Dear Dr. Green,
I am writing this letter on behalf of many European scientists who would like to express their very strong support for the Cassini mission, whose science return to date has been nothing short of spectacular. Nevertheless, the potential US cuts related to funding for the Cassini Solstice Mission give us much concern. From our perspective, the Cassini Solstice Mission is essentially a new mission because of the absolutely unique science it will return.
The potential for substantial cuts to the Cassini mission gives us
serious concerns in three separate areas, which we will deal with in
turn. They are :
1.The potential loss of the very large investment which Europe has placed into the Cassini mission and its scientists over the past 20 years ;
2.The potential loss of unique science ;
3.The potential loss of a substantial number of the youngest members of the outer planets scientific community
A large fraction of the science return from Cassini has been produced and led by European scientists, and two of the Cassini instruments are led by European PI’s. Such involvement has been funded by the numerous European national agencies and institutions who are partners in Cassini. These funds cover both the costs of instrumentation and their operation, as well as the salaries of the many scientists involved. Downsizing or ending the mission early would result in a considerable loss in return for the substantial investment made by Europe since the early 1990’s. The implications that this may have for future international collaboration is a real concern to those of us who are very proud of what the Cassini team has achieved to date. Cassini is a model for the rest of the world regarding how to conduct large-scale, international cooperation, and has resulted not only in tremendous advances in planetary science, but also in substantial enhancements in international relations.
The unique science which the Cassini Solstice Mission will return includes unique observations during the proximal orbits of the internal magnetic and gravitational fields, unique observations of Saturn’s rings, and the ability to study Saturn’s atmosphere from perspectives never before available. One of the outstanding science questions for Saturn, is how it’s axisymmetric field can exist in the form that it does. Being able to resolve this question during Cassini’s proximal orbits may overturn planetary dynamo theory as we understand it today. Leading up to the proximal orbits the Cassini spacecraft will monitor the effects of seasonal change within the Saturn system ; on its rings, magnetosphere, atmosphere and the coupling with its many moons. Being able to understand the variable outgassing at Enceladus will allow us to understand the importance of this small moon on the E ring and its effect in turn on the system as a whole. Cassini can be viewed as a Titan "pseudo-orbiter", which especially during the Solstice Mission will enable us to resolve whether Titan has a liquid interior. We will also be able to resolve the effects of seasonal changes on Titan’s atmosphere, and on the bodies of liquid on its surface—and all of this can be accomplished at a fraction of the cost of a new flagship mission. The total cost of the Cassini Solstice Mission is comparable to a Discovery class mission but, because of the huge investment in Cassini to date, will result in flagship-mission-class science.
Loss of the outer planetary community
The Cassini Solstice Mission is the only flagship-class, outer planetary mission on the horizon for years to come ; its proximal orbits in particular will greatly enhance JUNO science via comparative planetology. There are other potential outer planetary missions being discussed, but their future is uncertain, and will be even less certain if Cassini, a healthy spacecraft mission producing world-class science, is ended before its time, or is subjected to crippling cuts in its funding. One of the great strengths of the Cassini mission is the large number of young scientists who have been and are being trained on Cassini data. To date, almost 200 Masters and PhD theses have resulted, and over 300 young scientists have ΄cut their teeth‘ on Cassini data. Some of these young scientists are already playing high-profile, leadership roles both on Cassini and in the study of potential future missions. If the international community wishes to continue its exploration of the solar system, we must ensure that the outer planetary community is kept healthy, and that our generation continues to train the generations of the future.
In summary, we want to express both our very strong support for the Cassini mission, and our hope and concern for its continued success, particularly in light of the recent funding cuts which have already impacted the Cassini mission. Should Cassini be subjected to additional, significant cuts in funding, the result would be a disproportionate, and perhaps even debilitating, effect on Cassini’s science.
Prof. Michele K Dougherty