Historic Voyager Mission May Lose Its Funding

By Guy Gugliotta
Washington Post Staff Writer
Monday, April 4, 2005; Page A08

   Two Voyager spacecraft are still transmitting as they near the 
   outer limits of the sun's influence.

In a cost-cutting move prompted by President Bush's moon-Mars
initiative, NASA could summarily put an end to Voyager, the legendary
28-year mission that has sent a spacecraft farther from Earth than any
object ever made by humans.

The probable October shutdown of a program that currently costs $4.2
million a year has caused consternation among scientists who have
shepherded the twin Voyager probes on flybys of four planets and an epic
journey to the frontier of interstellar space.

"There are no other plans to reach the edge of the solar system," said
Stamatios Krimigis, a lead investigator for the project since before its
launch in 1977. "Now we're getting all this new information, and here
comes NASA saying, 'We want to pull the plug.' "

NASA officials said the possibility of cutting Voyager and several other
long-running missions in the Earth-Sun Exploration Division arose in
February, when the Bush administration proposed slashing the division's
2006 budget by nearly one-third -- from $75 million to $53 million.

The administration is rearranging NASA's finances to fund Bush's "Vision
for Space Exploration" to the moon and eventually Mars. Cuts in
aeronautics funding prompted by the initiative have already provoked an
uproar at some NASA centers.

Some members of Congress have also criticized the aeronautics cuts, and
last year several joined the public outcry over NASA's decision to
cancel a servicing mission to the Hubble Space Telescope, a move
apparently unconnected -- at least initially -- to the moon-Mars proposal.

"Voyager is the same [as Hubble] -- one of the classic American
contributions to space," said research physicist Louis J. Lanzerotti,
who last year led a Hubble study for the National Academies of Science.
"Voyager's photographs are all over astronomy textbooks."

Dick Fisher, NASA's deputy director for the Earth-sun division,
acknowledged that Voyager's looming demise is a direct result of the new
budget. He said the agency based its proposed cuts on a "senior review"
by outside experts who in 2003 gave Voyager a low priority among the
division's 13 "extended" missions.

"If we use that set of goals, we would be looking at certain missions
that would have to be terminated," Fisher said in a telephone interview.
"We have to [decide] whether to sweat the rest of the budget to pay for
this."

An extended mission begins when a spacecraft has finished its original
task but is still able to contribute new science. The best known one
underway is that of the Mars rovers Spirit and Opportunity, which are
exploring the Martian desert a year after the end of their 90-day
"design" mission.

Voyager 1 and Voyager 2, destined originally for a five-year journey to
Jupiter and Saturn, have been extended repeatedly ever since. Most
systems are functioning well, and both spacecraft are expected to
provide usable data until their plutonium power sources are used up --
probably in 2020.

Fisher said NASA has made no final decision on the cuts but has notified
project scientists of its intentions and asked for cost-trimming
proposals. He said the agency will make final decisions this month,
perhaps by April 15.

The other programs on the block are Ulysses, launched in 1990 to study
the sun; Geotail (1992), Wind (1994) and Polar (1996), to trace the
interaction between solar events and their effects on Earth; FAST
(1996), to study Earth's aurora; and TRACE (1998), to investigate the
solar atmosphere and magnetic fields.

The impulse for Voyager arose in the early 1970s because of space
geometry, Krimigis said in a telephone interview. Every 175 years, the
solar system's four major outer planets -- Jupiter, Saturn, Uranus and
Neptune -- are aligned in a way that one spacecraft can pass close to
all four without carrying extra propellant.

"I think it was the science adviser at the time, and the NASA
administrator, who went to visit [then-President Richard] Nixon,"
Krimigis said, noting that Nixon was lukewarm on the mission. "They told
him that the opportunity only arose once every 175 years -- 'and
Jefferson missed it.' " Nixon signed on.

The twin probes were launched less than a month apart in the summer of
1977. Each weighed 1,800 pounds and carried 11 cameras and instruments.
Computer memory was 80 kilobytes (an entry-level PC today has nearly
10,000 times as much). Electricity came from nuclear-powered generators
fueled by the heat of decaying plutonium. Krimigis said they knew from
the start that the probes could get a lot farther than Jupiter and Saturn.

And they did. A "Grand Tour" of the four planets ended in 1989. Both
spacecraft visited Jupiter and Saturn, after which Voyager 2 went on to
the first and, thus far, only flybys of Uranus and Neptune. Voyager 1
headed toward the frontier of interstellar space, overtaking the earlier
Pioneer 11 spacecraft, launched in 1973, whose power supply is dead.

Today Voyager 1, about 9 billion miles from Earth and traveling at
46,000 mph, and Voyager 2, about 7 billion miles away doing 63,000 mph,
are flirting with the edge of the solar system, where the sun's magnetic
field and the solar wind give way to interstellar wind.

Virtually nothing is known about this boundary. Data from the spacecraft
show periodic jumps in radiation levels -- expected when the solar wind
is no longer able to block incoming cosmic rays -- followed by smaller
declines.

"By 2006, the spacecraft may have crossed into the outermost layer of
solar atmosphere, where the supersonic wind has slowed and heated to a
million degrees as it interacts with the interstellar wind," said
California Institute of Technology physicist Edward C. Stone, Voyager's
chief scientist from the outset. "If Voyager is terminated, we will lose
the opportunity to observe [this] interaction."

For Stone, 69, and Krimigis, 66, Voyager has been what Stone described
in an e-mail as "the defining event that has shaped my career for the
last 30 years," and the Voyagers have amassed accomplishments
unsurpassed by any spacecraft.

The two probes have discovered 22 moons at four planets. Voyager 1 has
traveled farther than any other spacecraft, and took the first portrait
of the solar system from the outside looking in.

The probes found exploding volcanoes on Jupiter's moon Io, huge fault
canyons on Uranus's moon Miranda, geysers on Neptune's moon Triton, and
flew by Saturn's methane-enshrouded moon Titan almost 14 years before
the European Space Agency's Huygens probe landed there this January.

The Voyager mission today has a full-time staff of 10 people, down from
300 at the height of the Grand Tour. The probes' software has no storage
capability, so they must transmit their instruments' readings in real time.

The signal takes 12 hours to reach far-away Earth.

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