This paper presents a case study of a recent technological risk controversy: the use of plutonium dioxide radioisotope thermal generators (RTGs) on board the Cassini-Huygens mission to Saturn, in light of its gravity-assist swing by Earth in August 1999. The data consist of Internet dialogues on the topic, specifically, UseNet postings from 1 April 1995 through 31 March 1999. They illustrate the exponential impact of a very small and well-organized opposition movement, which utilized the Internet to exert pressure to abort the launch and flyby. Though Cassini went on to Saturn, the resulting political pressure on NASA has created an atmosphere of public controversy in which new missions may be very difficult to authorize if their goals and design require RTGs.

The success of the anti-Cassini activists raises questions about the nature of technological risk decision-making in a democratic but unevenly informed society. It underscores the empowerment of small but well-organized groups in the realm of natural and technological hazard policy and the potential of the Internet in heightening individual empowerment in such debates, particularly when science itself is under critical interrogation. It also raises less heartening issues of demagoguery in cyberspace.

Background

The Cassini-Huygens mission to the Saturn planetary system is physically the largest, scientifically the most ambitious, and organizationally the most international project ever undertaken by the National Aeronautics and Space Administration (NASA) or by its partners, the European Space Agency (ESA) and the Agenzia Spaziale Italiana (ASI).

Contested Decisions:

NASA dismissed solar power for mission instrumentation and temperature maintenance needs because of:

• the sheer mass of the Cassini Saturn orbiter and Huygens Titan probe combination, even without massive solar arrays

• the duration of the cruise to Saturn (seven years) and tour at Saturn (four years) and the need for reliable and durable power sources

• the orbiter's repeated movement through the ring system and the susceptibility of solar cells to impact damage

• the need to minimize moving parts that can fail

• the extreme distance of Saturn from the sun (1.4 billion kilometers), where solar energy receipt per unit area is about 1 percent that at Earth

Instead, NASA decided on the compact radioisotope thermoelectric generator (RTG) and radioisotope thermal unit (RHU) design, which generate heat and, in the case of the RTGs, electrical power through the alpha radiation emitted by ceramicized plutonium-238 dioxide.

NASA further opted for a Venus-Venus-Earth-Jupiter Gravity Assist (VVEJGA) trajectory:

• the 5,655 kg mass of Cassini-Huygens and its navigational fuel is close to the 5,760 kg launch limit of the largest American expendable launch vehicle (Titan IV/Centaur combination)

• gravity assists would give Cassini-Huygens the velocity it needed to reach the Saturn system during the careers of its science teams

Risk assessment performed for NASA as part of the Environmental Impact Statement for the mission characterized the risk of plutonium release on launch or a swingby accident as negligible and acceptable. Probabilities and their consequences in additional cancer deaths were estimated at:

• 8.0 x 10-7 in a swingby accident, resulting in 120 deaths over decades

• 1 in 1,490 in an early launch accident, resulting in 0.082 deaths

• 1 in 476 in a late launch accident, resulting in 0.044 deaths

The opposition:

The plutonium and the Earth swingby and the risk assessment performed for NASA erupted into controversy by 1996, resulting in sustained efforts:

• to stop or postpone the October 1997 launch

• later, to abort the Earth flyby in August of 1999

• now, to prevent the use of RTGs on subsequent missions

• to debunk risk assessment done for NASA (millions of deaths from the release of "the most toxic substance known")

• to argue that, with new technologies on the horizon, solar power is an option at Saturn if the mission had been scaled down and delayed

Prior Work in Hazards Perception

People often make up their minds about an issue before seeking facts about it, often taking the position of a reference group they trust, and then become very confident in their opinions. Once the pattern gels one way or the other, new facts and arguments are fit into the framework in a way that further solidifies it, to avoid the cognitive dissonance of holding two conflicting interpretations.

The public is often characterized, perhaps unfairly, as irrational and ignorant: It may be that laypeople judge hazards along multiple axes, not just the quantifiable probability of mortality/ morbidity. This implies that experts may have narrow, faulty perceptions of their own.

• People seem to judge hazards differently on the basis of the perceived control they have over the exposure: If they can choose the exposure, they often will accept substantial risks; but, if this is a risk they feel have no choice in, they may become very upset over the imposition of even the smallest risk. Cassini may be perceived as a risk imposed on the public.

• Another axial theme in technological hazards literature is lay sensitivity to fairness issues, to learning who gains and who loses from the deployment of a risky technology. With Cassini, the public may see the benefits flowing to "nerdy" scientists and the risks falling on average citizens.

• A prominent dimension consistently emerging in technological hazards literature is the dread factor: Is a given hazard seen as having the potential, no matter how small, of creating a really huge loss of life or particularly fearful diseases? Can it have effects that might be passed down through the generations? Is it linked with past incidents of sheer horror? Anything nuclear evokes dread, and the opposition to the plutonium dioxide on board Cassini may be driven more by this single factor than any other.

