[http://spacescience.hq.nasa.gov/missions]. The Voyager probes would consume
approximately $4.2 million of that total. For more information on NASA’s FY2006
Budget see CRS Report RL32988, The National Aeronautics and Space

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Administration’s FY2006 Budget Request: Description, Analysis, and Issues for Congress
by Marcia S. Smith and Daniel Morgan.
NASA will decide which missions to continue operating based on the level of
funding provided to NASA by Congress and NASA’s Senior Management Review
ranking of the science value provided by each of these spacecraft. Senior Management
Review is a process which uses scientists outside of NASA to independently review and
rank the science value for each extended mission.
109th Congress Legislative Activities
H.R. 3070, the National Aeronautics and Space Administration Authorization Act
of 2005, passed the House on July 22, 2005, and is currently in the Senate Committee on
Commerce, Science, and Transportation. Section 304 would require NASA to carry out
annual termination reviews within each of the science disciplines to assess the cost and
benefits of extending the date of the termination of data collection for those missions
which are beyond their primary goals. In addition, within 60 days after the date of
enactment, NASA would carry out such an assessment for the following missions: FAST,
TIMED, Cluster, Wind, Geotail, Polar, TRACE, Ulysses, and Voyager. NASA would be
required to submit the assessments to the Senate Committee on Commerce, Science, and
Transportation and the House Committee on Science within 30 days after completing each
assessment.
S. 1281, the National Aeronautics and Space Administration Authorization Act of
2005, was reported out of the Senate Committee on Commerce, Science, and
Transportation (S.Rept. 109-108, July 26, 2005) and is currently on the Senate Calendar.
Section 144 would require NASA, within 60 days after the date of enactment, to carry out
an assessment of the costs and benefits of extending the date of the termination of data
collection from the Ulysses spacecraft and the Voyager spacecraft. NASA would be
required to submit a report on the assessment to the Senate Committee on Commerce,
Science, and Transportation and the House Committee on Science within 30 days after
completing the assessment.

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