Countdown on track for Cassini launch
Protesters hold vigil at White House
October 12, 1997
Web posted at: 11:40 p.m. EDT (0340 GMT)
CAPE CANAVERAL, Florida (CNN) -- The final countdown has
begun for the launch of NASA's controversial Cassini mission
The Titan rocket with the Cassini spacecraft on board is
scheduled to blast off from Cape Canaveral at 5:55 a.m. EDT
Monday (0855 GMT), beginning an 11-year journey to the ringed
However, NASA forecasters said there was a 40 percent chance
that wind or rain might force a delay in the planned predawn
Some critics of the Cassini mission -- convinced its
plutonium-fueled generators pose a dire threat in the event
of a launch disaster -- cleared out of central Florida in
advance of liftoff. Cassini contains 72 pounds of highly radioactive plutonium.
But NASA officials involved in the project, who insist the
danger is minimal, made a point of bringing their families to
view the launch.
"I have 30 members of my family here right now, including my
two granddaughters, and there's more on the way," said
project manager Richard Spehalski. "I invited everyone I love
to the launch."
Cape Canaveral Mayor John Porter said, "I've met with NASA
people, and they've given me their assurances that the launch
Asked if he would stay in town, Porter said, "Oh, I think I
have to. This isn't the time for anyone to think you're
About 70 protesters held a candlelight vigil outside the
White House Sunday night. Several carried signs saying, "Halt
nuclearization of space: Stop Cassini."
NASA officials have repeatedly sought to reassure the public
that the plutonium-laden Cassini probe to Saturn doesn't pose
a threat. Saturday, a federal judge in Hawaii turned down a
request to block Monday's scheduled launch.
Opponents to the launch, including some past and present
Kennedy Space Center employees, fear deadly radioactive
plutonium could be showered over the Earth if something goes
awry, either during liftoff or during a planned flyby of
Earth in 1999.
But proponents insist that even if Monday's rocket blast
fails, little, if any, plutonium would be released and
radiation exposure would be minimal.
Start of 11-year-long mission
Cassini -- NASA's largest and costliest interplanetary
spacecraft ever -- will take seven years to reach Saturn.
Once there, it will spend four years orbiting the planet, its
rings and its moons, releasing a probe to land on the largest
The entire 11-year mission will cost $3.4 billion.
"The mission represents a very rare opportunity to gain
significant insights into major scientific questions about
the creation of the solar system, prelife conditions here on
early Earth and just a host of questions about Saturn
itself," said Wesley Huntress Jr., NASA's space science
NASA officials stress that the plutonium on board is not part
of a nuclear reactor generating energy; rather, the energy
released by the natural decay of the element will fuel the
probe. They say the technology has been used in about two
dozen other space missions without incident.
While solar panels are used in many space missions, Spehalski
said that is not feasible for Cassini because Saturn is so
far from the sun. Its solar panels would have to be the size
of two tennis courts to generate enough power, he said.
Both NASA and the U.S. Department of Energy, which built the
three plutonium "batteries" on Cassini, say that extensive
testing of the devices has proven that the chances of a
disaster are minimal.
"We've put them through explosions, we've put them through
impacts, we've put them next to solid rock fuel and burned
them, we've done pressure tests," said Beverly Cook of the
Energy Department. "The bottom line is this: We have tested
these to the conditions that we will have if there is an
Odds of 1999 reentry 1 in 1 million
NASA has set the odds of a radioactive release during the
first 3 1/2 minutes after launch at 1 in 1,400. The chances
of a release later in the rocket's climb into orbit narrow to
1 in 476.
In August 1999, Cassini will make a loop around Earth, using
its gravitational pull in a sling-shot effect to build speed
for the trip to Saturn. The chances that Cassini would
malfunction and fall to Earth then are set by NASA at 1 in 1
But Cassini's opponents dispute NASA's figures.
"I find that NASA bureaucrats in some sense are living in
fantasyland," says Michio Kaku, a physics professor at City
University of New York. "Pure guesswork has replaced rigorous
physics. Many of these numbers are simply made up."
Opponents want NASA to redesign Cassini to operate on solar
energy -- delaying the probe if necessary until the
technology exists to power it without plutonium.
"Saturn isn't going anywhere," said Bruce Gagnon of the
Florida Coalition for Peace and Justice. "We are not opposed
to space exploration. We just think it must be done
Reuters contributed to this report.