For Immediate Release

NASA Misleads the World on the Dangers
of the Cassini Space Ship's Fly-by of Earth

Jonathan Mark
Action Site to Stop Cassini Earth Flyby (
P.O. Box 1999 Wendell Depot, MA 01380 U.S.A.

Earl Budin, M.D. (
Former Assoc.Clin.Prof.Radiology UCLA Medical Center

The U.S. National Aeronautics and Space Administration launched the Cassini space ship on October 15, 1997, on a seven-year mission to study the planet Saturn, purportedly in the hope of "understanding the birth and evolution of our solar system." But by using 72.3 lbs. (32,8 kg) of radioactive Plutonium to run Cassini's 740-watt instrument panel, NASA created the possibility of unspeakable disaster for the people (and other life) on our own planet.

NASA plans to accelerate Cassini by using Earth's gravitational field on August 18, 1999, when it plans to have the space ship approach Earth in a so-called "fly-by" at a velocity of 10 miles per second. NASA claims that the odds against a calamitous mishap, namely the space ship entering our atmosphere are one in a million.

But there is important evidence showing that NASA has seriously underestimated the possibility of human or equipment error -- and the potential danger of any accident during the fly-by maneuver.

Jet Propulsion Laboratory, for example, in May 1997 reported 18 different types of malfunctions that may occur, including electrical short-circuits, meteors or space debris striking the space probe, and erroneous ground commands. If the craft does veer from its course even slightly, Cassini could plunge into Earth's atmosphere and burn up like a meteorite.

Cassini has more Plutonium-238 on board than any mission before. Because of its shorter half-life, according to physicist Dr. Kai Petzke from the Technical University of Berlin, the isotope Pu-238 is about 280 times more radioactive than the well known bomb material Pu-239. During atmospheric testing of nuclear weapons, many tons of Pu-239 were released into the atmosphere. But because Pu-238 is so much more dangerous, it would more than double the human-made Plutonium activity in the atmosphere if the 400,000 Curie on board Cassini were disseminated.


Major flaws in NASA's Environmental Impact Statements were exposed by the Nuclear Safety Review Panel appointed to study the safety of Cassini. Federal regulations require a separate evaluation whenever radioactive material is introduced into space. The panel comprised representatives from the U.S. EPA, Dept. of Energy, Dept. of Defense, Nuclear Regulatory Commission, and NASA. In its July 1997 Safety Evaluation Report (SER), the panel noted at least three major discrepancies.

(1) The most astounding error is that NASA claimed the Plutonium containers were "designed to withstand re-entry" into our atmosphere. In fact, the SER noted, these holders were NOT designed to withstand the heat of an accidental re-entry at the planned speed of 42,300 mph (64,000 km).

(2) NASA claimed that almost none of the Plutonium could become airborne in any accident. In contrast, the SER noted that nine kilograms could become airborne in respirable form, the only hazardous state.

(3) NASA estimated that in the event of an accident the Plutonium could cause 120 fatal cancers. The SER estimates that "tens of thousands" such deaths could result from a major accident.

NASA based its figures on the cancer-causing potential of Plutonium on the dose from general ionizing radiation. But the SER noted "the probability of a single inhaled particle inducing a cancer," which NASA ignored in all its Environmental Impact Statements, although it was reported in the Proceedings of the National Academy of Sciences (April 1997) from experiments financed in part by NASA. Moreover, even the SER fatality estimate could fall far short of the truth. The SER fails to mention that each kilogram of Plutonium contains trillions of radioactive atoms. The number of fatal cancers might be many times greater than tens of thousands.


What are the chances of the Cassini space probe entering Earth's atmosphere? NASA claims the odds are one in a million, but according to renowned physicist Dr. Michio Kaku that figure is based solely on the chance of an impact with a meteor in outer space. Meanwhile, far greater and more likely risks are posed by mishaps such as lost radio contact or misfired rockets. Dr. Kaku calculates the chance of a Cassini mission error is about 10 percent.

NASA has taken frightening chances from the beginning of this mission. For example, the Titan IV rocket it used to launch Cassini now has a 12 percent failure rate on lift-off. On April 10, 1999, military officials admitted to another mishap, a $250 million missile-warning satellite ended up in the wrong orbit following its launch aboard an Air Force Titan rocket. To date there have been nine documented space program accidents that released Plutonium into our environment.

Cassini is expected to be travelling around 10 miles per second for 55 days from Venus toward Earth beginning on June 24, 1999 during the height of solar flare activity. It is expected that a solar eruption, possibly the most severe this Century, will happen anytime between now and January 2001. A solar eruption during its last highpoint cycle in 1989 knocked-out power for 6 million Canadian households and businesses. Such an impact on Cassini would fry its communication's systems. In short, the agency has deceived the public to the real risks of an accident, its safety record is abysmal, and yet the stakes in this case are extremely high.


We are reaching a point of no return: on 24 June 1999 NASA directed Cassini's final fly-by around Venus to sling the space ship toward Earth. It is essential we all demand that leaders internationally, and especially in the United States, intercede in this misguided situation. Redirecting the probe in another direction is possible. The last "trajectory correction maneuver" planned by NASA before the Earth flyby is on August 11, 1999. Cassini can still be directed away from Earth and into deep space or other alternative. A petition was drafted by the Cassini Redirect Coalition and it calls for heads of state or other national leaders to make demands in the United Nations and in the International Court to stop the Cassini Earth fly-by.

The situation is extremely serious. And the key is to respond now, while there is time to protect our world from nuclear radioactive pollution. It's time to return to the worthy ideals the U.S. ratified by signing the UN Treaty in 1967: "the peaceful use of outer space." The health of ourselves and our world is on the line.

Last revised 7/13/99 7:46:01 AM