An Interview with Chris Russell
Meet Dawn's Principal Investigator Chris RussellThe following interview took place in Houston, TX on March 13, 2004, between Dawn mission Principal Investigator Dr. Chris Russell (UCLA) and Education and Public Outreach team member Jacinta Behne (Mid-continent Research for Education and Learning—McREL)
CR: It’s the person who ultimately has the responsibility for the mission; the place where the buck stops; the person that NASA will come to when they have a complaint or praise; they are some main point of contact between NASA and the mission. I’m the person who recognized the next thing that the community needed—in this particular community anyway—what they needed to do, assembled the team, and tried to get the where-with-all to do it. I’m a focal point—at least when it came to getting the job done.
JB: Have you noticed any changes in planetary sciences over the years?
CR: We are learning a lot more, and we are a lot more sophisticated in our understanding at the present time. I started doing planetary research in the early 70’s, and actually, if you assume that the moon is a planet, I started in the late 60’s on the Apollo program. Back in the early 70’s I proposed an investigation to NASA to do science at Venus. In ’78 I became the principal investigator of a Venus investigation, so I’ve been working in planetary science for quite a while.
JB: What brought your research from planetary science to the study of asteroids?
CR: Back in the Apollo program we made some interesting measurements around the moon. When we didn’t finish that set of measurements, I wanted to continue that particular job and finalize our moon work. At one point, I proposed to do some lunar exploration. The first time, that particular mission was not launched. The second time, when indeed it was launched, then another group got to engage in that exploration. I was a little bit disappointed, but the team that I had assembled to do those lunar measurements was very appropriate to asteroids and the asteroids were the next step after the moon. Those bodies have quite a lot of similarities and some differences. We need to investigate those differences.
JB: How are asteroids similar to the moon?
CR: Well, let’s take Vesta, the asteroid that we’ll travel to first. It’s got lava flows on the surface; it’s got craters; it’s smaller than the moon, but the rocks are not all that different than the moon; they both have an iron core; and they both have very similar minerals. So they are very similar in some senses.
JB: We know in addition to Vesta, the Dawn mission is going to investigate another asteroid called Ceres. In your opinion, what new science will the Dawn mission provide?
CR: In addition to going to Vesta, which is a comparison object for materials in the inter-part of the system, that part of the asteroid belt also marks a transition to objects that become more like the bodies in the outer solar system, in particular the icy bodies. We believe that Ceres will give us some surprises in that regard and will potentially be like some of the moons of Jupiter, especially Callisto and Ganymede.
JB: What do you find are the greatest challenges of the mission?
CR: Well, this mission has a lot of challenges and they are not just scientific and technical. It is a little bit like Christopher Columbus. He has to start off, go around, and find a new way to get to China. Then he has to go and get financing for it, so he convinces a certain set of people who have money to finance his particular expedition. So there is that aspect to it and that is the financing of it. But the Queen of Spain, also, wants to know that they are getting value for their money and the mission is going fine, so they will continue to invest in this particular program. There is a political aspect and a management aspect (that a person starting off might not realize that they are going to have to take care of) and that can be challenging all by itself. But, at the same time, we’re trying to advance science and advance technology. And that also has its particular challenges, making sure that the equipment works, or the measurements that you are making are going to answer the scientific questions that you posed.
JB: What is the source of propulsion for the space craft itself in the Dawn mission?
CR: One of the innovative aspects and the technology of Dawn is the ion propulsion engine. The reason we go to ion propulsion is because it makes extremely efficient use of fuel. The ions come out of the engine much, much faster than if you would burn some chemical in the rocket, and that allows us to carry a smaller amount of fuel, or to get much greater efficiency out of the fuel that we are carrying. That enables us to go to Vesta, get into orbit, go to low altitude around Vesta, then climb out of that low orbit, leave Vesta, and go onward—all the way to Ceres. This is a very novel aspect of being able with one spacecraft to compare two quite different bodies. So, the mission is a comparative planetology mission but it compares the planets with exactly the same instruments.