• Another issue occasionally raised in hazards literature is public trust of institutions responsible for risk assessment, risk management, and emergency response. The proposed study will attempt to evaluate the extent to which suspicion of NASA itself has inspired mistrust of its process of risk assessment in the case of Cassini.

• Gender, ethnicity, culture, and social class are sometimes raised as factors affecting hazard perception and behavior and hazard vulnerability.

Purpose and Focus

Research Questions

• Do UseNet debates on Cassini bring up the issue of perceived control over plutonium exposure as expected from the hazards perception literature?

• Are fairness issues raised?

• Do Cassini opponents focus on expressing or eliciting dread?

• Is suspicion of governmental institutions in general and NASA in particular expressed to discredit the risk assessment performed by or under contract to NASA?

• How does gender affect the debate?

Data and Methods

From this population, I created a sample, by confining my examination to a maximum of 250 messages per month. I chose to scan up to the first 250 messages turned up by the search engine, because Deja.com sorts message by "confidence," basically the number of times the keyword turns up in a message. From this maximum of 250 messages per month, I extracted only those on the subject of the spacecraft, saving their authors' names and e-mail addresses and an abstract of their messages in a word processor. Furthermore, I saved only the most recent posting by a given author and then categorized the author's stance on the basis of this comment as proponent, opponent, or neutral. If their stances were not decipherable from these comments, I would search on these authors' names and read their other messages on the subject, until I could classify their stances. Additionally, I did searches on author names and Cassini to identify numbers of postings per author as an indicator of interest level.

This method yielded comments by 937 authors. These individuals posted a total of 8,020 messages or forty percent of the Cassini messages dating from the four year study period.

Later, this text database became the basis of a spreadsheet database including fields for author name, login name, e-mail, gender, basic stance, central concerns raised in their messages, and number of postings an author had made on the subject. I also noted whether the message had been originally composed by the author or was basically a forward of someone else's writing. This database was sorted on various of these fields to yield the results summarized in the following tables.

The debate over Cassini is overwhelmingly a male preserve:

• fewer than 5% of the authors are female

• those women who do post are quieter than their male counterparts, making only 3.3% of the posts on the subject

This may reflect a greater male interest in technology. Too, it may reflect the lingering numerical predominance of men on the Internet over women.

Balance of opinions:

Also, the great majority of authors are supportive of Cassini:

• 60% are proponents

• 21% are opponents

• 20% are neutral or conflicted

These percentages depart significantly from the expected uniform distribution at the 0.000 level (a Chi-squared goodness-of-fit test statistic of 307.007 at 2 degrees of freedom).

Originality of messages versus forwarding of others' messages:

Proponents and neutrals are much likelier to compose their own, individual messages; opponents are far likelier just to pass on a message or article originally composed by someone else.

• 46 or 24% of opponents just passed on others' messages

• 36 or 6% of proponents did so

As measured by a Chi-squared goodness-of-fit test against an expectation of proportional numbers of passed-on messages, this disparity is significant at the 0.000 level (Chi-squared is 180.413 with 2 degrees of freedom). This suggests a certain thinness in the opposition, a sort of activism-by-the-forward-button quality.

Opinions by gender:

Within the limitations of such a badly skewed sex-ratio, there is a significant difference in the allocation of stances between the genders.

• 16 or 38% of the women were opponents, while 132 or 18% of the men were

• 19 or 45% of the women were proponents, while 468 or 63 % of the men were

Chi-squared for 2 degrees of freedom and n=781 is 10.769, which yields a prob- value of 0.005. When these results are calibrated for the sample size through Cramer's V, however, the strength of the association proves extremely weak at 0.117.

With these caveats, women are likelier to be opponents than are men. Were the sample of UseNet postings more balanced by gender, then, it can be expected that proponents and opponents would be somewhat more evenly balanced.

Distribution of opinions if sample had been gender-balanced (hypothetical scenario):

To see if a gender-balanced sample would be more evenly balanced, I created an artificial distribution of frequencies, weighting the proportion of authors across stances as though female and male authors were equally represented. Even so, the proponent position would still predominate far beyond the expectations of a uniform distribution of opinion (Chi-square = 199.805, which at 2 degrees of freedom, yields a prob-value of 0.000).

Neutrals are those generally asking for information or who make conflicted statements.

• some (20, or 11%) ask for elementary information and so are probably truly neutral, though interested in Cassini

• a large minority (72, or 40%) ask very specific, technically-informed questions, and they seem conversant with and supportive of the space program but never actually endorse it

• still others (12 or 7%) report conflicted emotions -- they are enthusiastic about the mission but troubled about its plutonium

• relatively few just pass on others' messages (14, or 8%)

Concerns of the opponents:

Opponents are dominated by three subtypes:

• those simply passing on messages from a handful of activist authors, often without comment (46, or 24%)

• those making independent compositions focussed on the risks of plutonium in general and during the launch and flyby phases in particular (46, or 24%)

• those interested in Nostradamus and astrology, who were genuinely terrified that Cassini could be the "King of Terror" Nostradamus predicted would come from the skies in summer of 1999 and destroy Earth (41 or 21%)

Concerns of the proponents:

Proponents, given their much larger numbers, discuss a wider range of issue types, with no one issue commanding as much as a fifth of the authors.

