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The following interview occurred June 2, 2002 between former Genesis Mission Design and Navigation Manager and LTool Manager Martin Lo and Senior Consultant Jacinta Behne, Mid-continent Research for Education and Learning.
J.B. What is your role in the Genesis mission design? What does your job mean for the Genesis mission?
M.L. I first started working on Genesis during the proposal phase leading the mission design. The most important aspect was the trajectory design. When Genesis was selected as a Discovery mission, I became the manager for the Mission Design and Navigation Team. At the same time, I was also leading the development of LTool, the new tool used by Genesis for its trajectory and mission design.
Around the time of the Genesis Critical Design Review—a major milestone for any space mission—it became apparent that the responsibilities for the two jobs were too heavy. I decided to concentrate on developing LTool, which was crucial for Genesis and where my expertise and knowledge can best serve the Genesis mission.
The trajectory is a mathematically calculated path using complex software. What we are working with is Newton's law of gravity. Moving bodies always obey the laws of gravity. We consider several bodies: the Sun, the spacecraft, and the Earth. The moon is there too. It is extremely complicated to find a path to take advantage of the gravity of multiple bodies as in our case. Since we can't avoid it, we might as well take advantage of it. Coming up with a trajectory design is not a simple problem.
J.B. You are working with a branch of mathematics called chaos theory. What new science or mathematics understanding is your work providing to the Genesis mission? Why is this important?
M.L. For the Genesis mission, we want an orbit that's always facing the Sun in order to continually collect particles streaming from the Sun via the solar wind. This can be done by using a "halo orbit" around the L1 Lagrange point. This is a point between the Earth and the Sun where the gravitational forces are balanced with all of the other forces. But this balance is very fragile and unstable. It is the seed of the "chaos" which we can use to great advantage.
Chaos is a bad thing if you can't control it or don't understand it. But, like any powerful technology, properly understood, "chaos" can be really useful. It can provide highly efficient controls as well as extremely useful orbits which cannot be computed with conventional orbit design methods. In fact, we will use a connection between L1 and L2 predicted by chaos theory which requires very little energy in order to bring Genesis back to Utah. How little you ask? Well, believe it or not, theoretically, if we performed the entire mission absolutely flawlessly without any errors, once the Genesis spacecraft is launched, the spacecraft will automatically go into the L1 halo orbit, collect the solar wind particles, and bring it all back to Utah right on schedule without firing a single rocket engine!
But if you don't handle chaos properly, even if you just breathe on the spacecraft, it can cause the spacecraft to fly off and escape the Earth completely.
Chaos theory was invented by Poincare at the beginning of the 20th century. It is really a part of something larger called Dynamical Systems Theory. This has been known for a long time by engineers intuitively. They had a seat-of-the-pants understanding; they knew the phenomenon was going on and tried to find trajectories that used it.
The work I do is good for the mission and it helps explain many interesting phenomena in the Solar System. It explains how comets in the Jupiter system get captured temporarily. The Shoemaker-Levy 9 comet that crashed into the planet followed this dynamic.
The neat thing is, what is the Genesis orbit? It is a collision orbit: you go out and bring things back to Earth. Some near-Earth asteroids may follow the same path as the Genesis spacecraft. In fact, some people think that the killer asteroid that caused the extinction of the dinosaurs followed a path similar to the Genesis trajectory. On the other hand, our knowledge of this can be used in a constructive way. For example you could use a small force to deflect them in particularly chaotic regions. Or, even more fantastic, you could capture them permanently for mining purposes.
J.B. That sounds like science fiction.
M.L. It does sounds like science fiction, but it is really true. In fact, it's even more fantastic than you can imagine. The halo orbits at L1 and L2 are actually "portals" to a network of dynamical tunnels that connects the entire Solar System. By jumping into the "hole" in the halo orbit, you enter this vast and ancient labyrinth of tunnels and passageways that connects the Kuiper Belt beyond Pluto to all of the planets, all the way to the Sun. Instead of the picture that Copernicus and Kepler gave us of planets in nearly circular orbits around the Sun, isolated from one another, the solar system is alive, breathing, and communicating, sending objects like comets and asteroids from place to place throughout the Solar System. I call this system of tunnels the "InterPlanetary Superhighway."
Now the portals and tunnels of the InterPlanetary Superhighway may remind you of the "wormholes" of science fiction, but they are not related. My portals and tunnels are honest-to-God orbits generated by Newtonian gravity, which have been traveled by comets and asteroids for billions of years. More recently, we have started using them for space missions. On the other hand, wormholes are really science fiction based on Einstein's general relativity theory of gravity. Sometimes reality can rival science fiction.
This has many serious implications. For one thing, the InterPlanetary Superhighway plays a major role in the development of life on Earth. Scientists are pretty sure that the chemical building blocks of life came to Earth via comets and asteroids. As we just mentioned, these objects can come to the Earth from the Kuiper Belt, from the Asteroid Belt, and even from Mars by following the paths in these tubular tunnels of the InterPlanetary Superhighway. They also shaped and changed the way in which life developed on Earth through spectacular crashes that caused the extinction of species and enabled the rise of mammals, which led to the development of humans.
The Genesis mission is perfectly named. Not only is the science of the Genesis mission to study the origin of the Solar System, but its trajectory has been the very means by which the life building and life shaping objects have come to the Earth.