JB: Is there heritage for ion propulsion? Has it been used before?
CR: Yes, it has been used before. In fact, we are using exactly the same engines as were used on Deep Space One, but Deep Space One only used one engine. We’re using three ion engines and we are doing a full science mission, whereas the purpose of the Deep Space One mission was to do technology demonstration. To prove that this technology would work and we are now taking that and applying it to a scientific problem.
JB: For a young person who aspires to someday work on a NASA mission, could you share with him or her what led you to your work? Would you have any advice for them?
CR: I’d like to share with you a secret to success in the world. What you should try to achieve is being paid for what you want to do. So if you are good at something and you enjoy something, what you try to do is to find a way where you can use that to make money and support yourself. Many scientists are just people who really have a talent, a love of doing investigations, trying to understand nature, understanding how things work, and then convincing the government or a university, or industry that that is something they really need for you to do for them. And that’s my secret for success.
JB: Did you always have a love of science? When did you know what you wanted to do? What path did you follow?
CR: I most likely followed the path of ignoring guidance counselors. When I was in high school, I took aptitude tests and stuff like that and they said “you have this great talent for doing science and mathematics and you should go into engineering.” I said engineering doesn’t sound as interesting to me as actually being a scientist. A scientist has a little bit more control of what he’s doing and he really gets into more fundamental things, so I ignored my guidance counselor and went into a pure science program rather than an engineering program. So, that was my first step. My second step was when I graduated from college and I was spending a summer doing work in between getting my bachelor’s degree and going in for my graduate degree. I went and I worked for a summer in a project that had an operational spacecraft and was measuring solar radio waves and also ionospheric phenomena. I really enjoyed that and working on space measurements. And when I got to my graduate school, where I was going to go into another branch of physics, I looked around and I said, “Is there somebody at this school who is actually involved in measurements in space?” I found a group, so then I transferred to a different group at the same school and continued my interest in space. Then it just took off from there.
JB: Tell me about your mission team, which seems so solid, so substantial. How did you assemble these folks? How did you know who you wanted, ...who you needed? What was it that brought these people together?
CR: Assembling a team is a difficult job, and the make-up of the team evolved a little bit as time went on. You look for people who first of all work well together, but people who are the most talented people in the field. If you go to a lot of scientific meetings, and you interact with people, you talk to people. You talk to people who know people. You finally end up with learning who are the most talented people and they work together.
If you go to a school yard and you take a look at the children playing in the school yard, you will find out that there is a certain group that plays together. Those people cooperate together. They have the same intellectual capabilities, and the same interests. It is the same in science as in the school yard. It is, it really is.
CR: When you get involved in planetary missions, it takes a very long time, both in the development phase and also in the execution. The further out you go into the solar system, in fact, it takes longer.
What happened with the Dawn mission is that NASA started a new program called Discovery, which is a PI led mission. The PI goes out and gets the team, and writes a proposal to NASA. He or she describes what the team wants to do and then tries to convince NASA that this is the next mission that should be funded. We started in 1994 with our first proposal. Our idea was to finish off the lunar exploration. We proposed that and a competing team won. They had a similar idea and they were going to do it more simply. We had a fairly complex idea, and they went for simplicity over complexity at that particular time. Then, we changed our focus to Vesta, and then eventually Vesta and Ceres. We tried to convince NASA with a series of proposals for focusing on those two asteroids. That took another six years. So, it was the year 2000 before we were able to convince NASA to start to fund us to do this study. It continued for another four years before they were really confident in us to continue on. Launch is 2006. And then with Kepler’s laws on how fast bodies would move around the sun, it takes a while to move out with ion propulsion. So we don’t get to Vesta until 2011, and Ceres until 2015.
So, we started in 1994 and we’re finishing the mission in 2015—twenty-one years later. It is a long business and it has been that way for a number of other projects that I have participated in—Galileo and Cassini. They are all missions that take a fraction of a career. One of the good things that you can do for yourself is stay healthy—exercise, and eat your vegetables. And if you are going to work in the planetary area it’s going to take a while to finish your objectives.