• the most common type of comment claims that the opposition is very small in number, if vocal, and unqualified (95, or 17%)

• the second most common concern is that the risk of the mission and of the RTGs is much overstated and fears over that risk are disproportionate (91, or 16%)

• proponents "flame" more than the other two groups (59, or 10%, compared to 4 of the opponents (2%) and 7 of the neutrals (4%)

• many simply enthuse about the mission and its goals (73, or 13%)

• as with the neutrals, these messages are overwhelmingly individually composed (529 or 94%)

Discussion

These postings did not reveal a stated concern over the control dimension, even among the opponents. This particular controversy, then, does not support the salience of control raised in prior work.

Fairness issues do come up, as expected, but are a minor part of the discussion, eliciting comments from 23 individuals. Their foci were opportunity costs on both sides of the debate and a few comments that NASA's monopoly in space hurts the private sector.

The dread factor, however, far and away dominates the UseNet debates on Cassini, as expected. Two thirds of the opponent postings expressed dread of nuclear contamination to one extent or another and, in the case of the Nostradamus discussants, of Cassini actually bringing on the end of the world. Among neutrals, the issue comes up, too, in the form of 12 authors asking about the probability of a nuclear catastrophe. Proponents inadvertently address the dread factor, mainly by trivializing the probability of an accident and the consequences of an accident should one occur (154 authors). Dread is the central axis of this emotionally-charged technological risk debate.

Another factor cited in the hazards literature and in this case study is mistrust of public institutions. Six opponents cite a conspiracy to militarize space, claiming that NASA is in "kahoots" with the Pentagon and that the small amount of plutonium on board Cassini is the proverbial camel's nose in the tent. Seven others assert that media have censored coverage of the debate over Cassini, because the corporations that own the media are themselves military or NASA contractors (7 authors). Both of these arguments are also often cited in the messages penned by a handful of prominent activists and forwarded by 46 of the Cassini opponents on UseNet. Interestingly, a few proponents (9) have claimed that the media in fact are biased towards the Cassini opponents because of sensationalist drama and do not give NASA equal time to defend the mission. So, suspicion over NASA's reliability as a government institution responsible for public safety is raised by opponents, as expected. Also, there is much suspicion of media, which is common on both sides of the debate.

There is a small gender gap in stance taken toward this debate, though both genders are likelier to support the Cassini mission than oppose it. The big gender gap, however, is in degree of participation in the debate: The number of men absolutely swamps those of women in UseNet discussions. Other demographic attributes could not be detected among the discussants, and it is unknown how these might affect the debate.

Conclusions

The Internet offers empowerment to political activists. A few people can alert others to gravely concerning issues and enlist them to spread the news. The population notified of the issue expands geometrically and, even if a small number of those exposed to the idea respond politically, the result can be tremendous political pressure. The "Battle in Seattle" over the World Trade Organization illustrates the potential of Internet organizing.

Examination of the forwarded messages among the 24 percent of opponents who simply passed on others' messages revealed that these overwhelmingly came from about 5 individuals. Similarly, among the 7 percent of proponents passing on others' messages, these emanated from about 5 individuals, mainly publicity employees of NASA. While they did not win their battles to cancel the launch or abort the gravity-assist around Earth, opponents may have won the war, as NASA and Congress are now more concerned about approving new missions that must depend on RTGs.

Potentially very empowering to ordinary citizens, the Internet offers a counterweight to the political power of great corporations and wealthy individuals. The demagogic use of the Internet, however, remains the shadow of empowerment. Appeals to conspiracies, ad hominem attacks, exaggeration, and other emotionally-manipulative devices are the hallmark of demagoguery, and they are abundant in this debate, particularly among the opponents but also among flame-prone proponents. The nature of the technology embodied in Cassini and similar missions makes it inaccessible to the average citizen, who yet must decide whether to act politically for or against this and other technological applications or, worse, for a democratic society, remain uninformed and apathetic.

Risk management decision-makers, particularly politicians, would be well-reminded that they may be hearing from an unrepresentative selection of their voting and contributing constituents in technological risk debates, as in many other issues. This sample may be responding to demagoguery, self- interest, or the rational consideration of risks and benefits: The source of political pressure may not be too apparent when decision-makers consider policy to manage a technological hazard. While one would hope they rely on risk assessment science in framing their responses, they must do so in an atmosphere of political risk and uncertainty, with its own Type I and Type II hazards to their own careers! The next phase of this project will query those decision-makers about the volume of constituent communications on this subject and their own quandaries in responding to them.

Bibliography