J.B. You are a mathematician, while many of the other design leads on this project are scientists or engineers. What is it like to work with people who are not mathematicians?
M.L. What makes my work exciting is sort of straddling two worlds where each has its own techniques. Usually the two don't talk. By being conversant with both, I can bring them together. That is my main contribution. Mathematical theory explains engineering and creates tools for solving more engineering problems. The way science gets done is that there is a real-world problem, which can be stated in an abstraction. This leads to something else in the real world. The interaction of the abstract and the practical is the most exciting part of my job. I find beauty in the design of nature when highly abstract ideas can be turned into useful engineering tools to solve problems in the real world.
J.B. Besides the Genesis mission trajectory design, what other work do you do at JPL?
M.L. I write proposals and studies for various missions. I have done a little work on the Magellan, TOPEX, and Mars Observer missions. Currently, I am working on a really exciting project, the Terrestrial Planet Finder mission. Here we are trying to fly a collection of five spacecraft in formation to create a telescope with a diameter of the length of a football field. One of the options is to fly this formation in a halo orbit at L2.
I'm also working with the NASA Exploration Team to figure out how to provide human servicing to missions such as the Terrestrial Planet Finder mission. Sending astronauts to the Earth's halo orbit is almost as difficult as it is to send them to Mars. It takes 3 months in a harsh radiation environment. I came up with an idea to put astronauts in a service station in halo orbit around the moon's L1. It takes about three days to get to the lunar halo orbit. It's a lot easier, faster, cheaper, and safer to put people in lunar halo orbit. You can just bring any of the spacecraft in an Earth halo orbit back to the moon using the InterPlanetary Superhighway in the Earth's neighborhood. It takes very little energy. After the astronauts have worked on the spacecraft at the lunar L1 service station, they can just send it back to its halo orbit around Earth's L2 and it's good as new.
My other focus now is developing a new technology based on this mathematical discovery. The name of the project that I'm trying to implement now is LTool, which stands for Libration Point Mission Design Tool. I have created a software tool using dynamical systems theory. It is a relatively new thing in the world of mission design. I should recognize that the first people who applied this are my colleagues from the university in Barcelona, Spain. In fact, there are many colleagues and friends around the world who have helped me build this intricate web of theory, tools, and applications. Genesis is perhaps the highest expression of this effort.
J.B. What is your typical work day like?
M.L. I get breakfast on the run at about 8:00 a.m., rush to JPL, and then the meetings start. Between meetings I dash to get e-mails and retrieve phone messages. These meetings are interactions with people, which is very important. It is there that I work with various teams doing different things working on different problems. There are management problems, technical problems, and coordination with other teams to see if we can collaborate. I work closely with Cal Tech, Barcelona, Purdue, UC Santa Barbara, U of Michigan, and U of Paderborn in Germany. I call my collaborators the "Lagrange Group."
J.B. Are there any barriers to your work at the present time?
M.L. One barrier is how new this whole thing is and trying to explain it to people and get them to accept it. There is a start-up cost. It sounds frightening and very mathematical. The concepts are easy to understand if explained properly. With the proper tool, you don't need to know all the math to get it to work properly.
Part of the problem is we're just beginning to understand it ourselves. I want to carry our excitement to the general community. I want to get more people involved in technical pursuits, especially in math and space. It is not a dry, dead subject.
J.B. What kind of education and career path led you to become a mathematician?
M.L. My training is all in theoretical math. At Cornell I took courses in differential topology and partial differential equations and differential geometry. I almost never saw a number!
When I was graduating, the academic environment was very difficult to get positions in. In fact, my thesis is based on some of the profound work of the Nobel laureate, John Nash, of the movie "A Beautiful Mind." My advisor told me only ten people in the world would understand my thesis. That seemed so esoteric; it really bothered me.
I discovered that I enjoyed the interaction between theoretical math and real problems—an interdisciplinary approach. At the time, my career path wasn't clear. I worked at Hughes, and did NASA proposal work, and from there got to JPL doing mission design.
J.B. What is your home life like? What are your leisure time activities?
M.L. I have a cat that adopted me and my roommate, Bill. His name is Clawdius. Actually he is a very sweet cat. I have a large garden. I enjoy eating and cooking—in that order. You have to grow your own tomatoes and basil and lemons. I do gourmet cooking. I like Chinese and Italian .you know, Marco Polo. I love flowers too. I do Chinese calligraphy and play classical piano.
J.B. What additional advice would you give to young mathematics students?
M.L. They really need to learn the basic skills like language and mathematics very well and how to work with computers, even if they want to do theoretical work. A broader knowledge of other subjects is important. You never know where a problem will lead you. When I was studying the algebraic topology of manifolds at Cornell, I never imagined that I would use it in any way besides doing pure research. But today, I am finding that these esoteric theories can now be computed using modern computers and software tools and applied to real-world problems.
This changes everything. I believe we are standing on the cusp of a new and exciting paradigm shift or sea change in how we do engineering. I remember reading somewhere the comment that we're still using essentially 18th century mathematics in solving most engineering problems. But this is about to change. This new combination of modern mathematical theory with advanced computational tools is going to revolutionize the space industry and engineering in general. Genesis is a leader in this brave new world.
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